Boost Leak Effect on Performance?

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Guru Meditation
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Boost Leak Effect on Performance?

Post by Guru Meditation »

Hi,
I have a whistling coming from my ZX TD aura 93. From drivers seat it sounds like it's coming from near the centre of the car through the bulkhead, it can also be heard from outside the car it only occurs under load and the greater the load ie up a hill hard the louder. I have bought a new inlet/exhaust manifold gasket on suspicion of this leaking but haven't fitted it yet. When I do fit it I will also check all the rubber tubing and seals to intercooler etc in case at fault. Just out of interest what kind of performance loss would you expect from a whistling leak like this? I realise without knowing how much boost you're losing you can't calulate it but as an indication I'd say that performance feels strong still but it doesn't really pull much over a 100mph-the most I've had was an indicated 110mph but once you hit 100 it is really slow acceleration. What kind of performance should I expect if no boost was being lost?
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Post by RichardW »

Most likely is the small rubber gasket between the intercooler and the inlet manifold. Leaves a gap about 1 - 2mm thick which whistles like a good un! Available only from main dealers I think (guys at AS couldn't find it when I wanted one for my BX anyway), but it only costs a couple of quid.
I doubt you will see much improvement in the performance, but it will save your ears! Most I had out of the BX was 110 indicated, and yes above 100 the acceleration was limited.
Jon

Post by Jon »

Hm, well I also own a ZX Aura TD 1993, and its been in my family since new and its ALWAYS whistled like this.
Its the turbo.(in my case) When I worked for Citroen years ago a few people complained about it, and some turbo's were changed under warranty. The one on my car is a Garrett. After about a year they all came through with a different turbo that didn't whistle so much under boost.Think it was a KKK but can't remember.
As the top speed of the thing is about 110mph flat out sounds Ok to me.Mine will show a bit more than this but I've increased the boost. It whistles even better now :-)I've seen 200kph on the speedo coming back from Frankfurt, dunno how accurate that is though. Felt bloody scary for the short while i did it.
The intercooler to manifold seal can also produce a whistle if its mis-seated or damaged, check this too.
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Post by Guru Meditation »

Thanks for the replies I guess mine sounds about normal! Ah well I don't mid a bit of perfomance turbo whine! A Nova owner would KILL for this. Anyone know how I can make it louder ;-).
I don't know what turbo my ZX is fitted with.
I'll check all the connections and might as well fit the inlet/exhaust gasket as I have it. If the whistle stays the same I'll know it's normal and won't worry.
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Post by AndersDK »

LOUDER turbo ?
Tap off engine oil - drive engine for 30 secs - stop and refill oil [:p][:p]
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