g50 transaxle

[mike]

hey guys...
ill be putting my superformance gt40 together soon and will be needing a transaxle.
i was set on the quaife.
erik from carquip suggested a modified g50 transaxle. he would handle making the trans "inverted" as well as installing a different 4th and 5th gear ratio.

i know nothing abt these transaxles...all i knew abt the zf is that it worked and everyone i dealt with said "heres what you need.." i understand the quiafe is a stronger duplicate as far fitment etc...

im going with a ford small block 427 and am wondering if this g50 route might be the way to go. looks like i can save a chunk a change but saving a few bucks now on a trans as expensive as these isnt my main concern.
i want them to last and work well. i also dont want any install surprises.
my engine will make abt 550hp at the wheels and tq will be over 500.

pros/cons? issues? comments?

thanks in advance for any advice...

 

[Doug S.]

Pros: you might actually be able to get a Porsche G50, getting a ZF or one of the new ZFQ units might prove difficult; the G50 is reported to be capable of quite a high power limit, check on those numbers for your SBF though; the G50 can be and usually is run inverted, which allows the engine to be set lower in the frame for a lower CG and better handling.

Cons: it's a Porsche, can you say "big bucks $$$$" if it ever needs to be fixed?; mid priced between the Audi units and the newer ZF/ZFQ/Ricardo/Mendoiloa units but closer to the top of that range.

Make sure whatever you're looking at has LSD of some sort is my only suggestion....

Doug

 

[Gregg]

Mike, at over 500 ft/lbs of torque I would go with one of the turbo Porsche boxes, either a 930 4spd or the G50/50 or 50/52. I think the major issue/concern is a fitment issue for the SPF. I am unaware of anyone putting a Porsche box into a SPF and would like to know if someone has installed one. I disagree with Doug's "big bucks" if it ever needs to be fixed. If you have concerns about service, ask Eric his prices and turn around time. You should also consider how many Porsche dealers are local to you as far as service and parts availability. As you probably know, there is a scarcity of of ZF's and most SPF builder's appear to be married to RBT and waiting over a year for a transaxle. I prefer the Porsche box over the ZF because I personally feel it is a better box and I have plenty of shops near me who can service same. Good luck with your decision.

 

[Howard Jones]

How about a link or contact information for Eric?

 

[mike]

thanks for the replies....
im still in the dark on fitment.....will i need adapters, will i have to modify anything?
erik is a member of our board.....heres his contact...

Erik Johnson
Carquip Sales
(303) 443-1343 ext 2 work
(720) 980-9407 cell

he seems to know what hes talking abt and was quick to reply to my inquiry.
as far as costs, here was his run down...

G50 short tail transaxle (G50/03) $6250
Inversion fee $285
Taller 4th gear to 0.96 $795
Taller 5th gear to 0.65 $795
New Limited Slip Differential $1495
Crate and Freight (est.) $300

Total for this build $9,920.00

these transaxles arent cheap by any stretch, but eriks alternative is cheaper than the zfq, at least at first blush....

will it work? i dont know. i admit ignorance. but at any of these prices i need it to work, work well, and not give me any surprises on install.
too much money to replace it after a year or find out i have to reinvent the wheel to make the install work.

i did address my concerns to erik and am awaiting his response.
i posted here because i wanted to get some thoughts from folks who maybe already did this and opinions from folks who arent selling a trans.

 

[Bill Musarra]

Mike,
Unless you have some bias against 4 speeds, you should at least consider the 930. I actually have found several on ebay. There are several Porsche bone yards where you can pick them up cheaper than new(Google). They probably will require a rebuild as most need new dog teeth or sincros by about 40K unless some old granny drove it. That should still keep you under the cost of new. There are some guys on the forum or some I know of that are well versed in German parts. The special gears will still cost the same. I plan on driving mine for a while before I take that route. Most will tell you that first gear is too low. As far as I am concerned, first is not the gear I worry about. What you will get is peace of mind in that the trans will take anything you throw at it.(screaming starts excluded) I don't think anyone on the forum has ever posted a failed 930. The problem is that they are getting hard to find. Then, how long are you willing to wait?? Spend some time and look around before you comit. A dollar is still a dollar, and can be put toward some other goody!!

Bill

 

[Gregg]

Mike, I have two boxes available. Both rebuilt and both lsd. One 930 4spd, the other is a G50/52 five speed. I think the first thing you should look into is whether any of the Porsche boxes will fit. There are plenty of SPF owners waiting year(s) for a zf/RBT tranny and if the Porsche was an alternative, I think there would be a few more cars on the road. The Porsche box may fit but may require some modifications to the chassis. I would spend my time researching what boxes will fit the SPF first. Good luck.

 

[mike]

Mike, I have two boxes available. Both rebuilt and both lsd. One 930 4spd, the other is a G50/52 five speed. I think the first thing you should look into is whether any of the Porsche boxes will fit. There are plenty of SPF owners waiting year(s) for a zf/RBT tranny and if the Porsche was an alternative, I think there would be a few more cars on the road. The Porsche box may fit but may require some modifications to the chassis. I would spend my time researching what boxes will fit the SPF first. Good luck.

im not wild abt a 4 spd..
as to the rest of your post, i agree...why would some folks have waited all that time for the zf if there was another alternative?
i dont want to reinvent the wheel installing a trans. i have no idea if the g50 will install cleanly and without incurring additional expense to make it all work.
thanks for the comments.

 

[EGLITOM]

Gregg

Can´t tell you anything about the fitment but for the engine you need an adapterplate and a flywheel which can take a porsche dimensional clutch ( a sachs powerclutch will be able to scope with your engines performance). Would go with the G50/52 for your kind of power
find onby a excel sheet with all kind of g50´s and there ratios in it. Play around with it and see what ratios you need to change. I use a G50/05 in my RCR and 3rd, 4th,5th gear was perfect for my high reving engine. I change the 1st and 2nd to longer ones in order to achieve a smaller RPM drop at shifting ( see the modified table in the excel sheet).
Also don´t underestimate the influence of tire size on the final ratio. I also put in a excel file with all kind of tires for the gt40 and there dimensions. you just need to choose the one you have and put the datas in the gear charts to find out how it fits.

I sourced my adapter parts from RCR. Another very good adress for high performance G50 boxes is G-box GBOX LLC. Porsche and Getrag service. Performance driveline engineering.

For the fit my only logical assumptuion could be. RCR are made to fit ZF´s, G50´s, 930`s and Audi transaxles ( also RIcardos). With the G50 in an RC one can achieve the same low engine position ( or even lower) than with an ZF. so if an ZF and an ZFQ fits a SPF a G50 should fit as well.

Hope it helps

TOM

 

[JohnC]

As a 2nd source for the G50 and G50/52 you should contact Roger Brown or Bobby Hart @ California Motorsports.

They won't be cheap, but their quality is superb, and FWIW, the SSC Aero, which currently holds the record for the fastest production car in the world, runs one of their transaxles.

They're a GT40s.com forum sponsor too.

 

[Erik Johnson]

If a G50/52 is more along the recommended lines, I have one of these too. I was simply trying to put together a solution that would not be as expensive. The G50/52 is a wonderful transaxle, but is relatively expensive in comparison to the G50/03, and in my opinion only really warranted in applications over 650 HP.

Still you can never have too much protection.

In relation to the gearing changes of 4th and 5th we typically do this in a V-8 application more for gas and cruising considerations. We have found that quite a few builders would like to have a taller 5th gear to lower RPMs at 80 MPH. I agree though that a taller 1st gear could certainly be useful as well. Keep in mind though that in order to change out the first gear on a porsche transaxle (G50) you need to actually grind the gear off of the shaft and weld a new one on. We do this work, and have never had any issues, but some people do not like the idea of putting that much heat against the mainstaft that is going to have 500 HP and ft-lbs thrown at it.

Just my thoughts on this, I would certainly like to hear everyone's opinions.

Thanks

Erik Johnson
Carquip Sales
(303) 443-1343 ext 2 work
(720) 980-9407 cell

 

[EGLITOM]

Mike

Just my honest opinion. I would look twice in the market who does your G50. Grinding of the gear and rewelding another one. I wonder how exact this could be done.
But moreover complete inputshafts with different 1st gear ratios are ready available as a billet ( i.e. from Quaife or powerhouse II). If Eric is not aware of this, i realy would question his competence . Even more as G-BOX is located in Boulder as well.
TOM

 

[Erik Johnson]

Tom if you wish to question my competence, I would be happy to chat with you sometime. We have been in business here for more then 30 years and transaxles compose 90% of the business generated and completed here every month. I would agree with you that there are other options out there regarding the new mainshaft. Powerhaus II however is not one of them. This company is no longer in business. I know because I used to be the General Manager there before they had to close. As to Quaife, gearing from them has been a bit hit or miss over the years. If you want to go with a new mainshaft and first gear, the only real solution would be to contact Mike at Guard Transmission.

GT makes a new shaft for these gearboxes and has had very reliable gears and shafts for quite some time. Prohaps things are a bit different here, and cost is not really an issue. The reason that I recommended a weld on first gear is due to the fact that we have done these for quite some time without failure, or issue, and the cost is quite a bit less then going with a new mainshaft and 1st gear.

I would agree that G-Box is another option, and anyone would be prudent to check into many companies before deciding on who they wished to work with. I have a very good knowledge of the people at G-box as they used to work for me at Powerhaus. They are all fine people, and Stan is an excellant builder. You will not get me to knock them in any way, however, we here at Carquip are just as capable if not more so, and specialize in working with these types of builds.

I absolutely agree that you should be very careful when it comes to deciding who you are going to trust with your gearbox build. There are really good companies out there and then there are companies that are not what they seem. It is very tough to know who to trust. My hope in joining this site as a sponsor is to bring my knowledge and experience to everyone here and to try to be of some help to you all. I am not out to get anyone, and I will always tell you what the bottom line is.

I always appreciate comments regarding anything that I post, and I realize that I am new to this site and it will take some time to build some trust here, however, that being said, I would really appreciate it if my competence were not questioned. I do not claim to know everything, but I am certainly more then competent in this field.

Should anyone here wish a second opinion regarding the quality of the work that we do here, please feel free to contact Fran at RCR. I am quite sure that he will be more then happy to speak highly of our work here, as we have on occasion been fortunate to have worked with him and his customers.

Warmest Regards and I hope to help,

Erik Johnson
Carquip Sales
(303) 443-1343 ext 2 work
(720) 980-9407 cell

 

[EGLITOM]

Erik

I´m far away from questioning your competence. If you ready exactly, i said if you would not know about the billet solution i would question it, but you definitely know.


There where just some thinks in your offer which made me curious.

1st. To my knowledge a g50/03 is not a what i would call a shorttail transaxle, this is more related to a G50/01 and G50 /02 ,but it probably depends on ones definition.

2nd. A G50/03 for this power application seemed a bit on the limit to me, especially your offer did not include a cooling system which you propose in another post

3rd. the already discussed input shaft proposal

Anyway i don´t want to offend anyone here and my intention is certainly not to drive away a sponsor from this forum, but IMHO i also think a proper introduction of yourself and your company in the correct partition of this forum could have avoided some missunderstandings and missinterpretations from the beginning.

BTW what do you mean with "hit and miss" regarding the quaife gears?

Thanks for your honest and constructive reply

TOM

 

[Erik Johnson]

Dear Tom,

Thank you for your reply, and I am sorry that I was not in the office here when you called.

To address your thoughts here, you are absolutely correct in that the short tail is actually a G50/01 and NOT a G50/03 as I had originally quoted. Minor malfunction in the mind on that one for me here. We do a great many of the long tail versions of these, and I am mistaken on this.

I don't recommend that the G50/01 be used in applications over 600 HP, even with cooling, as I feel that the turbo gearboxes, ie G50/50 and G50/52 are more reliable, however I do feel that the G50/01 will be well suited to this application as the HP and Torque figures are well below that mark. A cooling system is an excellant protective measure in any GT40, however, in my opinion.

In relation to the Quaife gears, we have seen these gears here and there for several years. I have advised people to avoid these gears as they were not very well constructed. They have been making the rounds for awhile from company to company, and crop up from time to time with someone offering G50 gears at a rediculiously low price. While I have no doubt that there are people who have had no issues with these gears, I still will not recommend them.

In regard to an introduction, I completely agree with you on this note. I should indeed have taken the time to address everyone here formally and introduce not only myself, but Carquip as well, and what we specialize in here. Not to worry about driving me away, I just did not want even a shadow of doubt regarding my desire, ability, and commitment to the forum and it's members here to linger.

As I am sure you can appreciate this is a relatively small group, (Porsche Transaxle Specialists) and even the slightest hint of incompetance can ruin a reputation that I myself, and Carquip on as a whole, have worked very hard in earning. No worries though, and certainly no hard feelings.

I will try to get our formal introduction into the appropriate section as quickly as possible so that everyone can get to know us here a bit better.

Tom, thank you for your comments, I can only improve my service to you all, as a result of them. Please, if you have any additional questions, or thoughts I welcome any and all.

Warmest Regards,


Erik Johnson
Carquip Sale
(303) 443-1343 ext 2 work
(720) 980-9407 cell

PS: Everyone, please do not hesitate to call me on my cell phone, I am always available to answer questions, and try to make myself always available to my customers. (I sometimes go to the mountains and can not be reached though.)

 

[BruceA]

Erik. I do believe you posted an introduction to yourself and your business on the forum here some time ago, introducing yourself and your company. Am I correct or is there something I missed?

 

[Erik Johnson]

I think that I may have posted this in the wrong location.

My fault on that one.

Erik Johnson
Carquip Sales
(303) 443-1343 ext 2 work
(720) 980-9407 cell