Hey I just finished installing the m45 supercharger on my 1999 sunfire gt. I took it for a drive and I only seem to be getting 3-4 psi of boost. I took the supercharger off another 1999 sunfire gt and it was producing 5 psi before i changed it. Anyone know what may be going on??
Thanks Mike
Best i've done is 6psi...and i just installed mine to.
weather has allot to do with it I think
dont worry about psi. every car has the potential to be different. even stock vs stock.
how is the car actually performing?
I'm tired of wasting my time... now I'm breakin' free.
The M45 kit is only rated for 4.5 PSI stock. Sounds like your right in that area.
FU Tuning
It runs great! I took it for a run today with nice dry roads and it seems to be running about 4.5 psi. Just wated to make sure nothing was wrong when i installed it, cuz as i said the car i took it off of was runnin exactly 5psi. Anyone one know what kinds of times i may put up? What r u guys runnin at the track?
other mods?
8 psi with m62 and IAT under 100
who did you buy the s/c from? ( just curious as i sold mine to a guy who had a sunfire and from canada and his name was sam).
not that it really matters , but just curious
good luck with the s/c.
Pulley size ? etc ?
My Cav
I give up...
i'm buying a VW those people love trees, so they should love eachother too... "Andy"
Jake wrote:who did you buy the s/c from? ( just curious as i sold mine to a guy who had a sunfire and from canada and his name was sam).
not that it really matters , but just curious
good luck with the s/c.
Yeh i bought that sunfire from a guy named sam and took off the supercharger, fuel system, and pcm and put it on my car. So I'm guessing this charger has quite a few miles on it. would that make a difference.
Also the pulley sizes are the same the only other mod my car has is a pacesetter header
if you have a free flowing exhaust the psi will drop also but you will be making more power just not pushing the supercharger as hard
air temp makes a big difference this moreing my M90 made 11lbs on my way home at 2 i only made 9 difference in 15C
JBO since July 30, 2001
hes right you know
i have seen almost 8 at wot on a colder night
in the day in the summer most i will see is 5-6
and that is with a 2.7 pulley
are you in canada?
If so that s/c started its life on my cav. AS far as miles, i put 15,ooo miles on it. Ran 5 psi everytime, maybe 6psi on rare cold nights . I had every bolt on mod/ meth injection and it ran strong.
is the stock pulley still on there ?
good luck
carey965 and i are both in ontario
if the temperature flucuates to much you will see it move but if your always say 80-90F then you will see the same boost all the time
3800 stock pully size is 3.8" i have a 3.4" every .1 on that motor gets 1lb so i should have 11 but when its hot i only get 9 but i have seen as high as 12lbs, its all about air density
JBO since July 30, 2001
Well I have been driving the car for a couple days now, and no matter if its cold or hot my boost always seems to stay the same, around 4-4.5. I have never seen it hit 5 or higher. I was thinking maybe the manifold gaskets may be leaking a bit. Is there any way to test to see if its leakin around the manifold. I have a smoke machine at work to test for EVAP leaks, exhaust leaks, etc. think if i shove the probe in the throttle body and pump some smoke in it if it will show me some leaks? Or am I just worrying too much??
Spray throttle body cleaner around the manifold where it meets the head while car is running. If it bogs or, stalls then it is leaking.
FU Tuning
4-4.5 is really about right. what other mods do you have? your boost gauge hooked up good? you do a boost leak test? i used my brothers boost leak tester for his dsm. basically a rubber coupler and a bike tire vavle stem and you pressurize it a little and listen.
where is your boost gauge hooked up to?
I would also try what john said.
good luck.
I checked out the manifold with a little bit of propane, and sure enough as I sprayed the propane around the manifold the engine reved up a bit. The manifold bolts were a little loose so i tightened the manifold bolts and I'm getting 5psi now. I think I'm going to take the charger off again, and replace the gaskets.
Thanks for the help guys.
awesome.
keep us updated. post up some pictures of the set up. I would be nice to see my old s/c.
The story behind how i got it : Gm gave it to RK Sport. Rk Sport put it on ebay for 2000$ shipped(us) and had a few buyers back out, and then i came along. I sold the injectors and map sensor (map i sold for 35$. someone got a deal
).
I ran it for 2 years, loved it. Ran it on my 96 z24 with alot of mods and it screamed, but i got out of the car thing so i sold it to sam for 1300$ shipped i think, i forget.
