Supercharged!!!
Discussion
Got my 993 back from Ninemeister on Monday, now sporting a rather meaty looking supercharger 
It's a bit good. Totally changes the character of the car - you can drive it really lazily as it has loads of instant torque. Sounds a bit different as well.
Of course if you rag it then it's an animal (2 wheel drive of course)...
No need to redline it though - I think the changes to the induction have strangled it a bit above 6500 rpm. Then again, high revs mean high wear, so I'm not complaining...
I thoroughly recommend this conversion! Time will tell re: reliability but plenty of these kits have been sold, so I'm fairly confident.
It's a bit good. Totally changes the character of the car - you can drive it really lazily as it has loads of instant torque. Sounds a bit different as well.
Of course if you rag it then it's an animal (2 wheel drive of course)...
No need to redline it though - I think the changes to the induction have strangled it a bit above 6500 rpm. Then again, high revs mean high wear, so I'm not complaining... I thoroughly recommend this conversion! Time will tell re: reliability but plenty of these kits have been sold, so I'm fairly confident.
The whole point for me was the 'stealth' option - I didn't want to end up doing a faux-GT2 and festooning the car with wings and skirts.
It said on the 9m website that no spoilers etc. were required - when I turned up there was some humming and hahhing, but Robin sorted it all out (great job). A small amount of material has been removed from inside the original engine cover, but everything still works (i.e. motorised spoiler).
So it looks completely standard, but carries a slightly bigger stick than usual Power is around 330 bhp, which doesn't sound monster but there's similar torque (in lb ft) and this is what makes the difference. I think the ninemeister can get similar N/A power, but this involves loads of revs and a Motec control unit. Those engines definitely don't have the low-revs shove the blower gives.
Driving it back from Warrington to Kent showed no appreciable increase in fuel consumption, surprisingly enough, and I was taking the piss somewhat on the M6 toll road
I presume the increased consumption due to the increased air flow is cancelled out by not needing to use the revs as much?
Rear tyres - well give me a few weeks
It said on the 9m website that no spoilers etc. were required - when I turned up there was some humming and hahhing, but Robin sorted it all out (great job). A small amount of material has been removed from inside the original engine cover, but everything still works (i.e. motorised spoiler).
So it looks completely standard, but carries a slightly bigger stick than usual
Power is around 330 bhp, which doesn't sound monster but there's similar torque (in lb ft) and this is what makes the difference. I think the ninemeister can get similar N/A power, but this involves loads of revs and a Motec control unit. Those engines definitely don't have the low-revs shove the blower gives. Driving it back from Warrington to Kent showed no appreciable increase in fuel consumption, surprisingly enough, and I was taking the piss somewhat on the M6 toll road
I presume the increased consumption due to the increased air flow is cancelled out by not needing to use the revs as much? Rear tyres - well give me a few weeks
clubsport said:
Sounds very impressive cyberface, did the engine need any additional strengthening or was the conversion more a factor of new mapping for fuel ignition.
i drove a modified rs with 300 odd lb ft once,,,didn't feel that fast until you noticed the speedo....
No - it's a simple bolt on conversion. There's an additional injector just after the charger output, controlled by a piggyback ECU to add extra fuel. The original ECU is retained for everything else.
9m reckon there's more to come if they then remap the original ECU in tandem with the secondary ECU - this is a load of rolling road work to get the curves nice and smooth. I believe another PH member with a bright yellow supercharged 993 is about to have this done (Colin).
As you say - it doesn't feel like a nutter fast car, until you come to slow down and realise you need to use more brakes
A change of pads and better cooling is probably next on the agenda - I can't make loads of suspension changes because I have to deal with humps in the road around where I live...
porktastic said:
The whole point for me was the 'stealth' option
'Stealth' in a Porsche
yeah, fair enough. But a 10 year old 993 (standard) isn't quite as lairy as anything with a GT2 wing, or a 996 with a GT3 bodykit. Personally I think a aventura green 993 is actually quite subtle compared to many modern cars. Then again, this may be due to where I live
abarber said:
Have you got an intercooler? What boost is it running. Very interested in this.. could be costly at some stage.
Cheers, Al.
It's a low boost setup, no intercooler or compression reduction. I think it's running 6 psi.
There are upgrade paths available i.e. smaller pulleys and higher boost, but you'll need the intercooler and perhaps lower compression. Mine is only putting out 330 bhp so it's not a massive power increase.
The intercooler will require a big spoiler though to fit. Check out the rennlist 993 forums, there are a few guys in the States who have had intercoolers fabricated.
Japslapr said:
What supercharger are you running? I have the Eaton M90 running 15psi on a 231 ci 6 cylinder. Is it a roots type blower? I saw the change the pulley's and thought that you might be running something similar to mine. What is the compression ratio of your motor?
It's definitely an Eaton blower but not sure of the exact model. Check my profile for a picture of the engine bay
Compression is not changed from standard, which I believe is quite high anyway (more than 12:1). That's probably the limiting factor in further upgrades. An intercooler may help, but will require bodywork changes.
Does anyone know whether a compact water injection kit could do as good a job as an intercooler without taking up so much room??
Yeah... that looks like the m90. You're definitely limited to how much boost you can run with that high of a CR. I'm running almost 16psi but have a 8.5 compression ratio motor. How much room do you have to work with under there? We have two different types of Intercooler's available for the M90. one of them is only 1" thick. Keep in mind that it is designed for a Pontiac Grand Prix intake manifold. But you could use the core and have a manifold fabricated. Here is the link to the site <a href="http://www.zzperformance.com/zzp/products/engine/short_stack_intercooler.htm">www.zzperformance.com/zzp/products/engine/short_stack_intercooler.htm</a>
We have a couple of guys running alcohol and water injection. It does help but not quite the same as an intercooler. It's also not as convenient (can't use it all the time).
I don't know if this helps any. But if you're really looking to get that thing cooled, it can get done without sacrificing too much room.
Here's my set up.
[IMG]http://img.photobucket.com/albums/v495/Japslapr/GTP002.jpg[/IMG]
[IMG]http://img.photobucket.com/albums/v495/Japslapr/Oilleak012.jpg[/IMG]
>> Edited by Japslapr on Friday 5th November 23:27
>> Edited by Japslapr on Friday 5th November 23:36
We have a couple of guys running alcohol and water injection. It does help but not quite the same as an intercooler. It's also not as convenient (can't use it all the time).
I don't know if this helps any. But if you're really looking to get that thing cooled, it can get done without sacrificing too much room.
Here's my set up.
[IMG]http://img.photobucket.com/albums/v495/Japslapr/GTP002.jpg[/IMG]
[IMG]http://img.photobucket.com/albums/v495/Japslapr/Oilleak012.jpg[/IMG]
>> Edited by Japslapr on Friday 5th November 23:27
>> Edited by Japslapr on Friday 5th November 23:36
A few answers:
The 9m/TPC kit uses the Eaton M90 blower running at up to 6.5psi (rpm dependent) on standard engines.
The compression ratio of the 964/993 are quoted by Porsche at something like 10.9 or 11.0:1, but in practise we have measured the compression on many 964RS engines (whilst blueprinting/rebuilding) and found them to be as low as 10.4, so the production 964 & 993 is unlikely to be more than 10.5:1.
In low boost installations like this, you should regard the blower as no more than an intake tuning device. What do I mean by this? As an example a perfectly mapped/cammed 964RS with our Motec +1 package will make between 330-340bhp at 6250rpm, i.e. much the same as a supercharged 964 or 993. Therefore at this rpm point, the +1 intake system/cams are producing the same volumetric (cylinder filling) efficiency (V.E.) as the supercharger, which we find is around 25% above atmo or the equivalent of 3-4psi of boost. The boosted engine actually makes a little more power with it's 6psi, but some of this is used to drive the blower. The best interpretation of this observation is that the supercharger is achieving 125% VE right across the rev range, i.e. fills the cylinder to perfectly tuned capacity from 2000 to 6500rpm, rather than just at one RPM point like the +1 atmo engine. Thus the engine is no more stressed than a perfectly tuned standard engine.
If the boost is increased more than 6psi there are signiicant temperature increases in the compressed gas, therefore intercooling would be essential to get rid of the heat build up. We can make a chargecooler (air/water/air) that will fit under the stock engine lid and run the dissipating water radiator at the front of the car (like the 996 installation) but the cost of this would end up at around £1500-2000 fitted.
I hope this helps!
The 9m/TPC kit uses the Eaton M90 blower running at up to 6.5psi (rpm dependent) on standard engines.
The compression ratio of the 964/993 are quoted by Porsche at something like 10.9 or 11.0:1, but in practise we have measured the compression on many 964RS engines (whilst blueprinting/rebuilding) and found them to be as low as 10.4, so the production 964 & 993 is unlikely to be more than 10.5:1.
In low boost installations like this, you should regard the blower as no more than an intake tuning device. What do I mean by this? As an example a perfectly mapped/cammed 964RS with our Motec +1 package will make between 330-340bhp at 6250rpm, i.e. much the same as a supercharged 964 or 993. Therefore at this rpm point, the +1 intake system/cams are producing the same volumetric (cylinder filling) efficiency (V.E.) as the supercharger, which we find is around 25% above atmo or the equivalent of 3-4psi of boost. The boosted engine actually makes a little more power with it's 6psi, but some of this is used to drive the blower. The best interpretation of this observation is that the supercharger is achieving 125% VE right across the rev range, i.e. fills the cylinder to perfectly tuned capacity from 2000 to 6500rpm, rather than just at one RPM point like the +1 atmo engine. Thus the engine is no more stressed than a perfectly tuned standard engine.
If the boost is increased more than 6psi there are signiicant temperature increases in the compressed gas, therefore intercooling would be essential to get rid of the heat build up. We can make a chargecooler (air/water/air) that will fit under the stock engine lid and run the dissipating water radiator at the front of the car (like the 996 installation) but the cost of this would end up at around £1500-2000 fitted.
I hope this helps!
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