I have a 73 914 with a 450 hp v8 and have went through 3 transmission and am in the process of putting a 915 in it with a wevo side sift kit installed but I was told that I need to change the gears to work and was hoping that someone out there could help with the proper gears so I don't have to spend money learning which gears work.

thanks,
Keith

that is the longest sentence i have ever seen breathe man......just breathe

You need to flip the Ring and pinion around, aside from that you should be ready to roll. I am sure there are gearsets that are better choices than stock, but you shouldn't have to change it to get it to work.

are you asking if you need taller gears that would optimize your v8's drivability ?

QUOTE (Travis Neff @ Mar 1 2005, 01:12 PM)

You need to flip the Ring and pinion around, aside from that you should be ready to roll. I am sure there are gearsets that are better choices than stock, but you shouldn't have to change it to get it to work.

He is right, the gears should work just fine but you will need to get the ring and pinion flipped and that is not a cheap endeavor. I have heard others say you can just run it upside down but logically thinking, what the hell difference would that make? I have always wanted to ask that question when someone says it.

We've got to see this!

Running it upside down would be the same as flipping the ring gear and pinion. Its not that big of deal on a 915 to change. Its the 930 that takes all of the machine work.

Bob

QUOTE (skline @ Mar 1 2005, 01:17 PM)

QUOTE (Travis Neff @ Mar 1 2005, 01:12 PM) You need to flip the Ring and pinion around, aside from that you should be ready to roll.  I am sure there are gearsets that are better choices than stock, but you shouldn't have to change it to get it to work. He is right, the gears should work just fine but you will need to get the ring and pinion flipped and that is not a cheap endeavor. I have heard others say you can just run it upside down but logically thinking, what the hell difference would that make? I have always wanted to ask that question when someone says it.

Scott,

Running it upside down would be exactly like flipping the ring and pinion as far as the direction the tranny would turn. I don't know what other issues would come up though such as where the lube would sit, how would you drain it etc..


Andrew

So, I am thinking, if you run it upside down, you now have 5 reverse gears and 1 forward gear. What am I missing?

For 450 HP I'd say neither. You probably won't be happy with the 915 gearing, and by the time you change it you coulda had a 930. You may break the 915 too, 450 HP is stretching it. How long have your 901s been lasting?

QUOTE (skline @ Mar 1 2005, 04:29 PM)

So, I am thinking, if you run it upside down, you now have 5 reverse gears and 1 forward gear. What am I missing?

Wrong you would have 5 forward and a reverse running a upside down 915 in a mid engine car.

QUOTE (skline @ Mar 1 2005, 02:29 PM)

So, I am thinking, if you run it upside down, you now have 5 reverse gears and 1 forward gear. What am I missing?

lets say the output shafts are turning clockwise......
flip it up side down and now they run anti clockwise



think long and hard scott

thanks for the replies. I have already fliped the ring and pinion. All you do is flip it over with no machining needed.
I haven't used the tranny to know what is wrong or not, but I want to be able to use first gear. The 901 tranny's first gear is like a granny low and I'm not into rock crawling my 914. A friend is a fan of the 901 and dislikes the 915 so he is trying to make me run the 901, but it just can't hold the HP.

Keith

QUOTE (skline @ Mar 1 2005, 01:29 PM)

So, I am thinking, if you run it upside down, you now have 5 reverse gears and 1 forward gear. What am I missing?

Scott,

That's what would happen if you don't flip the ring and pinion or run it upside-down. You rotated the tranny 180deg when you moved it from rear drive to mid-engine, that's why it would run backwards. To fix, you flip the ring to the other side of the pinion, whether by re-installing, or by flipping the whole tranny.

Listen to Aaron. He's right for once.


Andrew

Ok, I get it now. This is a first for Aaron. Good boy!!!

The 901 trannys haven't broke but I can tell the two main shafts are begining to separate because the tranny starts making more noise. I usally swap them before explosion happens. After taking the tranny's apart you can tell explosion was going to happen shortly.


Keith

To make a 901 last you need to swap out the intermediate plate for an Aluminum one, replace the two Bearings with brass roller retainers, with new bearings that have steel roller retainers. Where the intermediate plate bolts together remove the short studs and replace with thru bolts.

HERE IS THE MOST IMPORTANT PART

Let the gearbox WARM UP.
Dont apply full power with a cold gearbox.
iIf you do the above a 901 will handle 300hp.

If a 915 has a vent at the top like a 901, your garage is gonna look a little sloppy flipping it over. I heard of running the tranny upside down, and one of the benefits is that most of the weight is now lower. Never did it, never saw it or whatever..

Oh, if you have a 915 with the later R/P 8.xx ratio instead of the 7.15 that will help (I think they changed to the taller ratio R/P in 74)

QUOTE (skline @ Mar 1 2005, 02:42 PM)

Ok, I get it now. This is a first for Aaron. Good boy!!!

whatever scott! how many times have i proved you wrong in your own garage?????

the gt rear swaybar? the stock rear springrate? the year fo door sill changes???? i know you remember those

bite me

Call Renegade hybrids... They have a solution for the 915 trani for gearing...

off their web site
"CUSTOM 3.1:1 TALL RING & PINION: The stock gear ratios in the 915 are rather low for use with a V-8. Thus, we offer our custom made, tall ring and pinion, which will dramatically increase your top speed in each gear. Installing this ring and pinion in a 915 transaxle will create ideal gear ratios for use with a V-8 engine.
"

QUOTE (Aaron Cox @ Mar 1 2005, 02:23 PM)

QUOTE (skline @ Mar 1 2005, 02:42 PM) Ok, I get it now. This is a first for Aaron. Good boy!!! whatever scott! how many times have i proved you wrong in your own garage????? the gt rear swaybar? the stock rear springrate? the year fo door sill changes???? i know you remember those bite me

*cough* exhaust gaskets *cough*

I was a witness. Aaron still owes scott 5 bucks.

I hear there's a custom R&P set that is geared taller $$$ , but if you've already got the Wevo going on, you're already too deep into this trans to get into a 930 reaasonably. . . if you figure in shift linkage.

I hear 1st gear is too low and 2nd gear too high in the 915 stock.

-'Chung

QUOTE (chunger @ Mar 1 2005, 03:19 PM)

I hear there's a custom R&P set that is geared taller $$$ -'Chung

I think those are already NLA.

That makes sense. . . at the time I was looking supplies were short, and the manufacturer did not plan on making another batch.

-'Chung

whats the ballpark on the R/P? a kilobuck?

The 3.10 R&P is NLA. One sold just over a year ago for about $1500.

Check with Rod Simpson. I talked with him late last year and he had (2) sets of the 3.1:1 tall R&P left to sell. He was asking $1600 for each.

Bill P.

QUOTE (Travis Neff @ Mar 1 2005, 02:20 PM)

If a 915 has a vent at the top like a 901, your garage is gonna look a little sloppy flipping it over. I heard of running the tranny upside down, and one of the benefits is that most of the weight is now lower. Never did it, never saw it or whatever..

Actually, if you run the tranny upside-down the weight is moved higher - however, the output shafts are higher too, which can be a good thing on a car that has been lowered a lot. In fact, the factory ran the 915 upside down in the 935 turbo for just that reason. They also relocated the vent, used an external cooler, and added a pump for lubrication.

-Ben M.

I believe flipping the R&P in a 915 does require machine work. At least I had to pay for machine work when mine was flipped. I think the case has to be clearanced. Wevo 915 = $$$$, I'm 9g's into mine with tranny/parts/labor/shipping. Good luck!

Have you dyno'd that engine? What are the torque values?
Horsepower doesn't hurt 901s, torque does.

The only way to make the 901 last behind a V8 is to either not enjoy the benefits of a V8 or put the 901 on a shelf and cover it in plastic. Then it would last indefinitely.

For the price of a custom 915 or 930 go ahead and setp up to the Mendolla transaxle. They are stong enough for 500+ and they are in my opinion a better value. For the same money, as a rebuilt 915, you can get the right gears, mid-engine setup, etc.

Now if you want some real power maybe and X-trac will be in your future. Should be good for 800+ but that whole straight cut gears will really cut into the radio on a long trip.

I have to strongly disagree.

i rebuilt a 901 and bolted it up to a V8, never had a bit of problems and i drove it hard.
Finishing 7th out of 60 cars (with 10 instructors) kind of hard. I drove it hard and raced it hard, but always respected the machine.
If you abuse a transmission it will fail, even with a 1.7.
i could break a 915 or a 930 transmission if I really tried.

if you exceed the torque capabilities, a 901 will fail also, but I believe most 901 failures are not due to excessive torque, but abuse. It happens but not that often.

Scott Mann had a 901 behind his V8 (with a claimed 565 hp? ) and it last for many years and he pushed the limit constantly.

Brett, Elaborate on the mendolla trani...

QUOTE (RUDEPEST @ Mar 1 2005, 01:36 PM)

thanks for the replies. I have already fliped the ring and pinion. All you do is flip it over with no machining needed. I haven't used the tranny to know what is wrong or not, but I want to be able to use first gear. The 901 tranny's first gear is like a granny low and I'm not into rock crawling my 914. A friend is a fan of the 901 and dislikes the 915 so he is trying to make me run the 901, but it just can't hold the HP. Keith

Do Not Use 1st Gear!!

This is what splits your 914/901. . . I have many years on mine, only 400hp

QUOTE (Andyrew @ Mar 1 2005, 06:34 PM)

Brett, Elaborate on the mendolla trani...

I'm not Brett but,

Mendeola Transmissions

QUOTE (Sammy @ Mar 1 2005, 06:27 PM)

I have to strongly disagree. i rebuilt a 901 and bolted it up to a V8, never had a bit of problems and i drove it hard.

Sammy, this is meant as no disrespect - I hold you in high regard w/ full Guru status. (Seriously) Ok, then... You have to take into consideration how much you drove the car like that. You drove it for less than a year didn't you? It held up to what you demanded of it, but for how many miles? 1,000? 3,000? Would it hold up to that kind of driving for another 40,000? Probably not IMHO.

-Ben M.

But, say a 901 lasts for 10,000 miles; then you blow it. You jus go out and get a new one, after all, they are really cheap and plentiful. How many 901's would you need to go through to equal the cost of a wevo 915?

Whats the cost of a wevo 915? 5k?? More??

901 trani's can be had for 100 to 500, or more.

Ebay at 250 all the time. Rebuilt at 400 on ebay.

sooo... 10-15 trani's at minimum??

Wana know in all honestly what I would do if I had a 915 trani? I would start modifying my engine, and then one day put on a turbo and make 600rwhp...

then bam, no more 915...

I think of the 901's as limiters

You've got a valid point.

I think in terms of a really CSOB, who likes playing with chevys too. We need a C6 auto or Turbo 350 for midengines. Something really strong and REALLY cheap (atleast they are around here)

Yup. Really need a trani like that.. But unfortunately, for that to happen we would need to have 2 million 914 v8 owners, and v8 conversions to be around for 20 years strong...

For now, I guess we can go with 915's as strong cheap(relatively) trani's..


I plan on buying one in about 3 months or so.. Depending on how well the 901 trani holds up at the wcc (I'll be bringin spare trani's, cv's, trailing arms, bearings, calipers, linkage, wheels, cables, plumbing, ext.. lol)

Andrew

Holy crap this is the way to go,they even have a sequential box, only $10k. I am going out the tommorrow and check it out. http://www.markssandtrans.com/
CCLINSHIFTYGUY

That box has 4.57 R&P. Off road gearboxes have gearing for Big diameter tires.

I have a feeling they can custom gear to my specs and or intended usage. At least they had better be able to for those prices.
CCLINGEARINGUP

450HP narrows your transaxle choices severely. If it's a track car you're mostly considering, then the transaxles with the straight cut gears would not be an issue. For the street; forget it......way too noisey. For your kind of power, the two reasonably priced choises are the 930 (which can be run up-side-down to save on costs), or for a few more $$ go with the ZF (like used in the Pantera). Both of these will already have ratio's suitable for a V8.

Andy

Here is my major dilemma with the V8 conversions, I don't want to baby it and wait for the next shoe to drop. If I have a T56 6 speed tranny behind a V8 I don't have to be careful what gear I start off in. I drop the hammer and go. That is what a V8 teener should do. In the spirit of Porsche it should be able to handle a little abuse. I can't stand cars that I can't hammer every now and then. Not all the time but when I want to run it better be able to keep up.

Mendeola does a sequential box that seems like a nice box. I would just rather have a good standard gear box that can take the power. Why bother putting a V8 in a teener if you can't take advantage of the power capabilities. I know the car weighs 2600lbs, but if you got 247+ cubic inches then why not make use of it.

The cost of a 930 box is close to 10K, the same goes for the Pantera box. Mendeola can get you a box for 6-8K$ that will be able to handle the power and the parts will be easy to find. Plus you get an over drive or a very tight ratio box for your street terror.

ZF transaxle out of a pantera - PROBLEM SOLVED

Ben, absolutely right.
I drove the car for about a year and a half, prolly around 4000 hard miles.
After that it was shifting better thasn when I put it in. How long would it last? Who knows. Maybe 5 years, maybe more.
I paid $75 for the tranny and $50 rebuilding it (gasket set, had all the spare parts necessary).

Many years ago Brad and I had a conversation about an Audi turbo 5000 automatic transmission.

He said it would work and would be tough enough (it uses some of the same internals as a ford C4), I never got any farther than taking some measurements.

That may be the answer. Those trannys are available in the pick a parts occasionally.

The Audi 5000 tranny is worth a look. It supposedly can handle 450 but there are dissenting opinions on whether or not it can handle any power. Some say yes others say nay. They will allow you to run 930 CVs and different axels. You will have to do a different shifter as the mechanism is on top of the tranny. The gear ratios aren't bad for a V8. The turbo box is a little better as far as ratios. There is a lot of info out there about them.

The G50 is a better choice. They are getting pretty easy to find although price is quiet a bit more than a 915 they are strong boxes.

When I did my 914/350 sbc conversion I'd heard all of the stories about 914/901 transaxles and was very worried about this. I managed to buy 4 extra sideshifts at a steal and figured this would take care of the problem.

I've driven my car ~10k miles and I'm still on the first Transaxle and I don't baby it. I'm able to spin the 255/40 tires at will and do almost every time I drive the car. The 914/901 has really surprized me on how tuff it is. I think the secret is to start with a GOOD transaxle and not a 30 year old POS.
I do recommend that you use the larger 86mm 911 cv joints and axles.

Bob

With my V8 914 I only used 1st for creeping into the garage or on a trailer to go racing, but on many, many occasions I lit up the tires in second gear because someone wanted to see it or whatever.
I had victoracers on it (205-50-15) so they were plenty sticky. I didn't have an LSD but could leave two nearly identical marks on the pavement for as long as I wanted to rev the engine.

One time at Irwindale a guy came up to me and asked, "how can you post such fast times with your clutch slipping so badly?"
I said "clutch, my clutch isn't slipping."
He commented that he can hear my engine rev up to redline out of every corner like the clutch is slipping.
I told him that wasn't the clutch, it was the back tires
I swear I could steer that car with my right foot. Almost felt like a rally car.

On the right track, I could and did shift from 2nd to 3rd without even using the clutch and never damaged anything.