Erik

i only have the stock boost guage as of now...and was just trying to guess as to how much boost its actually running. or how extreme the port on the wastegate was. lets say i floor the car in first or second. the needle on the stock guage reads about 1/2-3/4 up on the orange semicirle part. i was under the impression that the top of the orange was about 7.5psi? i know i really need to get a REAL boost gauge, but just wondering how much boost you'd guess you'd run with these mods normally OR with a ported wastegate. i guess its running less boost than stock...but it feels fast as sh*t! i haven't driven it that much, but have never experienced fuel cut or any sort of hesitation thru the powerband since putting in the new TPS

also, this might be a retarted question, but how can a car be faster than stock, withouth running stock boost? i got to ride in a stock 91 T2 a few weeks back and am sure that my car was faster. although i don't think i've even running stock boost. is that just because the mods i have help the turbo spool faster enabling more flow (without as much compressed air)?

thanks

turbojeff

iTrader: (30)

Yeah, you need a boost gauge, I wouldn't want to guess what you boost level is by looking at the stock guage. With those mods it would seem like you'd need a FCD, do you have one?

A modifed car can be faster than a stock car running the same boost levels (or slightly less). The turbo exhaust side wheel is a restriction in the exhaust, if it spins more easily due to an open intake and exhaust then the engine doesn't spend as much energy pushing the exhaust past the turbo. Since the burnt exhaust gases can get out quicker/easier then the combustion chamber can be filled with more fresh air and fuel also.

My 87 TII has a mildly ported wastegate, soon to be an extreme ported wastegate, with the stock intake and a fully open exhaust the car was much faster than stock running 6psi boost, a manual boost controller allowed me to adjust boost up also. I added a TID mod (no one replied to my post about boost creep, is everyone here a poser? Body kits are for posers, hp isn't) and my boost went crazy, even in second gear it would creep (it was fast creep) over to 11+ psi in a second. I put the stock TID back on and left the cone filter on. Boost is controllable until the upper ranges of 4th but luckily I'm not getting to much time in 4th in the 1/4 mile.

I'll post what type of difference it makes to wildly port the wastegate when I get it done sometime this week.

Jeff
87 TII running 13.5's now for less than $2K

Keith

The boost guage reads out in units of millimeters of mercury. We like to see our pressure readout in psi (pounds/square inch). The conversion factor is .1934. Crunching thru the figures, we get:
5 = 1.0 psi
10 = 1.9 psi
15 = 2.9 psi
20 = 3.9 psi
25 = 4.8 psi
30 = 5.8 psi
35 = 6.8 psi
40 = 7.7 psi
On my boost guage (when the fool thing decides not to stick at -20!), I get a reading (max) of 35 in first and second, with it creeping up to 40 in third. I put a boost test guage on the car, and it read 7.0 psi in first and second, and a little over 7.5 in third. So, you see, it corresponds very well.

Irv, Keith's dad