944 turbo tuning

[edh]

ORIGINAL: nicksonmsport

also is the uprated afm/maf kit you can get worthwhile, if the std afm does not have a limiting factor??

When I said "not limiting" that's not exactly right... but people have built some very high torque engines with AFM's. It's a crude device that can restrict air flow and certainly a MAF gives you slightly quicker spool up and maybe a little better throttle response. It's a lot of money on its own for limited gains. Where a MAF from vitesse scores is that you are getting a proper air measurement at WOT (AFAIK the AFM will only work until it's wide open, then it relies on a pre-set map). This means you can alter some components, boost etc.. without needing a re-map. the Vitesse software can also be tweaked. I'd be more inclined to look at Tom Barks Augtronic stuff though & go MAP.

When you start chasing 350hp+, I think you really need to look at intake manifold / head (MarkK used a LR intake?), as well as bigger turbo, injectors, standalone management etc.., bigger intercooler, bigger rad probably (heat soak on long track sessions is your enemy). 300hp is easy and pretty cheap, 350+ isn't.

The well known / well respected chipsets are fine in simple setups - my 250 turbo with just a chip & boost enhancer made 285hp and 315 (I think) lb ft.

If i was doing it again and wanted big numbers then:

SPS BB hybrid turbo
? Intake manifold (Lindsey racing?)
Augtronic management & injectors to suit
Wasted spark ignition?
Downpipe/exhaust
Intercooler & rad (and bigger oil cooler)

But actually I'd be happy with 300 'ish, a wodge of torque, boost from very low down and as light as poss.. which I think reduces it to
SPS BB hybrid turbo
Augtronic management & injectors to suit
Intercooler (and bigger oil cooler)

LSD (late turbo boxes have these as standard)

I may have missed some stuff though - GPF might post as he has done all his own development so is worth talking to

 

[MarkK]

None of my business but if the car is going to be driven hard,under race conditions I would not over tune it,320 bhp but nice and reliable is very quick in a light 944 turbo,mine was still roady and quite heavy still with electric windows and alarm and it raced some proper high budget lightweight race cars and never disgraced itself,if you over stress it and drive it hard it's going to be less reliable,nothing more of a pain in the @r5£ is travelling to a track and the car breaking.
Would love to be proven wrong though,best of luck.Love to hear how you get on.

 

[George Elliott]

to finish first, first you have to finish

[8|]

 

[edh]

I agree with Mark []

 

[Lowtimer]

Me too. 300 to 320 bhp: cheap, easy and reliable.

 

[AndrewS]

ORIGINAL: nicksonmsport

i still cant quite get my head round these chip sets, i just dont trust them, or see how a decent map can be achieved just by telling some1 what bits your car has on it, and then they give u a chip/map to suit. i have always had custom remaps for my previous cars, and seeing how much work goes into achieving a decent map, i cant believe some1 can just provide a chip thats all good to go without even having the car near them!

Hi Nick,

During a Dyno shoot out, some cars with off the shelf solutions were achieving more power and torque than cars that had custom maps (May 2006, WeltMeister Dyno at Silverstone - 944 Turbo models); the cars were running largely similar after market components and boost levels.

The DME look up data on the DME EPROM is what determines the fuel delivery and ignition advance for a given throttle & AFM position and RPM (at WOT [Wide Open Throttle], AFM is ignored). Some chips are developed for real world use (i.e. on the road) where as most custom maps are designed on the dyno - which mainly benefits WOT mapping and max power (rather than the torque curve across the RPM range under differing conditions as is experienced on the road).

The 944 Turbo engine's electronics are now very antiquated compared to modern engine electronics that use ultra high powered direct coil ignition, very high pressure fuel delivery, variable intake/exhaust timing and direct injection; however, the original 944T system can still be usefully enhanced with a moderate increase in boost (1.0 bar), a remapped DME and improved spark delivery (97 RON fuel required).

Something to bear in mind is that the factory standard 944 Turbo was designed to be driver friendly and to not outperform 911 Turbo models. The boost delivery was made to be gradual (through the use of an electronically controlled single port wastegate) and the boost was moderate (0.75 bar peak). Using a Dual Port Wastegate (boost 1.0bar - 1.2bar), EBC and re-mapped DME, 3.0 bar FPR and high octane fuel will greatly increase torque and give up to 300 bhp using the standard injectors (the engine will of course be more slightly stressed than the original set-up, but should be almost as durable as the original specification).

With any Turbo engine running higher boost; AFR (Air Fuel Ratio) is very important and some of the better solutions are well developed in respect of delivering more power with safe AFR measures. A well designed off the shelf chip-set (along with some additional parts) will deliver a good value safe performance enhancement without incurring the cost of a full day's rolling road session.

Regards,
Andrew