Specialist tuning 944 / 951

[George Elliott]

Model cars should be 1:1 Scale according to Ewan?

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[JagdHamster]

RS4 2.7 V6 is a hell of a unit. Masses of grunt and loves to rev. Built by Cosworth, don't forget.

Only weakness is camshaft wear, but nobody knows what causes it (poss. heat or long oil intervals).

460BHP is an absolute doodle and pulls throughout rev range.

Some have gone to 700 BHP.......but up to 600 they are totally drivable.

 

[944Turbo]

Yes, was the cams and price of replacement that put me off!

 

[George Elliott]

RS4 2.7 V6 is a hell of a unit.

won't argue with that, but I would be reluctant to pull any Ali engine and replace with cast iron......

making power with cast iron is not so difficult, thats how Scania and Fendt do it but they are not light agile sports cars

at the end of the day, our M44/5x's are a pretty good basis for making power in a light compact form.

George
944t

 

[colin944]

What about Audi 4.2 v8 from an S8? Or a Lexus V8 a lot of tuners are now turning to these engines. Made by Yamaha and rummored to be based on a Judd design, can produce huge power and cheep and easy to get hold off and get parts for.

Also in the states I see 914's and Boxters being fitted with Audi 4.2. They seem to fit in very well, so surely they will go in a 944.

 

[944Turbo]

Too wide I imagine, The LS has the cam in the block rather than overhead cams and it is a fairly snug fit between the chassis rails. It a small lightweight package for a 6.3L , it is tricky to get accurate figures but it is either a few kilos lighter or heavier than the turbo engine - I think this depends on how many of the turbo ancillaries you include.

 

[colin944]

Have you seen the 944 with the 964 engine in the front. I wonder if you could do this with a 997 or 996 engine or even the gt3 engine. Now that would be interesting.

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[Indi9xx]

Producing something like (original thread post) this would end up being a special car, but to really get there, you would be spending a fortune.

I would suspect in the region of £10k upwards on the shell and body, this would see it dipped, body and corrosion repairs, re-dipped to be galvanised again, or passified by various available methods and painted. That is without the cost of stripdown or rebuild back into a car.

The engine you could easily spend £10k to £20k on, or more, depending on what you want.

A proper transmission rebuild will cost around £5k to make it better than new.

And then you could spend another £10k in generally improving the car to better than factory parts, such as a loom that is made to support the intended mods right from the word go, with all soldered terminals, original or better wiring connectors, etc..

It would not be hard to really properly restore a 944 to better than new build and parts, with decent power in a decent package and spend £60k on the project.

There are only two cars I would do this to, one is my ex TWR car, and the other may be my white turbo when I approach retirement age.

I am really interested to take a look at the various Macan engines, if the package is not too large, I suspect the Macan Turbo engine would possibly be a good engine for a 944 if you were not going for the standard 944 turbo base for a build. The 3.6 V6 Macan twin turbo engine, if it fits, would be an awesome powerplant as a base, with 395 BHP and 400 ft-lbs of torque as standard, I suspect these could be tuned just a little to make a 944 really dance.

3.0 8 valve 944 turbo engine is my preference though, with the car being built either as a GT or Club Sport spec.

 

[George Elliott]

Jon,

3.0L I understand, but why 8 valve (apart from the easy install of the 2.7 head)

This thing would be twin scroll, twin W/G, large plenum throttle body, twin injector (one for fine idle, second for bulk delivery, and twin spray for better atomisation) - and surely given these features it needs the breathing capability of 16 valves? I am thinking 9:1 comp ratio, water injection, motronic replaced, and up to 32mpg daily drive, (8mpg around Spa.)

Cams...? I would study the timing and lift of a few respected turbo units with similar valve sizes and swept volumes. Your comments would be appreciated on this aspect too.

thx in advance

George
944t

 

[tref]

I can't help thinking that most of the posts here are personal wish-lists for what they would like on their own 944, or provides a good solution to a perceived problem.

If you are looking to produce something surely unless it is something existing, you don't say "I want such and such engine", the spec is more " I want 200bhp per tonne, the weight distribution needs to be no greater than 55/45 front to rear, rear wheel drive, maximum weight of, torque no below bulls*** Nm for a range of at least 2.5k revs, and not less than..., oh and it needs seventeen cup-holders."

That is still allowing it to fit in a 944 shell, but otherwise you end up specifying a performance figure and a set of mods which cannot produce the figures you are after.

Me? Can I have a 928 engine in mine please? Without upsetting the balance.

 

[Indi9xx]

ORIGINAL: George Elliott

Jon,

3.0L I understand, but why 8 valve (apart from the easy install of the 2.7 head)

That is a small question which requires a massive answer to do it justice.

It is also a question that I get asked time and time again, so a very good question, but very few people I explain it to really do grasp it completely... So I think rather than making one of my super long winded posts, I will write a complete article on it and publish it on the website in the next week or so.

As a quick and short answer, here are some tit bits...

* 16 valve heads produce improved power at lower intake velocities
* turbo charged engines produce high intake port velocities, 16 valve heads stop getting their design benefits at these velocities.
* 16 valve heads benefit from increased low down torque, with a 3.0 engine, torque is very easy to get, unless you go crazy with the worlds largest and inefficient turbo. If anything, Torque stops being a target with the bigger engines due to limited traction and kindness to the driveline.
* 16 valve engines would benefit from a longer stroke and a narrower bore in a 944 engine to get the best out of the engine, so a 2.5 block (100mm) and a stroked 3.0 crank as close to 100mm as you dare, which would then mean using a 944S head, but then you are limited on valve sizes and valve shrouding... and this particular engine would again be torque biased due to the long stroke and small bore.

However I have often thought that putting a 944S head, onto a 2.5 block, with a stroked 3.0 crank, would create an awesome non turbo engine, especially with dry sump and a high rev limit.

Now I know lots of you will be thinking why are most production engines 16v, race engines, etc etc.. But that is because production cars want torque in ever increasingly small engines, which will therefore be driven in higher gears and return better mpg, emissions and driveability. Race engines use it so they can run a wild specification of engine strategy while still having an engine which will run bellow 6000 rpm and have some grunt to pull away.

I will put together an article, complete with diagrams, formulas and a full explanation, as otherwise it is a tricky one to get your head around which does fly in the face of common conceptions of 16v versus 8v, much of which is born out of non turbo engine experiences.

 

[Diver944]

Jon, have you seen what Tim Ayliff is doing with his 16v project? He's obviously using a lot of his Cosworth Turbo experience (which I believe are a 4 pot 16v engine) and is doing things that a lot of tried and trusted Porsche tuners wouldn't dream of. I think most of us are waiting to see how he gets on with packaging the engine and intercooler in the engine bay itself as the impressive 600+bhp figures have been on an engine Dyno so far.

Here's the link, but he is updating his Rennlist post more often than this one

http://www.porscheclubgbforum.com/tm.asp?m=767715&mpage=1&key=&#768046

 

[Indi9xx]

Have been watching that one with interest for some time, but a 16v head, even though its easier to source than the right 8v one, would still not have been on my parts list for that engine.

 

[George Elliott]

I will write a complete article on it and publish it on the website

I would look forward to understanding that a bit Jon, and appreciate your effort if you put it on JMG website, please don't feel obliged to do it in a week, but your reasoning would be appreciated at some time.

As Paul suggests, Tim's work on the short stroke 16v indicates considerable promise. Early days perhaps but its given us a glimpse of great things.
I am another who is watching that space.

There again, the 3.2 you made was a great engine, although no-one ever saw it to completion IMO which was a pity. I once heard one running and I marvel that a 4 cylinder 3.2 turbo could be so sweet. It was utterly class. [8D]

I thought that 964 engine was a photoshop job, what a dogs dinner with an air cooling fan facing forwards, it would be water cooled on wet days and understeer like a hovercraft. Porsche had the sense not to go there.

George
944t