Yes I know where Camberley is - I'm near Gatwick. Just round the corner for the North Americans here, but quite a long way for us!

Photos as requested. Alpine White with Marine blue leather spotless interior. 8J front 9J rear Conti Sport tyres

 

Very nice, looks like a great example. Is the intake manifold painted or powder coated? It does not look like a normal bare al manifold to me.

 

Ceramic coated I think, but not sure. Done by PO.

Mick

 

Got yeah, looks nice.

 

I would also be inclined to measure exhaust gas pressure upstream and downstream of the catalytic convertor.

 

^^^^ its ridiculous how much quicker spool up is without a cat in the way, especially if its a clogged cat.

 

If they don't emissions test old cars in your area, I recommend removing the cat and replacing it with a chambered muffler. I got mine from Sweet Thunder. They're based in the USA, but I'm sure they have something in the UK that's similar. Don't use one of those Cherry Bomb pieces of garbage or a test pipe. I've seen those Cherry Bomb things blow apart and a test pipe will make it all raspy and sound like a Honda with a fart can.

 

Thanks, another thing to consider. I'll see what local options there are.

Mick

 

First thanks to all for their time and input.

By way of an update:

Lots of checking, installation of a new 2 stage wastegate and manual boost controller, set to 1 bar on a calibrated external gauge, and a modest chip upgrade (Superchip in the UK) to just get rid of what I understand was the deliberate Porsche de-tune to make sure the 911 Turbo out-peformed the cheaper 944. Adds about 35 bhp apparently.

.... And we have a rocket ship. Boost comes in about 3500 rpm, and off we jolly well go! I plan to take it back and do an 'after' dyno run, but having too much fun in the sun at the moment.

Best guess is the stock wastegate spring was weak allowing premature bypass, but doing its job later in the rev range so stock bhp achieved, but late. All hoses, cycling valve etc checked and fine as I expected with a car that has had so much Porsche OPC attention.

Thanks again

Mick

 

Are you just seeing positive pressure at 3500rpm? That still sounds slow for a stock turbo.

How are you on exhaust leaks?
And be wary about chips, most of them are old tunes from the 90s that run pig rich with weird timing

 

What length did you use and what muffler in back? If you have any vid of the sound that would be awesome, I've been looking into replacing the exhaust, but can't find anything that sounds right (I'm admittedly far too picky).