Hello,
Sorry guys but im an intruder on your site. I own a 1970 VW Dune buggy that im currently building/restoring. I bought a Rotary 13B-RE (rare Japan only out of a Mazda Cosmo) Twin turbo motor with guestimated hp output from 350-450 after im done with it and I am shopping around for different transmission options. allot of us VW guys have gone with Porsche 914 and other Porsche trannys but I figured if I wanted real 914 tranny info I better go to the guys that really know them the best. So im sorry for invading your forum with these questions but it’s really a complement. I wanted to know if you guys knew the limits on the 914 tranny? What is the max HP they can take? I read that they can handle 300HP stock but??? I also read that some people with built motors were busting the first gears/ and that the first gear wasn’t even used with the v-8 conversion because of the torque characteristics??? How reliable have they been for you guys with big HP?? and my last question is, if its true that the stock 914 tranny can only handle 300HP and im going to have more than that, does anyone know what it takes and how much it costs to open one up/beef it up?

Thanks for your patience and help.
Brad.

You would be better off to find a tranny from a 930 or even a G50. The 914 gearbox wont last you very long. If you are going to go strong, you better make the whole driveline strong too. Good luck and welcome to the club.

Also, are you running the engine behind the trans or in front of it? Why would you need a 914 trans?

the motor will be running behind the trans. and im asking about the 914 because a lot of the vw guys are using them. but i heard they needed to be swaped around?? ive heard about the G50, do you know anything about them? would they work for my project and HP

Absolutely, the G50 would be your best best. The 930 would be the second best. Neither of them would require you to flip the ring and pinion. The 930 is only a 4 speed however as the G50 is a 6 speed. Both will handle what you want to run.

why not the 914 scott? the rotories have NO torque...

a 915 would be a cheaper alternative thn the 930/g50

Oh, The G50 in ready to go condition is going to cost you between 4 and 8 grand, the 930 you could pick up for around 2500 to 3500. They would both handle what you want to do in stock condition.

Read the horsepower he is talking about. The 915 would work but it may not handle the power he is talking about running

now im a porsche idiot so i apologize ahead of time for the stupid question. is the G50 a porsche car model or the name of the trany? and what year car am i looking for? and how available and expensive are they?

i read that, but i thought torque ate tranny's not high RPM screamers.

The G50 is the transmission used in some late model Porsches. They can handle up to about 650 HP without modification, I think. In any case, they are available, I had the opportunity to pick one up about a year ago for 850 bucks. I am still kicking my butt for not buying it. The cheapest I have found a 930 trans for was about 2500. That is in ready to go for your application condition. I would have to spend more on it to flip the ring and pinion.

2500 used? do you know how much mod is needed to couple a G50 to a VW? is the G50 similar to the 914 tranny?

Yup! They dont make the 930 transmission anymore. The G50 is the one to use now, they are still current.

I thought you were using a Mazda engine? Kennedy would make the adapter for that and the clutch.

yeah thats not the problem. on the 914 tranny some cutting needs to be done on the rear frame horns in order to fit properly, and some other mods too. but thats the 914, is it pretty close to the G50?

Post some pics of your car/engine/whatever!!! No intrusion at all!

g 50 is like 8 inches longer

BTW thats a WAG estimation

ill post some pics asap but i gotta findem first

is the 930 8 inches longer also or is it closer to the size of a 914 tranny? and what HP can the 930 handle?

Yeah, post some pictures of what you got with measurments and how much room you have to work with. I have a friend with a sand rail, he runs a type 1 that puts out 360HP on an actual type 1 case. That is the only thing that is stock. The heads on his engine were almost 5k. To me, it just seems like a waste for something you can only drive in nice weather and on weekends.

Hmmm, well I also have a sandrail...VW powered.
My experience in the dunes is that the transaxles take a bunch of abuse beyond strictly calculating the "street" maximum HP/T allowable.

You will probably be running tall paddles and pounding on first when you get stuck....or the relentless woop-de-dooos.

Long story short, torque is introduced into an off road vehicles driveline by more than the powerplant alone.

For this, short of going with a Mendeola, it seems that the 6 rib vanagon tranny is the best thing around...possibly this can even be beefed up and they are cheap and available. They are supposed to take 300 HP of piston and are geared and designed for a big ol' heavy van.

Anyway, around here that's what the <$50K rail guys use.

Good Luck
Sean

Do you mean to tell me that there are sand rails out there that are more than 50k?

ill get some pics up by tom. It is a a fiberglass buggy (for street use only) so it has virtually limitless room but it all depends on how far i want my motor to stick out the back.

i was quoted today for a built Mendeola tranny for the kind of power that im gunna have, at $6,200 a little to much for my wallet

I have to post that these turbo rotary engines still have lots of torque. My son's Turbo 2 will burn off the tires in the first 3 gears if you want. It has 300+ rwhp.

I agree that the lowly 12a motors were fairly weak.

Its like comparing a 1200 Bug motor to a 930 motor.


Geoff

Waaaay over!

You should see the guys that pull up in 200K+ motorcoaches pulling 50K toy haulers, unloading 100K rails and still smiling after they total their rail at 85mph.

I guess it's all downhill after your first mil'.

The sandrail craze is sick. 700hp Subaru or Honda powerplants...etc.

The top guys around here run VW's with 6rib bus trannies. Have a look at my friend Rob with his personal VW type 1 motor:

Bug Germanators

His 200hp-ish motor is about all I can fathom in the dunes...a ride with him is almost pants wetting. More than that seems like a liability.

Sean

supercharged ans Super flow heads?> what HP does that put out?

According to Rob, it's not the HP that's impressive on this motor, but the strong linear torque.

Of course, separating HP and TQ numbers is pointless (which is probably why "real" sports cars are rated in KW), but this engine supposedly makes great power *everywhere*.

He just installed it and is tweaking it up, so the final dyno will remain to be seen.

Sean

or check out these guys, trannys for rails and high hp vw


http://www.mendeolatransaxles.com/index1.php

wow....they "start" at $5,000...ouch....now that I think about it, I guess that is not too bad for a brand new transmission...still, it has to hurt the wallet and then some

and you can do a flip ring and pinion......ideas anyone......$7k will handle 500hp

The 930 gearbox was built to handle the 300 HP 930 motor, reliably. It should be able to handle significantly more, I would think. The 915 lasted through the 217-HP 3.2s, and should be capable of handling more than that.

The G50 was introduced in 1987 on the 3.2 Carrera (earlier 3.2s used the 915 gearbox), and versions of it were used up until pretty recently. The G50 is a five-speed; the "G60" is a six-speed. They are built to handle... Well, a whole bunch of power.

I would guess that the 930 box would be the most reasonable alternative. It is only a four-speed, though. But with turbo torque, you probably won't need too many gears.

--DD

what model/year car does the 930 come in? and i heard a guy talking about the 901 tranny, do you guys know anything about that one?

The 930 was first introduced in late 75 or 76 and went up till around the mid 80's. The 901 is the transmission in a stock 914

the 901 is the 914 and early 911 tranny, it basicly came in 3 set ups two were tail cone shifters. but each of these 2 were set up with the r=p in opposite directions, and the third was called a side shifter tranny because the shifter was on the side of the tranny.

basicly
901 tail shift tranny in front of motor is early 911 ( the one you want if you go 901 )
901 " " " behind motor is early 914
901 side shift is 914

scott t

so what exactly is the HP limit on the 901? or aprox? cuz there are a few of those going on ebay right now for around a $100 bucks.

They say, the 901 can handle up to 300 HP. Many V8 guys are running them stock in their car with no problems, but they do not use first gear.

Hey Scott,
Did you notice the time stamp on
this post?????

Lisa

because of the low bottom end torque of the rotarys do you think it would be safe to run a 901 tranny out of a early 911 and just start in second if i prestage the turbo's and luanch?

That is a good question, I am not sure what kind of torque you will be pushing off the line. The 911 901 must have been a little more beefy to handle the power of the 6, but then again, it didnt put out that much more than the 914. Hard to say. You could just try it, what have you got to lose? Its only money.

yeah money has absolutly no object to me
but it is kinda true that i dont have too much to lose though, there is a 911 901 tranny right now on ebay in good condition going for $175 it sure beets $2000 and really if it breaks i can always upgrade...

I am into VWs as well. I've contemplated the Porsche 5-spd for my '69 Beetle street car many times. I even have a few tail shift 914 tannies.

I agree with what has been said. Stick with the 911 based 901 tranny. Converting the 914 tranny involves flipping the ring gear, shimming the pinion, and buying a 911 nose cone.... plus what ever else I've forgot.

I do want to make one point. Be careful. Porsche DID put 4 spd trannys in some of their early cars. Be sure you're buying one with 5 forward gears.

Good luck and let us know how you fare. I'm still wanting a 5spd tranny in my Bug.

Rick

i've got an extra tail-shifter 914 transmission i'd let you have for $75....since you are local (antioch), no money spent on shipping

only problem is what direction do you do need? since you'd have to flip the r&p if the motor is going to hang off the back of the car...with a 911 gearbox, no flipping is needed........

hey mike,
is your tail shifter from the 914 considered a 901 tranny? and is it pretty involved project to convert this tranny to a rear engine set up?

You would still need to flip r/p. you want a 901 out of a 911 (no flipping needed)

does the rear tail shifter out of a 914 still use the same shift rod/hockey stick as the 911 901 tranny's?

and are the 911/901 tranny's axles the same as the 914 axles and CV's? or are they interchangeable or do they bolt up?

Nope, they are different, I am going to use bus axles on mine once I get the adapters. Right now I am running the stock CV's and axles.

same bolt patter on the tranny flanges right? just different length???

911 are shorter