944 differences...

[Rottbox]

Hi all,

I've had a quick google, but not really finding what I'm after (info I have found tends to focus on the engine, quite rightly so... but not quite what I'm after)

Lets say you were to buy a 944 for a track car project, and do an engine swap... using the best gearbox aswel, which I dare say is either a turbo or 3.0 s2 gearbox?

Considering all 944's s1 and s2 2.5, 2.7, 3.0 and turbo

if you where to upgrade all the useual things like dampers/springs, wheels/tyres, bushes, roll bars, brakes, engine, ect ect...

did the turbo or s2 have any changes the 2.5 or 2.7 didnt have?

I'm thinking along the lines of things like did the S2 have different geometry, or changes to the shell

basicly lets say I buy a s1 944 2.5 and by the time I've upgraded it, would I miss anything a S2 would of had?

If you go for the stronger gearbox from a turbo or 3.0, does it fit in a 2.5 rear subframe? was the rear sub different, stronger, different camber different lower arms, how about the front aswel? Saying I have to source s2 parts, will they all fit over?

I know things like bumpers and the dash changed, but thats all cosmetic that will just swap over, its major hidden changes I'm interested in...

thanks all, really appreciated!

Edited by Rottbox on Monday 22 February 12:56

Edited by Rottbox on Monday 22 February 12:59

Edited by Rottbox on Monday 22 February 13:04

[andy97]

There are plenty of people more expert than me but,

The 924S had slightly closer gear ratios which might be an option, not sure about LSD availability, though. Plenty strong enough for all n/a applications I'd have thought, but does benefit from the John Mitchell Garages front and rear quick shift kit.

The S2 and 250 bhp turbo (I think) had abs

The 250 Turbo had the option of the "big black" brakes (same as on a 928). Not sure whether they were available on an S2 but doubt they'd fit an early 2.5

The 220 bhp turbo was the only 944 that was homologated for competition (Group B)

You can fit the the thicker anti roll bars from the S2 or the even thicker ones from the 968 to the early 944 cars

The 2.7 head cannot be fitted to the 2.5, different bore spacing, the same as an S2, which Is a shame as it breathes better than the 2.5

The 2.5 had 15x8 wheels all round, the S2 and turbo had 16s (I think) and the fronts were 8 and the rears 9 inch wide (happy to be corrected)
B
The 944S was the first of the 16v cars, and on the 2.5 block, and used to be considered the least reliable.

Take your pick from that and others will be along soon to fill in gaps and correct me where I'm wrong!

The cars handle fantastically well, and my 924S race car is the best handling car I have driven. If you go down the 2.5 route, it's worth speaking to Augment Automotive near Gloucester for their ECU, cam and fuel pressure regulator upgrades - my race car achieved 19% increase in power. It also has the max negative camber I could get, 944S2 anti roll bars and has been lowered slightly. And lightened.

Edited by andy97 on Monday 22 February 14:09

Edited by andy97 on Monday 22 February 14:10

[blade7]

Unless you're thinking about spending a lot of money I'd forget about a turbo for track use. The 924S has the 2.5 944 engine and is light. Alternatively the 2.7 engined 944 could be uprated to 3.0 fairly easily. A tatty but mechanically sound S2 probably offers the most bang for the bucks.

[DavidJG]

One other thing - the 2.7 engine is quite rare - I'd avoid this one if you're planning to keep the engine that's in the car. From what I can remember of my 944 days, parts for the 2.7 were stupidly expensive compared to every other variant.

'Best' engine - I really loved my turbo. It was very lightly modded to raise power from 250 to around 300 bhp. This isn't a simple remap, but some light tweaks to the turbo and intake, followed by a rolling road map for the individual car. All that said, the S2 engine has a much less peaky power delivery - my turbo was very much 'nothing' until about 3.5k, then 'lots' from 3.5k to redline. The surge as it came on boost would always make me smile.

[andy97]

One other thing to consider is that if the engine does go pop, a 2.5 can be picked up for about £500; an S2 for upwards of £1k (I think), 2.7s are very rare and a turbo, no idea but they don't come up that often!

[blade7]

The 2.7 engine uses a 2.5 crank in the same block as an S2. The unique 2.7 parts are the head and pistons. Fitting a used S2 crank and lightly modified S2 pistons would give 3.0.
Saying the turbo gives nothing under 3.5k isn't really right, however the rush from 3k onwards is strong so it makes what has happened before seem slow in comparison.

Edited by blade7 on Monday 22 February 23:18

[benjj]

As the owner of an early car I generally work on the assumption that anything built after 1985 is completely alien. When I'm very occasionally proved wrong then that's fine.

[DavidJG]

benjj said:

As the owner of an early car I generally work on the assumption that anything built after 1985 is completely alien. When I'm very occasionally proved wrong then that's fine.

And the advantage of the early car (from memory, it's been a while since I had a 944) is that it's a fair bit lighter than the later cars.

[eldavo]

I track a modified Turbo S - it's not a cheap proposition to get it reliable and "right".

If you look in the March edition of Practical Performance Car magazine (think it's out any day) there's a feature on front engined Porsches that I took part in last year. Mat in his lightly modded 924S was having a whale of a time with an excellent smiles:£ ratio!

[Action jack84]

blade7 said:

The 2.7 engine uses a 2.5 crank in the same block as an S2. The unique 2.7 parts are the head and pistons. Fitting a used S2 crank and lightly modified S2 pistons would give 3.0.
Saying the turbo gives nothing under 3.5k isn't really right, however the rush from 3k onwards is strong so it makes what has happened before seem slow in comparison.

Edited by blade7 on Monday 22 February 23:18

Oh I need to look into this a bit

[speedyman]

Regarding the s1 having a reputation for being unreliable is a bit unfair, I can't think of one thing that was only evident with that car. Had mine for seven years without problems.

[blade7]

Action jack84 said:

blade7 said:

The 2.7 engine uses a 2.5 crank in the same block as an S2. The unique 2.7 parts are the head and pistons. Fitting a used S2 crank and lightly modified S2 pistons would give 3.0.
Saying the turbo gives nothing under 3.5k isn't really right, however the rush from 3k onwards is strong so it makes what has happened before seem slow in comparison.

Edited by blade7 on Monday 22 February 23:18

Oh I need to look into this a bit

The 2.7 was only in production for one year, 1989. It's a mystery why Porsche bothered unless it was to prove the block for the S2, or a larger capacity 944 turbo that was shelved.

[Action jack84]

My understanding is that the 16 valve S model didnt work out as well as they hoped . They then developed the larger capacity block tested as an 8 valve in the 2.7 which then evolved into the 16v 3.0 of the s2. Another theory is the S model was just the test bed for the 16v head in the same manner that the 2.7 was for the larger capacity block.

If i was to keep my 8 valve head and replace the crank and pistons as mentioned what kind of power would i be looking at getting from a 3.0 8v.

[edh]

There were quite a few changes between early (square dash) and later (oval dash cars), making it quite a big job to put a 3.0 engine into an early car for example.
Suspension changed with introduction of ABS - early cars also have different steering geometry I believe

All this depends on your budget and purpose. For very cheap, buy a 2.5 8V and modify. A 3.0 S2 is a fair bit quicker, but the base car will be more expensive. ~£8k buys you an S2 racecar, and you won't build a comparable S2 track car for much less.

[blade7]

Action jack84 said:

My understanding is that the 16 valve S model didnt work out as well as they hoped . They then developed the larger capacity block tested as an 8 valve in the 2.7 which then evolved into the 16v 3.0 of the s2. Another theory is the S model was just the test bed for the 16v head in the same manner that the 2.7 was for the larger capacity block.

If i was to keep my 8 valve head and replace the crank and pistons as mentioned what kind of power would i be looking at getting from a 3.0 8v.

Not sure if anyone had done it with a normally aspirated engine, I'd expect more torque rather than power. Then I'd bolt a turbo on it .

[andy97]

I think it's been done in the USA, some threads in it on Rennlist or PelicanParts, can't remember which.

[blade7]

andy97 said:

I think it's been done in the USA, some threads in it on Rennlist or PelicanParts, can't remember which.

2.7 heads and 3.0 cranks/104mm blocks sell for good money over there so it's mostly turbos they end up on.

[Action jack84]

May go the whole hog and turbo it then . 3.0 8v turbo should be good for an under stressed 260-270bhp . I realise much ecu work etc. would be required as well but in for a penny in for a pound

[blade7]

Action jack84 said:

May go the whole hog and turbo it then . 3.0 8v turbo should be good for an under stressed 260-270bhp . I realise much ecu work etc. would be required as well but in for a penny in for a pound

You saw the I used after my turbo comment ? I think you could end up in for many thousands of pounds you'd never see again.

[DavidJG]

blade7 said:

Action jack84 said:

May go the whole hog and turbo it then . 3.0 8v turbo should be good for an under stressed 260-270bhp . I realise much ecu work etc. would be required as well but in for a penny in for a pound

You saw the I used after my turbo comment ? I think you could end up in for many thousands of pounds you'd never see again.

For 260 - 270 bhp, the 2.5 turbo is more than adequate. See my earlier post - a very lightly fettled late model turbo will give you 300bhp. If you're going to build a 3.0 turbo you'd want to aim for much more power, otherwise the money you spend doesn't give you anything over the standard 2.5 turbo unit.