isnt 24 PSI on pump gas little too high? i though 21 PSI was the max on pump gas

 

No. A lot of people run 22psi even 23 on 93 around here especially in the below 60 weather. Of course, my car like Al said has mods to make it withstand more knock so I guess thats why 24psi was OK.

 

The main factor here is his boost gauge a defi mechanical which is reading about 2 psi higher than the acutal boost

On the street it was holding a steady 24 psi indicated which translates to 22 psi actual

A bit higher than some can hold on pump gas - but with the back pressure reducing mods the car was clean with zero knock

Many people do not appreciate how inaccurate 90% of the mechanical boost gauges on the market are - particularly the defi brand

I have found good success with Stewart Warner

PS - Once you have a accurate boost gauge in there I would not go over 22 psi even on pump gas that is plenty of boost on the street

 

True, I run 22.5Psi on 93 no knock

 

Well there ya have it!

 

damn you tom....now i have to go and spend more money so my car doesn't feel inadequate...are u happy now??

haha you gotta take me for a ride in that thing...route 37 won't know what hit it this summer...not like you're doing anything illegal or nethin on it tho...

 

Nice big fat and interestingly shaped torque curve. I will memerize mods. The meat is in the middle where it counts, need to take to strip!

OK everyone turn your boost back down to 22psi JK

Al is right, backpressure = knock especially at higher rpms when the engine expells the most volume of air. I kept knockin at 7500rpm due to the factory CB installed on mine.

 

impressive numbers, who did your ceramic coating for you?

 

why didn't u get ultra 94 at sunoco?? impressive numbers

 

Haha yeah I got a race waiting for me, 98 Cobra blown running like 8psi... should happen today or so, not too scared though being I raced a bolt on 02 GT with a Vortech at 10psi and ran away from him from a 3rd gear roll-on. Next time youre down Ill give you a ride. The powerband is like a Z06.

Performance Coatings.

 

I didnt get it for a couple reasons. First off, I commute with my car and on the Parkway and in norther NJ, there are not many Sunocos where I travel. So, Id have to use 93 and then risk some sort of loss. I think its better to tune on 93 since its everywhere and then just use 94 when I can for extra knock supression. I have a Sunoco up my street so MOST of the time I get 94, but yesterday for the purpose of being tuned again, I used 93. I try to only go to Shell or Sunoco.

Another note - 2 different Sunoco gas attendants told me Sunoco is CANCELLING 94. They told me this I guess because I always get it, but 2 different people at different stations told me so, so that sucks too! Hopefully by the time they cancel it (sometime at end of this year) I will have alcohol injection and I will careless.

 

Im in the process of getting custom flash with about the same mod as you. But 80 percent of times my car runs at 94 octane. Do you it'll make a difference by 1 octane level. If so I would most likely get a tuned at 93 if sunoco is in the process of cancelling 94 in NJ.

Do you run 24psi with 93 on regular basis?

 

I would follow the lead of this customer and so the tune on 93 but run 94 when you can - saftey is everything

 

Exactly. Its just an extra margin you can use, especially since if it goes up 40 degress you could use that extra 1 octane, and yes 1 octane does make a difference.

Just look at 91 vs 93 tuning of the CA guys vs the East Coast guys, major power increases from 2, so 50% of that (1 lol) must count!

 

He's not really running 24psi. It's a 23psi spike that tapers to 19 by 7500rpm or so according to Al's MAP sensor. Mine is very similar with a spike to 22 that holds 20-21 to redline, then drops to 19 by 7500rpm.