Boost and octane....

[40BelowSummer]

So right now Im running about 6psi non-intercooled with a 3.6" pulley on 91 octane (9:1 pistons). It seems to run fine with that octane and the car has been pretty reliable.

Here are a few things Im getting ready to install; aftercooler, bigger fuel lines, 48# injectors, and possibly water injection.

I am happy with the car at 6psi but would like to move up to about 10-15psi. I want it to safely run on 91 octane for daily driving (like it is now).

What octane and boost level are you guys running that drive your S/C SHO's regularly?

3.2L (9:1)
BBB/EH/StageII cams/Worked heads
S-trim w/ 3.6" pulley (6-7psi)
3" exhaust

 

[twr]

Right now, 10 psi and no charge cooling on 91 Octane (highest available in Colorado) Soon, 16ish psi with charge cooling on 91 octane. Later I'll be running more psi with low compression and charge cooling.

I'd say your safe runnign 15 psi with 9:1 compression and an after cooler.

 

[1slickRED89]

12 PSI on 94 pump with stock spark timing (as in i didn't pull any out).

 

[Lupo]

13psi max with charge cooling. I always use octane booster with the 91 cali gas. I'm sure I can go without the octane boost, but I would rather be on the safe side

 

[strings1732]

10-15 psi with no charge cooling other than the fact that the turbo is at the back, and I run 91 octane with no problems.

 

[TT SHO PROJECT]

highest iv ran on 89 is 10psi.. no real charge cooling... id think 15psi probably would be a safe max on pump gas(probably doable with out charge cooling)... ill know sooner or later if i ever get bigger injectors.. but i also run 4* less timeing than stock.. and of course the fmu helps. im all about blowing cars up lol once i get mine back on the road imma slowly up the boost to see how far i can take it with that lil turbo i got.

 

[sho_sc]

93 octane , double core intercooler, 8.5:1 Wiseco, a lot of timing pulled (while I figure out the tuning), and an absolute ton of boost.

 

[40BelowSummer]

93 octane , double core intercooler, 8.5:1 Wiseco, a lot of timing pulled (while I figure out the tuning), and an absolute ton of boost.

What injectors?

 

[DDakRT]

12 psi, no charge cooling and 94 octane.

 

[SinisterSHO]

93 octane , double core intercooler, 8.5:1 Wiseco, a lot of timing pulled (while I figure out the tuning), and an absolute ton of boost.

a ton?

 

[NWGRN94MTX]

Stock internals, water-ethenol injection, 12#, 100 unleaded Sunoco.

 

[yamahaSHO]

For 9:1 compression on the street, you could safely bump up the boost to 12 PSI without worries. You have the ability to kick back a few degrees timing. I'd worry about charge cooling if you plan to track the car and/or bump up the boost to more than 12 PSI.

From my experience, that's what I'd do... YMMV

 

[AutoSHO]

I agree with Jason... he ran his car hard all summer (including a day at the track) with no detonation or problems. I don't think you'd have anything to worry about at 12 psi on forged internals...

With charge cooling, the sky (or, the transmission) is the limit.

 

[Nick56289]

octane booster = useless

read up on toluene:type:

 

[chknhwk]

octane booster = useless

read up on toluene:type:

octane booster ≠ useless
toluene is a form of octane booster
MOST octane boosters are useless. When an octane booster is advertised as raising gas 1-3 points they're talking about xx.1 to xx.3. I.E. 91.1-.3, not 92-95.
However there is a thread on TurboMustangs.com where testing was done with some Torco fuel additive and the results were impressive. There were several back to back runs utilizing various different types of fuel along with varying amounts of boost and timing. The only two results that yielded an increase in boost AND timing along with no knock or detonation was either with the race gas or the Torco. It will take me awhile to find the link but I can if anybody is interested...

EDIT: found it.

 

[SHOMurph]

9.8:1, NTP Big ass intercooler, 93 octane 15psi and the beyotch wants more!

 

[Geek SHO]

a ton?

Yes, 2000 pounds of boost.

When the engine worked, I was using '91 octane with 9 psi, no charge cooling. I don't think the engine problems were a direct result of supercharging. I think it was my incomplete engine rebuild when I swapped in the 3.2. Eventually I'll put a heat exchanger in that box I call an intake.

 

[sho_sc]

a ton?

I guess I do need to clarify : more than 15 psi.

 

[Nick56289]

Your right octane booster isnt completely useless but it is mostly useless. With toluene you can easily turn 91 octane fuel into 98 octane fuel safely. Supra guys do it all the time. Its really useful if you are going to be running lots of boost. Heres an article. http://www.elektro.com/~audi/audi/toluene.html

 

[40BelowSummer]

I guess I do need to clarify : more than 15 psi.

Is it a secret??