Anyone done 3.8 conversions on the 996 Cups here?

 

Very common cheat in Porsche Open series... worth torque and some hp!
JM

 

But this is official, no cheat! There are people who do 3.5L conversions also, to jump down a class..

 

We've done a few...3.8 GT3R engines...the cup conversion is almost the same thing. What do you need to know??

 

Durability vs. how much you can tweak out of it. I'm interested in how the engine would last in 24 hour sessions.

 

Magnus

Last month during our 24 hour race there was a 997 Cup that was about 3.0 seconds faster than our fastest lap, and about 1.5 seconds vs. the fastest, pro driven (Lechner, etc..) 997 Cup, it was driven by the Supercup Bleeckmoolens family if I am not mistaken.

The car came first among the Cup cars at the end of the 24 hours race, and second overall, ahead of several 997RSRs.

After some investigation we found out that it has in fact a 3.9 ltr engine built by "Schmirler" in Germany, which is no one other than the reputed RS Tuning. So yes, they were very reliable, however, a very high budget and extremely fast 997 RSR with a 4.0 ltr engine, that was driven by Uwe Alzen, had numerous pit stops, both for fueling and heat related issues in the gearbox as well as engine it seems, I could not confirm this though, but obviously this hampered the final result.

 

Interesting, 3.9 will not be the target here. 3.8 should do enough. Though I wonder how much you should target to punch out from the engine and with what reliability you get it.

Nice work with the 3.9 engine. I presume they took RSR suspension parts also?

Regarding the 4.0 RSR, I thought Uwe got his engine from Schmirler also?

 

Magnus

I guess if the 3.9 made it, the 3.8 should as well, it is the same displacement as the RSRs. The key is having someone with the experience in building such engines for endurance racing, bearing in mind that the Cup cars themselves have to be thoroughly prepared to make it until the end of the race.

Alzen was driving for the Oktanas team together with Marc Benz as well, I am sure against a heavy sum of money as the team is very well funded. The car was prepared in Lithuania I believe, I highly doubt that RS TUNING was the builder (they could well be though). The engine was putting 540 BHP.

 

Jean, do you know how the 3.9l was achieved?

 

No problem with the rest of the car, it's just the engines power vs. running hours that would be the question. It should run a complete season so it's essential. Anyone got figures?

Lot of things can be said about Oktanas. Nice for them to get drivers like that.

 

Geoffrey, sorry I have no idea, it was kept very hush hush.

Magnus, according to Konrad's techs who worked with us, the 24hours is looked at as the equivalent of a full Carrera Cup season more or less. The budget per car is also similar to a full year season including a spare sequential gearbox.

As for Oktanas, at least the money is being spent on a good cause

 

Can imagine the 3.9 being done somewhat the same as Manthey conversion? (Honestly, I've got no idea, never seen a track 3.9 engine. But it's a guess)

I was hoping for up to ~48 running hours. Luckily, the ridiculously expensive sequential will not be used. Rather a standard one to keep things in budget. No secret taps with unlimited money here...

 

There is absolutely no reason for the 3.9 conversion to be any more than the 3.6 when you need to do a rebuild... The 3.8 is actually a Porsche conversion (we considered it on my 996 GT3 RS sequential at the last rebuild). the 3.9 was LESS expensive than the 3.8 because the pistons are cheaper but most importantly the con rods are MUCH less... I think that cost is really more related to revs than displacement. I know on my car that limiting it at 8300 vs 8500 we get MUCH more life than others who use the last 2-300 revs - I know for a fact that at 8700 you cannot get more than 30 hrs. At 8300, my engine has 32 hrs and is still strong...

If you can run a bigger displacement, I'd get the Schmirler conversion - he's a very reasonable - we got out 10,000 Euro silencer from him to pass UK noise tests and it robs of 0 hp which shows his quality!

JM

 

Nice, thnx for input.

 

JM, the 997 Cup I was talking about was prepared by Reinhold, I doubt he has used anything other than Mahle for his conversion, which brings me to the question that it might have been a 3.8 and not 3.9, what you say makes perfect sense.

I also agree with shifting a few hundered RPMs lower for a 24 hour race, it can make a difference.

As to the Schmirlers being reasonable, you must be a very very good customer of theirs to have such an opinion