951_RS

Now that I have bigger injectors I'd like to run higher boost to take advantage of the bigger turbo.
I'd like to run 18-20 psi depending on the octane I'd need to run for either. In other words I don't want to run 20 if I need 116 to do it. Just an example.
For tuning I just have a powerperfect so no timing control, unfortunately. I also have the old LR chips made for a pretty much stock car that has FQS adjustment capability.
So the octane increase can only be taken advantage of with more psi in my case.

What levels of boost have any of you run with different race gasses? Comparable turbo to mine is probably a LR super 48 or so for reference. It's a to4e 50 trim though in actuality.

Sorry for any misspellings I'm on my iPhone

Adonay

I bet with 104 octane you could run 24PSI all day long but dont quote me on that. Someone her may have a better idea.

gt37vgt

i ran 22 on 100 fuel okay ..do you have full use? limited use? or no use of the FQS ? as on some chips there is an FQS setting for given injector size .
Also its important to remember when setting up your boost control to keep the KLR involved so it can still pull boost out if it pings .

Cory9584

I've done that on 93 octane in cooler weather

951_RS

Full use of fqs and the klr is still hooked up with LR chip also. My afrs are mid to high 11's until redline and I have plenty of injector left. Guess I'll have to see what my turbo can comfortably push

toddk911

18psi on 93 all day long with good tune.

With an effecient or bigger turbo even more. I am running 20psi on 93 for some time now and no issues; although this is in cold climates.

Although I have talked with other 951 owners that ran 22psi in summer in FL on pump with no issues.

The safe rule seems to be 2 more octane for each psi increase.

So 18psi on 93, 104 lets call it + 10 octane to be safe and easy so that means 5 more psi = 23psi. Of course that is ball park.

951_RS

Thanks guys, good to hear some actual examples. I'm not even sure what my turbo can hold at redline anyways.

67King

That's a nice, efficient compressor. That will help.

Basically, an extrapolated rule of thumb is that for every PSI of additional boost, you need about 2.33333 points of octane. So, you should be able to run about 4.5-5.0 PSI more boost over stock.

Having said that, every octane point can also tolerate about 7 degrees higher inlet temperatures. So, you would need to have an idea for where your inlet temps are with the new turbo, versus the stock turbo.

951_RS

Thanks, I ran 18 psi today on a dyno run with no problems today, plus plenty of pulls on the way there to make sure it wasn't spiking too high and that everything would be ok. Car feels really great.

gt37vgt

nice to hear those numbers makes me feel a bit bitter about my 9.5:1 engine for 98 octane .

67King

Ceteris paribus you need an increase of about 6-7 numbers in octane for every point of compression you go up. You may have to run 104 to push it hard, or when it is hot.

beebone

I run 23lbs on Shell V-Power gas, which is 98 Octane

alxdgr8

Shell Vpower is 93oct in the USA.
IIRC 98oct other places is the same as 93oct here.

toddk911

So yet another person running over 20psi on pump. I know of another that was running 22psi on pump no problems for a long time as well.

Now check this out. Kind of apples to oranges but a guy I know local has a newer model Mustang Mach 1 with an SC kit running 10:1 compression and 20psi on pump for some time now on the street and 1/4 mile on weekends...............??????

alxdgr8

Once again, apples to oranges, but my friends civic makes 502whp @ 28psi on 93oct with a built LS motor.

DSM/EVO guys run 30+ on pump.