mighted1987

i would like to know two things if anyone has any information:

1. i just installed my boost gauge, it has vacuum and boost psi, on idle im at 20 on the vacuum side, when flooring it, it go to 0...my blower whine pretty damn loud, so i know it work, definitly, it run around 10-12 psi (previous owner words)...any idea?

2. is there any way to double check a boost leak from the blower? it hard to tell cause when i floor it it so damn loud but sometime..i feel like it just loud and doesnt give the power it suppose to have, is there a stuff you can shoot somewhere to see if im losing anything, im pretty sure since a couple week, i can hear a weird loud whine noise when slowly accelerating coming from the engine (but when im in car)...ill definitly will need to set it on the dyno to see what are the real number this car has...i know the previous owner had a huge freaking bills in dyno, he sended his programmer to roush like 2x time, then he went on a dyno locally and tunned it like 2-3 times until it work properly, i cant find the damn tuner i think he kept it, there is something in my engine with a roush sticker saying warning powertrain modification etc, contact roush...can this be used if i go to a dyno so he can pick up the read on the tune and maybe even modify couple things and see if im running to rich/lean?

im suppose to have 540hp, yesterday i went dragging 1/8, it was hot tho, i waited in line 40 minutes car was hot, we were two heavy guy in the car 230 lbs each, i got dominated by subaru STI 350whp 4x4, I spinned a bit on the launch, and didnt shift too agressive, but still, didnt expect to get whooped like that, i could feel that i wasnt running any decent power, on my way back home after some highway, the car was actually better, and it is alway WAY stronger in beginning of the day when i take it for the first time car cooled all night etc, so cruising around, first fews hard lauchs are definitly interresting, but god damn, the heat seems to kill this engine after 30 minutes.

anyway!

thanks for any information guys!

moosestang

Wow! Your writing is hard to read. It makes my head hurt. I realize this is the internet and no one likes the grammar police, but please try to type in complete sentences. Is English not your native language? I just realized you are in Canada, so may speak French.

Are you sure you have a boost gauge? Post a picture of the gauge, so we know what we are dealing with.

All these twin screw superchargers have what's called a boost by-pass valve. It should close when your engine vacuum goes to zero, if it doesn't, then you essential have a huge boost leak and the compressed air will be recirculated back to before the blower and be compressed again.

This is what it looks like on your compressor. Verify that it is closed with motor off, open at idle and it should close when you rev the engine hard.

moosestang

The purpose of the bypass valve is so during normal driving the compressed air generated from the blower isn't pushed into the cylinders. The blower is always making boost, but you don't want that boost being fed into the engine at idle or part throttle. If it's stuck open then your power will be way, way down. It should close after 1/2-3/4th throttle.

They do fail occasionally, not sure about the roush bypass valves, but I've not read about many failures with the other blowers.

moosestang

Your boost gauge could also be broken, leaking boost or hooked up wrong, but I wouldn't expect to see it reading an accurate vacuum either. What line did you hook the boost gauge too? I have mine tee'd into the vacuum line going to the fuel pressure regulator, like in the pic of the roush above. I think 20 in/hg at idle is in the realm of normal vacuum at idle. Mine is at 22-23 in/hg.

If you give it full throttle in second gear from 3,000rpms, does it spin the tires? Unless you are running drag radials, it should spin the tires by 4500-5000rpms.

What was your 1/8 ET and mph?

mighted1987

Im on 20" and my rear suspension got stabilising strut. The car hardly spin, im getting home. Ill take
Clear picture of my setup And even a launch
Video, my T doesnt seem to be plugged at the same place. Thx for your help. Stick arouns. Ill post video tonight

moosestang

A time slip from the track will tell you a lot about how much power you are making at the wheels. Post your ET and trap speed if you remember it.

If you have your gauge T'd into a vacuum line on the throttle body, then you won't see boost, but you'll still see vacuum. You need it tied into something coming off the intake manifold, after the blower. Either the line for the fuel pressure regulator like in the picture or the vacuum line going to the bypass valve.

808muscle

First of all mo way can a m90 make 540 rwhp. Flywheel yes. Not sure what the the original owner was telling you. With that blower you should be able to roast the tires in first and second at will.

moosestang

He never said rear wheel hp and the previous owner probably just said 540hp. When people ask me how much power my car makes, I generally say 500, because trying to explain the difference to a non car person is hopeless.

mighted1987

man i couldnt make the video im sorry, had to move asap after work with gf eating n movie.. tonight was a pretty good weather, cool not too hot, my car acted like a beast, didnt got time to travel too much to get it heating, so it was tearing first two gear, could also feel the tire spining easily, but like im telling you, the car is really geared up with alots of suspension component, im tired of talking and not showing, for sure my car doesnt make 540 whp, we be talking about the crank, my knowledge in car is weak and so is my english expression to identify correctly the pieces and etc. double checking again your picture, my T is made directly where the vacuum is, so im not at the same place, ill take a picture tommorow and if you can show me which is the other good tube to plug it in so i dont do it wrong alone, I do think the probleme with my car is it get killed in heat very easily...weird, cause tonight i could feel i had a good 400-450 rwhp.
sneaky supercharger:P

tommorow picture for sure thanks again, lotta information appreciate it

mighted1987

this is what im talking about for why i feel like this prevent me from spinning much, it grip alot.


this is how im plugged, directly in the vacuum.





is this how i should be plugged? into this tube? it is plugged to a huge kind of fan and go somehwhere plugged in the engine?


i couldnt make another speeding video, i already posted this one but maybe you didnt see it: