Well, I dont know if I'm being lazy or just stupid here but here's my situation: I am running the FP Green on my Evo VIII, full bolt-ons, cams, etc, etc. I upgraded the WGA to the Forge high boost one as well. I have read every thread that i could find regarding this thing, have played around with adjusting the WGA rod, and have come to the conclusion that the spring is too strong (19-24psi spring, i think). Anyway, I figured, what the hell, why not just tune for the higher boost levels instead of turning things down. I'd like to run 25-27psi and hold as much of that as possible to redline. What do I need to do to my fuel and timing maps to make this work? Any and all thoughts and input are welcome. Thanks.

 

Run 25psi (ish), the best gas possible and get used to the idea of running 4-5* till 5K and then ramp it up from there to 13 or so. Leave the AFR's in the 111.2-11.5 range or wherever you have them now assuming they arent EXTREMELY rich or extremely lean already.

Then spend lots of time logging and adjusting.

The best method is to start low and work up from there however as it makes it easier to know what you can push at each boost level (23,24,25,etc.)

 

a spike to 26 worked okay on my green setup but it's important to have good mods to go with it...ported exhaust, 02 housing, fmic etc...

 

25+ psi is possible with 93 octane. However, if your just getting started with tuning I suggest turning down the boost until you have a good feel for tuning the Evo. I run 25psi daily but I've been working on this tune for some time.. I didnt start out trying to tune for 25psi, not that the principles are any different but the chance of making a mistake that costs you money is much greater at 25+psi than it is at 21-22psi.

 

I think the key is precision. If you dont feel that you can tune the car precisely, then dont attempt to run 25+. I run 26 but on pump I am beginning to feel that the trade in timing that I can run isnt worth it. I'll see after I redyno the car I guess.

 

I agree. With the little bit of tuning I've been doing on my own car with higher boost pressure I don't really think the drop in timing to run a higher psi is going to cut it, not to mention the extra heat the turbo is going to push out. I would ramp up slowly from where you sit now, and if you don't see much of a gain going higher in pressure then drop it back down. Tuning 93 right to the edge tends to be picky, especially over the winter months when gas quality isn't as good and the air tends to be denser.

 

all this info is great, and i'm with JB, i think that the loss of timming isn't worth it. i've noticed more tq output with higher timing and lower boost, and hp numbers roughly the same as if there was lower timing and higher boost. So really it depends on what your supporting mods are and their exact specs to determine your performance limits. like JB sad, log, log, log, you make a change and then log, until you have it right where you want it.

 

Well Chris (Mellon), I have pretty much every conceivable bolt on, including cams, head studs, etc. I even have an Aquamist HFS-5 installed that I'm not running right now. Let's not include that in this thread though because I can always worry about that later.

SO yeah, I finally got the Forge WGA rod length fixed and if I am shooting for 25-26psi, what AFR should I be aiming at and where? Also, I am wondering about timing. And one last thing. From all of my reading lately, I have come to the conclusion the tuning should proceed in the following order:

1. Injector Battery Latency Compensation (for LTFT's and STFT's)
2. Injector Scaling
3. MAF scaling/tuning (for idle)
4. Open Loop (for fuel economy, etc.)
5. Boost
6. Timing
7. Fuel (AFR's)

If you guys could give your input here, I'd really appreciate it. I hope this post doesn't start a tuning methodology war, but oh well Thanks!

 

oh, and btw, I completed the first 4 steps already

1. Latencies
2. Injector Scaling
3. MAF
4. Open Loop

 

I dont see why you dont run meth injection if its already hooked up? That way you can run higher boost, but tune it safe.

 

I saw significant reduction in power when AFR's go into the high 10's so I'd say 11.2-11.5 area and as much timing as it can handle for the mods/boost/octane/weather etc..

I'd shoot for no more than a 1-2 count of knock for consistency.

 

I suggest doing all fueling prior to adjusting timing. Fueling has a wide window of acceptable AFRs at different load sites and will make roughly the same power within a wide range of AFR's as long as they are within the "window". Timing on the other hand has a smaller window at MBT and will vary depending on the specific Volumetric Efficiency (VE) of the engine that you are tuning. After you have properly timed the engine you may re-visit your fuel table and make any fine adjustments that may be necessary as a result of timing that you have changed previously.

item 4. on your list...
"closed loop" is when the ECU manages fuel with the o2 sensor (cruising, emissions, etc)
"open loop" is WOT and startup.

 

boost, afr, then timing.

u need to set your boost in order to know which cells to tune.
u need to set your afr's in order to to run timing accordingly.

The goal from tuning timing is to make the explosion happen when the piston reaches the TDC. That's why, after adjusting everything else, timing is then tuned in order to make the explosion happen at the TDC of the piston.

Of course, when u ajdust timing, u might need to fine tune your afr's again, as they may vary a bit. Then u need to fine tune your timing again.... and so on until u find your final setup...

Rgds+

 

There's no explosion..
And the goal is to have the peak pressure from the burn happen at ~14* ATDC.

 

Not entirely true ... you want to tune timing for peak cylinder pressure at ~15º after TDC. Firing the spark is just the means of starting the process ... engine RPM, fuel used and AFR of the fuel are also highly involved in the process.

Everything else you said was pretty much dead on.

EDIT :: ooooo ... beaten.