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Discussion Starter · #1 ·
Hi I have a 9k carlsson 1990 with and aftermarket dump valve fitted. I.ve had the car a few months now and this wekend was the first opportunity I have had to try it out a bit. On the twisty stuff it moves quite well although i know the rear anti roll bar bushes are worn.
On the straight stuff though, if you are cruising at say 50mph and floor the throttle the boost guage whips into the red and the car goes nowhere if you ease the throttle slowly the turbo kicks in nicely
but you have to be really gentle with the throttle, is this normal ?
When you give it too much throttle you can hear the boost escaping the dump valve is this normal ? I have the old dump valve and hoses do you think I should replace them or am I better sticking to the new valve ? cheers C
 

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Discussion Starter · #3 ·
do you mean the car doesnt accelerate at all?

Yes sort of it's like the apc is cutting in ??The boost guage is touching the red at this point and the car just doesn't want to go but if you ease back and let the boost guage drop it immeadiately picks up ?? is this normal ??

Regards C
 

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Are the rev's rising and not the speed? I.e is the clutch slipping?

A can't see that the boost would be in or near the red and the car not going but slightly lower and it would.

If the overboost was being hit then the boost needle would drop dramatically as it happened.

Andrew
 

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Actually mine sometimes does the same sort of thing... not a Carlsson though.

My suspicion is that it is a misfire that is aggravated by high boost.

How's your DI and plugs? Perhaps you are losing a cylinder under full boost.

I've replaced those on mine and it has helped but not cured it... got to investigate other possiblities when I get time, but DI and plugs is definitely first thing to check.

By the way, when you say you can hear the boost escaping, do you mean when you are accelerating hard, or when you take your foot off the throttle? If the latter, then it is normal
 

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Discussion Starter · #7 ·
Thanks for the replies.
The boost escaping noise happens when i lift off the gas so I guess thats normal ?

Are the rev's rising and not the speed? I.e is the clutch slipping?

A can't see that the boost would be in or near the red and the car not going but slightly lower and it would.

If the overboost was being hit then the boost needle would drop dramatically as it happened  [/b]
The needle doesn't drop so I guess that it's not hitting the overboost
Is it OK for the needle to go into the red?

My suspicion is that it is a misfire that is aggravated by high boost.
 [/b]
I'll check the plugs and Di but other than this problem the car goes really well and as I say if I just ease back on the throttle it picks up really well

Thanks for the helps so far C
 
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