Should we increase timing?

[Dano]

So with all the new tables exposed in ATR everyone is giddy with the anticipation of more power with timing advance….but what is better for the motor?

Is more timing less boost better, or is less timing and more boost better…..

IDK I am noob at this but have researched enough to ask this question of the heavy hitters on MSF [you know who you are]

Below is an excerpt from a tuning thread on NASIOC. I have to believe our cylinder to crank angles are close enough to a scoobie for this discussion to be relevant.

maybe DI is so different from PI it is completely irrelevant

Read....its a good read..... discuss…I want to know….

Originally Posted by Element Tuning
There has been so much missinformation posted I don't know where to even start. LOL! I'm going only to adress timing as it relates to which plug temp you use based on the EJ257.

I've already explained why more timing is harder on the engine but maybe it wasn't clear enough. It's understood that more ignition timing means you start the combustion process earlier than with less timing. Earlier means the rod will be pointed towards the cylinder wall more than more towards the head (verticle). The sooner you start building cylinder pressure the higher the force being applied to the rod with more angle. More angle means it will be pushing the piston harder against the cylinder wall. There are other less thab ideal effects to the crank and the rod itself.

How does this relate to cylinder pressure? More timing means more cylinder pressure for longer. You are exposing the engine to heat for a longer period. More ignition timing means higher in cylinder temps and lower EGTs. Yes lower EGTs mean higher in cylinder temps not the opposite. A high EGT just means you have more burning happening after the exhaust valves open.

So how do we end up at the same power level with less ignition timing as it relates to cylinder pressure? It's simple you burn it faster and therefore you can start the combustion process later. Better rod angle, less force being wasted slamming the piston against the cylinder wall, and you're compressing the combustion process so high cylinder pressures are reached for shorter periods. Pretty common sense stuff right?

There is a place for colder plugs but not as it relates to the original post. My race car puts out over 600 whp and it's run at wide open throttle anywhere from 10 to 20 minutes and I use a 6 range plug with no signs of overheating. Why is this? Water/meth injection slows down the combustion process, the race fuel I use also has a requirement for more timing, so a hotter plug works best.

Typed on Blackberry so if this reads funny with lots of spelling issues I'll correct later. Lol
Quote:
Originally Posted by Element Tuning
I often feel like when I post how it's read by an individual completely is completely different from one to the next . I think forums are a great place to learn but they are also full of incorrect information and misinterpreted information. To this day I learn new things all the time from our engine R&D. I think I highly benefit from being the guy that dreams up the build, tunes the engines, has the engines built at Element Tuning, and then has the engines dissected and evaluated. On top of this I have probably tuned thousands of Subarus at this point and am lucky enough to have tested good and bad combinations. I have learned a great deal from other peoples mistakes and benefited from other's sucessful builds. An enthusiast will never experience this broad range of setups.

I'm not bashing anyone for running high ignition timing. It's your engine, do what you want. When you are paid and entrusted to tune someones pride and joy that may have upwards of $50k in modifications you better not blow it up. I always take it slow and I know the limits of these engines better than anyone. Ok so with that said it's not that I never run very high ignition timing, I said it's bad! This isn't so much about the tuner, it's about an inferior engine design. Get it? You should strive to setup the engine so you can run less timing. 1 or 2 degrees of ignition timing in the wrong direction is all it takes to blow up a motor.

One more time, MORE IGNITION timing means HIGHER in cylinder temps. This is a by product of more HP. I think EGTs are so misunderstood and feared but no matter how many times I post the correct information it just isn't absorbed. Less timing increases EGTs and when was the last time you heard of someone blowing up their engine from too little ignition timing? Too much timing which equals lower EGTs is what blows up engines. I ran an entire season of "Unlimited" time attac competition with a bone stock EJ257 at 500 whp just to prove a point. Engine reliability is primarily about the tuning and keeping detonation at bay. To do this you have to be conservative with ignition timing. It's so easy to keep increasing power with more timing until bam....blown engine. Being conservative with ignition timing means your EGTs will be higher. It's completely normal for my EGTs to be 1000 C for 20 minutes of racing. Our stock engine had over 12k miles and never failed. Don't fear the high EGTs

Quote:
Originally Posted by Element Tuning
I've tuned others since I tested E85 a couple years ago on my own car. Prior to that, I have 8 years experience tuning with methanol. I am fully aware E85 is only E85 some of the time and other times is can be E65 (very tricky in the transitions in and out of winter). You may ask why don't I run E85 or even tune many cars with it any more? The majority of my customers run a water/meth injection system. With these systems we can make as much power as you can with E85 without the hassle of locating stations, increasing fuel injector and pump volume, without the fuel economy decrease, and without the starting problems associated with E85 at sub 20 degree temps (we don't really get E65 in the DC Metro area). E85 is cheap and I’ve thought about running it in my race car but I would have to run 1 extra gallon each session and therefore would have to transport 42 gallons to the track each event which is a PITA.

You’re avoiding the fact that high ignition timing increases stress on the engine. This is my main point. I have never said adding ignition timing doesn’t increase HP. It does until you blow your engine up. It’s very hard to reach MBT but I have actually once while testing on a dyno (reach the point where adding timing does not increase HP). All other times detonation would occur well before MBT was reached. A better engine is one that will make the same power with less ignition timing….this is fact.

The OP has a stock ecu with a hybrid motor. This combination is full of phantom knock from the OEM ecu mostly due to different noise characteristics of the 257 and the slight change in timing as a result of the differences in the block dimensions (changes cam timing as it relates to crank timing). If or when he gets a Hydra he will finally be able to tune that combination the way it should be by running the correct timing curve, correcting his ignition dwell times, and by having a fully adjustable knock threshold system that doesn’t suck.

How I would love if I could make 600 whp on an EJ257 with 0 degrees timing at peak torque and 13 degrees at redline like I have with an EVO. The closest I’ve come with the EJ257 is what I explained in a previous post. I once had the pleasure of speaking with a Pro NHRA team’s engine builder and I asked him, “how come you can’t get your motors to survive more than one pass?” He said, “Oh we know how but we can’t win that way. We push the engines with as much timing as they will take to finish one pass but they only get one pass.”

Just read some of these posts on Engine Building and you will realize people aren't learning from their mistakes as you read post after post about how they are on their 4th plus engine. LOL! Only run as much ignition timing as you need or as much as you need to win. LOL!

Ok facts:

A colder spark plug with no other changes pulls heat out of the combustion process therefore reduces power.

Adding ignition timing increases power up until MBT.

Adding ignition timing results in high cylinder pressures longer

Adding ignition timing increases in cylinder temps (this is how it makes more power) and reducing timing decreases in cylinder temsp.

Adding ignition timing reduces EGTs and decreasing timing raises EGTs

Higher EGTs means lower in cylinder temps (fuel hasn't burned as much therefore burns longer in the exhaust)

The EJ20X engine has a better rod/stroke ratio than the EJ257(5).

These are the facts so everyone should use these for what they are worth as I’m not going to continue posting on this thread as I’ve continued to beat a dead horse. LOL! My advice is to push towards modifications that allow you to make the same power with less timing. If you want to run as much timing as possible you can, I have, I have won races, and I have seen the engine aftermath. It’s a balancing act really about making competitive power and having a reliable engine.
Quote:
Originally Posted by Element Tuning
That is the major problem isn't it? You have to stop for the engine's sake. From my experience on a particular engine and turbocharger setup using VP C16 MBT was 34 degrees at redline (it's been years but I think I even saw a loss at 36 degrees).

I typically will not exceed about 29 degrees regardless of HP. I just know even at 29 the EJ257 has some serious loading on the thrust side of the piston. If I'm tuning a drag race only engine I will typically go up to 29 (on C16 or Q16 race fuel or race with Hydramist) if it will take it but a customer's car which will be used for road racing I really like to keep it closer to 26 degrees. At some point you just have to give up that last 20 HP or so for the sake of reliability.

[Wenis Prinkle]

hmmm i tried increasing the timing by a degree and i didnt feel any real power increase and had more trouble with knock. after lowering the timing back down some the car ran better with no knock. so if your looking for extra power im not too sure that increasing timing on these cars is the best way to do so. adding more fuel by lowering boost temps via intercooler or meth or extra boost would make for better safer power rather than increasing timing. my two cents...

[djuosnteisn]

It’s very hard to reach MBT but I have actually once while testing on a dyno (reach the point where adding timing does not increase HP). All other times detonation would occur well before MBT was reached.

This.

On our cars it is actually easy to reach MBT before detonation becomes an issue (at least in the upper rpms). I did exactly this on the dyno, with superskater watching.

Plus if done in baby steps (.5 to 1 degree increments), the ecu is quick enough, and sensitive enough to catch the onset of detonation and protect the motor. This can be used as a tuning aid as well, to help find best timing before detonation (if detonation is an issue, and MBT isn't reached).

[Dano]

So it's the difference in our motors that makes his concerns less valid or not apply?

[djuosnteisn]

I'll just add one more thought.


Detonation is what blows motors. The amount of increase in angle loading on a connecting rod from increasing timing 2 degrees (say like from 13 to 15) is almost negligible IMO. I think the OP in your quotes is simply trying to get a few points across.

The goal of tuning timing isn't to push it as far as you can.... it's to time the ignition accurately to produce the maximum cylinder pressure ~15 degrees after top dead center. That's how you optimize the torque for a given air fuel mixture. And that's generally what is meant by minimum timing for maximum best torque (MBT).


Can you run 5 degrees less than MBT? Sure. Will it appreciably increase the lifespan of your power plant? I doubt it.

Can you run 5 degrees more than MBT (pushing the motor into occasional detonation)? Sure. Will it appreciably decrease the lifespan of your power plant? You bet your ass.


Detonation is what kills, proper timing is what optimizes.

[Dano]

Ty brother Dustin

In my case I am going up about 4* advance. From 10 to 14 at 6k ish.


Sent from my iPhone using Tapatalk

[SJP0tato]

Originally Posted by Dano2010 In my case I am going up about 4* advance. From 10 to 14 at 6k ish.

What I hate is where we probably need the timing increase the most (upper RPM band) is where the knock sensor becomes useless, so there's no feedback if something's not right until you hear knock or the motor lets go.

[Frequentflyer]

Originally Posted by SJP0tato What I hate is where we probably need the timing increase the most (upper RPM band) is where the knock sensor becomes useless, so there's no feedback if something's not right until you hear knock or the motor lets go.

Well we haven't proven that the sensor is "useless" yet. I've upped my KR Active max RPM to 6750 and it appears to hear knock and pull timing up high. Now, it doesn't do it all the time, so that tells me that it does hear knock. If it mistakened engine noise for knock, I would think it'd do it every time at WOT above 5700, but who knows.

[djuosnteisn]

14 is a huge improvement over 10.

[superskaterxes]

4 degrees netted me an increase of 34 g/s with no other changes done, thats, well, impressive

[DSIT995]

Originally Posted by superskaterxes 4 degrees netted me an increase of 34 g/s with no other changes done, thats, well, impressive

wow, that is quite good for only making that change..........

Did u just do this?

[superskaterxes]

Originally Posted by DSIT995 wow, that is quite good for only making that change.......... Did u just do this?

yes 2 days ago, then i upped boost 6 lbs with no changes and broke 400 g/s lol consequently this was not on purpose but impressive none the less

[rodrigo]

mbc ftw.... eff yo tuning sukkas

[hnda etr]

Originally Posted by lenny127 mbc ftw.... eff yo tuning sukkas

Instead of swapping your turbo, we should just drop in a chevy 350 and TH400... Mr. Old Skool

[Dano]

Originally Posted by hnda etr Instead of swapping your turbo, we should just drop in a chevy 350 and TH400... Mr. Old Skool

/groan

and drop a 9" ford diff make it RWD.

BTW GTFO my thread with your games...this is serious chit!

Originally Posted by Frequentflyer Well we haven't proven that the sensor is "useless" yet. I've upped my KR Active max RPM to 6750 and it appears to hear knock and pull timing up high. Now, it doesn't do it all the time, so that tells me that it does hear knock. If it mistakened engine noise for knock, I would think it'd do it every time at WOT above 5700, but who knows.

Well we don't know if the knock the sensor is picking up is actual KR or engine noise...only way to figure that out is on a dyno to see if power drops...anything less than 1.0 I would ignore and let it rip!!

[rodrigo]

oh man ..i would love

[Speed3eak]

subbed for if someone ever finds out how accurate the knock sensor is @ high rpms.

[Dano]

I am not sure how we would be able to tell the difference between actual KR vs other noise in the engine without seeing a real HP loss due to deto, this of courese measured on a dyno.

I have my sensor on to 6.5K and 13* advance without any KR recorded running meth. I turned off the meth and KR was present immediately at 2*+ worth from 4.5K to 6.5.

This wasn't a targeted test for timing and KR but I just noticed it in some logs while I was making a non meth "winter" map. Can't get meth around here until next season FML.

From this limited "test" in my motor at least, the sensor appears to function correctly in the higher RPMs.

I have made no other sensor changes in ATR.

[Frequentflyer]

I agree. I get some KR above 6k every so often in the .3-1.0 range. It doesn't too it all the time, which leads me to believe it's really hearing some knock. If engine noise set it off, I would think it'd do it all the time. I don't spend too much time above 6k anyway as that's usually where I shift.

[Dano]

yup, more than likely real "noise" would be there all the time.


The only thing I could think of that would dispute that statement would be that more noise might be present with varying engine and AMB temp differences. Tolerances changing with expansion and contraction, etc.

[djuosnteisn]

Dano, why not just increase the upper rpm to 7k? That's what i've been doing.

Also, you can get meth in the winter, it's just a lil bit more expensive than buying it in bulk.




Heet says "hi". It's 99.9% methanol, and 0.1% rust inhibitor, but safe for the application (I verified that information with a HEET representative a while back). Be sure to get the yellow bottle with the blue label, the other one is a bit different, and i haven't verified the ingredients.

[Dano]

hahahah

edit: yes I need to set the KR max to 7 as well


I remember the days of buying a cart full of heet...like $4 for 12oz IIRC...vs. 4.30 per gallon of M1..

I need to at least spray H2O which would help a lot.

[Nataphen]

I'm new to tuning this particular car, and I still have a lot of questions, but timing advance is one of the things that I was curious about most of all since I haven't seen much info on it. If you are street tuning, would this motor adhere to one of the more common strategies of increasing timing in a given range until you start to see KR at 1*+, then backing off? I know that this motor is very different than the average motor, and that's a very old school way of tuning, so I just wanted to see if it was a good way to go about it.

Obviously, the best route would be on a dyno to get optimal timing, but I don't have funds to do that every time that I tinker with my tuning.

[Dano]

that's exactly how to do it on the street. To use KR as a feed back above 5700 you of course need to enable it in ATR. And enable it before you do any timing work to get a baseline of how sensitive the sensor is. In my car I run it all the way to 7K and don't see any KR.

Other motors may be more "noisy" in the upper rpms and/or the sensor is more sensitive.

One thing to consider when dyno tuning is that the dyno won't load the car down as much as the street so even if you tuning timing on the dyno you would probably pull back 2* for the street tune or at least monitor it closely when you get back on the street.

[Nataphen]

That's what I've been doing, so good to know, LOL. Raising the KR limit to 7k is one of the first things that I did. Like you said, we aren't sure how accurate it is, but I have seen it register some KR over 6k since I did that. I don't think that it's engine noise because it's not constant, so hopefully it's accurate all the way to redline.

It's probably safe to say that the inaccuracies would lean more toward showing phantom knock rather than not showing knock that is present, so I'm fine with that. Better safe than sorry and all those cliche things.

[Dano]

one way to weed out phantom KR would be to perform back to back runs, same AMB temp same BATs etc, adding/subtracting timing to see if the registered KR follows. If KR goes away consistently when you removing timing it is probably the real thing

I started this thread b/c I wanted more discussion of timing vs boost to make more power...LOL I think I subscribe to conservative timing and more boost as the guy from Element Tuning indicated. He isn't talking about knock breaking motors but the stress that starting the combustion process earlier places on the internals which can't be measured until its too late LOL.

[Speed3eak]

Well, given that knock is affected by load, doesn't that mean you should fine tune timing using 4th gear pulls (rather than 3rd)? I'm glad I haven't messed with my timing maps yet, seeing as I've been wussing out and doing 3rd gear pulls for WOT stuff.

[Dano]

absolutely...tuning should be done in 4th gear for our cars. Plus once you get to a certain power level 3rd gear won't do the trick anymore due to wheel spin.

As close to a 1:1 gear ratio without putting undue stress on the motor. IIRC our 5th gear is 1:1 but I wouldn't tune or dyno in that gear.

[Nataphen]

Agreed, boost>timing advance. On other cars that I've worked with, while very different, that's the logic that people have used. Increase boost to the maximum efficient range for the turbo/SC, then add timing.

One other question, is it better to lean out AFRs, or add timing? I would assume that the 11.76 AFR, which I believe DJ has said is optimal for the motor, would be best, then add boost, then add timing. Thoughts?

Gen 2 is 1.03:1 in 4th and .95 in 5th. Cobb entered 1.02:1 for the 4th gear value in their maps, but I changed it to correspond with the spec sheet. Not that it makes any real difference, I'm just anal like that. All the other ratios show the same as the Mazda spec sheet. Hell, for all I know, the spec sheet could be wrong, and Cobb could be right.

[Dano]

yes and that depends on the the geometry of the shortblock as well right. Depending on the crank angle at the onset of spark, different motors will have more stress than others. Apparently one particular scoobie motor sucks in that regard where the other model has less angle and thus can handle more timing. IDK I just glanced over the posts

AFR, that is the question. I don't have enough experience to speak too much on that but there is more HP to be had with leaner AFRs BUT....I would rather run 11.8 -11.9 and 13* advance than 12.2 and 11* advance. If that is what would happen.

its a trade off.

for the street the difference is minimal but a 12.2 AFR might get you up to and over the 350 or 400WHP mark for a dyno sheet vs 11.8.

In my 350WHP run I was running 12.2....when I was running 11.8 I couldn't make 350 so there you have it. I gained about 10WHP with the change to 12.2 AFR

Is that worth it for DD?? nope!

[Dano]

Originally Posted by Nataphen Gen 2 is 1.03:1 in 4th and .95 in 5th.

so 4th and 5th just about split the 1:1 ratio LOL...you can't get there from here

thanks for the info! I do believe Gen1s are different somewhere but it may just be 1 and 2nd IDK

[Nataphen]

Originally Posted by Dano2010 absolutely...tuning should be done in 4th gear for our cars. Plus once you get to a certain power level 3rd gear won't do the trick anymore due to wheel spin. As close to a 1:1 gear ratio without putting undue stress on the motor. IIRC our 5th gear is 1:1 but I wouldn't tune or dyno in that gear.

Originally Posted by Dano2010 so 4th and 5th just about split the 1:1 ratio LOL...you can't get there from here thanks for the info! I do believe Gen1s are different somewhere but it may just be 1 and 2nd IDK

I believe that gen 2 has higher gearing in 2-5, but 1 and 6 are the same. The jury's still out on whether or not that was a good idea, I guess it would just depend on what you were doing with the car. For straight line acceleration, obviously the gen 1's lower gearing is going to be better. If you were trying to hold gears on the autoX or road course, maybe the taller gearing would come in handy.

OK, back to the timing discussion, sorry for the derail.

[Nataphen]

I'm running 12.0:1 targets ATM because I can't boost up much. I'm maxing out WGDC, plus I have the stock fail pump that I'm working around until I can afford a CPE pump. When I get the pump and exhaust to alleviate the WG strain, I'll drop the AFRs and timing back down, start adding boost, then timing again. This is addicting stuff.

[Dano]

[cld12pk2go]

My strategy is to first dial in fueling, then add boost, then add timing, then enjoy...

[djuosnteisn]

I just wanna add a lil bit to the discussion, but i think in regards to timing vs boost for power, i'm not sure that a 2* difference is going to result it drastically different loading on the rod. If it were a choice between 10*... then i can understand the logic. And i agree fully, if it were that extreme of a situation, i'd opt for the more boost and less timing.


Also, based on the study we all did a long time ago looking at the fuel injection process... i'm inclined to believe that the spark advance values we see in our logs are indeed the REAL spark advance, and not just an adjustment to a base value.

Look in the OP of our injector thread, and you'll see a nice scope screen shot of the crank pulses and ignition:

Have you measured when the injectors...


With that said, the amount of spark advance our platform runs compared to most others is quite small. Most platforms are running like 20+ degrees of spark advance, where as we achieve MBT at ~16*.

Just trying to keep things in perspective. The logic is sound, but i'm not convinced spark advance is bad for our motors, at least not yet.



Thus far, i think the only 2 things that have contributed to blown motors in our early years were 1) Load Cap (causing all the blown motors once the cold months came) and 2) Potential design flaw / aggressive oem tuning (causing a super heated head & combustion chamber during long cruises on the highway coupled with aggressive timing, slow CL exit delays and a quick spooling stock turbo).


I don't think we need to be scared of timing, at least not yet. I pushed the living shit out of my motor, going 5* past MBT intentionally trying to make it detonate on the dyno, and it never did.

[superskaterxes]

What does it mean if your running 12.5 afr and 18* @24psi?

I think my motor is allergic to rod knock haha.


P.s. I picked up 30 whp and almost 60 g/s from 8 degree's of timing alone. Both of which were substantiated on a dyno. After the new atr came out and we could increase max timing, my car became a beast with no other changes.

[djuosnteisn]

Originally Posted by superskaterxes What does it mean if your running 12.5 afr and 18* @24psi?

Means your spraying water and methanol.... which makes our motors nearly invincible to detonation




Plus with a fully operational knock sensor and fast ecu... we've pretty much got the fail safe built in (coupled with an attentive driver of course).

[SJP0tato]

Originally Posted by superskaterxes What does it mean if your running 12.5 afr and 18* @24psi? I think my motor is allergic to rod knock haha. P.s. I picked up 30 whp and almost 60 g/s from 8 degree's of timing alone. Both of which were substantiated on a dyno. After the new atr came out and we could increase max timing, my car became a beast with no other changes.

Do you have a datalog from this that you could post up? I'm very curious to see your BATs (amongst other parameters). I'm hopeful a new TMIC on my setup will help me eliminate KR I keep seeing, I'm assuming due to higher BATs. Hopefully if it takes care of that issue I can start working on increasing timing, as mine is super conservative currently to combat KR (6* @ 5k rpm @ 17psi).

[superskaterxes]

Originally Posted by SJP0tato Do you have a datalog from this that you could post up? I'm very curious to see your BATs (amongst other parameters). I'm hopeful a new TMIC on my setup will help me eliminate KR I keep seeing, I'm assuming due to higher BATs. Hopefully if it takes care of that issue I can start working on increasing timing, as mine is super conservative currently to combat KR (6* @ 5k rpm @ 17psi).

yah its on my personal comp though. i can post it up sometime thursday or friday when i get home.