What's your take on psi/fuel safety

[Dave]

What's everybody's personal experience and opinions on how many psi you can run per pump gas... meaning 94, or 93 octane. No fuel additives, boosters, or race gas.

I'm pushin' 18psi now and the plugs say I'm rich as f---. Yah I need to get a charge air sensor. :) But the plugs tell me I'm fine, no salt or pepper.

Your take's?

[SwiftTech]

I can only run 13-14 psi MAX on the crap 91 octane here in ca. But if I pony up the 5.99/gal I can get 100 octane at a local 76 station at the pump too. So far I'm running 16 psi with it, but hopefully more soon.

[cordes]

I have run 22PSI on 93.

[Dave]

I have run 22PSI on 93.

That's the answer I want to hear!!

[SpoolinGLH]

Ive ran around 19-21psi on 94 octane on the street....I was looking for higher then 94 octane for race day.... and I usually get 109 octane unleaded for race day:eyebrows:

[Mario_V]

23 psi with 92 octane but I race at 7000ft of altitude. The greater the altitude the less need for higher octane :).

[moparzrule]

Well it kinda depends on your setup. I had a G headed 2.2 (with swirl pistons) so I had about 7.6:1 static compression maybe lower and I was setup to run 22 PSI on 93 octane with aggressive spark curves. I could have run 28 PSI no problem with a little de-tuning on the spark advance in the cal. I accidently ran 20 degree ignition advance for a couple days and pounded on it hard, no ill affects. If you run a swirl head your boost must be significantly less, they spark knock a lot easier. I love the G head, it's the best.
It also depends on what turbo you are running and what intercooler. Stock T2 intercooler and turbo I wouldn't go past 18 PSI on 93. Super 60 and dual stock core or spearco I'd say 20-22.

[WVRampage]

Watch the timing I burnt some rings up at 16psi and when the rings went I left up as soon as I saw the narow band guage moved to lean and I started to smell oil a few miles up the road and the dip stick was poped out and oil every were added oil and drove home real easy on it and the rear main seal started leaking bad due to the severe blowby,so be careful with you timing and mixture you should run it a little richer than you think you need to save the engine,unless you have the money to rebuild.I was running stock injectors due to a leaky +20 and fuel economy,I got stupid and raced a ricer on the highway up a long hill.

[TurboMinivan]

I can only run 13-14 psi MAX on the crap 91 octane here in ca.

Utah also gets 91 octane max. Still, my Caravan with a G head on a stock bottom end was dialed in at 19 psi on this pump gas for two years. I drove it like that every day. Harware configuration included a PowerStroke intercooler and a stock TurboII Garrett turbo.

FYI

-Dempsey

[Rattlesnake]

I used to run 36 on 94 with water injection with a FP raiser for 3 years and never heard or saw knock on the monitor.

[Alberta_Daytona]

15 on 89 octane...no problems yet....stock i/c.

old car 14.5 psi on 87 for 1 very hard year.

[Dave]

15 on 89 octane...no problems yet....stock i/c.

old car 14.5 psi on 87 for 1 very hard year.

Shoot I know that's possible, but that leaves your computer thinking it's slow. It's more than likely pulling mad timing, so even if you put 110 octane in, it wouldn't run ANY better. Unless of course you disconnected the battery. It knows youre running bad gas so automatically it retards timing and boost. So I'm assuming you have some sort of MBC.

Man that's dangerous. lol

[TrrboJeep]

Bryan, I'd say you're "approaching" the "you need to have everything dialed in just right" point or else.
Meaning that as you near max boost for a given octane, your timing and fuel need to be spot on to keep the pistons from getting hurt.
As you approach this "pump gas" limit, as far as boost goes, just remember that it is just the starting point for alcohol! :eyebrows:

With a couple hundred dollar alky injection system, you can continue onward and upward with the boost addiction. lol
Then, instead of concerns over the motor, you attention will turn to concerns over the drivetrain! :nod:

[Dave]

lol Thanks Joel. I'm gonna leave it at 18psi. Im running eiher Sunoco 94 or Shell 93 V-power.

I have 12* base timing, and waaaay too much fuel... 58psi static pressure. I'm afraid to turn it down. Ill turn it to 55psi static until I get my DD gauge whenever this dude replies back! :mad:

[moparzrule]

You guys worry way too much about boost with certain octane. These cars run 8.2:1 compression or lower if you have a 2.5. Honda's with 11:1 compression are running 8 PSI on 93 octane. Heck with 10:1 you can run 14 PSI all day long in a B18C1 GSR engine. I'd say you can run 14 PSI on our engines in stock T2 form on 87 octane no problem, I wouldn't do it non-intercooled though. I ran 17 PSI non intercooled on 93 octane with 15* timing for a month when my daytona was still a T1 with a MP ECU and a 4.7v diode on the MAP. I squished the FPR to 62 PSI static and ran .85 A/F ratio. lean is mean, LOL. I didn't care about that engine anyway I was building a T2 engine for it at the time.

[t3rse]

i've run 23 on 93 with no issues (on stock t2 turbo), my compression is lowered with custom ross pistons to 7.5 and dual core spearco. (egts around 1000, rich as a mofo, charge air at 120*).

[moparzrule]

I ran 1450 EGT's with 22 PSI on 93 octane for a year with zero issues. Dual stock core IC and my intake air temps on the dyno were 130 at 19 PSI (it would be less going down the road obviously) so it is a pretty efficient intercooler. Plus I have a super 70 so that helped a lot the air coming out wasn't very hot.

[Dave]

I'd say I'm fine then. Plugs look dark red and no signs of detonation. I'll have to get that damn tranny problems fixed so I can take it out Sunday for a 13 second pass.

[Tony Hanna]

As you approach this "pump gas" limit, as far as boost goes, just remember that it is just the starting point for alcohol! :eyebrows:

With a couple hundred dollar alky injection system, you can continue onward and upward with the boost addiction. lol
Then, instead of concerns over the motor, you attention will turn to concerns over the drivetrain! :nod:

+1
28 psi on 93 octane + methanol injection. No sign of detonation. I'm sure it would have been good for more, but the turbo was the limit at that point.
Then the trans died.:p