Porsche Enthusiasts Club Forum

My tweaked 87 Cosworth regularly went way past 140mph back in the early 1990's but apart from the head and perhaps engine management the 944T runs rings around it. We all know the 944T was a victim of it's own success but back in the late 80's it was plenty fast enough and today I think 350bhp with good throttle response is adequate for a road car.

Whats the maximum speed of a cosworth with a standard gearbox? I always suspected it was about 140 to 145 as that always seems to be the speed they top out at and start to dissapear in the rear view mirror of my 944 turbo's.. Perhaps its not them running out of gearing but them running out of courage (or maybe I have an abundance of stupidity).

Been baiting Cosworths for years, makes for excellent sport. I would not trade the high gearing of a 944 turbo for anything.. might not make it a traffic light blitzer, but once it gets rolling there is not much that can catch them. and a 930 turbo, even a tuned one, has to be suicidal to chase a 944 turbo down a twisty road

In fact the std turbo gearing becomes to feel really good once you get past 350hp, from which 5th gear even becomes a tad short. The S2's fifth gearset helps as it's slightly taller, but the difference is not worth the hassle of fitting IMO.
I have a 6 gear gearbox project in the garage, the 6th should help me net 200mph at 6200rpm if I can find a suitable and secured place to do the test. I need to purchase an LSD too, which is quite costly, and anyway that will all be when I am done fiddling with the engine. By then I will have finally reached my "ideal" 944T.

I was sure the 4 wheel drive cossie's bottomed out about 143mph due to gearing but was led to believe that wasn't an issue with the 2 wheel drive? Maybe someone can clarify that.

I have to add once north of 300bhp in the 944T very little on the road can touch you once rolling and scooby's and evo's simply disappear in the rear view mirror. Well they do on my private test track anyway. Ahem.

Stuart

First time I drove a 944 turbo with more than 400 bhp, or possibly more importantly, over 400 ft lbs of torque I found myself reaching to change gear for a six gear that was not there, even at motorway cruising speeds, as the extra torque just made it feel like you needed another gear to cruise in at around 80mph upwards and they become really quite quick to hit 175mph. The real surprise was how smooth they become above 150mph, they really do feel like some aerodynamics are beginning to work at those speeds.

Having said that, I have found the same true of my 911's over the years, they all really tighten up, squat down and stabilise at speeds around twice the UK limit.

Thank the lord for trackdays.

I think it depends how brave you are with the revs, it's one thing pulling 7k through the gears but holding over 6.5k for ages to get a few more mph in 5th made me twitchy about the engine. The standard 86 car was tested at 149 mph and the 500 at 154mph I believe but they may have been massaged press cars. Mine crawled to 160 on the clock a few times but that was probably a true 150 at best. I remember when I modified mine it was a totally different car and that rear wing probably had an effect on top end.

I think part of my reluctance is is I'm worried (probably unfounded) that hit the tuning route and I'll be fixing it on a regular basis but I guess that there's not reason with a chip here, 3 bar FPR there and a few other bolt on bits why it can't remain uber reliable still?

Performance and Reliability can go together I believe if Tuning is carried out tastefully.
My Guards Red 1990MY acquire from Simon Peckham in Jan 2007 is a good example. I was a bit dubious about purchasing a Tweaked version but exceedingly glad I did.
I mentioned in a previous post :-
"It has 161,000miles on the clock and has his tastefully modified rebuilt blueprint engine which has covered just 13,000 glorious miles.
I believe it was, and possibly still is the highest Torque 2.5L on the UK Power League 318 BHP 377 Ft lbs @ 4000rpm Hybrid Turbo (Min Lag) etc etc, It's Impressive Torque Curve (already posted in an earlier topic > Jon Mitchell Garage performance parts ) Just the ticket."

It has been very reliable in my 6 years of ownership (not wishing to tempt fate ) with no breakdowns and just one problem, an electrical one on the washer pump relay causing intermittent working of the washers. The engine has never missed a beat and runs like a sweet Swiss sewing machine.
If you want performance, reliability and peace of mind. I would highly recommend going down the JMG route.
Clive

The wonder of the 944 turbo is that they are so seriously over engineered.

I know when I talked with the original design engineers back in the late 80s there were two main comments about the 944. One was that it was very much pulled back to a minimum performance by the Porsche marketing department, and that everyone had had their hands slapped for issues with the 924 and 924 turbo, which forced them to go over the top with engineering the 944 and 944 turbo.

I have been trying to rack my brain to think of a single car that we have tuned which has suffered increased wear or damage due to our tuning... and I can not think of a single occasion where the reliability of a car has been hampered by correct tuning.

However, I can think of a number of occasions where we have repaired cars incorrectly tuned elsewhere.

As long as the chips are right, the installation is right, and the right products are used, there really are no drawbacks.

I always tell people who are about to tune a 944 turbo

"If your head gasket was due to fail in the next couple of thousand miles, it may fail sooner just due to the increase in pressure on it, and a good head gasket will not be any more likely to fail... but other than that, reliability will not be effected."

Sounds encouraging, and as you said earlier Jon you've never had an engine wear out. Maybe I'll get Christmas out of the way before I start 'tweaking!'

Exactly what happened with me! Always new my HG was needing done and my DPW and 18psi put the worn one in an early grave, how much earlier I don't know but upon inspection the HG was like a cheese grater and was a wonder it lasted so long!

As Jon says, the right mods will not detract from reliability. Getting things wrong on fuelling or boost levels will!

Cheers

Stuart