Hi guys, just wanted to throw it out there as I think I might me wasting my money using a 105 unleaded race fuel for my application... It's great fuel but I'm wondering if I even need to use it at this stage. Until I am ready to run a 10, have my car inspected and get all the relevant safety gear involved with super sedan. My engine will comfortably make the 200 ish hp required to run low 11's at only 10-12 psi boost. I'm running 7.5:1 comp.

The question is, could I be using 98 octane pump fuel?? Is the race fuel overkill for 10-12 psi???

Thanks in advance.
Mick

roses little nude bug street motor gains 20hp with 102 compared to 95 pump gas , we have the tune to run both .
it allows an increase in boost without fear of detonation.

Hi Mick, is the 105 you are using my blend or VP or other? the higher octane allows you to run a bit more advance. 98 is pretty good when you look at the dollars side of the equation but you will sacrifice some advance and so some hp.

For the record my 105 unleaded has some oxygen in it so works well with turbos which like a bit of oxygenation in the fuel.

in terms of compression ratio 105 is definitely over kill as generally 105 is aimed at around 10:1, obviously add boost and that changes the equation a bit but in the end you won't know the real answer unless you do back to back runs on a dyno.

Yeah lou, it's your fuel. Don't got me wrong. It works great and I'm really happy with it but I was just wondering if I really needed if at only 10 psi. But to be honest, we are about to up the boost a little and put a heap more base timing in so I'm probably best to stick with it. Thanks for the advice. If cleared it up for me a bit. I understand what the fuel actually does now.

Just another option (I'm running with this). 98 and water/meth injection. I'm doing a pre turbo set up from Greene Bros here. Just for reference, they run a 13b on 98 and pre turbo injection, 40psi boost, 850hp,8s and street driven.
Don't know how this would work in a draw through set up though.

I guess it is all about how complex you want to make it. Anything hitting 850hp is a serious bit of kit, like they say "lots of ways to skin the cat."

It's a mechanical system, pressurises tank with a feed from the turbo, feeds the nozzle on one side, air the other, one solenoid, just need a pressure sensor to switch the solenoid on at desired boost levels. http://wannaspeed.com/home/8-mechanical-water-injection.html 
There's some evidence out there that pre turbo injection erodes compressor blades, but I'm willing to take that chance.