Belt Slippage or Boost Leak
 

My car is running a little slower than normal I lost around 5 mph in the 1/8 an the 1/4 ,I think my belt is slipping causing doing a burnout I don't get that belt squeal anymore after I stop ,and the manifold gaskets haven't been changed in four years,I think that is a place to start oh boost gauge indicates 19 psi with a code three pulley so I know that's code use to indicate 17.5

Re: Belt Slippage or Boost Leak
 

I don't get that belt squeal anymore after I stop do u get the belt squeal during the run?

have you done the throttle reset?
when you last ran was the temp as hot as it is this month?
19 lbs of boost sounds like what the code 3 can put out.
try to add about 2 gal of 100 octane gas to just under 1/4 tank.
mph can also be lost by tire spin at the line. did the et drop?

Re: Belt Slippage or Boost Leak
 

If there's black dust all over the SC pulley, then you're having slipping issues. 17psi is about right for a 65mm pulley depending on supporting mods. I have a dedicated boost sensor with my Zeitronix setup. Using the datalogger through Eurotune V2 (Eurocharged program) will show a much different reading because it uses a MAP formula to convert to PSI. Not too accurate. I see a true 18 PSI through the Zt-2, maybe 20 PSI through Eurotune. Also, leaking gaskets would show lower boost, not the other way around.

Re: Belt Slippage or Boost Leak
 

I have the modded stock manis,dcai,large air filters,sl55 fuel pump,replace the belt car pull better,car has cork gaskets from prior owner 4 fours ago probably time to change them still going with oem gaskets an that night at the track it was 96 degrees an humid

Re: Belt Slippage or Boost Leak
 

car has been 7.89@90 on street tires but i can only muster that time on a lighter wheel an drag radials,an 8.20@87 on street tires now

Re: Belt Slippage or Boost Leak
 

on nitrous it a 11.3@122 all day but if i get what i lost i should be a 10 second car,

Re: Belt Slippage or Boost Leak
 

no belt squeal during the run just doing a burnout an the sudden stop cause the belt to squeal

Re: Belt Slippage or Boost Leak
 

I have NEVER had belt squeal...
I use the Goodyear "Gator Back" belt, I think it is without a doubt the best SC belt available.

Re: Belt Slippage or Boost Leak
 

The squeal is the sudden deceleration of the supercharger an belt after the burnout is over,i heard the same noise on two e55s also.

Re: Belt Slippage or Boost Leak
 

are you sure it is not the (blow off valve) listen to this one of my car from 2 years ago.

Re: Belt Slippage or Boost Leak
 

Blow off valve?

Re: Belt Slippage or Boost Leak
 

it proper name is supercharger bypass valve,,,,but it is a blow off valve..

read this https://www.google.com/url?sa=t&rct=...XAeWnGdIL7LwLQ

Re: Belt Slippage or Boost Leak
 

Interesting readings, u have pics of ur engine bay?
Or mod list would like to know more thanks

Re: Belt Slippage or Boost Leak
 

everything is to your left,

Re: Belt Slippage or Boost Leak
 

Interesting where is this valve located

Re: Belt Slippage or Boost Leak
 

Thats the sound lol woow