915 Transmission questions, Can I... Options

[mike_the_man]

I'm thinking about doing a V8 conversion, and I'm looking at picking up a 915 transimssion. The guy that's selling it says that you can run the tranny upside down, rather than flipping the R&P. He says that it offers more ground clearance, and you don't have to mess with the speedo drive. Is this true? I don't think I've ever heard about this before. Also, what is a good price for a 915 tranny in unknown condition? How much would it cost to rebuild? Sorry, I'm pretty clueless when it comes to transmissions. (IMG:style_emoticons/default/wacko.gif)

Thanks all,

[phantom914]

Actually, flipping the tranny up-side down will reverse the rotation as suggested. The question is, what other problems might be introduced? We need an expert here, maybe somebody who has tried it.


Andrew

[lapuwali]

There are two on Ebay right now. One is $500, no bids, the other is at $51 with a few bids and 6 days to go. Keep an eye on those and you'll know in a week what the rough going price is. I'd say $1000 is steep. A used 901 in average condition is about $150-200. A 915 is not 5 times better.

Flipping the R&P wouldn't be all that big a deal. It would be a lot easier than trying to mount the thing upside down and dealing with venting issues and the linkage.

As far as the speedo drive goes, just use an electronic speedo driven off one of the wheels or a CV joint.

[davep]

I think the factory did that sometimes, but it also used forced lubrication. Not a bad idea with high power throughput. Venting would have to be re-engineered.

[lmcchesney]

I would think flipping the tranny upside down would be great. Imagine, five speeds backwards.
L. McC

[Mueller]

I would think flipping the tranny upside down would be great. Imagine, five speeds backwards.

huh???

he asking about a 915 transmission, these come out of 911's which have the motor facing the opp. direction....hence, flipping it would be the correct direction (IMG:style_emoticons/default/smile.gif)

I think you need a special adaptor plate, I know Brad had one for doing this with a 930 box....better make sure Kennedy makes this before you commit and come out of pocket with too much money...

have you checked out the classifieds section yet? someone is selling a conversion kit with a 915 transmission for only 1K......sounds like a good deal depending on what is included in the kit.

[davep]

Flipping a 911 tranny for use in a 914 prevents the 5 speed reverse.
The factory reason was to gain ground clearance, and they flipped the R&P also.
I think the best solution for Mike is to get a good tranny through Brad. There is no point in getting a tranny that will need a full rebuild, especially since it is not a DIY project.

[mike_the_man]

Mueller, I'm actually talking about the kit and 915 from the classifieds. And, the more I think about it, the more I think it isn't quite what I want. Sounds like the 915 would be pretty expensive to make work, and isn't geared right. Anybody have any thoughts on this? Also, the kit is a Rod Simpson Kit, which I've heard isn't as good. There's no rad included, either. It's probably still a good deal, but I don't think I can afford it right now, and shipping would be pretty steep.

Any other thoughts on this? Is the 915 good for a V8 conversion?

[anthony]

V8 cars need the 930 transmission. Start saving!

[lapuwali]

There seem to be a good number of people who have actually had success using the 901 gearbox. Installing taller gears (not hard, as there are parts aplenty for it) helps, as Chevys prefer to cruise at 1500rpm, not 3000rpm. Use it as a four-speed, and simply remove first. Be relatively gentle on starts. This is far and away the easiest approach. All the parts are readily available, and you use the stock shift linkage.

I've seen a few 914/V8s using the 915, either with a custom made linkage, or one of the very expensive retrofit kits (like the WEVO or the Vellios). I've only seen one (the Renegade house car) using a 930. The 930 looks like a major pain in the ass to fit (requires a custom cable linkage). Renegade did it because they have essentially free labor, machining, and fabrication, and this is their top-of-the-line demo car.

If you really want the skinny on V8s, go hunt up the lists haunted by these guys. Porschev is one, I believe there's at least one other. You'll hear it directly from people living with these cars.

[John2kx]

Mike,

From my experience with a v8 powered 914, the stock 901 has worked well for almost two years now. Sure, I'd like to regear it and will do so in the future. In stock configuration, it's hard to beat for the money.

I have not babied mine but don't use it like a drag racer either.

Reading opinions about 915 vs. 930 over the years, it seems the 930 is the way to go but expensive. The 915 is a little stronger than the 901 but costs allot more to stuff into a 914.

I would opt for a regeared 901 over the 915 for the cost savings. If money is no object, go straight for the 930. From what I remember, the going price for a rebuilt, regeared 901 is about $2000. A modified 915 price tag is not in the memory banks and the 930 is about $6000.

John

[John]

If you are installing a 915 box in a 914, I would not "flip" it over to keep from "flipping" the ring gear over, If you do, you may have some problems shifting it. The 915/916 kit shifts out the bottom/side much like a side-shifter trans per the attached photo.

I would have to disagree and say that the 915 is a much stronger trans than the 901. It is a good conversion for heavy duty use 914's (V8's, BIG 6's, etc.). We had enough torque we broke several 4th gearsets with several 901 boxes before doing the 915 and haven't had a problem since.

[Brad Roberts]

Yep. NO need to flip a 915 upside down for a 914. Flipping the ring gear is pretty easy. You have to modify one shift rod and have the R+P reset. Flipping it would be a clutch/shift linkage/drain/fill nightmare. The 915 stock is not geared even close to matching the torque of a SBC. 1st is too short and 2nd is almost too tall. I have been driving around a 930 boxed V8 914 for several weeks now. It is SOOOO nice.. it puts a big shit eating grin on your face. The ratios are PERFECTLY split between the gears. It is a lot of work (and NO you dont have to run cable shift.) Sooner or later WEVO will have a mid-engine shifting solution for the 930 (at my request) It differs only from the WEVO 915 kit by the tail cover and some minor changes in movement of the hockey stick.

After you re-gear a 915 and set it up to run.. you could have had a 930 box for the same price.


B

[neo914-6]

Mike,
Deciding what kind of car you want and your budget will dictate your component selection. The 914/901 works and has limits. The good thing is if you break it you can buy another relatively inexpensively. My meager 283 and 901 tall geared tranny is still thrilling with it's power to weight ratio. The 915 and 930 trannys reliably allow high HP engines and amazing performance but at a higher cost. This is a major decision point since you can build a nice 6 or choose another performance car for the same money. Most of us never consider the costs when building a car so what the hell just go for it...
Felix

[ajracer]

Greetings

Hoping that maybe Brad or Fleix could shed some light for me on the V8 conversion whereby a 930 tranny is used.
I understand from my preliminary research that major modification is necessary to "flip R&P" and since I live in Toronto, Canada shipping would be expensive to CA.

I am still in the start-up phase for my project conversion but recently acquired a good 915 tranny and looking to
update to "taller gears R&P" Just today I located rebuilt excellent 930 tranny and now starting to second guess myself and think if it is possible to run the tranny "upside down" and make some changes to handle the lubrication
and venting. Is it possible or would the costing be greater than having the major mods to flip the R&P. Sorry for the long winded request. But hopefully I will only have to do
this conversion once, and that Correctly. Thanks guys.

Allan

[9one4racer]

Allan, you may want to check this out
914 V8 check out transmission page
930 tranny run upside-down

http://www.v8914.com/

[bob91403]

Mike,

From my experience with a v8 powered 914, the stock 901 has worked well for almost two years now. Sure, I'd like to regear it and will do so in the future. In stock configuration, it's hard to beat for the money.

I have not babied mine but don't use it like a drag racer either.

Reading opinions about 915 vs. 930 over the years, it seems the 930 is the way to go but expensive. The 915 is a little stronger than the 901 but costs allot more to stuff into a 914.

I would opt for a regeared 901 over the 915 for the cost savings. If money is no object, go straight for the 930. From what I remember, the going price for a rebuilt, regeared 901 is about $2000. A modified 915 price tag is not in the memory banks and the 930 is about $6000.

John

(IMG:style_emoticons/default/agree.gif) Everything I've read on the subject says the 901 will handle a great deal of horsepower. "Just don't do burn outs in first gear, it'll break". A lot cheaper to gear it up the way you want, and replace it if you wear it out.

[neo914-6]

Mike,
You may want to contact Paul (also in CAN) pgunn914v8@hotmail.com about his turbo V8 914. He actually chose a Pantera transaxle because of the power he's running but I'm sure he researched alternatives. Another source is discussions on the Pors-chev.com bbs.
Felix

[Series9]

I have a 915 limited slip with a Vellios conversion. It set me back about $5000, but I considered it necessary to handle the 3.6 (993).

If you light 'em up with a big engine through a 901 tranny, you WILL break first. It's a weakness of the tranny that really can't be fixed.

If you can't light 'em up for fun, you might as well keep the four cylinder.

Joe (IMG:style_emoticons/default/burnout.gif)

[spare time toys]

After you re-gear a 915 and set it up to run.. you could have had a 930 box for the same price.

So what do you have to do to a 930 box? Flip anything or plug and play with an adaptor? (IMG:style_emoticons/default/confused24.gif)