New Transaxle Comparison / Discussion Thread

Hi Dom,

In the spreadsheet, the column "length from housing to flange",
Is this a measurement to the centpoint of the drive flange to the "front"
or plane of engine mount of the gearbox?

Thanks
Eric
 
Tom, pls make me a favor,
I feel that the torque capability of many transaxle is really optimistic and does not take care of the impact factors.
Pls add to you spread sheet the following parameters, they will help to find the lyers:
1) Constant torque capability 880 Nm
2) Peak torque capability 1.250Nm
3) Output torque peak capability 9.000 Nm
4) N° of bearings supporting the shafts 3 + 3
5) Shaft center distance 85 mm
6) Width of the gears 22 - 26 mm
7) Modules used 2.5 - 3.0
8) Helical angles used 24 - 31°
9) Crown wheel diameter 235 mm
10) Material and heat treatments used on the gears 16NiCrMo12 Tremped and under low pressure carburised 3 times

I will keep my thoughts for my self by reading those numbers, but let us see who feels confortable to fill this data sheet.
I start
Hello Wanni,

This information that you request is of a highly technical nature, and some of it may only be known to the gearbox manufacturer.

I also would like to know of some of these specifications.

However, for the discussion of this forum, the main point is to compare the installation and overall basic parameters of the gearbox.
The design level parameters you seek will be difficult to find.

I also agree that the torque ratings of the gearboxes may be optomistic estimates only. And each gearbox may fail in a different manner - gear tooth failure vs beraring failure vs case distortion and binding failures, etc...

Anyway, I hope to have your continued input and learn more.

Cheers
Eric
 
Eric,

Thanks. Main face of transmission where it bolts to the bell housing to the center line of the flange.

I hope that is OK for all, and dimensions were taken off published drawings.

Best
Dom
 
Guys,

My appologies, but I have been traveling a lot lately, and will add the Elite transaxel to the spreadsheet as soon as I can.

Ron, the comparison was done without bell housings.
The 930 info was given to me so I took it for someone who measured it.
Does anyone have the exact dimensions without bell housing?

Best
Dom
 
The bell housing is part of the transaxle case on all porsche transaxles, so there can be no measurement ''without'' bellhousing.

Since for most of us the distance the ''bolt on bellhousing'' adds will be very important information, can we add ''length of bolt on bellhousing'' to the spreadsheet?
 
Mesa,

Thanks for your comments.

I remember an exchange between two suppliers, one showing a replica bell housing (10 mm) and one showing a shortened bell housing (50 mm).

That says to me that numerous bell housings with different dimensions are available on the market.

Can anyone provide any guidance on this one please?

Thanks
Dom
 

Russ Noble

GT40s Supporter
Lifetime Supporter
Dom,

I think the best you can do is note whether the measurements include a bellhousing. For those that don't, the input shaft length then becomes a critical dimension.

Cheers
 
Russ,
The - bellhousing - output shaft - clutch - flywheel - measurement interaction 'give and take' is a bit of a mistery to me. Can you or anyone here give a 'class' on the cause and effect of the variables and possible pitfalls?

Thanks
 
Hello Wanni,

This information that you request is of a highly technical nature, and some of it may only be known to the gearbox manufacturer.

I also would like to know of some of these specifications.

However, for the discussion of this forum, the main point is to compare the installation and overall basic parameters of the gearbox.
The design level parameters you seek will be difficult to find.

I also agree that the torque ratings of the gearboxes may be optomistic estimates only. And each gearbox may fail in a different manner - gear tooth failure vs beraring failure vs case distortion and binding failures, etc...

Anyway, I hope to have your continued input and learn more.

Cheers
Eric
Hi Eric, you are on the right way.
My wish was to bring the stories at the surface, but I could not.
Remember....I have been the only one declaring all those matters....risking an on run adjustment of my competitors. But still any declaration has been made.
Ask to your selve....why so many secrets when someone has any????
Ciao
Wanni
N.B.
Check the picture.

A BUON INTENDITORE::::pOCHE PAROLE.
 

Attachments

Russ Noble

GT40s Supporter
Lifetime Supporter
Russ,
The - bellhousing - output shaft - clutch - flywheel - measurement interaction 'give and take' is a bit of a mistery to me. Can you or anyone here give a 'class' on the cause and effect of the variables and possible pitfalls?

Thanks
Mesa,

In the context that we are talking, i.e. will it fit a GT40, the following needs to be considered.

Space is tight! The position of the transaxle is generally dictated by the wheelbase of the car which is pretty much fixed. The output shafts of the trans, ideally, want to lie on the centreline of the rear wheels. The forward position of the motor is dictated by the cockpit firewall therefore the position of the rear (bellhousing) face of the motor is also defined that way.

Given that there is a practical limitation as to how far forward the motor can go, then the distance from the rear of the motor to the centreline of the output shafts becomes critical.....

You can crib a bit by having a 'powerbulge' in the firewall to accommodate the waterpump (or use a remote electric w/p) and you can also mount the trans slightly rearward so the driveshafts run forward at a slight angle towards the wheels. Some would say that's not good, but within reasonable limits, for practical purposes, I would disagree.

But the critical dimension is from the output shafts to the rear of the motor which is why the bellhousing or length of input shaft must be taken into account.

You also asked about clutch and flywheel. Obviously there has to be sufficient space in the bellhousing to accommodate flywheel/clutch/release bearing. Some trans with integral bellhousings use moderately small diameter flywheels e.g. Porsche. Which means you can't use a normal Ford flywheel and starter because it's diameter wont fit inside the bellhousing so you have to go with a generally more expensive custom setup. But by the same token it should be lighter. Not all bad.......

Hope that clarifies things a bit for you.

Cheers
 
My ultimate favorite is the Porsche GT2 with a GT3R mainshaft.

Details:

-6 gears.
-Cable side shift, no rod or end linkage.
-Uses G50 style clutch components and drive flanges.
-Use of the GT3R mainshaft gives a 3.1 1st gear ratio and allows a removeable 2nd of any ratio to be fitted.
-Nice 0.75 ratio 6th gear.
-Handles well up to 700 + hp and more as proven by many Ultima builds.
-Stock Porsche motorsport LSD.
-Integral mechanical driven oil pump.

Price => $13500, with inversion procedures and oil pump modifications to allow braided oil lines for cooler fitment or direct oiling manifold.

Downside => Length is a bit long for most of the direct GT40 replicas. It is about 4" longer than your standard G50-52 unit. However no shifter on the back of the gearbox so it is a possibility!!!
 
My ultimate favorite is the Porsche GT2 with a GT3R mainshaft.

Details:

-6 gears.
-Cable side shift, no rod or end linkage.
-Uses G50 style clutch components and drive flanges.
-Use of the GT3R mainshaft gives a 3.1 1st gear ratio and allows a removeable 2nd of any ratio to be fitted.
-Nice 0.75 ratio 6th gear.
-Handles well up to 700 + hp and more as proven by many Ultima builds.
-Stock Porsche motorsport LSD.
-Integral mechanical driven oil pump.

Price => $13500, with inversion procedures and oil pump modifications to allow braided oil lines for cooler fitment or direct oiling manifold.

Downside => Length is a bit long for most of the direct GT40 replicas. It is about 4" longer than your standard G50-52 unit. However no shifter on the back of the gearbox so it is a possibility!!!
It is not bad at all, but...
in the 911 GT3 RS of ART Engineering, driven by Babbini, with the gearboxes tuned by GearFox TC, many modifications were necessary in order to shift faster, whithout burning the synchro rings and for lubricate adeguatly the LSD.
In state you are an expert of those boxes, tell me if I did correctly or not.
1) Synchro spring load doubled.
2) Synthered rings added with 3x3mm holes.
3) Gear cones for synchro rings with a double machining U shaped for lubrication increasment.
4) Exchange of the watercooler with an air cooler.
5) Closure of the pinion, in the diff side with a threaded tap with a 2mm hole for spraying into the LSD.
6) Machining at 6 mm all the lubrication channels in the case.
7) Preload of the pressure valve in order to open at 6 BARS.
8) Piping increasement at 10 mm diameter.
9) 5 mm by pass shortcutting the cooler.
10)Oil spray on the pinion in the exit side.
11)Superior gear oil in use.

Results:
1) Up and down shifting to the rev cutter in 60ms without synchro burning.
2) Perfect lubrication of the LSD internals
3) Operation oil temperature 84-86°C
N.B. A Sachs Race synthered clutch was used but with a spring system pushing the floter away from the flywheel and the pressure plate from the floater in order to minimise the clutch drag.

Tell me your opinion....
Regards
Wanni
 

Gregg

Gregg
Lifetime Supporter
Wanni, why is it that you must always "test" someone. If I was Ryan, I would not accept the bait to see if you performed the correct modifications. Are these modifications which you initially made, than found unsatisfactory?? If so, it would appear that your own expertise came up short. All you needed to post was the problems encountered and the modifcations required to remedy. To me, you still apear to be just a smart ass looking for a pat on the back. I know I said this before. You claim to have supplied many OEM manufacturers with gearboxes. If that is the case, you have already proven yourself and deserve recognition, but to consistently challenge and try and belittle others who are giving a go at transaxle manufacturing is in poor taste, all in an effort to make yourself look superior. I for one would never buy one of your products, superior or not, based solely upon your attitude and presentations herein. I do not believe what you say is based upon your culture. Point in fact is Paolo. Always a gentlemen, without an air of arrogance. Not so in your case. I will now await Russ to attack me:)
 
Thanks for the response Russ,

I guess I should have been more specific....I am only asking about ''within the bellhousing" component tradeoffs, cause and effect and pitfalls of the same.

examples = If you started with "X" bellhousing, "Y" transaxle and "Z" engine how do you go about figuring out what dimensions and relative placement within the bellhousing the various components should have?

I would think there are no set answers but I was looking for general enlightenment as a launch pad for self education.

BTW: I myself am not building a GT40 ..... but more on that as may car comes closer to delivery :)
 
Wanni,
You seem to have excellent knowledge of the transaxle business and I for one enjoy the tidbits of information from your travels within the racing community.

If you would like to educate us with information on what you have found to work in certain applications then, GREAT! I'm sure we would all welcome CONSTRUCTIVE positive teachings from you.

But REALLY, your antagonistic approach to backhanded self promotion is unbecoming of a professional businessman and gentleman. It would be good for the well being of your reputation as well as the company you represent to rethink your destructive approach a little and let your products stand on their own merit. Without attempting to belittle others involved in transaxle business.

On a lighter note -
Where is that US representative you have waiting for us? I would like to get more info.
 

Russ Noble

GT40s Supporter
Lifetime Supporter
Wanni, why is it that you must always "test" someone. If I was Ryan, I would not accept the bait to see if you performed the correct modifications. Are these modifications which you initially made, than found unsatisfactory?? If so, it would appear that your own expertise came up short. All you needed to post was the problems encountered and the modifcations required to remedy. To me, you still apear to be just a smart ass looking for a pat on the back. I know I said this before. You claim to have supplied many OEM manufacturers with gearboxes. If that is the case, you have already proven yourself and deserve recognition, but to consistently challenge and try and belittle others who are giving a go at transaxle manufacturing is in poor taste, all in an effort to make yourself look superior. I for one would never buy one of your products, superior or not, based solely upon your attitude and presentations herein. I do not believe what you say is based upon your culture. Point in fact is Paolo. Always a gentlemen, without an air of arrogance. Not so in your case. I will now await Russ to attack me:)
Haha.... you mean like you attacked Wanni?? :lol:

No, I agree with some of the things you (edit. and Mesa) say, but why bother mentioning it? You haven't really added anything to the point in question i.e. transaxle comparisons, have you Gregg? :mad::mad:

Let the thread develop and see what interesting tech comes out of it. I'm sure quite a lot will.:) I have always said the tech is more important than the way it is delivered. I would hate to lose some of the insights that Wanni has, just because he got chased of this forum because he doesn't do things quite the way some intolerant people would prefer.

Gregg, please don't look on the description 'intolerant' as an attack it is merely a statement of fact.

If I didn't support Wanni that would just leave people like yourself having a go at him and I could very easily see him saying 'stuff you lot' and disappearing from the forum. Then we would never have the opportunity to learn anything further from him.

You might think that's a good thing. I don't. But then you have said you would buy an inferior transaxle, so I've no idea how your mind works... :confused: ( at least Mesa isn't so blinkered)

Mesa,

If you have "y" transaxle and "z" engine then presumably the "x" bellhousing will match the two together and the manufacturer will tell you what parts are required to make it work. Or are you building your own bellhousing?

Cheers
 
Last edited:

Gregg

Gregg
Lifetime Supporter
"Haha.... you mean like you attacked Wanni?? :lol:"

Alright Russ, I'll try and play nice with Wanni and you are correct, I have added nothing to the point in question. I'm not qualified.

"Let the thread develop and see what interesting tech comes out of it. I'm sure quite a lot will.:) I have always said the tech is more important than the way it is delivered. I would hate to lose some of the insights that Wanni has, just because he got chased of this forum because he doesn't do things quite the way some intolerant people would prefer."

Me, chase someone off the forum.... NEVER. I seriously doubt Wanni would let my comments scare him off.

"Gregg, please don't look on the description 'intolerant' as an attack it is merely a statement of fact."

Russ, not taken as an attack, however I believe it to be an "opinion" and not a fact.

"But then you have said you would buy an inferior transaxle, so I've no idea how your mind works... :confused:"

I have the same trans you do, as well as others. I don't consider it inferior. I also considered who could service same, parts availability, reliability. That's one of the main reasons I would not use a zf. Look at everybody married to RBT. One wife is enough for me!:)

Cheers[/QUOTE]
Have you sorted your water pump issue?
 

Lynn Larsen

Lynn Larsen
Dom,
it sounds like nobody cares in getting deeper into transaxles or it became to technical.

Regards
Wanni
Wanni,

Maybe I took your comment shown above out of context, but this is what I was speaking about when I said "interest will ebb and flow, but never go away."

No worries my friend, it was poor attempt at humor.

Regards,
Lynn
 
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