Need help 91 octane Whipple 15psi = timing?

[SVTkel]

Okay I am being moved by my company and the place they are sending me only has 91 octane available.:dw:

My gen 2 whipple makes 14.6 - 15 psi at low to mid 11's AFR, and I want to know how much timing I can run on 91 octane.

So if your car is tuned for 91 octane at 15psi then let know how much timing you are running.

Thanks

 

[lwrs10]

A 2 degree drop from 93-91 is pretty normal. With 93 I had 21 degrees, but when I moved to a place with only 91 I dropped it to 19.....seemed to work out pretty good. This is with 16#.....

 

[MWR]

I'd run 17*, but I'm conservative.

 

[04torchred]

Kel what are you running now? With 15psi I would think 19-20* would be fine if you are up around 23* timing with 93.

 

[SVTkel]

I logged 18.5 to 19 in 2nd gear on the roads last night. Could not go any higher then max 2nd gear account traffic / safety etc.

19 seemed a bit high to me on 91?

Thanks

 

[lwrs10]

I logged 18.5 to 19 in 2nd gear on the roads last night. Could not go any higher then max 2nd gear account traffic / safety etc.

19 seemed a bit high to me on 91?

Thanks

Some people say yes, and some people say no. It all depends on how good of gas you get for me. I only get Chevron, and have not had any problems. But I have got some gas at other gas stations that pinged a little bit.....


You can run 17 to be safe, and your only talking a 10-15HP loss.....but its safer...

 

[SVTkel]

Some people say yes, and some people say no. It all depends on how good of gas you get for me. I only get Chevron, and have not had any problems. But I have got some gas at other gas stations that pinged a little bit.....


You can run 17 to be safe, and your only talking a 10-15HP loss.....but its safer...

Yeah, although it already feels weaker compared to my 94 tune.

 

[04torchred]

I would talk to a tuner like Lund or someone, but with 15psi I think you are okay with 19*. That isn't much boost for that timing. As long as your IAT2 temps stay low it should be fine also.

 

[PWORLDSTANG]

My tuner regularly tunes 15lb Whipple cars with 19 degrees of timing. Had I decided to go with a 15lb set up, that's what I'd be running.

 

[SVTkel]

Maybe I am okay then. I might drop it back 1 degree for good measure.

I have to admit I am quite happy with how the Whipple runs when part throttle and cruising. Perhaps it was in the tune, however my upper + lower + port never ran this nice.

 

[SVTkel]

I would talk to a tuner like Lund or someone, but with 15psi I think you are okay with 19*. That isn't much boost for that timing. As long as your IAT2 temps stay low it should be fine also.

Hey bud, I hear rumour that I can buy race gas at a Petro Can where I am moving. Now I wonder how much timing I could bump my 94 tune up to run 100+ octane on rare occasions?

 

[04torchred]

Hey bud, I hear rumour that I can buy race gas at a Petro Can where I am moving. Now I wonder how much timing I could bump my 94 tune up to run 100+ octane on rare occasions?

Full timing, I would run more boost along with it though or its just a waste. 17-19psi with 22-23* timing, where ever the car seems happiest on 100 octane is what I would do.