Ari,

I was only responding to John's post directly above mine that they do not have the same trannies. I know we've hashed all of this out many times before.

 

I am a bit shocked at the statement insisting that the 911tt and GT2 are the "Same exact tranny as the 996 TT's. The only difference is that the GT2 tranny has a cover plate over the front differential output shaft hole...as well as a seperate tranny oil cooler."
Perhaps you haven't read your SIT books in a long time? I have them both IFO me as I write this to insure that what I write is NOT so grossly incorrect. [911 Turbo MY 2001 PNA 488 120 and 911GT2 MY 200s PNA 495 220].

I realize that most of you don't have these books so, the 911 Tubo book states that the G96/50 is an evolution of the transmission from the 1996 911 Turbo (G50/51). It then lists things they did to adapt the transx to fit the new car. The ONLY upgrade on the new 996tt G96/50 is "stronger and quieter running gear sets". If it is essentially the same as the GT2 transaxle, why then does this same book say, among many other things "As a mechanical locking differntial would have an adverse effect on the PSM system, the 911 turbo cannot be equipped with a locking differential". I don't have the time to bother with each and every difference, but they are considerable. I don't think too many guys here even care, but if you are like me and crazy enough to consider things like buying a spare transaxle, knowing the difference is important.
The 996tt book establishes the technical parameters for the 996tt trans and NO WHERE does it state [as the GT2 book does] that this transx has "*cable shift mechanism * transmission oil cooling * oil pump for oil spray lubrication * asymmertic limited-slip differntial * adapted transmisson ratios with improved strength and acoustic characteristics of gearwheel sets * use of steel synchronizing rings." These are significant and expensive upgrades.

Ari, I hope this helps clarify that there are considerable differences between these two transaxles. There is no substutite for having the books tho, or you will always be at the mercy of whatever people say, and many times it is incorrect.

The feel of the GT2 trans is also quite different. The SIT book doesn't mention how the cable shifter affects the feel of shifting nor how it shortens the throw, NOR how it reminds me of my first 73 RS [back before anyone cared about them] with an 80% LSD. It is not as severe, but if you start off from rest with the teeniest amount of steering from straight, you hear the same type groaning noises from the differential. Probably not acceptable for a regular street Porsche but fine for a track oriented car. It always brings a smile to my face. I must add that reading the two different SIT books convinced me of how special the GT2 is and definitely affected my buying decision. Last, I wouldn't suggest that the GT2 is "better". It is much less sophisticated in feel, but the GT2 feels like a sophisticated and updated good old wild 930 - excatly how I like these cars [and for all you youngsters, the wild old modded 930 felt like an updates and sophisticated 73 RS!]. Apples and oranges. Take your pick.
JR

 

What I was debating you on was your statement that the GT2 had to use a different transmission than the others since the GT2 is RWD..which is not the case. They simply blank the front driveline output shaft hole on the GT2 transmission.

But yes, the transmissions are all the same, except for a few different pieces/parts and part numbers.

Not sure what part numbers you are using above. The actual part numbers for the transmissions are as follows:

TT: 996 300 010 50
X50/Turbo 'S': 996 300 010 55
GT2: 996 300 020 88

Because I wasn't talking about the entire transaxle. I was talking about the transmission, specifically. It's common knowledge that the GT2 has a LSD and the others do not.

Just a reminder; your part numbers above were incorrect..and the fact that the GT2 front driveline output shaft hole is blanked off wasn't mentioned in your manual.

 

Hmmm...something else I just noticed; "Adapted transmisson ratios". I know for a fact that the transmission ratios are exactly the same between the 3 transmissions.

Here are the ratios for both the GT2 and a standard TT...directly from the Porsche Tech manual:

1st: 3.82
2nd: 2.05
3rd: 1.41
4th: 1.12
5th: 0.92
6th: 0.75
Reverse: 2.86


The only differences are the oil capacities due to the tranny oil cooler.

By the way, no sarcasm is meant in this post...I'm honestly curious as to why this discrepancy exists.

 

I just figured out the answer. When they say "adapted transmission ratios", etc..they are talking about upgrades from the GT3 transmission...which is the base transmisson for the GT2.

It seems Porsche used the G 96/88 transmission from the euro spec GT3, and upgraded certain components for use in the GT2. The transmission ratios were changed to match those of the 996TT.

 

There is no difference between the TT and GT2 trans - albeit- the GT2 nose(the cover Scott refers to) is as per the GT3 trans- with the only difference being the ratios(in the GT3) and that the GT2 and GT3 have LSD.The GT2 adds the external oil cooler.
Any and all of these parts are interchangeable.
By simply changing the nose( you do not have to) adding the external oil cooler and LSD you convert TT to GT2.
How do I know--- I have just done it and are about to do another couple.
Various knowledgable people( thru experience) have tried to help you here John Rice-- and you seem to think a 2 minute read of Porsche propaganda see's your understanding( or should I say lack of it) greater than others.The forums have some extremely experienced ,respected professionals, some very knowledgeable amateurs as well as some doubtfull contributors--- but all mostly well intentioned.Spend a little more time soaking in ( and doing some actual research) before going off on a tangent.

 

Excellent post, Red. And I agree 100%.

 

I don't think we'll ever know for sure.

Facts:
Porsche claims "modifed" transmission right next to the $18,000 price tag on X50/S Models....
TT has no LSD, GT2 Does
TT has no cooler, GT2 Does
GT2 tranny will fit and work in an AWD car

Rumors:
The TT was offered with an LSD option in Europe
X50 Trans = GT2 trans - LSD and cooler

Red9: what's the cost of adding the cooler? and LSD?

 

As are cast and forged cranks. But that doesn't make them identical.
Completing that task, even multiple times, doesn't necessarily prove that the two trannies use the same grade of steel for the gears.
If I were a mod that would cost you a 2 day time out. Porsche technical manuals are "propaganda"? And I suppose the posts on this web board are not? Calling John's 996 education investment "a 2 minute read" is nothing more than a slap in the face. I don't know you, and I don't know John, but comparing the information presentations the two of you have provided gives me a strong feeling that John does research, while...

Oh, nevermind.

Jeff

 

It is too bad this becomes a juvenile spitting contest. If I accept the premise a couple you guys insist upon then it is fair to say that the original 1973 911 RS 915 transaxle is actually the same as the regular production 915, right? Whatever. Sure- they are more the same than they are different but..... I will leave it to others who wish to read up on this and if anyone reading this can direct me or anyone else to other genuine information resources, rather than making blanket statements without any technical referenve, I would appreciate getting more REAL education on the subject. Give some detailed facts and resources. That is what I have attempted to do, and I have been screwing around with Porsches since the late 60s and have made it a point to get every Porsche Factory technical book that I have been able to find over this time period. If the Factory lies, so be it, but don't suggest that I am some lightweight that just fell into Porsche and have no idea what I am talking about. Give me facts and resources and I will at least respect what you are saying.

JR

 

We have. I personally posted information taken directly from Porsche Technical manuals to you in this thread. But apparently, unless it comes out of your mouth..you don't want to hear it.

I'm now done trying to help you.

 

I'm going to sell my Gt2, buy a TT and pocket 30 grand, it's the same exact car.

 

No one is saying that.

I believe without a doubt that the GT2 is the better starting platform. Had I been able to afford one along with the mods I wanted install, I would have bought one in a heartbeat. I wouldn't have needed to convert to RWD, I could have used the stock suspension and brakes, and the weight savings would have already been there.

However, when GT2 owners act like it's a "completely different car" than the 996TT, when in all actuality there are very few deviations...with none of them being major deviations....they are only kidding themselves.

 

Interesting thread...I have nothing to add...except...the reason I sold my 1978 930 (RWD w/Andial upgraded turbos and ICs) was because I had trouble controlling the power (e.g., spinning out rounding corners)...AWD all the way baby! Admittedly I am not the fantastic driver that most of you guys are ...just wanting to have controllable power...in a cab.

 

Ya...I've heard those 930's were quite the handful. A totally different animal than the 993 and newer cars.