Big turbo build CX-7 :P

[torquemaniac]

I decided to make a thread about my CX-7 build to spice up the CX-7 forum a bit...most of the thread on here are about problems or cosmetic mods...time for more POWA for the CX-7

Ill have terrible gas millage, maybe destroy the transmission, but its gonna be fun while it last

My objective is to finish the engine build this summer...not so sure about that with only a driveway to work, 2 kids that require a lot of time (another baby girl due for august), a tight budget and lots of custom fabrication

The project started with finding a big turbo that spool fast, is in my budget and is reliable

After making a lot of research, I found the turbo I wanted : the Holset HY35

Holset turbo are reliable (the one I got had 305972km on it with no shaft play) and are used on Dodge Ram Cummins (turbo diesel)...they can be found for cheap because the Cummins guys like to upgrade to even bigger turbo (like we do with K04)

Holset are know for spooling fast (for their size) on gasoline engine, because the turbine is engineered for the colder exhaust gas of diesel engine

The HY35 was also engineered to spool faster in order to be used on Cummins with automatic transmission

Here are the specs of the HY35 :

Compressor wheel inducer 56mm
Compressor wheel exducer 76mm
Turbine wheel inducer 65mm
Turbine wheel exducer 58mm
Estimated A/R 0.65 (Holset dont publish A/R...)
Estimated flow rate 60lbs/min (in between a GT3071 and GT3076)

After a couple months at looking everyday at the local (Canadian) ads, I found my baby for 300$

Here is a picture of the HY35 versus the K04



More details of the build to come...

[torquemaniac]

The master plan :

Top-mount turbo setup with a custom tubular manifold (external wastegate)

L2A intercooler with 11 X 6 X 4.5 core, dual pass heat exchanger with 24 X 7 X 3.5 core, bosch Cobra pump

Monster 4'' intake with custom airbox and ram-air intake (I will replace the stock TMIC shroud with a custom composite one)

The Forge BPV recirculate in the intake to keep the sleeper effect

Debating if I put the MAF sensor in the intake, or between the intercooler and throttle (blow-thru mode)...the meth injection nozzle will be between the intercooler and throttle, so having the two so close may be a problem (theres only 8'' of piping after the intercooler)!



Test fit of the intercooler...

[MazdaBoy2.3]

Can't wait to see ya get this together!

[Zdraveca]

I love you!
sometimes i hate myself for trading mine

[torquemaniac]

Originally Posted by Zdraveca I love you! sometimes i hate myself for trading mine

Zdraveca, did the strut tower bar and floor cross member improve the handling on your CX-7?

[Zdraveca]

Originally Posted by torquemaniac Zdraveca, did the strut tower bar and floor cross member improve the handling on your CX-7?

Eh nothing worth mentioning. Springs did bigger diference

Sent from Pu

[torquemaniac]

Little update...

Received some Christmas gift this week :

- 3'' aluminum intercooler piping
- 4'' aluminum intake piping
- Dryflow air filter
- Silicone couplers and t-bolt clamps
- Heat exchanger
- 3.5 bar MAP sensor
- MAP harness
- Titanium heat wrap

Fabrication work done :

- Compressor housing mods (boost line port and flange for silicone coupler)
- Made a 3 ports EBCS with a SMC valve I had in stock
- Machined a MAF flange (need to redo this...some measurement were offset)
- Made a prototype 11/16 oil drain fitting for the block

Here are some pics...











After reading a lot about the Holset oil feed/drain requirements on the DSMtuner forum, I decided to make my own big mouth oil drain

Mandican took some measurements for me on its spare block, and apparently the oil drain hole on the block is 11/16 (about 0.68)

After looking for some tight radius elbow on McMaster-Carr, I found out that the 3/8npt elbow pipe fitting are 0.68 Inside

Bought a regular (steel) 3/8 elbow fitting for 1.25$, modified it a bit, machined a flange and pipe adapter, and voila...













The angle of the pipe fitting is offset, it was just a test...fit perfectly on a 3/4 ID tube...next it will be in stainless

[torquemaniac]

Finally decided on the axleback exhaust setup...I opted for a AT3030 muffler from AeroTurbine...this thing as a very nice tone (and supposedly improve HP and fuel economy)

I like the CX-7 dual exhaust exit look, but I dont like all the bends and complexity of it...after much searching and thinking, I decided to go with a single exhaust exit and use the N/A CX-7 left bumper guard to block the hole on the right side...with a 5'' tip

Its gonna be almost a straight line from the downpipe/midpipe connection to the exhaust tip (no sharp 90 degree turn)

Here is the routing that I will use vs a standard aftermarket setup (not my exhaust in the pic)



Here is the thread that made my mind : VWVortex.com - single to dual tip exhaust

This should be done in the next couples of weeks...if I finally get some good weather on the week-end

[Ozynigma]

Nice handcrafting. Watching this thread with great interest.

[fjanv4ap94]

Cool stuff, good luck with your build. I've been trying to convince my girlfriend to buy a cx-7 so I can drive it around lol.

Isn't the engine in the cx-7 and the speed 3 nearly the same?

[torquemaniac]

Originally Posted by fjanv4ap94 Cool stuff, good luck with your build. I've been trying to convince my girlfriend to buy a cx-7 so I can drive it around lol. Isn't the engine in the cx-7 and the speed 3 nearly the same?

Same good'ol MZR Disi engine...only real drawback is the automatic transmission (thank god there is the manual mode )

[Ozynigma]

Also the K04 turbo has one digit different on the part number and a smaller impeller to spool faster. So motor is down 10kW to 175kW and tuned for more torque to move the heavier CX7.

[torquemaniac]

More stuff came in this week...

SS pipe and mandrel bends for the downpipe and axleback


AT3030 muffler from Aeroturbine


Inside view of the muffler (very cool design)


The TRD 3'' to 5'' tip...so huge and beautiful


Work on the oil drain fitting...

OEM drain vs rev.A vs rev.B


Closer look at rev.B





Rev.B has a better looking design and is TIG welded on the top and bottom of the flange (because the weld line on the top of the flange will be removed near the bolt hole to clear the bolt head)

Only downside is that weld went bad on the bottom of the flange...will need to redo this and surface the flange on the milling

If the weather is good, I will fit the turbo in the car and make the exhaust manifold jig this week-end...

[Ozynigma]

Originally Posted by torquemaniac Finally decided on the axleback exhaust setup...I opted for a AT3030 muffler from AeroTurbine...this thing as a very nice tone (and supposedly improve HP and fuel economy) I like the CX-7 dual exhaust exit look, but I dont like all the bends and complexity of it...after much searching and thinking, I decided to go with a single exhaust exit and use the N/A CX-7 left bumper guard to block the hole on the right side...with a 5'' tip Its gonna be almost a straight line from the downpipe/midpipe connection to the exhaust tip (no sharp 90 degree turn) Here is the routing that I will use vs a standard aftermarket setup (not my exhaust in the pic) Here is the thread that made my mind : VWVortex.com - single to dual tip exhaust This should be done in the next couples of weeks...if I finally get some good weather on the week-end

Funny thread that one. So the chuckmeister didn't convince you to stay with a dual system hey

It was an interesting read for me because my other car just happens to be a 2009 Audi A4 1.8litre turbo. So apart from longitudinal mounting identical to what they were discussing for the TT. I am considering paying $1075 for a tune for that one. Apparently that alone can take the torque to the maximum the CVT can take so no point in any other mods (unless the first one is a manual box).

I was thinking about your single exhaust and doing the same to mine one day. Have you considered leaving the redundant second exhaust tip in place just for looks?

[torquemaniac]

Im on Marcus side...single exhaust exit with minimum bends...like a 3'' canon

The TRD tip cost me like 120$ with shipping...no way am I gonna pay for another one just for look

I had to order some Mazda parts (head gasket, crank bolt, friction washer...)for the engine rebuild, so I bought at the same time the N/A CX-7 bumper guard (they have only one exhaust exit and use what they call a bumper guard to fill the hole in the bumper)

I think its gonna look and sound kick-ass with the single 5'' exit

Here is the thread that got me inspired for the 5'' tip : 5" exhaust tips - Cherokee SRT8 Forum

At page 5 of the thread, you will see an unusual turbo setup (rear-mount)...wicked!

[Ozynigma]

Originally Posted by torquemaniac The TRD tip cost me like 120$ with shipping...no way am I gonna pay for another one just for look

Whoops, I think I realised that as soon as I hit reply. I couldn't figure what you meant by N/A but now it makes perfect sense.

I can't imagine the rear mounted turbo would be very efficient or responsive with the losses and lags between the headers and turbine and impeller and manifold.

I once read that the early BMW 2002 turbo's had long piping and horrendous lag.

[torquemaniac]

Originally Posted by Ozynigma Whoops, I think I realised that as soon as I hit reply. I couldn't figure what you meant by N/A but now it makes perfect sense. I can't imagine the rear mounted turbo would be very efficient or responsive with the losses and lags between the headers and turbine and impeller and manifold. I once read that the early BMW 2002 turbo's had long piping and horrendous lag.

The Mazdaspeed or CX-7 could be have a setup like with a rear mount turbo



You have a compound setup without the space constraint of the engine bay...the oil pressure coming from the pump could be enough to supply both turbo (just need a banjo bolt with a bigger hole on the feed side to compensate for the separated flow)...oil return line on the rear-mount turbo may require a salvage pump

[obijack]

What are you going to tune with?

[torquemaniac]

Originally Posted by obijack What are you going to tune with?

I use Versatuner!

[torquemaniac]

Fitment of the turbo in the top-mount position...





External wastegate positioning...




Ram-air shroud mock-up...




Random shots...



The turbo was positioned on a wooden support...this support will be use to make a steel jig

Now just wish I had something like this to make the manifold piping : icengineworks

[theschrum]

Very interesting build. Must post many pics when you build the manifold.

I'm anxious to hear how that Aero turbine muffler sounds on the MZR. I knew somebody that had one on his Corolla, but was too obnoxious and was removed.

[torquemaniac]

@PartiAudiMazdarati; had one on its MS3

Here is what he told me in PM :

I liked it, to be honest. It gave it a VERY unique sound, forum agreed no one's setup sounded like it. Dyno vid below:

2010 Mazdaspeed 3 Dyno Run - YouTube

2010 Mazdaspeed 3 Dyno Run - YouTube

I had 1 turbine muffler as well, but it was setup in place of the resonator, then I had straight pipe from the axle back. With my setup, I had no issues whatsoever for install, no boomy/bassy drone, but it provided a very mellow tone with the stock tips, mainly it eliminated the "buzz" sound with the stock pu exhaust.

When I added bigger tips, it definitely gave it a more beastly sound, much deeper, although still not "please pull me over officer" loud. Fuel econ also went up, guessing that's because of how the vortex works.

Very well made piece though man, definitely not a bad pick.

Best of luck

Its gonna sound awesome with my 5'' tip

[jtizzle88]

Damn this guy is serious with this build. I cant wait to see the end results.

[Tomas]

Nice project and all.
But I think simply slapping a BNR3 on a CX-7 would be the simplest and best solution. That Holset is going to be ueber lame to drive with. Especially on an auto tranny.

[torquemaniac]

Originally Posted by Tomas Nice project and all. But I think simply slapping a BNR3 on a CX-7 would be the simplest and best solution. That Holset is going to be ueber lame to drive with. Especially on an auto tranny.

The Holset HY35 was made for the Cummins with the auto tranny...it spool prety quick (I have a video somewhere in my favorites...will post this tonight)

Also, 4'' intake + water/air intercooler (minimum pressure loss, very short routing) + short runner manifold + 3'' turboback with minimum bends, high flow cat, straight through muffler...this should make thing ''unlame''

Right now with my rebuilt MS6 K04, I have full boost by 3300rpm (in 1st) because I was too lazy to properly alter the cam and ignition timing tables, and I still enjoy the response of the car (when I launch from a stop, 1st gear goes from 750rpm to 6000rpm in a blink of an eye...so launching is not a problem)

With an automatic car, you have to load the torque converter to have good response (1st gear on the CX-7 is good for this...very fast rpm rise)...if you want to drive like a mad-man, you need to use the manual mode and keep the rpm higher (almost like the RX-7...)

The BNR S3 is too expensive for my budget, and it would not be as fun to build

Next on the list of to-do, is the manifold design...this is gonna be fun

[Vansquish]

There are, you know, manual transmissions for DISI CX-7s. You'd just have to find one...

[Raider]

Originally Posted by Vansquish There are, you know, manual transmissions for DISI CX-7s. You'd just have to find one...

Yup, in Europe. And Japan.

[torquemaniac]

Transmission swap is another project entirely...maybe in 2015

[Tomas]

Isn't the CX-5 with the diesel going to be available with a manual? I thought I read that somewhere....

[torquemaniac]

Originally Posted by Tomas Isn't the CX-5 with the diesel going to be available with a manual? I thought I read that somewhere....

The simpler swap IMO would be a MS6 tranny...

@Tomas; , I cant find the damn video I promised...only thing I remember is that the engine was a 1JZ...I searched a bit tonight, but only found this : Holset turbo on 1jz?

[torquemaniac]

This is the manifold design im gonna fabricate (not my design...took the design here : Old Products )



This design fit perfectly with the turbo/exhaust port position, the runner length is short (low volume to fill = fast spool) and there is no super sharp turn (maintain good exhaust velocity = fast spool)

I will use those pipe to make the runners and the minimum bend radius will be 3.00 (to keep things super smooth) : 1.75" Stainless, 3.00" Radius, 11 Gauge, 180 Degree Mandrel Bend Columbia River Mandrel Bending

[torquemaniac]

Good news tonight...I contacted Columbia River Mandrel (same supplier has the runners pipe) to get a quote to make the MZR Disi exhaust manifold flange (I supplied a Cad drawing of the flange found in the MSF database)

Here is the quote I got :

1/2" SS304 $71.33 each
3/8" SS304 $43.40 each
plus a $20.00 set up fee, lead time about 4 days

Best of all, they use waterjet to cut flanges (no distortion from heat)...

Those price are the best I ever saw online (beats SURE and turbo-flanges.com)

[Raider]

Originally Posted by torquemaniac Good news tonight...I contacted Columbia River Mandrel (same supplier has the runners pipe) to get a quote to make the MZR Disi exhaust manifold flange (I supplied a Cad drawing of the flange found in the MSF database) Here is the quote I got : 1/2" SS304 $71.33 each 3/8" SS304 $43.40 each plus a $20.00 set up fee, lead time about 4 days Best of all, they use waterjet to cut flanges (no distortion from heat)... Those price are the best I ever saw online (beats SURE and turbo-flanges.com)

And buying anything from SURE means you end up on the terrorist supporting watch list. Ha!

I just remember on the old cx7 forum a guy went fully bolted, 180 hp. No tune, fuel pump upgrade. Popped block and sold it.

I am hopeful to see real power from these, now that one can be had cheaper than the 20g's back in the day, or 30, like mine lol.
Manual conversion is an oooooooh.

[Vansquish]

Originally Posted by Raider And buying anything from SURE means you end up on the terrorist supporting watch list. Ha! I just remember on the old cx7 forum a guy went fully bolted, 180 hp. No tune, fuel pump upgrade. Popped block and sold it. I am hopeful to see real power from these, now that one can be had cheaper than the 20g's back in the day, or 30, like mine lol. Manual conversion is an oooooooh.

Yeah, I've seriously considered dropping a manual into a used CX-7 and making it a bit of a sleeper/monster. I mean, it's essentially a funny-looking tall, MS6 with an automatic tranny, after all.

[torquemaniac]

Originally Posted by Raider And buying anything from SURE means you end up on the terrorist supporting watch list. Ha! I just remember on the old cx7 forum a guy went fully bolted, 180 hp. No tune, fuel pump upgrade. Popped block and sold it. I am hopeful to see real power from these, now that one can be had cheaper than the 20g's back in the day, or 30, like mine lol. Manual conversion is an oooooooh.

Popped the block with only 180HP...this is nonsense

Anyways, im doing an Eagle rods swap this summer (+ tuning and meth)...just need some unicorn dust to protect the tranny

[Monotonous ONE]

He was running a boost cut defender. no tune. no fuel pump internals.



He basically was TRYING to blow and didnt even realize it.

[torquemaniac]

Originally Posted by Monotonous ONE He was running a boost cut defender. no tune. no fuel pump internals. He basically was TRYING to blow and didnt even realize it.

Was this guy the founder of SURE

[torquemaniac]

Fabrication page of the Absurdflow manifold : Shore Motorsports: Fabrication & Installation

Nice to see how its done...

[torquemaniac]

New update : heat exchanger and pump fitment for bracket machining











Picture of my good'ol ram-air intake :


Received the manifold piping and flange (very nice product...just took 10 business days before they shipped) :


The manifold fabrication jig is in progress (made it very sturdy and assembled with bolts so it can be dismantled to welding ease)

Also did some piping in casting resin to make the manifold mock-up without scrapping my precious stainless pipes (will post pictures of those tomorrow)

Major set-back for the exhaust fabrication...my beloved Lincoln mig welder suddenly died...electro-mecanician at work took it apart and told me the circuit board is toasted

A new circuit board is 200$ + shipping ...I will try to find a cheaper solution

[torquemaniac]

Piping mockup (with this I should be able to make a very nice manifold shape without having to scrap stainless pipe in the process)