Cost of 930 trans/rear-end swap for V8?

Scot · 07-18-2002, 03:27 PM

Now that I have my 350 Chevy (Chebbie as some call it)..914.....it still has the original 914 transmission and transaxle (is that the right name?).

I hate the gear choices too.... at 75mph in 5th, it is doing something like 3300 rpm...which is a lot for that noisy chevy....

anyway.... anyone have any idea's how hard it would be to have someone install the 4 speed 930 porsche transmission and transaxle? (plus the cost of the parts)?

what other choice do i have that will take some abuse? I think a few quick starts and I will have pieces everywhere.

thanks

Scot

Brad Roberts · 07-18-2002, 03:34 PM

I have done several and have one in progress right now.

Best thing since sliced bread. I have used the 930 box in V8 conversions for over 8 years now.

Dont puke:

Figure a minimum of 5k for everything.

Hydraulic clutch for the 914
New Flywheel/PP/Disc/ThrowoutB/Ring gear
Custom shift linkage or cable shift
Axles/CV's/Stub axles
Rear tranny mount
Flip ring gear in tranny (only 2-3 people around US can do this correctly, dont be fooled when you call somebody..they ship it out 99% of the time)
Core tranny (short or loing bellhousing 930) 76+77 had short 77 and up have the long bellhousing.
Limited slip is 1200-1400 at 80%

You will love it. Its like driving a 67 Muncie 4 speed Camaro

B

Brad Roberts · 07-18-2002, 03:40 PM

You should really join the Porschev group on Yahoo.

Your not going to get much support from the "Porsche" people.

I'm a car guy and dont really care what powers what.

Just so happens I have been in the Porsche arena for awhile.

I'm not old enough to build street rods yet...lol

Oh.. BTW, mathematically your car would do 180mph with the 930 box.

B

campbellcj · 07-18-2002, 04:10 PM

The guy I bought my 2.4/four from has a sweet 350 crate motor car with a 930 4spd and a cable shifter. Apparently it shifts like a megabuck race car and first gear is good for well over 60mph...only downside is that the trans setup cost him more than the entire 914 I bought from him...

Scot · 07-18-2002, 06:46 PM

are there any other choices beside the $5k 930 option? I am not going dragracing weekly, but would imagine some auto-x type starts here and there.

What about a 901 or 915 trans? I have no idea what I am talking about other than I would guess my setup would completely toast my stock transmission and transaxle right now.

thanks

Scot (was hoping $2000-$3000 tops.?)

rich · rich's Garage

There has been some discussion here about having the gear ratios changed in the stock transaxle. Try contacting Renagade or Rod Simpson. Your transaxle should hold up fairly well. I think you could toast several 914 transaxles for the cost of the 930 swap.

sammyg2 · 07-19-2002, 11:42 AM

A 915 tranny will cost almost as much to flip the ring gear and install.
I looked real hard at that option, but ended up staying with the 901 tranny (being a cheap so and so).
BTW, renegade hybrids and Rod simpson both offer modified 901 side shifters with higher 3rd, 4th, and 5th gears. oops, just saw that Rich posted the same thing, beat me by this much :-)

I also remember seeing someone trying to sell a 930 short bell housing tranny all set up for a 914 V8 in the recycler www.recycler.com for around $3500. No idea if it is still in there, but it is worth a look if you are in the market.

Brad Roberts · 07-19-2002, 01:27 PM

I agree the 901's are throw away boxes, but why waste your time re-gearing a box that is known to break under extreme loads ?

Same thing with the 915 box. By the time you buy the tall R+P and have it installed, you could have bought a 930 box and had it flipped for the same price without re-gearing it.

The 930 box withstood 6500rpm 425lb-ft drag race launches for several years before I broke a stub axle. In a 911 this equated to 60 foot times (on a concrete launch pad) of 1.28 with the front wheels 1.5 feet off the ground. Oh.. the car weighed exactly the same with the SBC (all aluminum engine..Donovan 400CI)

B

Old Car · 07-21-2002, 06:07 PM

scot

vertex in miami fl. can do a 915 box for you cheap they quoted me 350.00 for flipping the ring and pinion on my 915 box. and they also do rebuilds for 1050.00. its not over yet. you have to source a 915 box also. i got mine for 500.00 (84 carrera) what a steal! then you need custom axles, 914-6 axle stubs and 69-71 911 hubs and a cable shifter. thats just one way of doing it. a 915 with a flipped gear will handle 300 hp all day long. some people say they can handle more but that requires $$$$.

Brad Roberts · 07-21-2002, 07:02 PM

I have people safely putting 425hp through 915's.

The part your missing:

The 915 is not geared correctly for any of the SBC's. 1st is way to short and 2nd is a tad too tall.

All your numbers are dead on for parts and rebuild prices, but have you priced the tall R+P for the 915 ? so it makes the box livable on the freeway and makes the gears "better".

Again, your right back to the price of having a 930 box purchased and flipped. Same cable shift linkage crap and same clutch arm headache (in a 914).

Until you drive a V8 car with a 930 box.... you will never know what your missing.

rich · rich's Garage

I've never driven anything with the 930 box, but I was in Brads shop (BRM9148)about 2 months ago.My friend and and I are still talking about it. We were truly impressed. We didn't get to meet Brad or drive any of the V8 stuff he had filling up his building but we'll be back.... Hey Brad, How about a Porsche V8?

Old Car · 07-21-2002, 09:30 PM

scot was saying $2000-3000 tops.915 yes, 930.....NO.

im using a subaru turbo boxer engine. my 915 already has an 8:31 r&p (3.875 to 1) which will match my power band well. in my case low compresion,small displacement and turbo lag will love any short first gear.on second gear my engine will be on full boost and will welcome a tall ratio.

sure a 930 box is great but can you afford one?

i personaly like the subaru engine because its smooth, quiet, wheighs under 250 lbs and it mimics the original design of porsche
by configuration(flat four) and low center of gravity. you can get a new factory ej22t short block from subaru for only 1100.00. these engine's crankshafts are so tough that they can rev up to 9000+ rpms without failure.my set up should be putting out about 325 hp. below 6300 rpm.

i can understand why you would favor a 930 box for a v8 drag car.

Brad Roberts · 07-21-2002, 09:39 PM

Hey hey.. cool. Somebody else figured out you can use the Scooby engines.

We are gathering parts for a twin turbo conversion using a Scooby engine that was never brough into the USA.

It will be in a 914 using a aftermarket lap top programmble injection setup. (Autronic)

Little lesson in what kills 901's (not that you need one)... torque. That's all. A turbo engine doesnt make torque until a couple thousand RPM's off idle and under load. I feel a 901 will live just fine behind 325hp.

Can I afford one ? Yes. I understand the 930 box is not for your Scooby project, but just daily driving a 4 speed and being able to lug the motor around town in 3rd gear (using the torque of the SBC) is very appealing to my customers. They can drive it and hammer the gas any time knowing full well it will pull istelf from 2k RPM to 6500 without shifting until needed.

Old Car · 09:54 PM

brad, glad to hear youre also doing the scooby swap.

i just dont like that number 901!

that engine your using from japan is nice. theres one on e-bay right now. EJ20TT 280hp twin T. for only 1300.00.

Brad Roberts · 07-21-2002, 09:52 PM

I hear you about the 901.

We run them in our race cars with 325-350 hp.

The biggest problem we have is bad R+P's.

We may go through 3-5 boxes before we find a good R+P

Good luck with your project and make sure you document your procedure.

B

Dave at Pelican Parts · Dave at Pelican Parts's Garage

LOL! Talk to Ferguson about R&Ps! His would last 2-3 years before he tore the teeth off of the pinion gear. His comment to me, "Know what this says? This says that I have enough torque!" With that big grin of his... That was a really nifty Six!!

The Scooby swap has been done before. There's someone up in Chico, I think, who has a website documenting the swap. And I've heard it reported a few times as well. I think life is even easier with the Scoob, because you don't need a tranny adaptor. The same bolt pattern is used as the VW trannies (which is the same as on the Porsche ones). Flywheel is another story, but...

--DD

Brad Roberts · 07-23-2002, 01:19 AM

Eric Tischer is the guy your thinking of Dave. He is a engineering student at Chico state.

I applaud his "cheapness" on the conversion, but I could never build a car like that and expect to sell it later on to break even.

B

anthony · 07-25-2002, 05:42 PM

Probably a dumb question but how come nobody runs a 930/15 transmission upside down in a 914? Don't they run the trannys upside down with a flipped ring and pinion in 911 race cars to get a lower center of gravity?

Old Car · 06:40 PM

on a 914 if you run the 4spd upside down you dont need to flip the ring and pinion anymore. your engine will be really low yes but the tranny will be higher and you have to cutout the trunk sheet metal and replace with a tube frame.another thing to watch out for is tranny lubrication problems which might occur. theres a guy that has a v8 twin supercharged 914 with an upside down 930 box i think he spent 17 years building it.