🔧 BUILD LAME Turbo V6 Camaro

[GTPpower]

Maf is only fuel on these cars...there are some adder tables, but that is mostly from commanded.

How much boost are you running? That's a lot of kr. Is the scanner reading the wideband correctly?

 

[GTPpower]

I understand what you are talking about now asking if the maf controls timing. So yeah, I guess it technically does.

 

[v6buicks]

15psi. Yeah, the scanner appears to be reading correctly when I'm just eyeballing both displays.

 

[GTPpower]

Can you turn it down? Or is that your wastegate pressure?

 

[v6buicks]

Can you turn it down? Or is that your wastegate pressure?

I can turn it down. I have an MBC. Spring pressure is only 8 psi.

 

[GTPpower]

I would turn it down 3ish psi and pull a couple degrees of timing out as well. It's baffling to me that you have that much kr. What intercooler do you have?

 

[v6buicks]

I would turn it down 3ish psi and pull a couple degrees of timing out as well. It's baffling to me that you have that much kr. What intercooler do you have?

Intercooler is something like 24" x 18" x 3" from ebay. As far as pulling timing should I just subtract from the whole table? Both high and low octane?

 

[GTPpower]

Yes and yes. You could pull 6 or 7 degrees out of that and leave your boost alone too.

 

[v6buicks]

Yes and yes. You could pull 6 or 7 degrees out of that and leave your boost alone too.

Hmm. My timing would be negative in some spots if I did that. Can the ECM even do that? I don't mind turning the boost down a bit, but that's not fun. lol

 

[GTPpower]

Yeah it can be negative. I'm looking at your commanded timing. You are commanding 16-17° at wot. That's a bit much imo for a turbo car. You're better off with more boost and less timing, especially since you have all the cooling from e85. You may not need to pull that much because e85 seems to get exponentially worse with more timing advance. I would pull 6 or 7 degrees and try it. You'll probably be able to add some back.

 

[10sec]

17 degrees of timing is not a bit much, pulling timing and adding boost will just create more heat. That is not good advice IMO.

 

[GTPpower]

Oh then by all means, add more timing.

 

[Mr_Roboto]

https://www.theturboforums.com/thre...aro-update-428-whp-on-a-dynojet.338233/page-5

I don't know that he's around too often but I'd PM this guy and see about some pointers. May have posted the thread before. It's 5 pages and worth reading. He talks about what his tuning looks like in it which is really helpful. He ended up at 379 at the tire and 428 with a 50 shot so it got really good results. I don't think it was near as modified as yours is even, just a stock engine far as I skimmed through the thread.

 

[v6buicks]

I remember hearing a few times with the SC cars to tune for the smallest pulley you could throw on with 0 KR and 18 degrees. I'm not saying thats applicable to a turbo a car, but just a conversation adder I guess.

And I don't really even know what you mean by WOT timing. Isn't the timing going to change a bunch depending on RPM and stuff? Mr_Roboto I haven't read your article yet, but I will once I get some coffee.

 

[GTPpower]

Timing will change a bit at WOT, but it does stay fairly consistent. It "should" technically increase as your RPMS do, but I wouldn't worry about that yet.

Pulling back your timing to 10-12* will help with spooling the turbo as well. But, my main concern is all your kr. You're going to be sticking in a new engine if you don't do something. We need to get rid of it and slowly adjust the car more aggressively to see what the problem is.

 

[v6buicks]

So the turbo spooling way quicker with the GTP timing wasn't all in my head? Damn. I have a ton to learn. Then again, isn't that how anti-lag works?

 

[GTPpower]

Yup. Lower timing = faster spool.

That's not true for every situation....there are limitations to that, so don't take it to the extreme.

But, we run like -5* timing in my buddy's turbo car while trying to spool it up.

 

[v6buicks]

Interesting. So what is considered to be my WOT timing if we are just talking about one number? There seems to be a big range in my "WOT" areas.

 

[GTPpower]

Your final commanded timing is not just from that table. See all the other adder tables? They all input into the final number.

 

[v6buicks]

If I look at the most extreme situations (rich AFR, hot charge, hot engine, high rpm) all the adders seem to put the timing at 18.

 

[GTPpower]

I'm just going off of what your screen shots of the scan is showing. Actual timing plus kr is about what commanded is. You're definitely up there.

You'll make more power on less timing and more boost than the opposite. Keep timing lower until you max out the turbo.

 

[v6buicks]

I read a little blurb in theturboforums that stuck out to me. I guess it's not that I didn't know any of these individual facts. I just never put all the puzzle pieces together or gained that holistic understanding. The basic notion I had prior was "more timing = more power" boosted or not which isn't really the case at all. It's more or less a necessary evil which can be minimized with boost. Now I'm starting to understand why more boost makes tuning a lot trickier and sensitive.

If you could magically have all the fuel burned the instant the ignition occured the optimum timing would allways be at TDC regardless of the engine or that engine's speed. In reality since burning the fuel takes some finite amount of time you must have ignition before TDC. The slower the fuel burns the more you must advance the ignition. There is some penalty for this as the burning that occurs before TDC is counter productive. The more advance the more counter productive work occurs. In the boosted engine the cylinder pressure at ignition is higher making the mixture burn faster; therefore the ignition will not be advanced as much for optimum power.

This principal is why an engine that is not octane limited on pump fuel always makes less power on race fuel. The race fuel burns slower and the ignition must be advanced to accomodate. Since further advancing the ignition is further counter productive less power is made.

After reading that, I think I'm just going to run it on the 8 psi spring and leave the timing as it is. Considering that I mostly have a cut and paste tune with limited skills, I think it would be safer to start out with a lame but safe boost level and work on dialing things in that way. Once I have that figured out, I'll turn up the wick and start the process over again. I still have no clue as to what the "process" is, but I guess I'll keep taking baby steps until I figure it out.

 

[GTPpower]

That works too. I would pull both back, but either will work. Start conservative and slowly add more to find the limits.

 

[v6buicks]

I don't get it. It doesn't make sense to me that I suddenly have KR when all I did was modify the MAF frequency, adjust the hz vs. airflow table accordingly, and my actual vs commanded AFR is pretty darn close. I have almost half the boost and it's doing the same dumb crap. Yeah, I'm short shifting, but the whatever the problem is starts way before that anyway. I'm gonna have to walk away for a while. The dollars per disappointment is getting very high, and the dollars per win is not applicable after two years of no recorded ETs or dyno pulls.

 

[GTPpower]

Try this:

Go to
Engine>Fuel>Power Enrichment>Throttle>Hot

Change every cell there to 30.


It looks to me like it's entering PE way too late, then it can't dissipate the heat quickly enough. Try that and see if that helps.