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Enthusiast ![]() Joined Sep 22, '10 From pomona, ca Currently Offline Reputation: 1 (100%) ![]() |
sup guys, just finished up my 5sfte project. im in the middle of tuning right now and i stumbled on a small issue. im sure its something minor. but whats happening is that my turbo kicks in at 4k rpm and its only boosting around 3psi max lol
its feels great though. since i work all day and only rest on weekends its hard for me to diagnose at the time because by the time i get out of work its dark... anyway im thinking it might be that i have too much free play on the wastegate actuator arm or a leak somewhere. do you guys know what else it might be? would back pressure affect it? i ask because my down pipe is a 2.5" and drops down to a 2" to my stock exhaust this is my first turbo project and its been a blast..... so help me guys! lol specs on car: 94 gt 2.2 rebuilt ported and polished 460cc injectors Safc2 t3t4 external wastegate turbo 7psi spring fairly large intercooler with 2.5 piping |
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Enthusiast ![]() Joined Sep 22, '10 From pomona, ca Currently Offline Reputation: 1 (100%) ![]() |
Well I set my timing at 8 degrees. Wen im at full boost (8psi right now) the safc is set at -12% on high map. so im guessing timing is not advancing much, but I could be wrong.... I have a walbro 255 and 460 injectors. So far so good, im not seeing knock or hearing any funny noises. Im not finished tuning yet. Right now im staying on rich side 11.2 afr's at wot, im taking small steps up. Eventually I want to hit 11.9 afr im also putting together my water/meth kit for added protection :]
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Enthusiast Joined Apr 12, '12 From California, Japan, Sometimes Europe Currently Offline Reputation: 0 (0%) ![]() |
Well I set my timing at 8 degrees. Wen im at full boost (8psi right now) the safc is set at -12% on high map. so im guessing timing is not advancing much, but I could be wrong.... I have a walbro 255 and 460 injectors. So far so good, im not seeing knock or hearing any funny noises. Im not finished tuning yet. Right now im staying on rich side 11.2 afr's at wot, im taking small steps up. Eventually I want to hit 11.9 afr im also putting together my water/meth kit for added protection :] There are too many variables for me to say for sure what it is, I dislike guessing. I'd also prefer not sending you on wild goose-chases if you get my drift. There are a number of things, that come to mind from reading post X, Y or Z here. 1. Sounds as thou you are suffering from some restriction, it could possibly be a small vaccume leak or that the waste-gate is lose or the spring rate etc - 2. Depends on the specifications of a turbo-charger, T3/T4's come in a number of specifications. It would help to clearify A/R trim and inducer / exducer sizes are housing inlet and outlet. 3. I don't know the complete layout of your exhaust system from the turbo-manifold back. If you are using the factory catalitic converter this could contribute to partial restriction. However, most use a 2.5 ~ 2.8 all the way back, some use a tride and true 3 inch. A high flow catalist and 2.5 to 2.8 inch full length should is an aprox average. ( If you have a manual boost controller, set it back to a lowest setting ) when you free up the exhaust system ie reduce back pressure, you will flow more thus create more boost, thus this is why the waste gate is very important in controlling. A lot of guys have a restrictive system, and so they increase the boost achieve the desired boost level thru the power band, this is due partly because pressures increase as rpm increases. I'll write a general article in the forced induction section look for it, should be a new post. Regards, Mick - |
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Lo-Fi Version | Time is now: February 22nd, 2025 - 12:15 AM |