RR

Why doesn't any tuner use any of the parts from Porsche Motorsport to modify the GT3 engine.

In particular I am talking about the intake that is on the RSR. The intake on the RSR has 6 throttle control valves - 1 for each of the 6 cylinders, and along with cam mods and ECU mods and air intake mods allows the motor to run up to 435HP.

In October issue of EVO they have an article on Porsche Motorsports. The 3.6L motor is good for 10,500rpm's and almost 500 normally aspirated power.

I have posted this question before, only to get people telling me that the RSR and cup cars need their engines broken down after every race etc etc blah, blah.

But I don't see why or how putting an intake like this would jeopardize liability.

FVD sells intake manifolds for the 964's (6900 Euros) which combined with new cams, and ECU gives another 30HP.
Further the new M5 has 10 throttle control valves for each of its 10 cylinders - and I know that, that engine wont need to be broken down every few thousand miles.

Does anyone have any legitiamte answers to this? Or is it just too expensive to do?

Mr. RS

I spoke recently with one of the teams running the Porsche Cup Cars here in the UK about engine rebuilds. Porsche state that the race engines need to be refreshed after 25 hours running. One of the cars they look after had just reached this so they took it apart.

Nothing needed replacing. At all. The engine was making more power now than when it was new and revved more freely.

They just bolted it back togeather and stuck it back in the car.

Therefore, it would seem reasonable that you could mod the car in the way you describe in terms of longevity.

I beleive the problem would be in drivability, RSR's etc are designed for racing, not stop start traffic conditions.

True, you could reprogramme the ECU but then I suppose it just comes down to cost.

Question is, do you really need the extra 35hp over the GT3 or would the money be better spent on good driver training?

Over too you.

P.

RR

Thanks for your response, that is really interesting and certainly a testament to Porsche engineering.

Your last point makes a lot of sense too. But sometimes the modding, new spoiler, interior upgrades, exhaust etc. becomes a bit of a hobby.

Would I ever need the extra 35HP probably not. But do I really need a GT3 in the first place when any other car can get me from Point A to Point B, probably not either.

But the GT3 is more fun, lets me really take advantage of that rare track day, and the extra 35HP would be fun too.

I'm still curious about it and would seriously consider it, if it was available.

Karl S

I think there are two main problems with the mods you are suggesting:

1) Emissions - the RSR intake is designed for maximum power with no worries about emissions compliance. It makes no accomodation for a MAF, for example. The DME fuel maps are not designed for this intake. In all likelihood, this will negatively impact the emissions of the car

2) Driveability - Modern Porsche engines are highly engineered systems, with all the parts designed to work together and in conjunction with computer controled throttle, air/fuel mix, etc. If you change a major component, such as the intake, without changing anything else, you are liable to run into unexpected problems resulting in poor driveability in certain conditions.

The old days of simply bolting on a few aftermarket parts and getting big HP gains are long gone, I'm afraid. At least with respect to Porsches.

Karl

Steve Weiner-Rennsport Systems

Hi:

In the spirit that with enough money ANYTHING is possible, one certainly could fit one of the 6-throttle, CF intake systems from a GT-3R or RS.

That said, the ECU would need totally different mapping or a conversion to MoTeC (using street GT-3 or Cup cams) and would not be OBD-II compliant.

In short, it would not longer be street legal so this mod is best suited for a track/race car only.

As Karl so wisely said, these engines are VERY complex, highly engineered systems that preclude simple modifications without making many other changes (even using all Factory parts).

Dare I say this, but someone could aquire a complete GT-3R or RS engine and do a nice conversion that could be backwards compatible,... In that fashion, one would have the HP (oh my) and be able to retain OBD-II compliance by reinstalling the original GT-3 motor.

Karl S

Steve,

Great idea. You'd really have to keep the original GT3 street engine around so that you'd have something to use while the R/RS engine is getting a $25K rebuild after every 25 hours or so of use Now, of course if you own your own shop and could do your own engine swaps and rebuilds ... all of a sudden it starts to actually look practical!

Karl

macfly

My $.02 worth is you'll go faster with tires and suspension upgrades than more power.
I still think the GT3 is plenty fast enough for me!

Yargk

I remember some rumors about using those six throttle bottles just after the GT3 came out and that a few European tuners were trying it. Supposedly they were good for more than a couple ponies. Although I think the car doesn't really need that much more power (if I had one, I'd shave weight off and fiddle with the suspension), I think this is an interesting point since I haven't heard of anyone actually going to the six throttle bodies even though there was discussion about it previously.

Steve Weiner-Rennsport Systems

ROFL,..Clearly, you've never driven a GT-3R or RSR.

That additional 100 HP and close ratio gears makes it addicting,......

NJ-GT

At a recent track day, a GT3R could not pull away from my car. The owner was revving to 7500rpm, because he was told that the engine will last longer that way. So far he has the entire year running that engine without problems. However I was able to rev 8200rpm with piece of mind.

Steve Weiner-Rennsport Systems

A good driver always makes all the difference on the track but pull those restrictors on the race car and its a different story, all things being equal (especially with a GT-3 RSR),.........

That gent received good advice as it does last a lot longer when you do not rev it to redline all the time.

That applies to ALL of these cars.

Steve Weiner-Rennsport Systems

Yargk:

This issue is all about throttle response when using long duration, narrow lobe center cams and having a single throttle per cylinder makes a huge difference here.

I too, would rather spend the $$$$ on a set of Motons and a good set of close-ratio gears. Those two things will make a FAR bigger improvement in overall performance both on the street and on the track.

Kevin

RR;

I have purchased a GT3R engine.. It has been a nice experience seeing what Porsche has done. The GT3 Engine is similar, but yet vastly different. I have taken a different approach and am turbocharging it. However, with the changes I have had the chance to get camshaft specs, piston specs, crank, rods, valve sizes and port configurations.. All this data can be used to build a stout GT3 engine that can go longer than the 80 hours... `

Phokaioglaukos

I know where to get Motons, but what is a good source for close-ratio (and lower geared) gears for the GT3?

How do you compare Motons to the GT3RS suspension bits?

Steve in FL

Guard Transmission and Porsche Motorsports are sources for GT3 gear sets.