Starting build again

[philsrb]

After a long pause with my build, i am starting again!
Currently i am looking for the gearbox choices, it seems that this is not as easy as i first thought!
In the beginning i wanted a gt3 tranny, due to a much more limmited budget at the moment i am thinking of cheaper options.
Only criteria is that id want a 6speed cable shifter.
From what i concluded reading the forums, choice comes down to 996 and 997 gearboxes.
What about those? Which ones are recommended?
From what i can see longer gears would be a wise choice since our engines have a lot of torque and wheelspin doesnt exactly help...
I have found very cheap gearboxes which are 96.00 and 96.30 if i remember right.
The turbo equivalents are a lot higher priced (almost gt3 prices)
Pdk trannys are cheap,i doubt thst those csn be programmed for our engines though...

[AlexCim]

I bought my transmission off the factory, it is a G97/01, which they suggested even for a 720hp car. I have a Quaife LSD installed too. Seems to work well.

I am going to change the gear ratios myself. 1st is useless, and 7200RPM in 6th is 295km/h (that's gonna piss me off). I am probably just going to change final drive ratio to something lower than 3.44 rather than mess with anything else.

[Steve_D]

I have a 6 speed and, like me, you will find you don't need 6. The amount of torque we have means I normally go up the 'box two at a time. Even a four speed would be fine.

Steve

[F.C.]

Steve_D said:

I have a 6 speed and, like me, you will find you don't need 6. The amount of torque we have means I normally go up the 'box two at a time. Even a four speed would be fine.

Steve

LOL +1 I have a cable shifted G50/52 5 speed and still find myself going around roundabouts in 4th and 5th gear!!
I feel I would like a taller top (currently 210mph) as an overdrive for M/way cruising but totally agree a 4 speed for the road would be perfectly acceptable with the torque and light weight combination of these cars.

[356Speedster]

It's always fun when this topic comes up because it polarises opinion ;-) I think the first thing to say here is there are no right answers because it's completely down to personal preference. When people say the Ult would be OK with a 4-speed 'box, there's a lot of truth in that.... the car's (relatively) low weight and high torque (spec dependent of course) will allow it to pull long ratios, however, it's whether this is the feel you want which will really dictate if this is an option you want to go for.

The G96/30 is just the 4WD version of the Carrera 2 'box, I think. If that's the case, it will have low gearing (c.180-185mph max speed @ the limiter in 6th), it will not be as strong as the TT & GT 'boxes and you'll need to convert it to 2WD. If this is OK for your application, just get a std C2 'box and save yourself the 2WD conversion.

I have a G96/50 twin turbo 'box and personally, I feel it suits the car perfectly. It's got good ratios, so treads the line between giving an edge to acceleration, as well as being good for cruising. I drove it to Le Mans last yr (so pretty much 1,000miles of motorways) and it was fantastic. Revs were low and the engine was barely audible.

When I'm "on it" and I use all the gears it's very rewarding and at no point do I wish it was a 4 or 5 speeder, because the ratios are still fairly wide (by modern car standards). Sure, I occasionally block shift or maybe use only 4th & 6th gears if I'm feeling lazy, but the great thing about the G96/50 is I have the choice depending on my mood. I can hoon it thru' the gears, or just be lazy.

I picked up my 35K miles TT 'box for £2,200 so it was cheaper than a 00/01 'box. Some sellers take the piss on their prices, but hunt one down via a Porsche specialist or Porsche dismantler and you should get a good price on one. Just my 2p worth

[DHGTR]

One of the best pieces of advice I think, is , be honest.

Very very few people will drive their car at 200mph, so what does it matter if your gearbox isn't geared for that. You can tell anybody anything about the car and they won't know any different, so just tell them it does it if you feel the need.
Whereas you will probably do lots of motorway driving and hard accelerating to around 100mph, if doing tracks you may want to be quick up to around 140 -150.

Just understand how you think you will drive it and select a gearbox for those needs.

Dave

[Paul.B]

All I would add is, the G50 (air cooled 911's) series are far more easy to modify/maintain/upgrade. The later 996/997 (water cooled) Getrag boxes are in effect fixed. You can't change ratios and the there is little or no aftermarket support industry. The boxes out of the GT2/GT3 may be different but they are big money.

[356Speedster]

Paul.B said:

All I would add is, the G50 (air cooled 911's) series are far more easy to modify/maintain/upgrade. The later 996/997 (water cooled) Getrag boxes are in effect fixed. You can't change ratios and the there is little or no aftermarket support industry. The boxes out of the GT2/GT3 may be different but they are big money.

The 00/01/30 boxes are certainly more difficult to service, but they can still be opened up & worked on, so they're not completely fixed. The TT & GT boxes are not a service concern at all.

[barriejames]

Hi same thing really as soon to be looking for a box and just wanted to ask what the typical rev range is at say 70mph as I do not want high revs at normal motorway speeds?

[F.C.]

barriejames said:

Hi same thing really as soon to be looking for a box and just wanted to ask what the typical rev range is at say 70mph as I do not want high revs at normal motorway speeds?

IMO you need to get a box with modified 5/6th gear in order to get a relaxed m/way cruise, Mine is geared for 210MPH at 7200 rpm which equates to just over 70 MPH at 2500rpm.
To my mind it would be nice to gear top for 225mph (overdrive) to give 70MPH at 2000rpm
That 500rpm will make a big difference to noise and fuel consumption.
Bearing in mind 4th will still bring nigh on 170mph at standard gearing and 7200rpm.

[philsrb]

Thanks for all those replies...
Just spoke to ultima, they said that the 996 997 boxes are now used for all their new builds, precisely the standard boxes from the c2 porsche...they have had no concern with damaged boxes due to cars weight not stressing the box. Furthermore, it should be possible to change ratio by means of a different pinion option for those.
However for the g96.50 and g97.50 and the gt boxes, the bellhouse is different from the standard ones.

Is there anyone who has any idea about a good and cheap source for 97.50 gearboxes? I am in germany, but i cannot find anything cheap!
Gt3 gearbox i found for 6500€ but i do not want to spend this big money on gesrbox...
On the other hand, the 97.00 i think from rwd porsche is to be found for about 1000€...
Do you think it would be worth spending an extra bit on a 97.50 box?

[UltimaCH]

If you are based in Germany, I would recommend you get in contact with Spatz through here. He has plenty of sensible info and perhaps pointers to a "cheaper" box.

[356Speedster]

F.C. said:

IMO you need to get a box with modified 5/6th gear in order to get a relaxed m/way cruise, Mine is geared for 210MPH at 7200 rpm which equates to just over 70 MPH at 2500rpm.
To my mind it would be nice to gear top for 225mph (overdrive) to give 70MPH at 2000rpm
That 500rpm will make a big difference to noise and fuel consumption.
Bearing in mind 4th will still bring nigh on 170mph at standard gearing and 7200rpm.

My std G96/50 is geared for bang on 200mph @ 6700rpm, so it sounds like we're pretty similarly geared. In my 1,000m LM trip, I found the cruising engine speed to be lower than a normal road car and quiet. Wind & tyre noise were more than the engine noise, LOL! I think it averaged around 30mpg, which included some *ahem* playing ;-) What more can you ask for in supercar, really?!

I really don't get the 200+mph gearing comments around cruising. It's a supercar, not a long distance cruiser, but maybe I just use / see the car differently.

philsrb said:

Thanks for all those replies...
Just spoke to ultima, they said that the 996 997 boxes are now used for all their new builds, precisely the standard boxes from the c2 porsche...they have had no concern with damaged boxes due to cars weight not stressing the box. Furthermore, it should be possible to change ratio by means of a different pinion option for those.
However for the g96.50 and g97.50 and the gt boxes, the bellhouse is different from the standard ones.

Is there anyone who has any idea about a good and cheap source for 97.50 gearboxes? I am in germany, but i cannot find anything cheap!
Gt3 gearbox i found for 6500€ but i do not want to spend this big money on gesrbox...
On the other hand, the 97.00 i think from rwd porsche is to be found for about 1000€...
Do you think it would be worth spending an extra bit on a 97.50 box?

Any Porsche 'box needs a simple adapter plate to fit the LS engine. The TT / GT boxes do have a slightly different design to the Carrera 'boxes (& will use a different rear mount too), but this isn't an issue. There are a few suppliers that can cover this for you, I'd wholly recommend Auto Bionics.... they can supply everything you need, ready to fit with no messing. They usually keep a supply of TT boxes in stock pre-converted to 2WD and ready to go. Plug & play in it's most simple sense.

Alternatively, for a basic 'box alone, as I mentioned above, just get a few Porsche mags and call around the specialists / dismantlers. I got mine from Ramus Porscha in the Midlands, they have a massive supply of Porsche bits ;-)

[cooberpedy]

Hi Phil, it depends on what engine you are going to use.
In case of an LS7,
you don't want to route nearly 700Nm of torque to sticky semis through a gearbox which is designed for roughly half of that .....
So, why would you think a company like PORSCHE uses different types of boxes for their GT and turbo cars... not for economical reasons for sure!

In my opinion, only the tt and GT boxes are up to the job.

If you want one, i have a G96.50 spare (relatively cheap ).

Cheers
Cornel

[ezakimak]

AlexCim said:

I bought my transmission off the factory, it is a G97/01, which they suggested even for a 720hp car. I have a Quaife LSD installed too. Seems to work well.

I am going to change the gear ratios myself. 1st is useless, and 7200RPM in 6th is 295km/h (that's gonna piss me off). I am probably just going to change final drive ratio to something lower than 3.44 rather than mess with anything else.

I was speaking to a local gent who races Porsche GT3’s as he had a couple of boxes for sale. He said that even at tracks like Philip Island they only 295km/h down the straight. Its probably only Bathurst and Tamora air field where you could top 300km/h here. Apart from the relaxed crusing revs you would get with an overdrive for 6th gear I can’t think if any other reason why you would want the 300km/h ++ top speed. To this end I think I would go for an over drive 6th rather than a final drive swap. Just add more down force then you won’t need the high top speed anyway.

Ryan

[UltimaCH]

Hear, hear...

[cooberpedy]

Just for the record:
This is how revs/speed will be with a G96/50 in an Ultima!

[845ste]

wow!
but with g50/52 - turbo 5 gear???
it would be interesting to compare.....
thankss

[Storer]

Dom

How about re-posting that fab spreadsheet you did for gearboxes to help new builders?



Paul

[Ult-Jim]

I found it under Ultima Stickies, Ultima FAQ here at bottom of first page
http://www.pistonheads.com/gassing/topic.asp?h=0&a...