Hey guys wanted to know if you all have ever seen boost loss from a tune. I had a friend of mine tune my car with hp tuners and I am only getting like 5psi wot. Stock was 8-9psi with a 3.8 pulley and I changed it to a 3.5 pulley with supporting mods. I have good vacuum and the bypass valve is working correctly any info would definately help.
Tuning Help
- Thread starter 05GTPcmpg
- Start date
ported heads, ported exhaust manifolds, 180stat, colderplugs, cai, ported throttle body, custom exhaust, ported lim, 3.5pulley, custom tune. But I have not mest with the duration of how long the valves stay open (cam, rocker arms) Just ported everything out to improve flow of air through the motor. Car runs great except for wot and it runs good but only getting like half boost.
id you read just what I typed? ........ Boost is a measurement of restriction. LESS restriction LESS boost. Things like ported heads flow exhaust better, as do ported manifolds. Hot days you also make less boostdude yeah I know how boost is measured :th_lightbulb: but the stock cam, valves, heads, are all stock. I ported the intake ports and exhaust ports but that shouldnt change the boost pressure, it will just be more free flowing but its still a sealed unit. I was wondering if anyone out here has ever seen boost drop from a tune with hp tuners?:th_skull:
Z34Phoenix
Florida Tuner
YES hp tuners will suck all your boost!
Please re read what he had to say up there. your mods increase flow. you are correct that durration and lift has not changed, but since you can get more air in because of the lowered restriction you will have lower boost.
think of it like this. you have the same set of lungs. start running. now take a straw and try to run just breathing thru it! cant go too fast without passing out can ya? your car without the porting is the straw. get it? you havent changed your lungs or your lung muscles at all. just the pipe feeding air to them. same as your car. more flow mods equals less boost. if you are worried check the before and after values of the MAF sensor in your data logs.
Please re read what he had to say up there. your mods increase flow. you are correct that durration and lift has not changed, but since you can get more air in because of the lowered restriction you will have lower boost.
think of it like this. you have the same set of lungs. start running. now take a straw and try to run just breathing thru it! cant go too fast without passing out can ya? your car without the porting is the straw. get it? you havent changed your lungs or your lung muscles at all. just the pipe feeding air to them. same as your car. more flow mods equals less boost. if you are worried check the before and after values of the MAF sensor in your data logs.