supercharged lt4 questions
supercharged lt4 questions the car i sold in my sig was recently finished by getting a supercharger and nos put on it. nos isnt being used tho. hes having alot of problems with it. and i wanted some input from any experienced people that have had forced induction.. the car doesnt start pulling till 3500. thats the first problem.. it breaks up real bad and blows black smoke. then at 4 on up it pulls hard. a supercharger should build boost alot lower than 3500. so we were wondering if the map sensor needs customized cuz instead of vacuum its getting pressure... also with the new 60lb injectors what should the fuel press be set at? and should the vacuum line on that still go to the intake?
Black smoke is a definite sign of being way too rich.
Sounds like you need some tuning help.
What is your fuel pressure?
I assume you are not running an FMU.... you shouldn't be with big injectors.
If you have a typical 8# kit, it will not make much boost down low (maybe 2-3# max at 3500)
Verify your long term fuel trims are OK under normal use, as if the car is lean at cruise (computer adding fuel), it will then also add fuel at full throttle also.
Ignition related issues usually only crop up at high rpm, when boost & cylinder pressure are highest, so I tend to say you have a fuel issue.
Sounds like you need some tuning help.
What is your fuel pressure?
I assume you are not running an FMU.... you shouldn't be with big injectors.
If you have a typical 8# kit, it will not make much boost down low (maybe 2-3# max at 3500)
Verify your long term fuel trims are OK under normal use, as if the car is lean at cruise (computer adding fuel), it will then also add fuel at full throttle also.
Ignition related issues usually only crop up at high rpm, when boost & cylinder pressure are highest, so I tend to say you have a fuel issue.
im un certain of his excact supercharger. but i do know he has 60# injectors and the aeromotive fpr and i think its still set at 45psi. im not sure what it should be at. brian at pcm for less has been trying to tune it for the guy and has been a huge help to him he said as he had previously been a huge help to me with that car before the supercharger. just a few questions came up i thought id ask. the one with the map sensor and the fuel pressure.
the car seems to run rich at idle but super lean on your way to 3500 rpms
the car seems to run rich at idle but super lean on your way to 3500 rpms
