Fuel, timing, intake temps?

[Dave]

Mmmm'kay! Well I'm kind of concerned here with the whole detonation thing. I have a Mishimoto intercooler (1,020 CFM's, .2psi drop, 15 fins - bar and plate), T2 Garrett turbo, 2 piece intake, Accufab regulator and +20's, ported G-head, & FWD performance Stage III computer.

So I'm wondering some things here.

How many degrees of timing can I run safely here?

If the timing is low enough (but not too low as to affect my performance) can I safely run 18psi on 94 octane, or will I really need 1 gallon of 110 octane for every 3 gallons of 94?

With the FWD P. calibration it automatically messes with the fuel curve, and timing curve, and it raises the base timing. That worries me with this whole detonation thing... of course I have forged pistons, but they are pricey so I don't wanna toast them.

Just want some tips here on how to tune this beast.

Thanks.

[cordes]

I would just put the cam timing striaght up and the ign. timing at 12*. Then start at 12-13 PSI, and give it a go. Up the boost an lb at a time, and watch for signs of detonation. Once you get to your desired boost level I would then try to play with the timing to shift the powerband, or increase ign. timing to maximise power. Prudence is the key.

I ran 22PSI for most of this past summer with a T2 turbo, +40s, SRT4 IC, and a stg.5 cal. It worked pretty well, but my EGTs were always rather high. I decided to tone it down and focus on my omni.

[gasketmaster]

Get a scanner and monitor the knock retard :)

[turbovanman²]

Get a scanner and monitor the knock retard :)


+2. Thats what I do when racing in the summer. :nod:

[8valves]

Mmmm'kay! Well I'm kind of concerned here with the whole detonation thing. I have a Mishimoto intercooler (1,020 CFM's, .2psi drop, 15 fins - bar and plate), T2 Garrett turbo, 2 piece intake, Accufab regulator and +20's, ported G-head, & FWD performance Stage III computer.

So I'm wondering some things here.

How many degrees of timing can I run safely here?

If the timing is low enough (but not too low as to affect my performance) can I safely run 18psi on 94 octane, or will I really need 1 gallon of 110 octane for every 3 gallons of 94?

With the FWD P. calibration it automatically messes with the fuel curve, and timing curve, and it raises the base timing. That worries me with this whole detonation thing... of course I have forged pistons, but they are pricey so I don't wanna toast them.

Just want some tips here on how to tune this beast.

Thanks.

First and foremost, that's way too much of a race gas mix. Usually a 1:5 ratio is acceptable when using 110, espescially when you're still using such a small compressor wheel. You flat out won't have the airflow there to really need it in my opinion. You might even be able to get away with even less of a mix if you really need to mix at all.

Compression ratio comes in to play here a lot as well. You're more than likely sub 8:1 so you should be fine and dandy again. I've run 20-22 psi on everyday whereever its available 93 octane for two years now without having a problem on a 50 trim, and 26 psi still on 93 octane on the 30R which is a WAY bigger compressor wheel.

The G head will help, I'd honestly say you shouldn't have a thing to worry about at 18 psi.

Aaron Miller

[Dave]

First and foremost, that's way too much of a race gas mix. Usually a 1:5 ratio is acceptable when using 110, espescially when you're still using such a small compressor wheel. You flat out won't have the airflow there to really need it in my opinion. You might even be able to get away with even less of a mix if you really need to mix at all.

Compression ratio comes in to play here a lot as well. You're more than likely sub 8:1 so you should be fine and dandy again. I've run 20-22 psi on everyday whereever its available 93 octane for two years now without having a problem on a 50 trim, and 26 psi still on 93 octane on the 30R which is a WAY bigger compressor wheel.

The G head will help, I'd honestly say you shouldn't have a thing to worry about at 18 psi.

Aaron Miller

Wow, that saves me about $5 a gallon for race fuel!

Anyways Al (5spd. mini on HERE) has a scanner and I'm sure he'd be fine if I borrowed the scanner for a day and play with all that stuff.

Ill start at 12psi with 12* timing, on 94 octane (v-power from Sunoco) and go from there. I also have an EGT gauge and Dawe's A/F lights. So I should be sound as a pound. :thumb:

Thanks guys.

[turbovanman²]

So I should be sound as a pound. :thumb:

Thanks guys.


Ok luv, terraaa, :nod:

[Dave]

Ok luv, terraaa, :nod:

Simon.... http://www.xanga.com/Images/wtf.gif are you hitting on me?

[turbovanman²]

Simon.... http://www.xanga.com/Images/wtf.gif are you hitting on me?


Hahaha, no. You said "sound as a pound", thats british, so I said some back. Don't watch too many british programs do ya?

[Dave]

Hahaha, no. You said "sound as a pound", thats british, so I said some back. Don't watch too many british programs do ya?

I've seen Austin Powers... that's as British as it gets.