JohnF

[quote]Look forward to handing you some of my hard earned soon!!

<hr></blockquote>

Are you having Motec fitted?

 

Joey

DIY'ing will be brakes, suspension knock etc

Will NOT DIY serious engine work!!

Tony

Next year will try and decide between s/charger & motec + bits.

Won't go too stupid, as I have a tip anyway & the gear ratios suck - but i drive alot around town.

I am leaning toward s/charging at this point. It is not, however, on the top of my cash burning agenda

 

JohnF

I was thinking of the same choice earlier this year but I had a bit of annus horriblus in 2001 with the car and shelved the idea with a view to seeing if the car would be reliable for a while.
I have printouts of 9M supercharger and motec conversions (I haven`t posted as I didn`t think 9M would approve) and from what I can see of the supercharger conversion I don`t think it will really matter about the tip`s gear ratio`s with the amount of torque available throughout the rev range.
I had 9M dyno the car prior to a trackday recently with a view to upgrading the engine.The dyno run showed I had already gained about half the benefits of motec and the trackday indicated I needed help going round corners - then the clutch failed so plans are shelved for a while.

 

Tony

have a look ar the lightened flywheel article here:

<a href="http://ww.pumaracing.co.uk" target="_blank">Benefit of lightened flywheel</a>

he other articles are a good read too.

If you need a new clutch etc, a lightened f/w may be of benefit too.

I've e-mailed Mark (supercharged 993 tip), and the s/c seems to match the tip well.

My main deision before I spend the serious money is whether to spend it on this car, or whether to get a 993 & upgrade that. Then the decision will also involve manual or tip. I think I will stick with a tip, as I do so much street driving, that a manual will just pi55 me off.

 

just a bit more on this topic, I recently bought a 964RS which came with recent dynamometer readings ( 2 lots) showing max 300 bhp. It had the MAF conversion by Tech9 Motorsport based near Liverpool airport - another '200 miles from London' place. The proprietor Phil Hindley races in Porsche Cup and also prepares customers cars for race and track, see <a href="http://www.tech9.ms." target="_blank">www.tech9.ms.</a> PS the car is faster than me !

 

Just to add flame to the fire, there are technical reasons why the 964 engine is better than the 993 when it comes to normally aspirated performance, I don't like the varioram system either 'cause it only gives a benefit below 3500rpm and I like the packaging of the 993RS even less because of the head and intake size.

For the supercharger package, all that matters is capacity and they give 94bhp/litre at 4.5psi and 100bhp/litre at 6psi.

Anyway, to all the Home county dwellers out there, why not drive only 200 miles if it means you get the job done better and save on labour charges?? We're also a friendly lot up north you know!

 

I know this will cause heated discussion, but what are the thoughts on s/charging & compression ratio??

I expect for low boost, the stock pistons & C/R can be kept.

If I was to s/c the 3.6, I would probably not want to replace/machine pistons unless it was a relatively minor excercise.

 

John

If higher boost is required then I know some people have used Turbo pistons to achieve lower comp ratio sucessfully. The cost of this would not be peanuts. Of course, if your car has a lot of miles and leaks a bit of oil when it comes to the SC bit, then an engine rebuild at the same time would make sense and replacing the pistons would be relatively cost effective.

 

Christer

plan is slight rebuild (top end where needed, machine pistons to lower c/r), maybe look at oil pump (my pressure is a bit low, though this involves splitting the bottom end = $$$£££)

Then add s/c and plant the right foot & throw wallet away..die poor, but smiling.

<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />

 

John

Never mind throw away the wallet -just sell the other 15 cars you own.

 

I'm trying...anyone who wants a 1979 Merc 280 CE in metallic light Blue, £2000 and I'll deliver it to your door!!!

 

This is directed to NineMeister:

While reading an older Porsche World & 911 mag, I saw an ad from 930motorsports regarding supercharging the 964. Is NineMeister still doing these conversions? Anything I/we should know before adding this 'kit'? Do you have a list of referals that could be emailed to me?
Is this the TPC kit available state-side?
I know there was a man on this board from Texas a while ago who was installing the TPC kit but he definitely had problems with it (fuel issues if I recall) and then suddenly sold the car without the s/c on it. I'm not sure he ever got it all sorted out and drove it for any length of time.
Just as everyone, I'd love to increase my HP by 50% (or there-abouts) but not at the price of many head-aches.
Any comments in general about these kits would be valuealbe.

Thanks,
Steve
<img src="graemlins/wave.gif" border="0" alt="[byebye]" />

 

Steve

do a search for CecilH on the 993 board. He's has aTPC for 16000 miles with no probs.

 

Steve,

The TPC supercharger kit is still sold by 9m throughout the UK & Europe, but for all US sales you should go direct to TPC in Maryland, just make sure that you mention my name though. If any potential Euro customers are reading this, please call me, because if you call the 'states you will be redirected to back to me anyway and have wasted an international call.

Now, regarding the pro's & con's of supercharging a standard engine, there are many ways to look at the effect of compression, boost and temperature. The TPC kit uses a positive displacement Eaton blower at relatively low rpm, at which speed it is around 85% efficient and as a result does not increase the intake temperature significantly, hence why it does not need charge cooling (I said need, which means that it would benefit from it as would any other forced induction system, but the benefit is small at low boost). Secondly, whenever I have measured the compression ratio of a 964 engine I have never measured one cylinder set at more than 10.6:1, so there is a significant tolerance to go at below the factory quoted 11.2:1, which of course we can take an advantage of. Finally, if you calculate the intake supercharging pressure of the standard 964 plastic manifolds, at peak torque on a totally optimised standard engine (read ninemeister MoTeC) you find that with a 113% volumetric efficiency (VE) the standard engine is actually "boosting" itself by nearly 2psi. So, by fitting a 4.5psi blower, we are merely adding 2.5psi of boost over and above peak VE, BUT we are giving the engine this supplemented VE everywhere in the rev range, hence the characteristic flat torque curve without really stressing the engine.
Regarding the compression, yes dropping the compression to run higher boost is desirable, and this can be achieved by simply machining the tops from the pistons. We machine the 964 pistons almost flat for out turbo conversions and have no problems with longevity whatsoever.
The only fuel issues to consider is that the TPC kit uses a 7th injector in the centre of the intake system supplementing the standard injectors. The extra fuel required under boost is added as required and the system works well but has to be mapped slightly over-rich to ensure adequate distribution to all cylinders, but the extra fuel is ok as it also acts as a charge coolant. Ideally the best place to add fuel is through the original injectors, but they are not even up to the job of getting the best from a standard engine, let alone a boosted one, so unless the original ecu is reprogrammed for bigger injectors OR you fit a MoTeC system or similar, the only other solution is to raise the fuel pressure via the pressure regulator. There are systems on the market that can be boost control adjusted but I have not tried them and have heard of reliability problems.

If anyone wants to open up a supercharger thread I would be happy to comment as I think this topic is best covered seperately for clarity. If anyone wants me to start it, let me know.

 

[quote]Originally posted by NineMeister:
<strong>
If anyone wants to open up a supercharger thread I would be happy to comment as I think this topic is best covered seperately for clarity. If anyone wants me to start it, let me know.</strong><hr></blockquote>

Colin. I, for one, would be interested in your views on supercharging - what performance gains can be expected; the costs involved and whether there are any issues that need attention to.