DISI-MZResponse

[Enki]

Some of you may know that I have smoke coming out of my valve cover; a sure sign that the rings are done. This thread is (primarily) to chronicle my little experiment (and secondarily to learn new things).


Before this gets in depth, here's a TLDR:

MazdaSpeed Forums Presents: YouTube

MazdaSpeed Forums Presents: YouTube

Great, now that that's out of the way, some points of explanation as to why before we get to the what:


Explanation

1. Yes, this car is my daily driver, but no, I'm not worried about reliability too much. I work from home and have access to use vehicles I don't own.

2. The primary reason I'm doing this weird ass build is to test a couple of theories that I will get to in the Reasoning section; this is in preparation for a much bigger build not involving the Mazda.

3. It will take me quite a while to finish. I'm not made of money, so things will take time to purchase/pay off.

4. This thread is going up “early” because there might be some other cool shit to test or other things to in my plan to adjust; this post represents the public planning and discussion phase of my build, and is subject to change.



Great, now on to the major changes compared to a “standard build:”

Major Changes

1. Destroked from 94mm to 78mm (1.88 liters final displacement) or 76mm (1.8 liters final displacement)

2. Stock bore will be kept to help with high RPM breathing and cylinder wall thickness/thermal mass

3. Custom grind from scratch cams are unlikely to happen, but someone is investigating alternatives that I might wind up running; otherwise, I will be using stock cams

4. Extensive headwork will not be done, as changing the runner size can actually hurt drive-ability without VCTS present; most likely going to just have gasket matching and some bowl work done to open up a bit more flow

5. Full corn (E85) + tree bark (meth); with any luck, I'll be able to hit 400 WHP on upgraded injectors with no meth spraying

6. Very high static compression ratio; 12.8:1 pistons will work, however, destroking to 1.8 liters will reduce the effective compression to 10.54:1. I'll be working with Wiseco to increase overall compression as much as possible

7. Stock turbo boost levels were an original goal, but it is likely I will need to increase boost to hit the same airflow due to the reduction in displacement; I'll do this sparingly, but I'm going to start with a 15 PSI spring.

8. Electric water pump and supporting modifications to the cooling system like removing the thermostat; electric water pumps will lose a lot of flow if the head pressure climbs, so it's best to run them as open to flow as possible

9. Dual oil coolers (stock + aftermarket) for endurance applications

10. TMIC for sleeper look and improved radiator airflow/cooling

11. 3.5" exhaust to increase breathing efficiency out the back

12. Ditching the stock radiator and fan setup for heat rejection coated radiator and high flow fan

13. Lightened internals/FW to improve throttle response and rev matching

14. Sleeper engine bay

15. ???

16. Profit



Reasoning

1. Destroked to increase volumetric efficiency higher up in the RPM band, thus reducing power drop off I was experiencing (which as it turns out was mostly due to turbo hotside sizing), and hopefully help with MPG. Hopefully the drastic increase in rod ratio will also reduce NVH with BSD. This will also limit how much timing can be run due to piston dwell @ TDC, allowing a longer spray window before overrunning and getting misfires.

2. Stock bore kept for thermal mass, reliability, and again, MPG. Without doing any significant work to the valves/head, keeping the bore stock will help with VE.

3. Cams will likely be stock but might wind up reducing lift (which will allow for higher compression pistons) in exchange for significant gains in duration (which will also help breathing at higher RPMs). There's also the possibility of four lobes HPFP being an option.

4. Mostly exhaust work to improve efficiency and reduce reversion in the higher RPMs. The goal is to make the most power I can as efficiently as I can without having to use as little aux fuel as possible.

5. Staying with full corn, despite possible power increases due to improvement in fueling headroom because of major change 6, and because there is a real possibility that aftermarket injectors are coming.

6. E85 is prevalent where I live, so I'm going to make the most of it; this means maximizing compression in order to squeeze (pardon the pun) the most efficiency out of the fuel. This will help with MPG and power at lower boost levels, as well as power up top in the rev band.

7. Running a really high compression ratio (13:1 or maybe even higher) will probably reduce the amount of boost I can run, even on E85, but this doesn't bother me so much. Again, going to see what this setup does, and with any luck make more power than what I was on stock block.

8. Electric water pump is for a couple of reasons; being able to have the same velocity/volume of water flowing through the engine at all times (especially at idle), and to make it possible to more rapidly cool down the engine during track days when shut down. It will also help keep the stock water pump from cavitating at higher RPMs and further reducing cooling efficiency when it's needed most.

9. Keeping the stock oil cooler to help with warming up the oil, especially in the winter, but also adding a secondary thermostat controlled oil cooler to keep it under 230 during extended track sessions; this should also help take some cooling load off the radiator.

10. TMICs are less laggy, don't weigh as much, don't block the radiator (arguably important in the desert), and aren't TOO efficient; this is important because of all the alcohol I'll be spraying into the cylinder, not including meth which will bring temps down further. Too cold, and it runs like shit. Phate can attest to this.

11. Increasing overall airflow means touching everything, including the exhaust. My shit is a hair too loud now anyways. System will be custom, probably mild steel and all vbands.

12. More radiator = better cooling. Bigger fan will help with that as well, and a real *adjustable* thermostat control for it will be nice.

13. New crankshaft will be lighter than stock, as will the new clutch and flywheel assembly (which I need anyways due to burning mine up at the strip). My motivation for this will be explained in the Goals section.

14. Nothing is better than shitstomping someone who knows these cars, popping the hood and having them ask how I got it so fast when it looks so stock. Glorious.

15. ??????

16. Yes please.



Goals

To get a feel for why I'm doing this, check out the following video, and keep a close eye on the tach:

MazdaSpeed Forums Presents: YouTube

MazdaSpeed Forums Presents: YouTube

Realistically, I'd like to have traction in all gears (including first), as well as having close to or over 400 WHP as is feasible (I'd like more if it will support it, but even 400 WHP isn't a goal). For whatever reason, I was not able to get VersaTune to bring the boost down in 1st and 2nd enough to keep traction, which hurt me pretty bad ET wise at the strip; thus, I gained ~40 WHP but lost .4 on my 60' and had TERRIBLE wheel hop issues in both 1st and 2nd.
Honestly, I'm not terribly worried if I get to the power goal or not, as I'll be able to make up some lost power with RPM and mechanical advantage; more on that later. Obviously, I don't want it to be a dog, and I will tune it so it isn't, even if that hampers my RPM goals somewhat.



The Science

Here's where shit goes off the deep end; I don't claim all of this is correct, but I've spent considerable time researching this and have pulled the vast majority of formula from trusted sources (like Garret and Borg Warner white papers, etc).


Let's start with gearing (ignore drive shaft RPM in pic, as it doesn't apply):



As everyone who's done a 60-100 pull knows, 4th gear ends at 100 MPH when you shift at 6k (give or take, depending on tire size). Well, what if you could do that same pull in 3rd?

It's a similar benefit to running diesel gears, only you don't need Hulk levels of torque or a modified transmission to do it.

"Well gosh, Enki; that's swell...but why?"

Glad you asked, but I hope you have your thinking cap on. Take a look at this:



As you can see on the left side, there's a bit of speed gained when you shift higher (duh). Shifting at 8,000 RPM instead of 6000 RPM nets you a 33.33% increase in MPH between shifts; as the gear goes higher, this speed gain becomes considerable.
My best speed at the dragstrip was 120 MPH (prior best was 117); this was done not with a significant boost/timing/fuel change, but with a 500 RPM bump in redline.

On the right side of the picture, you can see that I'm anticipating giving up some torque; I don't really have to down low (because motor will be built), but I'm betting I won't have the fuel to hold more than say 300 WTQ @ 8k, especially considering I wasn't able to hold it on stock displacement @ 7k. Anywho, assuming I take a 14.29% loss in torque (at 6k RPM), shifting at 8k RPM nets me a 35.45% wheel torque gain for 11 MPH over shifting to 2nd...And that's how you should (probably) interpret the data. By the time you'd get to 4th gear, you'd already rack up 53.5 MPH of somewhat significant mechanical advantage. The downside is you'd be down on axle torque in 1st compared to the original number... But let's face it: Who is on street tires and doesn't make enough power to blow the wheels off in first?

"That's got to be bullshit, Enki."

Well now, hold on a sec. I have an anecdote that fits this criteria. I once ran into a friend on the street (in Mexico, of course...small world), and had a friendly race with them. It couldn't be more even if we were parked next to each other. They got the jump, but I was able to reel them back in on every shift until I had put a bumper length on them; and for no reason other than I shifted a couple hundred RPM later.
I'll leave it up to that person as to whether or not they want to confirm or deny, but it happened.

Also, there's this video which at least partially backs up my ideas on this build (science alert):

MazdaSpeed Forums Presents: YouTube

MazdaSpeed Forums Presents: YouTube

If anyone is interested, I have some ancillary data pertaining to tire size effect on MPH and RPM drop at specific shift RPMs:

This is 3000 RPM in 6th gear, by the way; horizontal is width, vertical is aspect ratio (assuming 18" wheel):

The tire size info is useful because I can use it to fine tune my RPM to MPH goals very easily; reduce the size a bit to gain effective torque at the wheel if I'm not going through the traps at redline, or increase the size to reduce torque and gain MPH if I'm hitting rev limiter a bit before the traps.

Shift/RPM info:


And here's some graphical data to help interpret the above (non tire size) info (click for big):
http://www.mazdaspeedforum.org/forum/foru...1&d=1442904850


Misc Tech Stuff

Displacement goes to 1.8 liters, on the dot; rod ratio increases from 1.6 to 2.27:1 as well, assuming linear transference of stroke to rod length; this will also reduce peak rod angle from 17.75 degrees to 12.72 degrees, which should also help with side loading of the pistons (allowing for a shorter skirt and lighter weight, helping response even more). This will, of course, hurt power production until an RPM threshold is reached, but I'm not really worried about that.

Another side effect of stroke reduction is the reduction in compression ratio; assuming stock pistons are used and stroke reduction is added to rod length, the effective static compression ratio will drop from 9.5:1 to 7.87:1. Obviously, I'm not looking to run regular 87 octane so this won't do. Upping the static to 12.8:1 pistons (on a stock crank/rod build) will see compression jump to only 10.54:1


Upgrades

Bigger big turbo? Don't mind if I do!
I'll be going to the 7163 from the 6758 for a couple of reasons. It will spool faster, and it will flow more air more efficiently on both the hot (larger hotside wheel *AND* larger AR on the hotside for one) and cold sides, as seen below.

This is how the planned boost curve (20 psi peak reverse taper holding 300 WTQ) looks on the compressor map on the 7163 (point 1 = 3k RPM, point 6 = 8k RPM):


And if I kept the 6758 (point 1 = 3k RPM, point 6 = 8k RPM):

Just makes sense to upgrade, especially considering the 7163 will spool faster than the 6758, even on stock block.


3.5" exhaust!
Downpipe will still be 3" from the turbo, but as soon as there's room, I'll kick it up to 3.5." Should help with both spool (maybe) and top end flow (almost certainly). Ancillary research suggests hit or miss power improvements over 3" exhaust, but seems to be largely variable dependent (setup, air quality, etc). Might as well give it a shot.
Speaking of exhaust, the destroke build has 5 PSI less reversion at 8k RPM than the stock build had at 7500, and only 3 psi more reversion (which I can tune out with more boost) than the stock/6758 build had at 6k...But with compressor efficiency that's still on the map past 6k. At any rate, below is exhaust size/area/estimated HP supported numbers:



As you can see, the 3.5" exhaust has about 35% more area for flow, and should at the very least more easily support ~400 whp...Provided it fits.
I'm also going to redo my crankcase evac setup to dump right to exhaust so I don't have to empty a catch can anymore; should also allow for more overall venting, if set up correctly (will probably need advice on where to put this). It's also going to be full vband, so I'll be able to test/compare muffler setups.


Drivetrain upgrades!
Shifter fork pads, and a Quaife helical LSD. Trans is going to be out anyways, might as well dive in and bulletproof it.


3.5 BAR MAP!
Don't really see myself going past 30 PSI anytime soon anyways (but I might need to depending), especially not with the littlebig turbo.


HIDs!
55 watt low beam and 35 watt fogs, both in 4300k.


TMIC!
Picked up a Corksport unit, along with a borrowed but pristine stock shroud for teh sleepaz. Might have to go to an ETS unit to improve flow if I wind up having a hard time getting airflow into the engine


Radiator and fan!
The Koyorad radiator has provisions for temp sensor, which will come in handy for the 1600+ CFM fan that will be going on the back of it.


Intake mani!
Corksport and/or CPE needs to get their shit together though.


External water pump and thermostat!
If shit ever goes wrong, will be an easy swap. The impeller is going to be cut off the stock pump, and the tstat housing (hopefully) replaced with a dual AN fitting unit.


Supplemental oil cooling!
Derale makes a decent inline tstat with partial flow through for oil systems. I'm going to use one of those to supplement the stock oil cooling system for race days.


Aluminum skid plate!
Aero is FTW. I'll probably tape up parts of it with aluminum tape as well, just cause.


LED lights!
Aaron's favorite! +50 whp!


Modified stock valve cover!
No breather cap, but bigass AN fitting will be welded in place of the stock breather tube thingy.


Aluminum underdrive pulley kit!
...Maybe! Since I idle 42% higher already (1k-1100 RPM), a 15-20% underdrive won't hurt anything.... But I gotta find one to run



Other Plans

I'm going to get brand new of the following items in addition to everything already mentioned above:

Headlight housings (mine are proper fucked from sand and sun)
Clutch slave
Throwout bearing
Throwout fork
Coolant/etc hoses (silicone where available)
Boost tubes (silicone where available)
PS cooler (mine is old, time to upgrade)
Power steering pump
AC compressor
Tensioner pulley
Higher amperage alternator, might have it tested too!


Stuff to anodize:
Intake piping
TMIC cold pipe (after porting/polishing/gasket matching)


Stuff to ceramic coat:
Exhaust mani
Downpipe
Intake mani
Genpu valve cover


Stuff to get heat rejection coating:
Intercooler
Radiator
AC Condenser


Community Benefits

Well, when this is done, we should have the following:

Source for stroke/destroke drop in crankshaft
Source for camshafts (with differing HPFP profiles, possibly)
Source for high output alternators (possibly)
Possibly another option for autox racers as far as build plans go



Misc

What else should I consider replacing?

Is there anything else that would be worth testing (that isn't nitrous or nitro-methane or anything completely retarded)?

Does anyone have any input on any part of this list/post? Math, experiences, etc?

@phate; What are your experiences with high(er) compression?
@RE-ACTIONENGSPEED3; What does your boost curve and power output look like when spinning to 8k? Care to share, even if in private?


EDIT:
I'm still waiting to hear back from Scat, and Wiseco is waiting on me; the rods will be sourced from Pauter most likely; this is up for grabs though.

Also, any information that might even be remotely useful to the platform (like cam/crank blueprints) will be posted here for the community at large to do with what they will, as will all knowledge gained from this little endeavor.

As a side note, I'm still trying to figure out who will build my engine (as I don't have the SSTs or ability for keying/pinning). Right now it's between Freek and Overspeed.

[speedfreak2013]

So much research done here glad to see it hope all works out

FIRST!

[Hammology]

This is very ambitious and different. Can't wait to see how it pans out.

[PurplFox]

Love the idea of de-stroke. Just makes a lot of sense with the amount of low end torque we have. even with stock cams this should be fun.

[anavrinIV]

When you say smoke out of the valve cover, where is it coming from? I'm pretty sure my gen1 has a ring/ringland issue and i was getting smoke when I removed the oil cap.

Other than that this can't happen fast enough, I'm about giddy just reading it
@mize13;

[xfeejayx]

Might not even be close, but make sure the rod clears the side of the cylinder before you go about your build. You're increasing the length, but shortening the crank throw, so likely OK. It's a problem on some engines in my world.

Yes VE will go up, but you're likely to lose mass. Yes, you'll have more efficiency, but be less effective at flowing (and making power). Maybe the flow improvements will take care of that?

I don't fully get why you're going this route, but kudos for doing it. Looking forward to the build and data.

[Code Monkey]

Not this shit again....

[JgamB]

I clicked "subscribe to this thread" in the thread tools so I didn't have to make an inane post about subbing for progress.

[Code Monkey]

I never looked into it, but is it possible to make out engine non interference?

[xfeejayx]

Originally Posted by Code Monkey I never looked into it, but is it possible to make out engine non interference?

Not the way he's going. Without doing any math at all on my end, I think he might find that he can't do what he's looking for because of interference issues. Higher lift, bigger overlap, and smaller stroke with higher compression all hurt your clearance.

[faeker]

most of what you said is gobble de gook to me, but the video helped me realize your intentions. That sort of response would be awesome.

[Realgib3]

Originally Posted by Enki Reasoning 1. Destroked to increase volumetric efficiency higher up in the RPM band, thus reducing power drop off I was experiencing, and hopefully help with MPG. Hopefully will also reduce NVH with BSD. Why not go with the 83.1mm (2.0L) crank? Rod ratio with that crank is still through the roof and good for 11k+ rpm 2. Stock bore kept for thermal mass, reliability, and again, MPG. Without doing any significant work to the valves/head, keeping the bore stock will help with VE. 3. Cams will likely be similar to a 26x Evo grind, and include a touch more lift than stock as well. Oh, and they will also have 4 HPFP lobes synched up with valve/injection events. Considerably more aggressive than current options? Or mostly just different because of the HPFP lobe? 4. Mostly exhaust work to improve efficiency and reduce reversion in the higher RPMs. The goal is to make the most power I can as efficiently as I can without having to use more meth than I already am. Why the lack of work on the intake side? I know the intake side already outflows the exhaust by quite a bit, but flowing more on both sides is always nice. 5. Staying with full corn, despite possible power increases due to improvement in fueling headroom because of major change 6. E85 is prevalent where I live, so I'm going to make the most of it; this means figuring out what our dynamic compression ratio is with stock cams, and going a bit higher despite having high overlap cams. I.E. efficiency. 7. Running a really high compression ratio (13:1 or maybe even higher) will probably reduce the amount of boost I can run, even on E85, but this doesn't bother me so much. Again, going to see what this setup does, rather than shoot for a power goal. I ran ~12.8:1 last year and it's amazing. You won't be limited at all by octane with the fueling solutions you're running, so don't worry about that. Goals EDIT: I'm still waiting to hear back from Comp Cams, Scat, and Wiseco, and the rods will be sourced from Pauter most likely; this is up for grabs though. Also, any information that might even be remotely useful to the platform (like cam/crank blueprints) will be posted here for the community at large to do with what they will, as will all knowledge gained from this little endeavor. As a side note, I'm still trying to figure out who will build my engine (as I don't have the SSTs or ability for keying/pinning). Right now it's between Freek and Overspeed. Displacement goes to 1.88 liters, on the dot; rod ratio increases from 1.6 to 2.19:1 as well, assuming linear transference of stroke to rod length.

So I'm sure this will just be the beginning of some good discussion on these topics, but here are my overall thoughts.

- I love the thought of destroking and have done quite a bit of background work when I was contemplating a similar build. With that said, it's not remotely needed if you're only wanting to rev to 8k. To me, this only needs done when revving well over 9k. The fact is, our 2.2xL setup will hold all the TQ you need to 8k and will rev to 8500 (and make power) with ease if you have the proper tuning available.

- On the same topic, but a different piece of it, to make power to 8k, you don't need any head work or cam upgrades at all (not that headwork would hurt though). I recently posted this in another thread, but @Etipp98; car made peak TQ (~430) @ 7600rpm on a bone stock engine, top to bottom, on a 62mm turbo. I have other guys on 58's with very mild porting + valve springs that hold TQ to 7500rpm+ as well. I'm not saying headwork is bad, just saying that none of this stuff really comes into play until well well past the 8k rpm limit you're shooting for.

[Enki]

Originally Posted by anavrinIV When you say smoke out of the valve cover, where is it coming from? I'm pretty sure my gen1 has a ring/ringland issue and i was getting smoke when I removed the oil cap.

Anywhere that isn't pulling vacuum. Specifically, the breather hose on top behind the HPFP where I just have a filter.

Originally Posted by xfeejayx Might not even be close, but make sure the rod clears the side of the cylinder before you go about your build. You're increasing the length, but shortening the crank throw, so likely OK. It's a problem on some engines in my world. Yes VE will go up, but you're likely to lose mass. Yes, you'll have more efficiency, but be less effective at flowing (and making power). Maybe the flow improvements will take care of that? I don't fully get why you're going this route, but kudos for doing it. Looking forward to the build and data.

I'm not worried about cylinder clearance, not on a destroke build anyway. When you destroke an engine, you move the rod closer to center; adding longer rods helps a bit more.

Of course massflow will be lost; the cylinder won't hold as much volume. That's another reason I'm doing what I can to improve spool, so I don't have less massflow for very long (during WOT anyways).

Per OP, I'm doing this to test shit out for my V8 build, which will be similar in scope but much, much nastier overall.

Originally Posted by Code Monkey Not this shit again....

What shit? I did some googling a while back and didn't see anyone with an actual destroke build...

Originally Posted by JgamB I clicked "subscribe to this thread" in the thread tools so I didn't have to make an inane post about subbing for progress.

Your non faggotry is appreciated, buttlicker.

Originally Posted by Code Monkey I never looked into it, but is it possible to make out engine non interference?

Yes. See below.

Originally Posted by xfeejayx Not the way he's going. Without doing any math at all on my end, I think he might find that he can't do what he's looking for because of interference issues. Higher lift, bigger overlap, and smaller stroke with higher compression all hurt your clearance.

Correct, unless I can get valve reliefs deep enough (which would hurt compression severely). It's unlikely, but I'll be talking with Weisco about it more to find out for sure.

Originally Posted by Realgib3 So I'm sure this will just be the beginning of some good discussion on these topics, but here are my overall thoughts. - I love the thought of destroking and have done quite a bit of background work when I was contemplating a similar build. With that said, it's not remotely needed if you're only wanting to rev to 8k. To me, this only needs done when revving well over 9k. The fact is, our 2.2xL setup will hold all the TQ you need to 8k and will rev to 8500 (and make power) with ease if you have the proper tuning available. - On the same topic, but a different piece of it, to make power to 8k, you don't need any head work or cam upgrades at all (not that headwork would hurt though). I recently posted this in another thread, but @Etipp98; car made peak TQ (~430) @ 7600rpm on a bone stock engine, top to bottom, on a 62mm turbo. I have other guys on 58's with very mild porting + valve springs that hold TQ to 7500rpm+ as well. I'm not saying headwork is bad, just saying that none of this stuff really comes into play until well well past the 8k rpm limit you're shooting for.

Great info! I'll put it in the OP.

Also, I'd like to spin higher, but Versatune only goes to 8k (which is higher than what APV3 allows on GenWon, BTW).

If I'm going to have custom cams made, might as well have custom cams made, right? No sense spending a ton of money for stock 4 lobe cams (which I'm super interested in testing, mostly for the effect of hopefully stabilizing fuel pressure). Also keep in mind I'm going for flow over boost, and I'm sure Etipp98's boost up that high was significantly higher than anything I've been running (stock MAP sensor). 360 WHP on stock boost would be hilarious in a sleeper car.

[xfeejayx]

Originally Posted by Enki I'm not worried about cylinder clearance, not on a destroke build anyway. When you destroke an engine, you move the rod closer to center; adding longer rods helps a bit more. Of course mass will be lost; the cylinder won't hold as much. That's another reason I'm doing what I can to improve spool, so I don't have less mass for very long (during WOT anyways).

Increasing rod length (to get your higher compression) decreases the clearance from rod to cylinder. Again, don't think it's going to be an issue, but can be because of that.

I meant mass airflow, not metal. Sorry, should have been clearer.

[Enki]

Originally Posted by xfeejayx Increasing rod length (to get your higher compression) decreases the clearance from rod to cylinder. Again, don't think it's going to be an issue, but can be because of that. I meant mass airflow, not metal. Sorry, should have been clearer.

Right but I'm not doing that. My rod ratio calculations are based on static piston dimensions and removing stroke from the crank and adding it to the rod; this would, actually, increase clearance as the big end of the rod would be further away (at 90 deg crank angle from TDC/BDC) than it was with stock stroke.

Edit:
I knew what you meant, and was referring to cylinder volume or massflow (but just put mass). I'll update my prior post for clarity.

[Enki]

Originally Posted by Realgib3 Why not go with the 83.1mm (2.0L) crank? Rod ratio with that crank is still through the roof and good for 11k+ rpm

Wasn't even aware this was an option. What crank, and from where?

Originally Posted by Realgib3 Considerably more aggressive than current options? Or mostly just different because of the HPFP lobe?

Poking around the net has only yielded suggestions that there are cams available, but no info on what those cams are or how they are set up. I'm also not sure I trust the stock cam numbers that are available (IIRC, from PTP John).

Originally Posted by Realgib3 Why the lack of work on the intake side? I know the intake side already outflows the exhaust by quite a bit, but flowing more on both sides is always nice.

If I need more air to go into the cylinder, I can turn up the boost. There will be some minor headwork on the intake side (depending on the intake mani), just nothing drastic like on the exhaust side.

Originally Posted by Realgib3 I ran ~12.8:1 last year and it's amazing. You won't be limited at all by octane with the fueling solutions you're running, so don't worry about that.

Better spool, MPG, HP? Details man, let that info out!

[Realgib3]

Originally Posted by Enki Wasn't even aware this was an option. What crank, and from where?

The non-turbo 2.0l MZR/Duratec crank OR the ST crank. Both are forged from the factory, but the ST crank has a BS gear and is considerably more expensive. I was going to go with the standard MZ3 crank, but I was pushed away from it, only because I had heard rumblings of the crank not holding up well over 500whp (which I cannot confirm and even if true, would still be more than fine for your goals). I can look again for some links from back when I was about to switch last year. In the end, just because of my power goals, I was going to go with the Billet Cosworth 83 crank or have K1 do a billet 83 crank for me, like they do the billet 94 for the 2.2 Evo builds.

Originally Posted by Enki Poking around the net has only yielded suggestions that there are cams available, but no info on what those cams are or how they are set up. I'm also not sure I trust the stock cam numbers that are available (IIRC, from PTP John).

I worked with Web last year on some grinds (using stock 3 lobe hpfp). One for my car and one grind for more reasonable levels. The reasonable grind I came up with was still a lot more aggressive than what I've seen out. Very little overlap at 0* VVT Adv (high boost/rpm), and a mild amount of overlap at full vvt (where the exhaust pr is still low and can benefit from some overlap).

Biggest difference is the lift though. On this platform, many have pointed at the fact we're saturated on stock head/valves at just over 10mm lift, so they say it's pointless to go higher. However, you actually want to go considerably higher to have the most amount of duration at or above that 10mm lift.

Anyway, cams is its own huge topic, but I'd be happy to go more in depth later on, but I will say that on a mid-sized turbo cam for this car, you'll want a minimum of 11mm lift to really benefit.

Originally Posted by Enki If I need more air to go into the cylinder, I can turn up the boost. There will be some minor headwork on the intake side (depending on the intake mani), just nothing drastic like on the exhaust side.

Understandable. The exhaust side can definitely give you major gains, especially (in theory) with a cam upgrade as well.

Originally Posted by Enki Better spool, MPG, HP? Details man, let that info out!

Ugh, everything. The "spool" time to full boost on a log-type, single gear pull isn't greatly affected, but transient response of the turbo and even more so the off-boost response of the engine are in another world. Along with that, I got 31mpg on 50/50 e85 and hp, well I wish I would have been able to dyno. On 35psi, with just 11.5* timing (timing is the one thing you have to get used to during tuning on that compression) I believe I hit higher MAFv than anyone ever has, but again, never got on a dyno and never had a clean run at the track.

Overall though, I will say the compression was my favorite part of that build.


EDIT: I also want to make it very clear that these ECU's can support higher rpm, we just live in a world where if Steve@Versatune or anyone @ Cobb don't want to do it, then we can't have it. It's sad really, because these cars would be entirely different animals with the real rpm they need.

[Enki]

Originally Posted by Mazdazilla6 The one thing that I think deserves some explanation is the destroke. I don't forsee huge gas mileage gains as rule of thumb is greater stroke and smaller bore for MPG.

The higher compression should at least partially offset the reduction in stroke as far as MPG goes; stroke gives better MPG simply because you're able to burn fuel more efficiently and harness that heat as work....which is exactly what upping the compression ratio does.

Originally Posted by Mazdazilla6 I'm also a bit confused as to why you think this will pick up spool? Sure you'll be able to rev faster but the majority of what spools a turbo is heat expansion much more than actual gas flow over the turbine.

Never said it would pick up spool; in fact, I wholly expect it to spool slower. The head work, exhaust work and change in EFR is all an effort to reduce the negative impact in spool.

Originally Posted by Mazdazilla6 Lastly with such a large drop in displacement and trying to spool such a turbo so fast I would have concerns with ending up on the far left side of the compressor map and hitting really bad surge. It would make more sense to me to enlarge everything you can (head, cylinders, charge piping, intake mani) to have great spool and avoid surging at lower RPM.

Not even remotely concerned about this if I'm honest. I know it will spool slower (anticipating 3500-4k full boost threshold), and I'll only be running a 10 PSI spring at the start. It may be an issue if I up the spring, but I can always modify VVT advance if that's the case.

Originally Posted by Realgib3 The non-turbo 2.0l MZR/Duratec crank OR the ST crank. Both are forged from the factory, but the ST crank has a BS gear and is considerably more expensive. I was going to go with the standard MZ3 crank, but I was pushed away from it, only because I had heard rumblings of the crank not holding up well over 500whp (which I cannot confirm and even if true, would still be more than fine for your goals). I can look again for some links from back when I was about to switch last year. In the end, just because of my power goals, I was going to go with the Billet Cosworth 83 crank or have K1 do a billet 83 crank for me, like they do the billet 94 for the 2.2 Evo builds.

Didn't even consider Cosworth...I'll have to look into that. Ideally, I want a crank that will handle upwards of 400 torque at low ish rpms just in case I decide to change up the power curve to be more stock like. Not sure how much of a difference 5 MM in crank throw will make displacement/power wise, but I'll plug it all into my spreadsheets and find out.

Originally Posted by Realgib3 I worked with Web last year on some grinds (using stock 3 lobe hpfp). One for my car and one grind for more reasonable levels. The reasonable grind I came up with was still a lot more aggressive than what I've seen out. Very little overlap at 0* VVT Adv (high boost/rpm), and a mild amount of overlap at full vvt (where the exhaust pr is still low and can benefit from some overlap).

Interesting. I've not actually decided on a cam grind yet, as I'm still pretty far off from that point for now. If I can't get 4 lobe cams, I'll probably just stay with stock cams for better comparison with a stock engine...Since it will all be keyed and pinned, I'll be able to swap cams out myself if I want to dabble with regrinds later.

Originally Posted by Realgib3 Biggest difference is the lift though. On this platform, many have pointed at the fact we're saturated on stock head/valves at just over 10mm lift, so they say it's pointless to go higher. However, you actually want to go considerably higher to have the most amount of duration at or above that 10mm lift. Anyway, cams is its own huge topic, but I'd be happy to go more in depth later on, but I will say that on a mid-sized turbo cam for this car, you'll want a minimum of 11mm lift to really benefit.

Yeah, I'd imagine there are other ways to get duration without getting lift; though the lobe profile might cause the valves to behave strangely or possibly even break components.

Originally Posted by Realgib3 Ugh, everything. The "spool" time to full boost on a log-type, single gear pull isn't greatly affected, but transient response of the turbo and even more so the off-boost response of the engine are in another world. Along with that, I got 31mpg on 50/50 e85 and hp, well I wish I would have been able to dyno. On 35psi, with just 11.5* timing (timing is the one thing you have to get used to during tuning on that compression) I believe I hit higher MAFv than anyone ever has, but again, never got on a dyno and never had a clean run at the track. Overall though, I will say the compression was my favorite part of that build.

That kind of response combined with a 7163 should be pretty fucking amusing then. As far as timing goes, I'm anticipating the rod ratio to impact timing in a way where I will need significantly less timing to reach MBT; with the higher dwell at TDC (and higher compression), factory timing might yield surprising results...Just another thing to test.

Originally Posted by Realgib3 EDIT: I also want to make it very clear that these ECU's can support higher rpm, we just live in a world where if Steve@Versatune or anyone @ Cobb don't want to do it, then we can't have it. It's sad really, because these cars would be entirely different animals with the real rpm then need.

I agree, and I hear neat things are coming this way in the world of VersaTune...Not sure if that will include the ability to break my tach needle off or not, but time will tell.

Thanks for the input, folks; keep it coming.

[SofaKingAwesome]

Crazy motherfucker!

[HawkeyeGeoff]

So much win going on here. I absolutely love the build idea man; @IamJamen; you ganna like this. Subbed til I die.

[Enki]

Called Comp Cams, they directed me to Web Camshafts because they don't do much import shit (despite the email communication I had from last year with their direct injection guy who is no longer employed there). Web Camshafts who does regrinds ($877 for the set, custom configuration) for us currently; unfortunately, they don't fuck with the HPFP side of things, so I've emailed Comp cams to start this conversation over again.

Worst case, I'll run bone stock cams just to see what it does, though I'd be happier testing out more things (like fuel pressure stability when there's a lobe for every injection event).

[Mazdazilla6]

Definitely filled with interesting ideas and I'm really interested to see how the cam stuff works out for you. Also happy to see another 7163 build, that turbo has really gained a lot of popularity over the past year.



The one thing that I think deserves some explanation is the destroke. I don't forsee huge gas mileage gains as rule of thumb is greater stroke and smaller bore for MPG.

I'm also a bit confused as to why you think this will pick up spool? Sure you'll be able to rev faster but the majority of what spools a turbo is heat expansion much more than actual gas flow over the turbine.

Lastly with such a large drop in displacement and trying to spool such a turbo so fast I would have concerns with ending up on the far left side of the compressor map and hitting really bad surge. It would make more sense to me to enlarge everything you can (head, cylinders, charge piping, intake mani) to have great spool and avoid surging at lower RPM.


Can't wait to see how it all turns out!

[Enki]

In case anyone was wondering what a higher redline would do...



Don't think 4th gear could see redline @ 11k, and 5th/6th would be entirely useles for racing.

[Tokay444]

All I can add at this point, is our heads flow like shit.
Like one of the worst flowing heads I've ever tested.
Put the work in on the intake side as well.

[SNOW_QN]

Wow. This is gonna be fun to watch. Looking forward to the progress.

I like the idea of a 4 lobe for the hpfp. I wonder how well it would work at higher RPM, and how far you could take that without needing aux fuelling?

My business partner has some cnc machines that he once told me he could make cams on. I'll ask him about it tomorrow.

Sent from my SCH-I545 using Tapatalk

[Enki]

The limit is still the injectors, so realistically, there's probably no power to be gained from a 4 lobe cam. If you've ever seen a graphed log of hpfp pressure, however, you'll know that our fuel pressure is very, very spiky; within this, there might be a HP or two to be gained from just smoothing this out...Maybe.

[SNOW_QN]

Ah, gotcha. Didn't even think about the injectors.

I still like the idea of a 4 lobe. Does seem like it would smooth things out with basically a lobe for each cylinder during its revolution.

I'll still ask him.

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[Enki]

Well, still no response from Comp Cams as far as making a set for me, so as of this post, I'll be using stock cams (brand new though). Even so, that should result in some good information.

Also, I'm a bit worried about the effect of extended high RPM on the timing chain. Is there a beefier chain we can use in these engines? A cursory search only reveals information regarding the timing chain recall, but nothing specifically about an upgrade.

[Code Monkey]

Didn't SP post a picture of a beefed up chain like a year ago?

[Enki]

Probably but I doubt they'd divulge.



@Realgib3;

Was this the crank you were referencing?

https://www.vividracing.com/catalog/...i31drsbcd33r64

Displacement would be 2.0 liters exactly, boost would be able to drop down to 21 peak and still maintain 300 tq @ 8k rpm while gaining a slight bump in efficiency across the compressor map (~1%). 10k RPM would be off the map about the same as the 6758 running 24 psi @ 7k, assuming 100% VE for both.

[Realgib3]

Originally Posted by Enki Probably but I doubt they'd divulge. @Realgib3; Was this the crank you were referencing? https://www.vividracing.com/catalog/...i31drsbcd33r64 Displacement would be 2.0 liters exactly, boost would be able to drop down to 21 peak and still maintain 300 tq @ 8k rpm while gaining a slight bump in efficiency across the compressor map (~1%). 10k RPM would be off the map about the same as the 6758 running 24 psi @ 7k, assuming 100% VE for both.

Yep that's one of the cranks and I think massive speed shop has the same for sale.

As for the timing chain, I personally think we're fine, but to run the multi-link chain (which I cannot verify is stronger or not) you can run an ST VVT and crank side sprockets, but have to get a custom exhaust cam sprocket made. When I was going to get it made, the cost for a single was regarded.

[RE-ACTIONENGSPEED3]

i have made some search for making a billet crank for our cars and even to make a de-stroke kit.
In my country they all work with this shop Forged and Billet Engine Internals with great results , i have contact them about a billet crank for our cars, they told me they need an oem crank and a minimun of 3 cranks pre-order with cost 750-800 $ per unit. They even make a de-stroke kit. I have in mind somethind like Realgib3 mention to make it around 2000cc and rev 9000rpm or more ...

[Enki]

1. Enki

[865ms3]

love seeing how meticulous you are with everything. just finally caught up on your last build thread.

a lot of this is over my head, but looks very promising. subbed to see progress.

i just went with the easy "build the block and slap a precision+meth" setup on.

[Enki]

So I've realized I wasn't reading the turbine map information correctly on Matchbot, which I only figured out by comparing my 6758 to the 7163 at the same boost levels. My issue wasn't overall exhaust flow through the turboback, but rather restriction in the T25 hotside; thus, upgrading to the 7163 will inherently flow more exhaust and a brand new turboback might not be required (though I'm still going to do it because there's some other stuff I want to set up on it that I'm adverse to doing on the Full-Race components, like crankcase evac).

I'm also going to look into having the hotside either ported or extrude honed, and I'll probably hit a HP target (based off fueling limits), then carry that HP level as long as possible; this might mean a peak of 350 WTQ starting as low as 3500 RPM and turning into 400 WHP @ 6k, carried to 8k (or higher if that ever becomes possible).

This will also increase efficiency of the compressor, making sure that the air I'm flowing is always on the map and always at least 60% efficient (or higher).

Also, since I'm not hearing back from anyone, I might have to compromise and go with SP63's 12.8 pistons (if they will even sell them to me). Should still be enlightening.

[Enki]

OK so the guys at Full-Race don't think there's enough room to port/hone the hotside on a 7163 to increase the AR by any meaningful amount, so that's pretty much out of the question now.


In other news, I talked to Weisco and they have an off the shelf 12:1 compression piston we can use (~550 for the set with rings and whatnot), but in order to go higher they'd need something from us; namely a stock piston with this Devcon epoxy shit on top of it filling out the combustion chamber so they know how much volume there is to play with (this means having rings, a head and head gasket in place with valves, stock rod and crank to be set at TDC for casting with the epoxy which can probably be added via the spark plug hole).

If anyone can assist with this, please let me know; I'll compensate materials/parts/time for sure.



Edit:
@Realgib3; where did you get your 12.8:1 pistons from? SP63?

[WetzMS3]

Originally Posted by Enki In other news, I talked to Weisco and they have an off the shelf 12:1 compression piston we can use (~550 for the set with rings and whatnot), but in order to go higher they'd need something from us; namely a stock piston with this Devcon epoxy shit on top of it filling out the combustion chamber so they know how much volume there is to play with (this means having rings, a head and head gasket in place with valves, stock rod and crank to be set at TDC for casting with the epoxy which can probably be added via the spark plug hole). If anyone can assist with this, please let me know; I'll compensate materials/parts/time for sure.

Would need to be done with damn near new OEM pistons and a clean head so any build up does not alter measurements?

[Enki]

I think close enough is good enough. A few hundredths of a mm is probably not going to skew things enough to matter.

[Etipp98]

The 12:5 pistons were made by wiseco but ordered through pablo.

[udntknw]

I have a compete set of brand new OEM pistons and rods at the house. Also still have the empty block (eventually will go to Mike). @batmsp3; has two cranks with hairline cracks in them. You have a head (unless it's already gone).