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944T performance - lack of

rcsalmons

rcsalmons

New member
Hello

A couple of months ago I purchased a 944T that had been standing a number of years. I have changed the belts. fuel pipes, brake pipes and have serviced it.
Drove it for the first time this weekend and am underwhelmed by the performance compared to my previous S2.

So my question to the knowledgeable is where should I begin in seeking the lost performance?

The car runs smoothly just lack that bit of.............

Thanks

Rich[FONT=verdana,geneva"]

Also sorry havent checked but is a 1988 944T S going to have a CAT?
 
first thing is to check for boost leaks and then once you have done that see what is actually happening boost wise, i.e. if it is making boost or losing it as well!

jack
 
Hi Rich,

Firstly yes I am pretty sure your 88 will have a cat. I don't think this will be the problem.
The most likely problem is associated with either wastegate, cycling valve or dump valve.
You have of course changed the petrol in the tank? (you mentioned the car had been standing)
Whereabouts are you based? If you are in the South East I would be happy to have a look

Cheers
Tom
 
could be wrong, but I think Tom meant change the actual tank itself... presumably because if it has been standing it could have corroded and might be leaking, amongst other things??
 
ORIGINAL: tommo951

Hi Rich,

Firstly yes I am pretty sure your 88 will have a cat. I don't think this will be the problem.
The most likely problem is associated with either wastegate, cycling valve or dump valve.
You have of course changed the petrol in the tank? (you mentioned the car had been standing)
Whereabouts are you based? If you are in the South East I would be happy to have a look

Cheers
Tom
Click to expand...
Important thing to clarify is if the motor is making good power up around 4500+ rpm. If it is then it is likely that one of the things listed is leaking/worn and therefore not helping to produce good instant boost low down. Recently my other car went through a long set of diagnostics with a recoginised Saab Guru who spotted correctly that the performance characteristic was lethargic, slow to boost, poor bottom end etc. Unfortunately he ignored that fact that the top end was superb and the G-tech performance figures showed an on-spec performance. I mentioned right at the start that I thought the wastegate actuator was worn but he felt that since the car had no boost leaks and produced correct boost at higher rpm the actuator must be OK. He checked everything you could think of (6 hours at no charge to me!) and found no problems. Last week I replaced the actuator and now the car is fixed. The moral of the story is don't under-estimate how problematic all these boost control gubbins tend to be. The same issues seem to be a common thread across all turbocharged petrol cars that I have experience of.
 
Are you sure it is a 250 Turbo?

'88 model cars were generally either 220's or Silver Rose. If it is a 220 it isn't going to seem that different to a S2 except it will be more laggy.

Either way the waste gate spring will be shot so it is unlikely it will achieve it's original boost levels anyway.

You could try a Boost Enhancer or Accuboost to interrupt the air signal to the waste gate. These are pretty cheap and may give some improvement. Ultimately the problematic waste gate is still there and will need addressing eventually.
 
Rich
I had a S2 and was thinking the same!! as well as a 250bhp 964. I thought mine was not right and possibly the spring or the wastegate was shot or cracked.

Mines had all the belts, all oils, water pump etc recently done at Northways and it goes better know, both Ray and Paul said it goes as well as most of the other 250bhp turbo's they look after. It only really goes in the 4500-6500rpm range which compared to the grunt at the low end from the other two is a bit disappointing.

The upside was by opening it up to the atmosphere it went like a rocket so the advice was go for a boost enhancer a say a Promax stage 1 £299
 
ORIGINAL: rcsalmons

Hello

A couple of months ago I purchased a 944T that had been standing a number of years. I have changed the belts. fuel pipes, brake pipes and have serviced it.
Drove it for the first time this weekend and am underwhelmed by the performance compared to my previous S2.

So my question to the knowledgeable is where should I begin in seeking the lost performance?

The car runs smoothly just lack that bit of.............

Thanks

Rich[FONT=verdana,geneva"]

Also sorry havent checked but is a 1988 944T S going to have a CAT?
Click to expand...


Hi Richard,

[1] Firstly, if it is a UK 1988 Turbo 250 (Silver Rose), it is unlikely to have a Cat. To make a check; look at the centre silencer. If it does have a Cat (and we have seen earlier than 1990 cars that have in the UK), it will be obvious by the shape and crease marks across the body of the cat silencer. Also, the exhaust gas will be moist and have a characteristic smell (like a modern car's exhaust). The 02 sensor will also be present and hooked up at the back of the engine too (near the blukhead).

[2] If the car has lost performance: A 250bhp car is much faster than an S2 as it has so much more torque (258lbft +), so if you are feeling under whelmed by the performance - a quick test by an experienced 250bhp Turbo pilot will clarify by how much. However, a turbo usually feels fast when experienced for the first time, hence it is likely that something is wrong.

[3] Things to check: Boost leaks. These can be investigated by pressurising the hard pipe from the intercooler exit into the inlet manifold (there is a specific device for doing this, but something can be creatively fabricated with some thought). A weak wastegate won't help, but the electronic boost control system will compensate to quite an extent. You should see 1.75 (0.75 bar above atmospheric) absolute maximum boost pressure to about 5,800 rpm on the in car gauge when it will then drop to 1.5 bar absolute (0.5 bar above atmospheric). Loss of boost is the most likely cause. Boost leaks can be easily fixed and look for detached vacuum hoses and loose intercooler hose clamps (and stone damage to the intercooler).

Check for boost leaks first. If the boost seems OK, we can start to look at other potential problems. Good luck.

Regards,
Andrew
 
Andrew.

Thanks I think the boost is probably the problem as I am pretty sure it is not holding 1.75 bar on the gauge.

I am bringing it over to your place sat am for Andy to have a drive and if there are no obvious probs I will probably leave it. for you guys to do your stuff.

Rich
 
I wouldn't bother with a standard one as even a brand new one from Porsche (£££££) will bleed boost too early and give excess lag and lack of response. Get a TiAL or a Lindsey Clubgate with a 0.8 bar spring and you can run that at the standard boost level which will not yield any more power but will vastly reduce lag and increase the drivability.

If the insurance worries you explain that it's a £1500 part from Porsche or a £300 aftermarket version that does the same thing, no power increase, no increased theft risk.
 
Appreciate what your saying Paul. At the moment though I just want to prove my problem is with the w'gate. Pretty sure it is and thought if I could get one rel cheap before going ahead and buying d port w'gate.

Cheers

Rich
 
another quick check is to start the car from cold and carefully check the temp of the pipe that exits the wastegate and rejoins the exhaust system, with a good wastegate (non leaking) it should stay cold at idle,
Tony
 
If you bought a dpwg and the car went better then wouldn't that be establishing / confirming that your problem was the wastegate? If it doesn't work, no loss as you should do that change anyway?
Good luck.
 
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