I am going to 3,8 L with my engine this winter and will have 7600 rpm as max. For those who have done the revised gearing do you have any usefull information before tearing down the gearbox. I will problably use these gears 3,154 2,000 1,560 1,241 1,000 0,829. The gearbox will also have the Paul Guard LSD, oilcooler as GT2/3 and 300M axels from EVO. The car is X50 from beginnig so it has steel syncros on first and second gear. Maybe doing steel syncros on third to sixt gear to? The car is running on 265 and 315 so according to my calculation the top speed would be around 200mph.
Any inputs?

Peter

 

Peter,

Yes I do, talk to Pam or Brian Copans at BMC&G in West Chester Ohio +1 (513) 779-3302. He works on all the Porsche Cup team cars and did all the work on my gearbox.

I did steel syncros but I chose not to do the LSD as that can be very dangerous in the wet!, Brian advised against it. The gears used were all Porsche Motorsports gears from Germany.

Do a search under threads by me and you will see all my post about it. One thing to consider, when you change 1st to a taller gear which is a must IMO, that's the worst of the bunch, remember you will be putting more power through the clutch in first at least that is the case with my GT700 so make sure you take that into account especially if you intend on upping the HP to a GTXXX kit.

I love the way the car drives now, its like a racing gearbox in that you bang through each gear so quickly now, you have to pay attention or you will hit the rev limiter. I lengthened 1st and 2nd and shortened 3rd thru 6th, so the spacing is perfect now and matches the turbo's spot on...no lag here!.

I am going to change 6th myself as it's to short as at highway speeds I am turning way too many RPM's and wish for a 7th gear now....I am looking at throwing in the Ruff 6th gear....good for some 237 MPH...

Ship the tranny to Brian like I did and get him to do the work, he is the best in the business bar none! He is very very busy at the moment with the new 997's so plan this in advance, I would not let anybody else touch my tranny and oh yes it ran me $11K USD with shipping.....not cheap.

Hope that helps.

PS: Mention my name to Pam when you all.

Ben

 

Ben,

Thanks for the information. I am already using the Quaife ATB Differential and i must say that the car feels faster from start and faster on the track. The car will drift easier and feels different but better. I am changing to the lamell differential to se if there is any difference. The pros says the lamell is better on the track. The engine will give around 720 at the crank so i will check the clutch. Ben have you done any acceleration test from 60-130?

Peter

 

Peter,

No, I have not done any test's as I am still waiting for the MAF fix for the GT700. I am also dropping my tranny in the next month or so as I am having slipping problems with my Tilton/Wevo setup...have to figure out what the hell is going on with that. I can have that tranny out and back in, in like 4-5 hours...blindfold.... I have done it that many times..

Ben

 

I have blown and rebuilt my X-50 tranny, the myth of steel synchros in this "upgraded" tranny is in fact a myth. All the syncro are brass, seen em myself. I replaced 3-6 with steel syncros, one and two were ridiculously expensive and at my track not really needed.
Ben is the expert, but just my 2 cents from my tranny problem.

 

Thanks Tom but I would not call myself an expert.. ........Brian Copans would take that credit and you are quite right, it's all too bloody expensive..oh well I guess that's the price of admission...right..and we love being admitted or is that committed to the loonie bin

 

You need this!

http://www.pistonheads.com/sales/119373.htm

I thought Marky boy would have been interested in it!

 

I'll take two while we are at it..... ..would be very nice to have Steve.

 

Hey you know it!

Everything about the porker is cool, but imagine one of these as your box.

If it was £7/8k cheaper would definate go for it! but that's a lot of dosh to justify 4/5 track days a year, lol

looks awesome though!

 

Jean has a similar transmission. $26k US is a hefty price tag.

Craig

 

Hi Craig, so very similar costings as this is 14k sterling, expensive piece of kit.

I take it Jean benefits with this on track?

 

Yes, Jean is an experienced track driver.

I would consider such a transmission for half the price (e.g., $13k), but I simply cannot justify $26k (even though it would probably increase my whp by more than 50).

Craig

 

PV

IMO if you raise your redline then you do not need to change gearing, the gearbox configuration of these cars (gear ratios and HP curves) makes you go fastest when you shift at redline, the higher it is the better. The best you can do for performance (not engine health though) is to shift at redline or close to it. I would save the money in highly tuned TTs except if you have a particular track configuration in mind, and competition you want to blow their socks off.

This sequential gearbox is excellent for that purpose..or a quartermile

You do benefit a lot from the fast shifts, especially if you have it well installed and can shift with your foot flat down, which I don't, since I did not get a chance to fit a small part required yet.

FWIW my gearbox is different from this Holinger, it was a one off production, modified by Ricardo (GT Ltd) the Veyron builder, and F1 and many other series in the UK, it was built for Roock's 993GT2 for Le Mans and then for Konrad.

The cost new was 45K Euros (58K USD), hardly justifiable for anyone other than competing for a world title!!
Obviously I did not pay that much, the deal was closed in a supermarket next to the track when I offered to buy a chocolate to Konrad who did not have change !

Upgrading a TT gearbox with steel synchros , stronger gears, custom ratios etc.. would cost you close to $12k for a top notch job + the cost of the original gearbox. If this sequential Holinger has all that including cost of the box itself, I would say sell your stock gearbox for 4-5k USD and buy the sequential by adding another $15k instead of $12k, but this gearbox is definitely far fetched for 99% of us.

Craig I still owe you a response I think.. sorry for that.

 

Thats tempting. Problem is that, even with $5k for my tranny, I would still have to fork over an additional $21k for the Hollinger. I'd pay $15k for the Hollinger tranny. In fact, I will pay $500 to anyone who can broker the deal for me.

Craig

 

Steve sent me that link too... wow.... Im having fun at 8K rpms... like Jean said... if u raise ur rev limiter u dont need shorter gears....
markski