Little transaxle discussion regarding modification.

[Mike]

So I'm just in the planning stages right now, trying to figure out which kit is right for me and such...

I'm kind of stumped on which transaxle to go with. Right now my brain is thinking Ricardo, but with the kind of bhp I want to make (900+) I'm afraid that even this box will need a good upgrade...which got me to thinking if this huge heavy beast was actually necessary. So my question to anyone with a little knowledge is...

Which transaxle, excluding Ricardo, is capable of supporting 900+bhp with upgrades but yet be in a smaller less bulky case than a Ricardo? To add, similarly in price.

My thought process here is if there is another transaxle that wieghts 3/4 the wieght and can still hold up to the power reliably then why not...i'm already going to be rear heavy with a dohc in there...

 

[Eric A.]

The only one that I can think of would be a beefed up 930. Some of the race boxes might be useable but I don't know how they would be for street use.

 

[Rick Muck- Mark IV]

Hewland LG will do it, but not sure you would want one (price and lack of civility)

 

[Tom]

I think the reality is that with a relatively light car like a GT 40, your traction will be the limiting factor in at least the first 2 to 3 gears. Tires will break traction before you ever get close to laying down 700 ft-lbs of torque.

I doubt the Ricardo will cause any problems, given that it was designed with a sizable safety margin delivering 500+ ft-lbs in a 3500 pound car. If you want something different, the 930 is a strong 'box, as is the G50 50/52 (rare) and the G50-86 (GT2/3/Cup Car) 6 speed. I suspect that on the G50 series, builders would recommend a billet side plate, and a pump/cooler. All of which can be provided by GBOX, Coppins, CMS etc.

Good luck.

 

[BruceA]

Toms right, you will be smoking the bags in most gears with that sort of power. Have a look on Youtube for the vids on the Turbo Ford GT and see how they have over 1000 hp (crank) and see how the car performs there. They dont seem to have any issues with the gearbox.

 

[Cliff Beer]

900hp in a 2WD vehicle of 2500lbs is really only helpful at say 100mph+ Up to these faster speeds 500-600hp will get you there just about as fast given the inevitable wheel spin. You must be planning on doing some very high speed driving.....?? In which case I would be as concerned about aerodynamics as the choice of transaxle.

In any case, the Hewland LG will take it. If you're planning on doing some drop clutch burn outs with 900hp then I doubt any of the porsche transaxles will take it repeatedly without choosing the strongest (probably 930 turbo) and performing the mods indicated above. Even then, no guarantees about longevity.

That's an awful lot of hp. Not many drivers are capable of putting such power to the ground without killing themselves in the process!

 

[Mike]

Appreciate the replies i'll look into some of the suggestions you have given.

900hp in a 2WD vehicle of 2500lbs is really only helpful at say 100mph+ Up to these faster speeds 500-600hp will get you there just about as fast given the inevitable wheel spin. You must be planning on doing some very high speed driving.....?? In which case I would be as concerned about aerodynamics as the choice of transaxle.

In any case, the Hewland LG will take it. If you're planning on doing some drop clutch burn outs with 900hp then I doubt any of the porsche transaxles will take it repeatedly without choosing the strongest (probably 930 turbo) and performing the mods indicated above. Even then, no guarantees about longevity.

That's an awful lot of hp. Not many drivers are capable of putting such power to the ground without killing themselves in the process!

I do infact, got me. Looking to compete in standing mile events. In which case gearing and aero all come into play. It sounds like the ricardo may be the best viable option available right now.

Oh trust me i've tried to put down about 800ish (crank) to the ground with a heavier car (3500lb) and it just wasnt happening with street tires. Definetly not something anyone can just go out on a whim and do. Realistically with this project 900ish isnt for street driving its no where near practical, but thats the beauty of turbos.

 

[Cliff Beer]

Ah, got it. Yes, in that case if you want to compete in standing miles like the Texas Mile then you're going to need serious hp and aero. Will be tough to beat Joe's twin turbo Ford GT or the hennesy GT - both are cranking out well over 1,000hp.

It seems like the limiting factor for this kind of thing is the contact patch, assuming you have decent hp and aero. Four wheel drive will get you going faster to about 120 or 130 or so. The Veyron does such a nice job over the mile because it has all three (4WD, hp and aero) in stock form.

Is there some kind of blown small/big block V8 out there with 4WD???

 

[Erik]

A very common question, which gearbox will hold and handle 900 HP without breaking.

Well I would have to say your best bet would honestly be the Ricardo, but since you would like to explore other options, I would have to then recommend that you go with a G96.96 which would be a GT3 gearbox. I would certainly recommend that you install a better pump and cooler with this gearbox, so in reality a GT 2 gearbox would be better as you would not need the pump and cooler from the GT 3.

I have one of these that could be modified to handle the kind of HP you are talking about. We have seen these handle 1100HP in the Mosler cars, and should be able to handle 900 HP just fine for yours.

I would further recommend that you have the internals Cryogenically stress relieved as well as REM Micropolished to reduce the friction created in the gearbox, as well as give the internals the best strengthening options out there. This will allow for cooler operating temps, as well as less driveline loss.

Here is what you should consider though as this would not be a cheap option.

G96 gearbox with upgraded OS Giken Limited Slip Differential, (the only differential that will handle this kind of HP in my opinion) Inverted, with Cyro/REM, Cooler in and out fittings installed, Taller Porsche Motorsport 5th, and 6th gear sets, with gear oil.

Price, you better sit for this one. $17,875.00 plus shipping.

Benefit of knowing that you wont die at 200 plus mph due to gearbox failure- PRICELESS.

There are some less expensive ways of building this gearbox, but I would not recommend them if your goal here is to actually run this car to it's maximum speed, which I am not sure is aerodynamically possible, but you would know more about that then I do.

Regearing this gearbox will give you a top speed at 7000 RPM with 335/30/19 tires of 209.292 MPH

I hope that this option is at least helpful in the respect of showing you what it would take to build a gearbox to do what you are asking it to. While the Porsche option is lighter, and just a bit smaller, it is a pretty expensive option, one which not too many wallets can endure. LOL.

Let me know if you have any questions that I can help you with on this one. We do a lot of these gearboxes so I know quite a bit about them.

Comparing apples to apples here though I think you can see that perhaps the Ricardo option is not as bad as it once appeared. I am sure that Fran Hall can help you with a Ricardo, should you decide to go in this direction, but I am sure that you already knew that.

Warmest Regards,


Erik Johnson
GBox Sales Manager
(303) 440-8899 work
(303) 895-4828 cell

 

[Cliff Beer]

Mike, incidentally, the Ford GT X-1 (roughly 700hp) also uses the standard Ricardo box.

Erik has some great suggestions here. Very gracious of him to take the time to explain the pros and cons, and suggest a bullet proof option.

You least expensive option may be the Ricardo for the time being - I've seen a couple of new ones in the $9,000 range and a couple of rebuilt ones for about $7,000. That's a lot of transaxle for the money!

 

[Mike]

A very common question, which gearbox will hold and handle 900 HP without breaking.

Well I would have to say your best bet would honestly be the Ricardo, but since you would like to explore other options, I would have to then recommend that you go with a G96.96 which would be a GT3 gearbox. I would certainly recommend that you install a better pump and cooler with this gearbox, so in reality a GT 2 gearbox would be better as you would not need the pump and cooler from the GT 3.

Excuse me if I seem clueless, G96.96 = GT3 = GT2 has better pump & cooler? I'm not opposed to the Ricardo idea it just seems like such a huge and heavy piece at first glance I'm hesitant to want to use it.

I have one of these that could be modified to handle the kind of HP you are talking about. We have seen these handle 1100HP in the Mosler cars, and should be able to handle 900 HP just fine for yours.

I would further recommend that you have the internals Cryogenically stress relieved as well as REM Micropolished to reduce the friction created in the gearbox, as well as give the internals the best strengthening options out there. This will allow for cooler operating temps, as well as less driveline loss.

Here is what you should consider though as this would not be a cheap option.

G96 gearbox with upgraded OS Giken Limited Slip Differential, (the only differential that will handle this kind of HP in my opinion) Inverted, with Cyro/REM, Cooler in and out fittings installed, Taller Porsche Motorsport 5th, and 6th gear sets, with gear oil.

Price, you better sit for this one. $17,875.00 plus shipping.

Benefit of knowing that you wont die at 200 plus mph due to gearbox failure- PRICELESS.

haha, yes I would prefer not to die attempting this, as my future wife might not like this idea. Price is really not a huge deal, I mean I'm going to wind up paying around 30k for an almost rolling chassis. Not to mention motor costs and all the other small things that will incur since I plan to attempt something wild.

There are some less expensive ways of building this gearbox, but I would not recommend them if your goal here is to actually run this car to it's maximum speed, which I am not sure is aerodynamically possible, but you would know more about that then I do.

Regearing this gearbox will give you a top speed at 7000 RPM with 335/30/19 tires of 209.292 MPH

I'm assuming in 6th gear? final drive and 6th ratios?

I hope that this option is at least helpful in the respect of showing you what it would take to build a gearbox to do what you are asking it to. While the Porsche option is lighter, and just a bit smaller, it is a pretty expensive option, one which not too many wallets can endure. LOL.

Definitely helpful, how much weight are we talking here? Shaving off weight anywhere I can would be nice.

Let me know if you have any questions that I can help you with on this one. We do a lot of these gearboxes so I know quite a bit about them.

Comparing apples to apples here though I think you can see that perhaps the Ricardo option is not as bad as it once appeared. I am sure that Fran Hall can help you with a Ricardo, should you decide to go in this direction, but I am sure that you already knew that.

To be honest I haven't done a whole lot of research just yet into upgrading and whatnot available for the Ricardo. It's definitely on the list of things to do along with your suggestions.

Warmest Regards,


Erik Johnson
GBox Sales Manager
(303) 440-8899 work
(303) 895-4828 cell

I'm just going to post some of my questions and comments in red above. Huge amount of thanks for typing up all that for my benefit and anyone else who is interested.:thumbsup:

btw, sent a PM about some not-related stuff.

 

[Mike]

Here is a question i couldnt find the answer to, has anyone put a sequential transaxle into a gt40? Or maybe where one might find such a thing at what cost?

 

[Erik]

Hey there Mike,

Okay so here are some answers for you.

The G96.96 is a GT3 gearbox and comes standard with a transaxle cooler. I am not a big fan of the setup though, as I have seen these fail from time to time.

The G96.88 or G96.50 is a GT2 gearbox and 996TT gearbox, they are essentially the same, but do not come with coolers.

The 209.292 MPH is in 6th gear and has a final drive of 3.44 and gear ratio of 0.775. There are some aftermarket gears also available but I would not recommend them given your HP and Torque. Stick with the Porsche Motorsport gearing. This is the tallest ratio currently available through them.

Weight savings is pretty great, the GT2 gearbox weighs in at about 180 lbs, and the Ricardo if memory serves is right about 240 lbs Fran Hall might chime in though with an exact weight which could be slightly less.

Now in reference to your question of a sequential, yes, I am sure that you could do this, however count on at least doubling the cost, and then some to make it hold up. I am not really a fan of this option for your application as it will not add much in the way of saving time in the shifting and could cause potential issues that I do not think that you want to experience at that kind of speed.

Just my .02 cents. let me know if I can help with this.

Warmest Regards,


Erik Johnson

PS in reference to your PM, not at this time, but we will certainly keep you in mind if something changes.

 

[Lynn Erickson]

Hey there Mike,

Okay so here are some answers for you.

The G96.96 is a GT3 gearbox and comes standard with a transaxle cooler. I am not a big fan of the setup though, as I have seen these fail from time to time.

The G96.88 or G96.50 is a GT2 gearbox and 996TT gearbox, they are essentially the same, but do not come with coolers.

The 209.292 MPH is in 6th gear and has a final drive of 3.44 and gear ratio of 0.775. There are some aftermarket gears also available but I would not recommend them given your HP and Torque. Stick with the Porsche Motorsport gearing. This is the tallest ratio currently available through them.

Weight savings is pretty great, the GT2 gearbox weighs in at about 180 lbs, and the Ricardo if memory serves is right about 240 lbs Fran Hall might chime in though with an exact weight which could be slightly less.

Now in reference to your question of a sequential, yes, I am sure that you could do this, however count on at least doubling the cost, and then some to make it hold up. I am not really a fan of this option for your application as it will not add much in the way of saving time in the shifting and could cause potential issues that I do not think that you want to experience at that kind of speed.

Just my .02 cents. let me know if I can help with this.

Warmest Regards,


Erik Johnson

PS in reference to your PM, not at this time, but we will certainly keep you in mind if something changes.

the 240 is the ship weight of the Ricardo. Mine weighted in at 196 lbs with oil

 

[Mike]

Hey there Mike,

Okay so here are some answers for you.

The G96.96 is a GT3 gearbox and comes standard with a transaxle cooler. I am not a big fan of the setup though, as I have seen these fail from time to time.

The G96.88 or G96.50 is a GT2 gearbox and 996TT gearbox, they are essentially the same, but do not come with coolers.

The 209.292 MPH is in 6th gear and has a final drive of 3.44 and gear ratio of 0.775. There are some aftermarket gears also available but I would not recommend them given your HP and Torque. Stick with the Porsche Motorsport gearing. This is the tallest ratio currently available through them.

Weight savings is pretty great, the GT2 gearbox weighs in at about 180 lbs, and the Ricardo if memory serves is right about 240 lbs Fran Hall might chime in though with an exact weight which could be slightly less.

Now in reference to your question of a sequential, yes, I am sure that you could do this, however count on at least doubling the cost, and then some to make it hold up. I am not really a fan of this option for your application as it will not add much in the way of saving time in the shifting and could cause potential issues that I do not think that you want to experience at that kind of speed.

Just my .02 cents. let me know if I can help with this.

Warmest Regards,


Erik Johnson

PS in reference to your PM, not at this time, but we will certainly keep you in mind if something changes.

That pretty much covered all my questions. Thank you so much for taking the time to reply.