MaTTSuN Posted September 5, 2008 Share Posted September 5, 2008 ok i got my car back on the road this week and was wondering how much boost i can run. Here are my mods: - big azz front mount intercooler - Mega squirt - BOV - 60mm 240sx throttle body - 3inch exaust - ARP head studs the turbo is stock and im running the 81 stock turbo motor with stock turbo injectors its hitting about 7psi right now just wondering what i can safely run with the stock fuel system i was thinking about 10psi maybe 12 anyone do higher with the stock stuff? Quote Link to comment Share on other sites More sharing options...
MaTTSuN Posted September 5, 2008 Author Share Posted September 5, 2008 forgot the new pics Quote Link to comment Share on other sites More sharing options...
Tony D Posted September 5, 2008 Share Posted September 5, 2008 without increased fuel pressure (To effectively increase those stock fuel injector's flow capacity) I think you are treading on thin ice at anything over 10psi... Quote Link to comment Share on other sites More sharing options...
MaTTSuN Posted September 6, 2008 Author Share Posted September 6, 2008 ok thats ok just wanted to be safe but want to get the most of what i got for now. i think my fuel pressure is about 40psi stock 10 psi would be nice since i only have about 6-7 right now prob put a good tune on it tomorrow and go from there if i wanted to go any higher with the stock injectors what would i need the fuel pressure to be @? Quote Link to comment Share on other sites More sharing options...
jeffer949 Posted September 6, 2008 Share Posted September 6, 2008 Do you have a wiedband O2 sensor? if so you can go higher than 10psi. Just keep watching your afr's under boost. I think i ran mine up to 13-14psi on the stock injectors and stock fuel pressure. That was on a megasquirted stock engine with the stock t3 and injectors and a front mount. Quote Link to comment Share on other sites More sharing options...
MJLamberson Posted September 6, 2008 Share Posted September 6, 2008 Do you have a wiedband O2 sensor? if so you can go higher than 10psi. Just keep watching your afr's under boost. I think i ran mine up to 13-14psi on the stock injectors and stock fuel pressure. That was on a megasquirted stock engine with the stock t3 and injectors and a front mount. It didnt lean out on you? Quote Link to comment Share on other sites More sharing options...
Challenger Posted September 6, 2008 Share Posted September 6, 2008 "Megasquirt" Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted September 7, 2008 Share Posted September 7, 2008 ok i got my car back on the road this week and was wondering how much boost i can run. Here are my mods: - big azz front mount intercooler - Mega squirt - BOV - 60mm 240sx throttle body - 3inch exaust - ARP head studs the turbo is stock and im running the 81 stock turbo motor with stock turbo injectors its hitting about 7psi right now just wondering what i can safely run with the stock fuel system i was thinking about 10psi maybe 12 anyone do higher with the stock stuff? Not to be an ass.. but I dont know what your BOV, 3 in exhaust and throttle body have anything to do with how much boost you want to run. In order for your engine to perform and run without blowing up you need 3 things.. fuel and air and proper spark. You can run 25psi on your stock bottom end with proper tuning.. enough fuel and if your turbo can produce enough boost. If your going to be running the stock fuel injectors.. your very limited to how much boost you can safely run. The turbocharger you have will also vary how much boost you have available. Quote Link to comment Share on other sites More sharing options...
MaTTSuN Posted September 24, 2008 Author Share Posted September 24, 2008 thats just my set-up just so yah know... im getting some 340cc injectors soon so i think ill leave the boost intill i get those. Drove it in the first rain and wow as soon as its out of vacume in 1-3rd gear she just spins. my tires are not 2 bad either... bfg radial T/A's %80 i also have a big holset hx40 to go on in the spring 2 much rain to even bother with that here for the winter but then again it could be fun ill prob end up turning the boost up to 12 and go from there if my wideband reads ok ill keep going . can always just drive around in vacume intill im in 4th or 5th haha Quote Link to comment Share on other sites More sharing options...
Clifton Posted September 25, 2008 Share Posted September 25, 2008 You still never answered the wideband question so I assum you don't have one. If you have Megasquirt how did you tune the afr? If you did manage without a wideband and it was tuned good check your datalogs and look at the injector duty cycle. Quote Link to comment Share on other sites More sharing options...
MaTTSuN Posted September 25, 2008 Author Share Posted September 25, 2008 sorry CLIFTON i do have a wideband and i have been data logging and tuning with the afrs. im pretty sure i mentioned i have a wideband at the end of my last post if you posted an hour ago its earlier then me and im at 645 am on the west coast hehe side scan sonar is not up to temp yet here also Matt Quote Link to comment Share on other sites More sharing options...
Clifton Posted September 25, 2008 Share Posted September 25, 2008 Sorry, I didn't see the wideband post. It was even earlier here. As long as you don't run out of duty cycle and the afr is good and it isn't knocking bump it up. I wouldn't go above 15-16 psi, not to say you can't but I wouldn't on the stock turbo. FWIW, when I had 550's my DC was well past 100% towards redline but my afr was still in the 12's so I ran it until I could got larger inj. I also ran 440's at maxed at 96% DC at redline for a few years on the stock ecu. Quote Link to comment Share on other sites More sharing options...
jc052685 Posted September 26, 2008 Share Posted September 26, 2008 forgot the new pics you stole my avitar:mrgreen: Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted September 26, 2008 Share Posted September 26, 2008 With stock injectors, and stock ECU I needed to run 65psi of fuel at 14psi boost. With stock fuel pressure and MS, you might be able to go over 10psi but watch out at the higher rev's when the fuel supply starts dwindling. My suggestion is to Datalog he AFRs at 10-11-12psi and keep it where you can rev to 5500rpm without leaning until you get larger injectors. Set your rev limiter before it gets lean by using the timing method. Quote Link to comment Share on other sites More sharing options...
Flexicoker Posted December 7, 2008 Share Posted December 7, 2008 Sorry, I didn't see the wideband post. It was even earlier here. As long as you don't run out of duty cycle and the afr is good and it isn't knocking bump it up. I wouldn't go above 15-16 psi, not to say you can't but I wouldn't on the stock turbo. FWIW, when I had 550's my DC was well past 100% towards redline but my afr was still in the 12's so I ran it until I could got larger inj. I also ran 440's at maxed at 96% DC at redline for a few years on the stock ecu. How can you have over 100% duty cycle? Quote Link to comment Share on other sites More sharing options...
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