TheSamba.com :: View topic - getting a transmission to hold more HP/Torque

Fri Apr 30, 2010 11:09 am

i have used the search for several days but i can't find any info one how to get the stock bug, bus or a 914 transaxle to handle more then 250hp
i know the stock transaxles are almost bullet proof to 250hp, but how do i get it to hold more HP/Torque/Newton meters

i want to run a high horsepower type 4 engine with a massive turbo for racing offroad, or on the drag strip

now i don't want to use a special transaxle or anything. im curious to what do i have to do to a stock transaxle to get it to hold the power. i know the bus transaxle is stronger then the bug so im more inclined to using the bus, but i want the 5th gear option outta the 914.
i know im gonna need a new ring set, larger/stronger gears, and better cv's.

any more info would be of massive help thanks guys

Fri Apr 30, 2010 11:32 am

http://www.ranchotransaxles.com/service.html

Dale

Fri Apr 30, 2010 11:38 am

Just wondering.....but off road racing how often would you even be using 5th with a 914 tranny that may have a lower gear ratio than a type 1? I've rode in a buggy in the sand and being a lighter frame I hung mostly in 1 and 2 and very rarely in 3rd. A 6 rib bus tranny would likely suit your needs. Are you going to be entering races?-Jon

Fri Apr 30, 2010 11:52 am

endurance racing in the desert, dunes, light trails through the woods, rally races, w/e i feel like doing

Fri Apr 30, 2010 12:01 pm

dale thank u for the link!

Fri Apr 30, 2010 12:38 pm

You'd have to run an unlimited class to run a turbo for off road racing......IF turbos are even allowed. The abuse an off road trans sees is substantial. Thru the bump on the gas is hard on them. Also, any trans will hold a 250hp engine, if you drive the car like it came from the factory. A split case trans will work....for a short while. Now, if you want it to last, that's a completely different story! Call Rancho, or any other well reputed trans builder and tell them what you're going to do with it. Let them give you suggestions on what you'll need to accomplish your desires.

Fri Apr 30, 2010 1:47 pm

I don't know where you are getting that a stock type I transaxle will handle 250 HP but that is incorrect. You need to start upgrading them around 100 HP.

If your really serious about off roading a 250 HP type IV, you need to step up to the plate and buy a Mendeola transaxle.

Fri Apr 30, 2010 2:01 pm

vwracerdave wrote: I don't know where you are getting that a stock type I transaxle will handle 250 HP but that is incorrect. You need to start upgrading them around 100 HP.

BS, my stock 6v trans lasted with 150 lb ft of 1915 turbo going through it, and I never broke anything. Just the same, I replaced it with a Pro Street. Still have the same axles, though.

Fri Apr 30, 2010 3:07 pm

How much off road racing do you do?

How many passes down the drag strip have you made?

Fri Apr 30, 2010 3:12 pm

vwracerdave wrote: If your really serious about off roading a 250 HP type IV, you need to step up to the plate and buy a Mendeola transaxle.

Do you seriously think the only answer is a $6k transmission???? :lol:

Fri Apr 30, 2010 3:20 pm

Hotrodvw wrote: Do you seriously think the only answer is a $6k transmission????

Yes, if the guy is serious about 250 HP.

Fri Apr 30, 2010 3:24 pm

Maybe we should introduce you to the 091 bus trans, 930 CV's, microstub axles, etc.... Many have done it, and still do with no more than $2500 invested. He CAN make it work for a lot less than a Mendy.

Fri Apr 30, 2010 4:15 pm

Yea I agree with VWDave, I would not short cut the tranny in any fashion, if the guy is willing to go all out on the serious engine, he must have a worth wild car that can hold up, thus may as well have the right tranny for the job.

Ever been stuck 50 miles from the closest person when thing go bad? Thing is things can go bad when they want, racing or just roaming around..

I blew a tranny once that held together till the next day I started the engine, thing is is would not go into gear or anything, weird thing is it got me home, must of had some stress cracks that developed further into fractures.

All I am saying is if he has the bucks for a Type 4 Wild Motor, don't talk him out of some clearity of mind, you are not the one out in the desert, this guy is and trust me, he is looking for valid input, not B.S.

50 miles is a long way on foot regardless of the weather and preperations.........

Oh by the way, side step your clutch a few times at RPM's see how many times you can do it, think that is the point on applying HP to what ever surface you are riding on.... They all break sooner or later, may as well put it off as long as possible is my stand point and I guess Wild Eyes as well........ RB

Fri Apr 30, 2010 5:20 pm

Hotrodvw wrote: Maybe we should introduce you to the 091 bus trans, 930 CV's, microstub axles, etc.... Many have done it, and still do with no more than $2500 invested. He CAN make it work for a lot less than a Mendy.

i was quoted 3500 for a transaxle to hold the power of my street turbo engine... not a transaxle that will "work", but one that will do the job, do it right, and do it for quite some time... that's just the transaxle, not the axles and such... but you know what? when you have 9-10K in an engine, why would you cheap out on the transaxle?

Fri Apr 30, 2010 5:40 pm

I am interested in hearing which case it is based around....

I do like the idea of the Berg 5-Speed in a bus box set-up, but I thought a clear cut off for that set-up is around 225 HP, this is based on the longer
out put shaft or what ever it is called, twisting off, they do have the optional chromoly one available but I am not sure of HP ratings..

This is all hear say, i have never spoken with Berg about there 5 Speeds, but I do know when in a bus box you can pop wheelies,lol..

Thing is in the past Porsche Tranny's have been run and even 914's suposedly.. Just takes a little re-gearing or just have the engine to turn it over...

Point is the Mendeola Trannys are nice and they have been used with most power plants that are out at some point in the past....

Thing I am worried about with any tranny I run or will run, is cracking the case, not ripping out the gears........ RB

Fri Apr 30, 2010 5:44 pm

Berg 5's are not known for their strength.

Fri Apr 30, 2010 5:46 pm

As noted....... RB

Fri Apr 30, 2010 5:49 pm

If you treat the stock tranny well, it will last . Mine is a living testament. 1973 SSC irs over 300 track launches 100+ launches with slicks, 60' in the 1.71 - 1.9 with slicks. Just went 11.9 behind my turbo 2110. I keep my slicks at 22 pounds, and preload hard, as in the back of the car squats 2 " when I am at the tree waiting for the lights

Check out my youtube page, 14 videos of beating on the tranny.

http://www.youtube.com/user/Billyisgr8

Kevin

Fri Apr 30, 2010 5:58 pm

Your not pushing it hard enough,lol... A 73 Stockers have the fine tooth gears which rip out easier than the pre 69's I think which are the corser geared design which can take way more punishment......

I think it is pre 69 that was the last of the dual side cover cases then after that they went to the fine tooth gearing and single side cover cases which are actually stronger than the dual side covers... This is all bug cases mind you....

What does SSC stand for may I ask, or is this something I am supposed to already know,lol....

I got it, Single Side Cover, Sorry about that, you are running a built tranny like mine if you are not ripping out the fine tooth gearing is all I can say or you are delicate on it,lol...

I run 8" and 10" wide rears on my rod, thus keeping the tranny together is the objective for me at all costs.... RB

Fri Apr 30, 2010 6:00 pm

RailBoy wrote:

What does SSC stand for may I ask, or is this something I am supposed to already know,lol.... RB

single side cover.... 73-up