Screamin Yellow 06

Ok, I got a Saleen series VI blower and the JDM stage two kit. I'm running a 3.4" pulley and 107.5" belt which is supposed to give me 10psi boost.

The only time I ever see 10psi of boost (more of a peak spike) is from a 1st gear dig and in the red close to the rev limiter. After that it's 8psi. with it still floored through the other gears. From a roll or cruisin down the highway and dropping down a gear or two I also only see about 8psi. Never 10 in those cases/ Don't get me wrong, it hauls a$$ but shouldn't I be seeing 10psi on a more regular basis. Basically everytime I floor it and the boost kicks in?

I thought I fixed my boost problem with the boost actuator stop bolt adjustment but I'm starting to think I don't have it completely there yet.

From what I understood the Saleen Twin Screws make boost at even low rpms? Unlike cetrifigals that get max boost at the highest rpms. I have a good idea of how the s/c works and I'm thinking there's still a couple psi in there for me to tap. I live in Charleston SC so I'm basicaly at sea level. It hasn't started to get humid yet and I get the same boost at night with the cool air as I do during the day when it's warmer. It also doesn't seem to matter much if the engine is cold or warmed up.

When do you (people with s/c's) start to see decreased boost readings? By that I mean what are the most noticeable conditions (temp, humidity, etc.) and what kind of reduction you typically see (1-2psi?)

I'm still just not sure if what I have is normal or if I need to be trying to get that extra couple psi.

Please tell me what you typically see your boost gauge reading under various conditions (regardless of what boost you're running.) I'm still just tyring to get a better feel for where I stand at the moment.

Thanks!

Perdi

Yeah, I just put on the 3.4 pulley today, and had it Mustang Dyno'd... Max Boost was 7.91...so just shy of 8 ... Probably has to do with the LT headers though in my case... I thought that the 3.4 was good for 9.5 lbs of boost (according to the list on JDM's site)... I don't have any guages so I have no idea where I am boost level wise thru different gears... I definately feel a difference and seems like there is a lot more torque....

I dunno exactly how much difference there is between the 3.8 and 3.4 pulleys cause it was tuned on a dynojet the first time. I'm guessing it was probably good for another 40-50 HP and 60-70 TQ...

cheftjpeck

Boost: it can be effected by a few things. First is your tune can affect the boost in how the timing is set. I will say I had a canned tune and was max boosting on a 3.6 pulley at 6-7psi. With my new custom tune I am regularly seeing an avg of 7psi but maxing at 8.5 psi. it also has allot to do with how you drive your car. A supercharger whether twin screw or not still needs to build a little boost over the rpm of the gauge. For instance...when driving at 3/4 throttle and getting it up to 4000 rpm before my car will shift I am seeing a boost at around 7.25 across the spectrum, whereas if I lay into her and really bring her up and get above the 4200rpm is when I see her start to max at above 8psi. at 5500 rpm. which is slightly higher where the torque curve meets your rwhp curve.
a set of LT headers will take away a little boost....about .5 to .75 psi....but your torque of course is increased and thus your rwhp. ..
have your car get dynoed and see what you can get her to do... I have read where allot of saleen drivers are getting close to the same boost on a 3.6 pulley as opposed to a 3.4 pulley. It also has to do with the tune in the sense if you did not replace the fuel pumps and the tuner who sent you the tune is going to probably be a little conservative as to not cause any problems by running light on fuel....allot goes into what effects your boost...(well allot more than you would think)
good luck

jdback19

My turbo is set at 9 psi and my boost gauge reads 9 psi. [8D]