944S2 More ooomph
Discussion
The simple cost effective answer is the one we all know. Sell the S2 and buy a Turbo which already comes with uprated suspension and brakes to match the extra power. If you're still not satisfied, then an extra £1000 will see you with a modern wastegate and remap which will really smooth out the power delivery and see you knocking on the door of 300bhp and 300lbft
If you want to be in the mid 300s then the 9M supercharger now becomes very attractive as you are going to have to pay another couple of thousand to get the Turbo up there so you might as well stick with the S2 that you already know.
BTW I saw the 9M 968 track car for sale at Eynsham Hall - IT LOOKS FANTASTIC
If you want to be in the mid 300s then the 9M supercharger now becomes very attractive as you are going to have to pay another couple of thousand to get the Turbo up there so you might as well stick with the S2 that you already know.
BTW I saw the 9M 968 track car for sale at Eynsham Hall - IT LOOKS FANTASTIC
Thom said:
ninemeister said:
The issue is primarily that the intake port is completely the wrong shape and furthermore overlarge
I suppose the opposite would be correct on a turbocharged engine ?
Edited by Thom on Wednesday 20th September 18:01
...or supercharger.
Apparently (and I cannot substantiate this with fact) we had a visit by an ex-Porsche engineer whilst we had our supercharged 968 on display at Autosport in January and he commented that the 968 engine had always been designed for forced induction, but because the car was so fast they detuned it to fit within marketing requirements by fitting the "turbo" head onto an atmo engine. It came as no surprise to him that we were making 360bhp with our 7psi boosted engine as Porsche had found similar results with their development engines. If only ....
ninemeister said:
fitting the "turbo" head onto an atmo engine.
Interesting. The 16V head of the S2/968 is basically the same as that found in pair on the 928 32V, and it's difficult not to believe they used the 928 32V head on the S/S2/968 to save some cost (the cam chain design seems to have always been fine for the 928 32V but not so on the S/S2/968) ...
davey68 said:
i find the power delivery of my standard turbo pretty off/on,?
Is it a 250 rather than 220 car?
I think its a case of TADTS- they all do that sir, 220s are more gradual & being a smaller turbo its a smaller punch- even when more bhp as mapped above a stock 250.
Ive driven quite a few 944Ts but never with that dual port malarky= all with stock wastegates, some rebuilt & much more power- mine was over 300, but all had quite a big hit as the boost wound up.
Definately replace the tired old wastegate with a dual port design like a TiAL 38mm with adaptor plates from www.speedforeracing.com for $370 (a bargain at the current exhange rate). When I took my old wastegate off, I found it was opening and bleeding boost at only a couple of psi boost. This really exagerates any lag effect when the full boost arrives
davey68 said:
i find the power delivery of my standard turbo pretty off/on, what is the best mod to smooth out power delivery, improve throttle response for reasonable money? have heard of dual port wastegate as a good mod, and also the MAF kits. Any thoughts?
As others have mentioned the wastegate is part of the battle, so is controlling it correctly so also think about adding an Apex-i boost controller to max the boost under all conditions - forget about using the ecu as it will never come close to the Apex-i in accuracy or response.
My next choice would then be to ditch the KKK turbo and fit a modern ballrace turbo like the Garrett GT25 or similar (depending on power output). These turbos make a nonsense of the turbo lag of old, they make boost earlier in the curve, reduce back pressure and hold onto the boost to the redline. It will be a custom fabrication job to fit one but I guarantee that the effort would be worth it.
ninemeister said:
ditch the KKK turbo and fit a modern ballrace turbo like the Garrett GT25 ........ It will be a custom fabrication job to fit one
You're not wrong there - I have a ballrace Garret/KKK hybrid which has been a nightmare to fit even though the manufacturer had a dummy 3 litre engine and exhaust system to build it onto. It's fitted now though
and may even be up and running before the month is out. I nearly soiled my pants when I saw the 9M 968 on EBAY today - http://cgi.ebay.co.uk/ws/eBayISAPI.dl
Why couldn't you guys have put it up for sale last July when my Turbo ate a bolt form the airbox
thanks guys, yeah my car is a 250hp. had it inspected by peter morgan and he thought it drove and boosted very well. i think its performing ok but i would like to improve throttle response and boost delivery. 9M do you do performance upgrades for 944T then? I know promax do extensive mods like dual port wastegates, chips, boost controllers etc
getting the car full service and belts/water pump next week but after ive recovered from that i might look into upgrades more to improve driveability than to get massive power outputs.
getting the car full service and belts/water pump next week but after ive recovered from that i might look into upgrades more to improve driveability than to get massive power outputs.
davey68 said:
9M do you do performance upgrades for 944T then?
Erm, kind of yes and no.
Yes we can engineer upgrades for the 944T, but no we do not sell the usual stuff that everyone else does because we have limited resources and have been concentrating our efforts on our atmo 964/993, GT3 & 993TT tuning programmes.
That said there is a limited number of customers willing to spend more than the value of their car on having the best, so although it is pretty rare that we see a 951 these days for a "whatever it costs" package if anyone is thinking Motec, ballrace or 3.0 litre turbo conversion we would be pleased to take it on.
FWIW my S2 is noticeably quicker with the Promax kit fitted, more so mid range than top end although I'm sure there's more up there too, the pick up in gear is a lot more instant too. I can't comment on how much of this is due to the decat as opposed to the chip but on the whole I'd have to say for the money (400 odd quid) it certainly a worthwhile mod and I'd recommend it.
Thom said:
(the cam chain design seems to have always been fine for the 928 32V but not so on the S/S2/968) ...
Now that's a good point that I hadn't thought of before. If this is the case (namely that the cam chain on the 32v 928's is not a big issue, whereas it can cause problems on the S2) then why so? Are they the same cams? I believe it is the same chain ... what is the difference in the set-up? Oli.
ninemeister said:
bite-me said:
ninemeister said:
Hmm, tuning a 944S2. Obvious suggestions are:
1. Fit 968 engine (and box)
2. Supercharge S2 engine
3. Sell car and buy 968 or tweeked 944 turbo
If still not satisfied:
4. Supercharge 968 or further modify 944 turbo
1. Fit 968 engine (and box)
2. Supercharge S2 engine
3. Sell car and buy 968 or tweeked 944 turbo
If still not satisfied:
4. Supercharge 968 or further modify 944 turbo
1>
then it ceases to be an s2 doesnt it ? also not sure about changing the running gear/clutch/torque tube
2>
as already stated, you can "not" tune an s2 cheaply, bunging in a SC will cost big bucks
3&4> then your not tuning an s2 are you ? DOH
Sometimes make me wonder why I bother.......
The 944S2 and 968 engines are capable of making 300bhp n/a, but you will not get this power from the standard engine without radical modifications because the problem lies in the cylinder head design as mentioned above. The issue is primarily that the intake port is completely the wrong shape and furthermore overlarge, so achieving a decent intake velocity is impossible without adding material. So, let's say you only want to add 30-40hp, you will need to take your 944S2 engine, remove the head, weld up the ports, machine new ports of the optimum shape, refit it, fit reground cams, and then remap it - total cost in the order of £5000 or alternativelyyou buy a used 968 engine for sub £2000, fit it for £500 and sell your old engine for £1000.
To achieve 300bhp you will need to do all of the above, fit radical cams, new springs, solid followers, individual throttle bodies, Motec or similar, headers and a free flow exhaust - total cost around £10-12,000 if done properly. Alternatively you can do the same engine swap as above and fit a blower, total cost around £7,000.
D'oh indeed.
As was first said by zcacogp
The general line is that the S2 is pretty much untunable, without spending big bucks. N/A engine, no boost increase potential, all a bit limited. Most mods that people do seem to be limited to the handling ...
It's already been said that its "not impossible" to do anything to an s2, but the problem is that anything major is going to COST BUCKS.
so chipping/decating/air filters, is realling not going to do "that" much. ok....
The mods mentioned come in three catagories:
1> major work/upgrades/turbos etc:
This all cost's money
2> Engine swaps
This then defeats the question of tuning a 944 s2, cos it then ceases to be an S2, doesnt it ? It is a 944 with a 968 engine, or a v8 engine or whatever NOT an S2
3> Sell it
Which funnily enough is the same as the above answer it is NOT an S2.
I am not saying... and I will say it slowly.. 1 am not saying.... It is not possible to tune an S2 to get shi t loadfs of power or performance, and I'm not saying that you should not do it.... my ideas and thoughts on this have changed over the years... hey its your car, do whatcha want to it.
But the answer is you CAN NOT TUNE a s2 for peanuts or without majorwork.. really simple.. not sure why this concept is that difficult to understand.
A convo I had with nick-968 a while ago,,,, you don't get something for nothing... you pays your money you makes your choice
Well thanks to everyone who replied, even if it has gone off on a tangent somewhat! Just to clarify things a little, if I wanted turbo equalling power I would have indeed bought a turbo. I am more keen to maximise the standard engine by removing any restrictions, which the cat most definitely is. Anyone with a long enough memory will remember how these pieces of (expensive) junk strangled power outputs about 13 years ago. Although porsche claim the same output for both cat & non-cat S2 (they were bound to) they do claim better MPG figures for the non-cat car. I do agree that the real beauty of these cars is the handling, in fact the biggest difference I made was replacing the (admitedly knackered) anti roll bar bushes for powerflex items. Not cheap, but transformed my car for an hours work. Thanks again all.
zcacogp said:
Now that's a good point that I hadn't thought of before. If this is the case (namely that the cam chain on the 32v 928's is not a big issue, whereas it can cause problems on the S2) then why so? Are they the same cams? I believe it is the same chain ... what is the difference in the set-up?
Don't quote me on this but I think valve springs on the S/S2/968 are quite stiffer than on 928 32V, logically requiring more effort to rotate camshafts and inducing more shear effort on S/S2/968 camshaft sprockets.
The T-belt of the S/S2/968 is nearly twice as thick as the T-belt of an 8 valve 944 while compression ratios for all 944/968 lie between 10.5:1 and 11:1, which adds up with this theory.
Edited by Thom on Friday 22 September 17:57
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