My question is how much boost can I safetly run without getting to close to maxing out my rc 550cc injectors. Oh I also have a 255 pump. I will be adding a 3mm head gasket, head studs, and a ported head. I would like to run 17-18psi. This on a turbo car by the way..dont know if that changes anything.

Thanks
Martin

 

675 is a nice size for 18psi, 550 might be a little undersized.

 

i guess it comes down to what injector % load you feel comfortable running at!

 

every car is a little different, but your af will tell the truth

 

Dude, 550CC is sufficient to about 8psi @ 8K.

i had to learn that by making my AP1 feel like an AP2 until i upgraded to 750CC.

I was MAXED on my RC550. 18PSI is a dream on 550cc

 

With a fuel pump I doubt they max out at 8psi. My car is at 9psi and my tuner told me they were no where near there limit. There are plenty of people that do like 14psi on 650cc. I am thinking of selling mine for some 750cc.

 

Id run 750cc.

Depending upon the efficieny of your turbo setup. the 550's may max out around 12-15 psi. Also depends upon fuel pressure.

You dont want to push the injectors to a high duty cycle. its better to buy an injector a little bigger than what your goals are.

750cc injectors are very easy to tune. the car should run stock like if the engine calibration is done correctly.

 

Iv'e got 550cc injectors and a 255 pump. At 10psi boost & stock compression the AFR is 10.8:1 @ 85% on the injectors. So there is little headroom left, but hey injectors are cheap. If you go the 3mm head gasket route, go with bigger injectors like the guys are saying.

 

Yeah I'm going to upgrade to some 750cc injectors. Anybody want to trade for some 550cc I can include some cash on top.

Mase1 I have never tried to fly a tuner out before but how much would something like that cost me. That is of course if you would be willing to fly out to Chicago. I'm thinking of getting a few guys together to make the cost a little lower.

Do people tune cars over the phone? I guess this would work by Mase for example telling a less competent tuner what to do. I know its a stretch but it would be a lot cheaper than flying a tuner out to you.

 

i was just up chicago over thanksgiving time to take our 1400 whp Ford GT up to a trade show. Could have tuned your car then

I'll PM you and we'll discuss some options.


Mase