Cheeksyboy

I think it was 327 on the last run (Colin can correct me if I'm miles out!).

It's very tractable and Colin has given it a nice fat/flat torque curve, so it's very drivable.

The numbers are only really for pub talk as the car seems to perform well enough for me as it's only for track day fun and not racing, and especially given that the car has not been on a diet (still weighs over 1300kgs) and still has its carpets, sunroof, aircon, etc....

I'm still learning how (not to) drive it and there's still plenty of time in the car to come.....and that's what I'm looking to learn how to find next....more power would only confuse me!

Sire

Mine engine produces 292 HP with the Vitesse kit

BigMikeATL

At the wheels?

NineMeister

No, flywheel.

wtdoom

Thanks for the replies , what is a vitesse kit ?

power_up

It looks like a MAF conversion.
http://www.vitesseracing.com/html/91..._air_flow.html

ras62

The figures for the cars running the Motec are very impressive, but is this down to the flexibility of the Motec software or is it down largely to the use of larger injectors, i.e would it be possible to use larger injectors on the standard remapped motronic and achieve similar gains?

NineMeister

In truth it is down to these factors and a lot more besides. I have never seen a 964 with Motronic make more than 308hp (flywheel) on our dyno and that includes all the RS and stock variants we have tested with 3.8 engines and mass flow (hot film) conversions and I have numerous runs which prove this limitation. Back in 2002 when we installed the first Motec conversion onto a stock 964 I recall first tuning the car with standard injectors and finding that I had run out of duty cycle before I could get the engine as rich as I wanted it, then later revisiting the dyno with 803 injectors fitted and immediately finding another 20hp, hence the fuel injectors are definitely a huge part of the equation. I think I discussed this with Geoff Everett (ex AMD, now sadly departed) and he commented that the Motronic system on the 964 switched from sequential injection to batch fire on high load in order to maximise fuel flow from the undersize stock injectors.

With Motec running sequential injection with larger injectors you gain control of the duty cycle of the injector and the injection start point in the cycle, hence with careful fine tuning you can maximise the fuel capture in the combustion chamber and achieve a higher mass fraction burn (% of burn used to produce power) resulting in higher nett cylinder pressure and more power; this usually netts 5-10hp on its own. You can also fine tune (trim) individual cylinders to optimise cylinder to cylinder performance, again another ploy that finds 2-3hp. Running Alpha-N with MAP also junks the air flow meter & stock air filter & box, netting another 5-8hp with an optimised intake tract and filter. It all adds up, a little here, a little there, a lot in total. Do a search on Rennlist and you will find a lot more information that I and others have posted over the years, notably Geoffrey Ring of Racetek who has independently tested everything I have pioneered and has verified all the data I found.

Finally, for those interested in RWHP, the best results we have seen from a stock 964RS with a 9m Motec kit is 295-297bhp at the wheels (325-330 flywheel), try as I might I have never achieved the magic 300hp. The 9m Motec+1 with ported heads and cams makes 310-315bhp at the wheels (345-350bhp flywheel), neither of which is bad for a near stock engine with standard pistons & cylinders.

Hope this helps?

NineMeister

A good live remap of the stock system will yield similar peak power as any MAF kit that I have tested.

Porsche964FP

Throttle response?

ras62

Thanks Colin, very interesting and certainly food for thought.

evoderby

Talking about horsepower, did you know a well bred horse can deliver a 'peak ouput' of close to 15HP ???

This means a 12 horse carriage weighing around 600kg can achieve the same instant acceleration as a 1200kg 9m-ed 964....for about half a second that is;-)

NineMeister

The throttle response is more likely to be linked to the accuracy of the mapping than the air flow meter, thus a badly mapped MAF will have appaling response compared to an accurately mapped flap meter. The same is obviously true for Motec conversions, which raises a very interesting point.

A few years ago, just after the Motec M400/600/800 range was introduced to supercede the top end M8 ecu, a new customer arrived to 9m in a 964RS with a M600 ecu fitted. The mapping on that ecu was appalling and not only would the car not start when warm, it would also only make 275hp on the dyno. Since this was the first M600 we had the oportunity to work on, even though we could translate our existing M48 maps many of the parameters for idle control and cold start were so radically different that we would have to spend around a week fine tuning the maps until we could achieve a satisfactory (for 9m) performance under all operating conditions. We offered to split the cost of this with the customer, however faced with the fact that he had already paid someone hansomely to do this job we came up with an easier solution and fitted our tried and tested M48 conversion instead, crediting him with the cost difference of the ecu. From memory the engine made around 330hp after having the correctly mapped M48 fitted, customer went home happy with the new performance (& his bill) and I subsequently spent the next six weeks fitting the M600 to my 993RS & getting my head around the new software....

Then roll forward to this year, June 2012. Another 964RS arrives on "Motec", the customer complaining of poor idle, impossible cold start and dubious performance advantages over his previous MAF conversion. What we found was that the car was fitted with a Motec M4 on stock injectors. For those who are unaware of the Motec ecu numbers, the M4 is a four injector system running the same software as an M4-8 which has eight injector drivers. Someone had fitted the M4 and converted the car to batch fire injection. Suffice to say that this RS made less power on the M4 than it did on the re-fitted stock injection system (with or without the MAF kit). At best the engine scraped 295hp on the MAF with a very lean mixture, on the Motec it made 282bhp. With the 9m M84 kit fitted(including injectors) the RS made 328hp with a brand new M84 fitted and would now cold start on zero throttle.

Hence with any engine management system, Motronic, Motec or other, the performance achieved is related not only to the capabilities of the product but also of the abilities of the guy installing the product and whether he can tune it properly.

evoderby

Unbelieveable that companies in this day and age can still get away with creating a mess to the extent you have just described Colin. Indeed it's up to the surgeon to choose the appropriate tools and apply them in the right manner!

Glad you were able to sort out the mess created by others, not the most pleasant type of job I imagine...

springer3

Great posts Colin, and a good caution to anyone thinking about wasting money on a quick fix and expecting a large power increase in the well-developed 964 engine. This reminds me of a sign at an old fashioned garage:

Labor Rates:

$10/hr
$20/hr if you watch
$50/hr if you help
$100/hr if you screw it up and bring it to me in a box