clouddomino

So say with a racing ported head (maybe a Lindsey set-up) would that enable more boost?

2bridges

I give up..... you are totally missing the point here. Fuel octane will sustain a certain amount of compression before it will combust (without ignition).

Due to variations in fuel - running the ragged edge of detonation is rediculous for the street on pump gas. Some people do it.... I just call those people idiots

Edit:
sounded a bit harsher than intended.

Rogue_Ant

agreed.




Rogue

clouddomino

So instead of blaming the inability of 21+psi on head design, then the fault is the fuel. So to remedy this wouldn't be safe to say that with proper octane and timing advance that 21+ is definately possible. So the fact is not that it isn't possible, it just isn't good for the engine to run 21+ on pump gas.

clouddomino

I'm not claiming any mastery of these cars or they're set-ups. I'm used to working on small block chevy's for dragging. So it's a learning experience for me, I'm just trying to relate some of my mechanical know-how from that to these cars. And from experience I've learned that with the proper time and research anything is possible, it's mainly what your financial situation is... Is that not true with 951's as well?

Rogue_Ant

Not BS. I help my friend tune his Eclipse. He was tuned for ~25.5-26psi on pump gas. However we had to pull a lot of ignition timing to not knock (peak of 8.4 degrees total advance). We just retuned it to ~23.5psi and managed to get 17.2 degrees advance without knock. Completely stock longblock with ARP headstuds. Larger turbo (Holset H1C), 3" exhaust, Front-Mount IC, upgraded fuel-pump, injectors and AFPR.

The biggest thing holding our cars back is the inability to monitor knock effectively. Without knock monitoring you are simply guessing, period.



Rogue

clouddomino

Thanks Rogue excellent example of import tuner's pulling 25+ psi on pump gas. I'm just trying to figure out a way to do this with a 951. Surely there's something that can be done to advance and tune our cars so they can run boost safely without detonation... right???

lart951

I have ran 19psi on pump 91 gas for almost a year no problems reported. *









*so far

clouddomino

lart951 what type of set-up are you running? Chips, injectors, headwork????

lart951

55lbs injectors, authority chips, lindsey power perfect MAF, lindsey super 61 turbo . tial 38mm.

clouddomino

You took the autothority chips to dyno tune or a running a specific stage?

Bri Bro

He just told me he was at the track running 25lbs on 91 octane...but with water injection. Try this without injection and you will not run for long.

ninefiveone

I think you should consider the differences between a Lancer EVO and a 951 motor. From your experience with small blocks I'm sure you know something about how engines work, how to tune the, and how changing different thing change power, etc.

Rogue_Ant

The main issue is, like I said, the inability to monitor knock. Our lack of logging ability is really the problem. That is why I've been working on being able to log knock (Knock Thread). But we, the community, don't know what a safe threshold is. I do believe some might know, however they tend to stay quiet.

Besides software issues, the common Japanese head is better at warding off detonation then our 8v heads... however I believe that advantage is null compared to our 16v variants. Just not many boosted 16v guys really pushing their motors.

BTW if you want to look at the logs from my friend car, you will need the DSMLink client:

DSMLink

And here two different pulls/tunes (all third gear):

~25psi
~23psi


Rogue

lart951

I tune my a/f ratio with the power perfect.