Horse power limitations?

[civic1234]

OK, I have a K24A4 Turbo charged with Precision 6266 sidewinder, forged internals 1200cc injectors etc etc the works.

I know that the developer of the Hondata is also a tuner himself and I would like to ask if you can shed some light on a very specific question regarding HP limitations.

The car is very very well tuned on all part throttle and full throttle just like a factory tuned turbo car. Runs flawless and no hiccups for 5 months now.

Here is the question:
Engine is Dyno tuned, it produces 340 WHP at 15 PSI (Dyno jet) using 93 pump gas fuel at 65% Duty cycle. Found out that MBT for this engine combo at full load after peak torque is 12 degrees of timing on the dyno under 11.5 AFR and is very smooth power with no knock. I then tuned it on E85 (E82 according to my flex fuel gauge) and I was only able to bump ignition timing 2 DEGREES!

Any less than 2 Degrees and it lost power, any more than 2 degrees and it also lost power. The 2 Degree bump was only able to produce an additional 20hp in mid range and about 15 hp on top end. I then raised the boost to 20 PSI and was only able to add 2 degrees as well. I'am now sitting at 10 degrees total timing under full load 20 PSI.

If this pattern continues, I will be at around 5 Degrees total timing by the time I hit 25 PSI. I was planning to go up to 30 PSI eventually but Im Afraid that even with E85 my timing would be so low that it wont make any more power. I will be in the 1-2 degree timing by the time I hit 30 PSI on E85 providing I have enough injectors later is my guesstimate.

This was all dyno tuned and back to back results were accurate, The Precision 6266 is not yet maxed out at just mere 20 PSI that I know for a fact, and I have enough octane to support more advance if needed... Precision 6266 is used by supra guys up to 35-40 PSI, Yes its a BIG ASS turbo!

1. Have I reached my engines VE that adding timing or raising the boost below the max PSI of the turbo will no longer produce power?
2. When is too little timing "TOO LITTLE" that it no longer makes sense to use that timing and just lower the boost?
3. Have you experienced tuning where you were limited by only 2 more degrees of timing using E85 when other K series engines like 6-8 degree additional timing?
4. What is the least amount of timing you would run until you decide that either the VE of the engine or turbo size is maxed out???
5. Is there any instance on other engines that you have tuned in the past that adding timing even on E85 does not produce any more power VS 91-93 pump fuel?

Ohhh and BTW the engine has rock solid 160 psi Compression on all 4 and its as healthy as Olympic runner!

[civic1234]

No reply Hondata???

[civic1234]

Hello??? anybody there???

[Spunkster]

I'm sorry, but I really don't have an answer to this as I do not tune vehicles on the dyno. This would probably be a question better answered by a tuner that has more experience and may have encountered something like this before.