New Transaxle Comparison / Discussion Thread

#1
Guys,

What I would like to see is a comparison between all of the available mid-engine transaxels available both today and in the near future.

What that would include is:
- length
- width
- weight
- torque capability
- comparion to the original ZF unit
- cost (and where the price originates)

That includes:
- ZF old
- ZF RBT
- ZFQ
- Wanni's
- G50
- G50/50
- 930
- Renault
- Audi
- I think Graziano produce a box or two as well
Any others

If I had the time to put together a spreadsheet, I would gladly do it.

That would pretty much put all of this discussion behind us, and we can then decide how much money we wish to spend, and with whom we wish to work.

Any further comments? Did I include all of the available units for mid-engine mounts?

I would this to be a free open discussion.

Best
Dom
 
#2
Re: Transaxel Comparision

Please excuse the last line.

A couple of other points:
- servicablity and costs (G50, G50/50, 930, Audi, ZF etc)
- availablity of each box - say a new box is coming out and it has the desired features, when will be the first ship date

Hope this helps.

Dom
 

Russ Noble

Newbie
GT40s Supporter
Lifetime Supporter
#3
Re: Transaxel Comparision

A bit of work involved there Dom! You missed two of the high torque, original fitment, homologated trans. ie T44 and LG600. Both are fairly thin on the ground secondhand but both are being remanufactured and are available new. There is also Richards TRT unit waiting in the wings as well as the Renegade/Mendeola offering. New trans seem to be coming out of the woodwork everywhere at present! Can only be good. Cheers
 

Ron Earp

Member
Admin
#4
Re: Transaxel Comparision

This would be a great piece of information for the FAQ or links page.

Most of it is "non-subjective", except when you get down to things like "torque capacity" (yes, I know it shouldn't be non-subjective but it will be in discussion due to indivdual experiences and opinions), and servicibility/costs.

A spreadsheet would be a good starting point.

Ron
 
#5
Re: Transaxel Comparision

The whole point of this exercise is to get as much competitive information into the open. In all of these various threads, I have not seen much technical information.

People experess themselves differently. I know for sure that Yanks use different words than Brits to express themselves (god help us with the Ausies and NZs). So imagine someone from another language.

I am not making any defence of anyone or his selection of words, nor am I trying to trash anyone or their work.

If you don't like someone, don't buy his product. If you choose to purchase for these reasons, you may later find that the product you chose to not purchase is actually the best for your application.

Before I plop out $10,000 or more for a box, I want to know what is the best out there. If I can buy a better box for $15000 or $20000, which for a mega bucks, euro or ££ repro car, the small extra money may make sense.

I would appreciate if people could help me find the details of these boxes.

Thanks
Dom
 

John Fitzpatrick

Member
GT40s Supporter
#6
Re: Transaxel Comparision

I'm going to be pulling my ZF dash 0 box shortly to clean it up and rework the clutch. I can get the measurements and weights then if they're not posted somewhere else. I know it's not a common enough item to be of specific interest, but it might be of some use for comparison. Specifically, which ones would be needed? How about for the bellhousing? And finally, which would be more usefull, a spreadsheet or an AutoCAD drawing?
John
Oops, I just viewed your (very nice) drawing, Chris- I'll just pull the dimensions you have on it.
 
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Steve Briscoe

Newbie
Lifetime Supporter
#7
Re: Transaxel Comparision

Guys,

What I would like to see is a comparison between all of the available mid-engine transaxels available both today and in the near future.

Best
Dom
Me too. This is a great thread title through which much can be learned. Thank you Dom.

I can follow the discussions in the engine section fairly well. However, I'm lost in the transaxle section. I understand just a little about input shafts, bell housing length, sequential and oiling. However, I don't know all of the reasons why. If someone, anyone, who is highly knowledgeable would like to compare the specifics of transaxles and WHY you need certain components to be structured in a particular way, it might be understood by a broader array of forum members and buyers of transaxles. I don't want to be a drag on this thread so if someone can point to a book that explains transaxles, I can study on my own time. Or, someone here might go retrieve all the forum member input that responds directly to
Dom's question and flesh it out.

Thanks. I'm glad to be able to read member input. It's helpful and I appreciate all the guys that are working hard to resolve the transaxle shortage problem.
Steve
 
#8
Re: Transaxel Comparision

Guys,

Thanks for your kind comments. This is what I hoped to achieve.

When I get a few minutes, I will post the first draft of my spreadsheet on this forum.

Good luck to all !!!

Best
Dom
 
#13
Re: Transaxel Comparision

Ian,

Thanks for the good work. I made a mistake and noted the ZFQ's torque at 550 Nm, and it should read 750 Nm, or 550 Ft. Lbs torque.

Do you mind to resize it again please?

Thanks
Dom
 
#14
Re: Transaxel Comparision

Dom,
Gearfox 906H is from 86 to 92kg depending on final drive ratio choice. You might want to include it in the .xls. Great work btw. :) You started this thread asking if anyone has some kind of comparision. You ended doing one yourself.


DBLDREW asked to share experience that I had with various gearboxes in racing. This is irrelevant to sinchro boxes that we're talking here but it does tell about some of the manufacturers’ background.
I'm glad to share personal experience. But first I have to ask - if someone doesn't like my opinion, based on hands on experience. Does it mean that I will be treated same way as Wanni? Can’t say that it makes me scary but it doesn’t add enthusiasm as well.

Also I want to announce that Gearfox T906 is chosen for new player in the field of fastest road going supercars – Murena Automotive. I’m not revealing any tech. information and images because I’m not sure if I can do it in this forum and this thread in particular.
I choose T906 for simple reasons – it is proven in most exotic and extreme supercars. Pagani, Koenigsegg, Apollo to name a few. Also because it is simply a piece of engineering art. It’s design is “parametric” in some way. Wanni anticipated most of what different customers may require from his gearbox. So its design is flexible enough to adopt almost any street going application. I’m thankful to those who was attacking him. Those attacks made him share more tech. info and made me look closely at his product. One thing I don’t really like – the price :)


Thank You
Ted
 
#15
Re: Transaxel Comparision

Ted,

Thanks for your comments. I have noted the weight at 92Kgs, giving the transmission a abit of handicap.

Like many, I have found this exercise very educational. All of this discussion has raised my level to better understand:
- design ideas
- strategy to handle all of the various components, and the various applications
- effectively eliminate the disharmony and brought the discussion back to the technical aspects (which was the original objective)

Where I have not done a good job, and will update the spreadsheet once I get some time, is to incorporate more info on the Ricardo Ford, the T44 and other units currently in the market place.

Through my Porsche friends, I will try to get some further cost, dimensional and performance information.

I agree that the Getrag Porsche boxes are good, and now they are used, affordable for these applications. But these boxes are limited to torque.

Thanks all and keep all of the comments coming !!!

Best
Dom
 

Ron Earp

Member
Admin
#16
Re: Transaxel Comparision

Fellows,

With your persmission I'd like to take this thread, parse it, and begin a new "Transaxle Comparison" thread that has the data sheet and important comments. This is likely to be a highly viewed/used thread and it could do with some clean up and less off topic banter.

Ron
 
#17
Re: Transaxel Comparision

Do it !! Take the emotion out, and make it usable. I want everyone to contribute, but the useful information is too important, and it needs clearing. We can always get the competitive point of view from the various manufacturers.

Dom
 
#18
Re: Transaxel Comparision

Just wanted to jump into this thread because this is an interesting topic. Any of my input will of course be IMHO.

first what my GT40 replica is utilizing as far as drive train

1989 G50-05 LSD (used) 135lbs. $3500
KEP flywheel $250
KEP 600 ft lb alum PP and disc $600
TO brg and TO fork $200
Mark Williams custom CV axles $1700
Audi clutch slave $30
Toyota shifter (used) $45
HiPerf shifter cables $180
Gear reduction starter $150
------------------------------------------------------------------------
Total $6655

Also spent a lot of time machining cases to shorten and to fit earlier flywheel so starter would fit, est $500 of machining. The pre '89 G50's don't have these problems. Machined my own adapter which incorporates mounts. 60 hrs labor ($200 from KEP) Also scratch built trans end of shifter linkage and modded Toyota shifter. And scratch built the rear mount. About another 120 hrs total labor (but I'm slow).

The Porsche factory rating on this trans is 325 ft.lbs. torque which is very conservative. The general consensus is it's worth about 400 ft.lbs. But no dumping the clutch at that power.

-------------------------------------------------------------------

Now I want to discuss 6 speed transmissions/transaxles, because I think they can be 90 percent hype unless the application is carefully custom tailored.

Here's some ratio comparisons

Borg Warner T5 (typical AC Cobra kit trans)
1 - 2.95
1 - 1.94
3 - 1.34
4 - 1.00
5 - 0.63
Final - 3.36 (for the sake of argument, my Cobra actually was 3.30)

9.91 combined 1st gear ratio
2.12 combined top gear ratio
7.79 spread from bottom to top

Ford GT. (Ricardo) 300 lbs.
1 - 2.61
2 - 1.71
3 - 1.23
4 - 0.94
5 - 0.77
6 - 0.63
Final - 3.36

8.77 combined 1st gear ratio
2.12 combined top gear ratio
6.65 spread from bottom to top

With the same power plant and final ratio the BW is going to have more low end accel and one less (time consuming) shift with the same top speed. The only way the GT is going to gain from the extra shift is to concentrate and shorten the power band. (which I'm sure they did) In other words more power over a shorter rpm range. Probably with induction, exhaust, cam and computer tweaks. So if your just throwing a 6 speed at your normally 4 or 5 speeded V8 setup you're not going to realize much or any perf gain. Maybe even loss with the extra shift. Basically this comparison shows the 6 speed as just adding another ratio in between the bottom and top and in fact less of a spread between bottom and top.

Here's another comparison

'07 Honda Civic 5 spd.

1st: 2.666,
2nd: 1.534,
3rd: 1.022,
4th: 0.721,
5th: 0.525,
Final Drive: 4.437

11.83 combined 1st gear ratio
2.33 combined top gear ratio
9.5 spread

'07 Honda Civic 6 spd.

1st: 3.267,
2nd: 2.130,
3rd: 1.517,
4th: 1.147,
5th: 0.921,
6th: 0.659,
Final Drive: 4.765

15.56 combined 1st gear ratio,
3,14 combined top gear ratio
12.42 spread

And the Honda 6 speed is behind a higher revving engine and/or taller tire/wheel combo so the top end is probably the same or greater. So we can see Honda has gone the other direction (that IMHO I prefer), instead of adding another ratio in between they've added the ratio outside the normal bottom/top thereby increasing the spread. Way more low end and about the same top end. This would also give you more capability at the track etc. without having to change final ratios.
 
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#19
Thanks Kalun. From your noted, can I assume that the Ricardo transmission weighs 300 lbs?

Great post. Gear ratios mean alot.

One of the reasons for the thread was to get as much info about a set up as possible. The transmission is a major factor, but so is vehicle weight, tire size, gear ratios etc.

Best
Dom
 
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