better? 915 or boxster (5sp) transmission in 914 Options

[Wes V]

In light of the fact that it is possible to use either transmission in a 914, it poses a couple questions.

Which transmission is stronger, 915 or boxster 5 speed?

Which has the best support for repair?

Which has the best selection of aftermarket gears?

After going through the expense of doing the Wevo conversion on the 915, would it shift as well as the boxster with cable shifter.

Am I correct that the total cost of converting a 915 using the Wevo kit would come to close to $2500 minimum. ($2000 for sideshift kit and another $500 for shifter) This assumes you do the work your self.

It seems like the 915 would cost twice the amount (for all hard parts and used transmission) that a boxster would cost.

Wes

[Chuck]

(IMG:style_emoticons/default/welcome.png) The 915 is going to be cheaper to do. As I understand, the Boxter transmission requires a fair amount of work to get it to fit into the 914. One member here (abc123 I believe it is) did a Boxter transmission. There is a writeup here as well as on the Pelican Parts board. He hired it out and I believe the total cost was close to $20k. The 915 has been done many many times and there is a lot of help out there for getting it in.

The Boxter tranny is easier to shift. It is also stronger.

Depending on what you're doing, the 901 may be your best choice. Replace the shifter bushings and put in a Rennshifter and you should notice marked improvement. I plan to run my 901 with a Rennshifter behind my 3.2. I'm sure others with more knowledge than me will chime in on some of your other questions.

[Aaron Cox]

i believe andys stuffed an audi or boxster tranny in his 914. cool little sub frame.

there is a pic of it in the 'paddock section' in a thread called 'springs and perches'

[andys]

I'm not sure how one would go about adapting the Boxster/Audi 012 transaxle to a type IV motor. The starter mounting provision is not in the traditional 914 location. You'd also need an adapter plate, as the bellhousing is not the standard Porsche circular type design. The 6 speed Boxster transaxle, though circular bellhousing design, has the starter in the 12 o'clock position.

Andys

[Brett W]

You can not use a Boxster transmission in a 914 with either and aircooled 6 or a four cylinder. There is no provision for starter.

[jd74914]

Its been done Brett . . . how I don't quite know. This scar has a Boxster 6spd and 3.2L /6. I wish there were more pictures to figure out how.

[andys]

i believe andys stuffed an audi or boxster tranny in his 914. cool little sub frame.

there is a pic of it in the 'paddock section' in a thread called 'springs and perches'

Here's a slightly better photo of the install. Transaxle is an 01E 6 speed. This is however a V8 conversion.

Doesn't the 6 speed Boxster locate the starter on the engine block at 12 o'clock and points forward? No starter mounting provision on the trans, right?

Andys

[Brett W]

Not sure about the 6 speed but my five speed would not work behind any four or 6 without an adapter plate and some sort of starter setup.

[Brett W]

Here is another pic.

Notice the cutout for the nose of the starter.

[PRS914-6]

The 915 gives some nice options...I bought a used one for $500.00 and rebuilt it.

Gears are readily available in almost any configuration
WEVO kit makes a nice installation and works great
No cable shifter required
Bolt in deal, no fab required

No need to buy a $500.00 shifter. WEVO, good shift linkage (Patrick) and 911 sport mounts will give the desired results.

A stock 915 shifter can be had for about $50.00 if you look

I have a re-geared 915 in my car with the above. It shifts like butter and I'm quite happy with it. First gear is good for 52 mph.

[jimkelly]

doesn't 915 require RP to be flipped? at what cost and who does it?

my understanding is that the 930 box is the best of the bunch?

but a 901 box can handle 300hp and long as you don't have fat grippy rubber.

patrick motorsports for linkage - http://www.patrickmotorsports.com/category/10/

fun 901 box video - http://www.renegadehybrids.com/914/Subie/Videos/Video01.avi

jim

The 915 gives some nice options...I bought a used one for $500.00 and rebuilt it.

Gears are readily available in almost any configuration
WEVO kit makes a nice installation and works great
No cable shifter required
Bolt in deal, no fab required

No need to buy a $500.00 shifter. WEVO, good shift linkage (Patrick) and 911 sport mounts will give the desired results.

A stock 915 shifter can be had for about $50.00 if you look

I have a re-geared 915 in my car with the above. It shifts like butter and I'm quite happy with it. First gear is good for 52 mph.

[Brett W]

Yes the 915 Requires the ring or the tranny to be flipped.

[Aaron Cox]

as do any rear engine trannies that are going into a mid engine config

g50 - upside down
930 - flip or run upside down
915 flip or run upside down

[andys]

Here is another pic.

Notice the cutout for the nose of the starter.

Brett,

I've never actually seen a Boxster 5 speed engine and trans assembled together. Does the starter fit the pocket of the trans, or is it located elsewhere? In that pocket location, would the strater not run into the right cylinder bank? I don't quite see how it would fit. Got a photo of the assembly?

BTW, that model of transaxle is the same as the Audi 012 5 speed found in nearly every Audi/Passat front drive car from somewhere around '97 and up. You don't need to pay Porshe prices. I've seen low mileage 012's for $300. The only thing you get with the Boxster version (if it's included in the sale), is the shift linkage for the two push-pull cables.

Andys

[roadster fan]

I have a Boxster 6-speed, and the starter pocket is at the 12-o-clock position. I really cant comment on what would be required to make that fit with a aircooled 4 or 6.

The issue with the Boxster 6 speed mated to non-aircooled motors looks to be how tall it is and modifications are required to the trunk to make it fit. The rear trunk support (dog-bone shaped support) needs to be notched. I think the pelican thread on the subject had some good pics, IIRC.

Jim

[Brett W]

Actually my gearbox is from a 99 Passat. According to the Getrag website it is the same as the Boxster tranny. But I know for a fact the output shaft flanges are different, but they are interchangeable. I thought the starter came out at the twelve o'clock position but didn't see it in the pic of a Boxster engine.


The tranny featured in the Pelican article is a different tranny. It is a G50 variant.

[Dr Evil]

What are you going to put it on? V8, /6, /4?

[Brett W]

Me?

[EMRoadster]

as do any rear engine trannies that are going into a mid engine config

g50 - upside down
930 - flip or run upside down
915 flip or run upside down

Anyone have any good souces for info/tips/specifics etc. on what should or should not be done when running a 915 upside down?

Thanks,

[LvSteveH]

The 915 is fairly simple to flip the ring and pinion internally, so it's uncommon to see them run inverted.

The 930 requires quite a bit of work to flip the ring and pinion, so you'll see several cars running them inverted instead. The G50 diff is not able to be flipped, so they all run inverted in a mid-engine configuration, but do so without complaint.

as do any rear engine trannies that are going into a mid engine config

g50 - upside down
930 - flip or run upside down
915 flip or run upside down

Anyone have any good souces for info/tips/specifics etc. on what should or should not be done when running a 915 upside down?

Thanks,