Hello all
I would just like to compare my experience to others out there.
I recently fitted a boost gauge to my 95 S2 Coupe to see if I could shed some light on what appeared to me to be abnormal behavior at WOT. Symptoms are as follows. When I stamp on the throttle in any gear from 4th to 6th the boost gauge will spin up to 1.1bar and the car will surge forward, but then, while the boost is being maintained at 1.1bar, the surge factor becomes .. er .. lumpy. It's fairly subtle and the car does not jerk about or anything, the acceleration is just not smooth. It's almost like it is bouncing against some performance ceiling.
I can only maintain this state for a couple of seconds (but up to 6k rpm in lower gears) due to the possible incarceration problems if caught doing, what is by that time, plenty over the national limit. All the while the boost is kept at 1.1bar
I did have a boost leak a while back (hole on IC), but tested the system on the weekend and found the following:
I blocked the hose at the MAF end. Removed the hose from the IC at the hard pipe that runs along the side of the motor and pressurised it there back to the MAF side. Managed to pump it up with a bike pump and it held pressure for quite some time (had to block the cam breather first). I then moved my pump to the hard pipe and pumped the whole bit from there to the engine. This pressure I could see on the boost gauge and I managed to get 0.5 bar with the bike pump without a problem. This pressure held for about 15 seconds and slowly leaked away. I could hear a hissing if I listened to the IM, so the leaking was most likely past a valve or the rings. I could smell that carkcase oil smell after a while.
So seems the leaks are fixed. Or are they ??
Any ideas ?? Is my car doing the "normal" thing ?
Thanks
Andre
I would just like to compare my experience to others out there.
I recently fitted a boost gauge to my 95 S2 Coupe to see if I could shed some light on what appeared to me to be abnormal behavior at WOT. Symptoms are as follows. When I stamp on the throttle in any gear from 4th to 6th the boost gauge will spin up to 1.1bar and the car will surge forward, but then, while the boost is being maintained at 1.1bar, the surge factor becomes .. er .. lumpy. It's fairly subtle and the car does not jerk about or anything, the acceleration is just not smooth. It's almost like it is bouncing against some performance ceiling.
I can only maintain this state for a couple of seconds (but up to 6k rpm in lower gears) due to the possible incarceration problems if caught doing, what is by that time, plenty over the national limit. All the while the boost is kept at 1.1bar
I did have a boost leak a while back (hole on IC), but tested the system on the weekend and found the following:
I blocked the hose at the MAF end. Removed the hose from the IC at the hard pipe that runs along the side of the motor and pressurised it there back to the MAF side. Managed to pump it up with a bike pump and it held pressure for quite some time (had to block the cam breather first). I then moved my pump to the hard pipe and pumped the whole bit from there to the engine. This pressure I could see on the boost gauge and I managed to get 0.5 bar with the bike pump without a problem. This pressure held for about 15 seconds and slowly leaked away. I could hear a hissing if I listened to the IM, so the leaking was most likely past a valve or the rings. I could smell that carkcase oil smell after a while.
So seems the leaks are fixed. Or are they ??
Any ideas ?? Is my car doing the "normal" thing ?
Thanks
Andre
