Audi 016,Porsche 944,Re-spline of 016

[Julian]

Managed to get a loud bang, followed by unhappy noises as I coasted to a stop the other day. My Audi 016 in my DRB GT40 is now not happy, and neither am I! Will pull the trans on the weekend and have a look, but I'm not optimistic about what I'll find. It was toughened up with a case stiffening plate, plus a Quaife ATB diff centre, so I was hoping for a little more life than under 1900 km.

Mind you, I'd just had the engine finally sorted with a lot of time on the dyno, but still not happy about it breaking the first time I gave it full throttle in 2nd gear. Motor made 386 RWHP on a hot day, so I suppose it's a bit much for trans considering the car is mostly for track use, not that it's seen much while I iron out problem after problem.

Anyways, see my post in the parts wanted section if you can help with a G50 trans!

Cheers,

Julian

 

[Joe]

Re: Audi 016 goes Bang!

I've been trying to follow the 016 posts on relative strength. The guys on the porsche hybrids forum are using 944 turbo transaxles with ls1 making 500+ crank horsepower and the thing that breaks is the axles. They act like fuses.There has been a number of discussions about using the audi trans LSD in the 944 transaxle but I'm curious if the audi box is for some reason weaker. The 944 cars are about 2200 lbs. Could that be the diff? Is the 944 016 a better choice for your application?

 

[Pete McCluskey.]

Re: Audi 016 goes Bang!

Julian keep looking for the G50 I've not heard of anyone breaking one.
Although I'm sure it's possible. Bad luck BTW.

 

[Woody]

Re: Audi 016 goes Bang!

Sorry to butt in Julian
Pete , you say you haven't heard of anyone breaking a G50 are you refering to a G50/50 or all G50s in general? Just that Ive got a G50/01
and have been thinking of up grading to a G50/50. Are they really that much stronger given that we pay twice the price.:cry:
I would really like to know if anyone has broken one and how much power did it take:shocked:
Any comments
Julian
With any luck this may start a good conversation that may help you decide too:thumbsup:

 

[Russ Noble]

Re:G50 Failure

From another thread....

Well, after much fooling about and much spent, my proper motor is finally done and ready to go in to the 40. I've had my DRB GT40 registered for nearly a year and not driven it since rego as it was built initially to get through registration requirements with a suitable motor and I have since spent the last year getting a roll cage, proper exhaust, decent engine and body and paint. Time flies when you're spending money...

Anyways, after two aborted attempts the engine got on the dyno on Thursday. Result after a bit of bedding in was 415 HP at 6900 rpm. Couple of things to note:
1) Since motor is brand new they only gave it 20 deg total ign advance. Guessing it should be closer to 35 - 38 deg total advance, so that should get the power up a bit.
2) Power was still climbing at 6900 when they decided to stop! Think the combination is a bit more revvy than I had planned! Not a bad problem to have given the short gearing in the 016 trans. Not sure how hard I should rev the cast crank and I beam rods however, but there's only one way to find out! My previous track car was a bridgeported and turboed rotary, so 8500 rpm was the fuel cut on that one, though I won't be going near that with this motor.

Anyways, soon as the car is back from the painters (hopefully in the next couple of weeks) I'll get the engine in and sorted out. Then onto chassis dyno and tune the motor to go properly.

Quick specs are:

Ford Motorsport Boss block
347 stroker bottom end (scat crank, rods, KB forged pistons)
Edelbrock Victor Jr Ali heads
Lunati solid roller cam 244/250 deg at 50 thou, 598 thou lift on both
50 mm downdraft throttle bodies and manifold from DC&O
Wolf V500 ECU to run it all (including 8 LS7 coil packs for spark)

Looking forward to getting it in the car and on the track. Acceleration won't be an issue I'm thinking...

I think you might have been a bit optimistic thinking the 016 was going to do the business.......! Particularly if you were going to track it!

Still I agree with Woody, we could turn this into a "G50 Failure" thread. We don't have one of those yet. 930 and ZF yes, but not G50, could be interesting.....

 

[Rodolfo]

Re: Audi 016 goes Bang!

Audi 016 goes Bang!

:-(

not a good news for me...

 

[Terry Oxandale]

Re: Audi 016 goes Bang!

I've got an 016 on standby for a worse case scenario, but as you've already conceded, 385 RWHP is pushing it pretty hard.

 

[Pete McCluskey.]

Re: Audi 016 goes Bang!

Sorry to butt in Julian
Pete , you say you haven't heard of anyone breaking a G50 are you refering to a G50/50 or all G50s in general? Just that Ive got a G50/01
and have been thinking of up grading to a G50/50. Are they really that much stronger given that we pay twice the price.:cry:
I would really like to know if anyone has broken one and how much power did it take:shocked:
Any comments
Julian
With any luck this may start a good conversation that may help you decide too:thumbsup:

I was thinking G50/50 worth the extra money IMHO.

 

[Jack]

Re: Audi 016 goes Bang!

There was at least one really well prepared G50 for sale here recently. Doc Kaler's gearbox.

 

[Doc Kaler]

Re: Audi 016 goes Bang!

It's still listed, FYI.

 

[Dave]

Re: Audi 016 goes Bang!

Is there anyone in the world that makes gear sets for 016's?
Straight cuts or similar?

I guess high hp sticky track tyres and getting on it popped the box.

Have any of the RF Boys had this problem? Who else use's the 016?

 

[Pete T]

Re: Audi 016 goes Bang!

The 944 cars are about 2200 lbs.

You're about 800-1000 lbs short. Try 3000-3200 lbs. I will have mine down to about 2700 lbs but I have fiberglass front fenders, hood, front bumper/spoiler, rear bumper, sunroof delete and non-pop up headlights. To get below this you need to gut the interior, remove the A/C, power windows, use a plexiglass rear hatch, fiberglass doors. The GTR and GTP race cars were about 2000lbs. and the D-Production cars were about 2200 lbs.

We have a guy with a supercharged LS1 in his and he drag races it often. He dyno'ed at about 600 HP and over 450 Ft. lbs. at the rear wheels. Another has a GSN turbo V6 also running about 600 HP at the rear wheels. Both cars have a 951 (944 turbo) transaxle. The guy with the LS1 also had the internals cryo treated.

The 951 transaxle is a pretty stout piece but not unbreakable. With a little machining you could put the internals into an AUDI case.

Although I am using a G31 in mine. It is much stronger than the 951. Unfortunately not really usable in a mid-engine car.

 

[Julian]

Re: Audi 016 goes Bang!

Cheers for the thoughts everyone.

I can get a G50 or G50/50 easily enough, but the costs to convert to add up very quickly. Though I will sell off the KEP adapter kit, clutch, starter and Quaife LSD to help a bit. I've been wondering if it is worth the extra to get a turbo /50 or /52 box and have more peace of mind given the car is for competition use. I've also been wondering if I can afford any of it too!

Mind you, I've also considered a 930 box, which I understand is also similar in strength to the G50 turbo boxes and cheaper than a G50. But the gearing is so tall with large gaps. At 7000 rpm motor rev limit I'd get 90 kmh in first, 150 kmh in second, 215 in 3rd and about 326 kmh (200MPH!) in 4th. Which is nice at Le Mans, but not so much for the short events I typically do. Our longest straight on a track in West Australia sees a speed of maybe 220 - 230 kmh for a very quick car. So that basically rules out a 930 box if I'm to get any use out of the motor top end power.

I too have read on this forum the process for putting 944T box internals can be butchered into an 016 case, but it's not straight forward. We'll see what damage there is once I get the trans out shortly. I'm getting good at that unfortunately!

 

[Ron Earp]

Re: Audi 016 goes Bang!

. At 7000 rpm motor rev limit I'd get 90 kmh in first, 150 kmh in second, 215 in 3rd and about 326 kmh (200MPH!) in 4th. Which is nice at Le Mans, but not so much for the short events I typically do. Our longest straight on a track in West Australia sees a speed of maybe 220 - 230 kmh for a very quick car. So that basically rules out a 930 box if I'm to get any use out of the motor top end power.
!

That is with the standard 4.22 R&P but remember you are not stuck with that. I have the 5.12 R&P in my Lola and at first I thought I'd have to change it for the 4.22 R&P. But now with two track days of testing I think it is about perfect. We reach the 5.9k RPM rev limit in 4th about 600-800 feet short of the braking zone at the end of two ~4000 ft straights, about 145 mph. Just let it ride a couple 100 more RPM and it is good. Seems like a great fit for the one track we've done.

Here is a good applet for the 930:

Gear Ratio Calculator - Porsche 993 Turbo

I don't know how many ratios are available for the 930, for sure 4.22 and 5.12.

 

[Russ Noble]

Re: Audi 016 goes Bang!

Ron that'd be a very expensive way not to really achieve anything!

Standard 930 ratios are 2.25, 1.3, 0.89, 0.64 and first is next to useless trackwise with the 4.22. Julians calcs seem to be a bit off. At 326 kph in top the other gears work out at 234, 160, and 92. So 3rd would seem to be in the ball park for his estimate of top speed on the track. Thus he has effectively a three speed box with first a bit on the low side and fourth not used.

With a 5.12 he winds up with 76, 132, 193, 268. First will be totally useless, but second would make an ideal first and 4th is over the top for him. So I think the 5.12 would be generally worse for him.

I haven't done it yet but next time out at the track I am going to try second gear off the line which at 6500 gives 90mph (about 145 kph) with the 4.22. The standard first just breaks into uncontrollable wheel spin when booted hard at any speed! Acceleration is blisteringly fast in 2nd, right on the limit of wheelspin with hot tyres so I'm sure if I can find the combination of revs and clutch modulation it will be almost unbeatable off the line. It's pretty good now, just gently using first to get it rolling and then getting it straight away into second.

Julian obviously has an eye on costs, so a 930 with maybe some ratio changes at a later date would not be too bad. Do the calcs for a G50 turbo and you may find that 1st and 5th are out of the ballpark! Not so sure about the non turbo....For track work any porsche will be better than an Audi simply due to the lower motor position

 

[Randy V]

Re: G50 Failure

I think you might have been a bit optimistic thinking the 016 was going to do the business.......! Particularly if you were going to track it!

I was thinking the very same.. Ditto for the 924/944 gearbox as it is very close to that of the Audi box..

When I first looked at the gearbox out of my 944 racecar, I thought about all the guys that were putting them in these cars and I asked myself -
How can anyone expect a gearbox smaller then the average lunch-pail to take any sort of abuse?
Now the G50/03 I'll be running may not be the most stout of gear-boxes, but I have to believe that since it's easily twice the size (transmission component) of the Audi, that it would be substantially stronger.

That's not to say that the crown wheel would be much stronger than that of the 01x Audi...

 

[Doc Kaler]

Re: Audi 016 goes Bang!

G50.50 3.44:1 final @7000RPM and 25.6" R6's:

3.15:1 = 49.22 mph
1.789:1 = 86.66 mph
1.269:1 = 122.17 mph
0.967:1 = 160.33 mph
0.760:1 = 204 mph

on my calculator.

 

[Ron Earp]

Re: Audi 016 goes Bang!

Ron that'd be a very expensive way not to really achieve anything!

I suppose different needs for different folks and locations. The 930 with a 4.22 and 275-50-15 tire yields top speeds at 6000 RPM of:

1-49 mph
2-84 mph
3-122 mph
4-171 mph

With a 5.12 and all else the same:

1-40 mph
2-69 mph
3-101 mph
4-142 mph

We've got both gear sets but since we're against a horsepower limit, that is don't want to make more, we're getting about all we can out of the 225hp we have with the 5.12 for this particular track. We don't do standing starts so 1st or 2nd isn't a concern. Essentially for racing purposes we've got a two gear box and we hope that will be easy on the driver.

The 4.22 might make 2nd gear usable in two corners though, so that is something to think about. But, as you say it is not an inexpensive proposition to swap out R&Ps on these.

I suppose it sort of boils down to the track, the intended RPM range, as well as the sorts of tires that he'll be running.

 

[Howard Jones]

Re: Audi 016 goes Bang!

Ron, you make a very good observation about using only two gears, 3rd and 4th, Very easy on the shifting dynamic for the driver and much less monkey motion in the cockpit. Then there is the added advantage of leaving a corner slightly below the power band versus after as in trying to use 2nd instead of 3rd. You will find that you can concentrate on your right foot/grip and not have to spend time shifting 2-3, just sort of feed in power and drive away smoothly in 3rd. This will be a big deal in a long enduro.

I have a 1.76 2nd and 1.36 3rd with a 3.44 final. I almost never need to slow down enough, less than 60mph, to use 2nd. That car of yours on dot slicks will never see slow enough speeds to need 2nd unless you need to cruise a yellow flag in a corner or pull back onto the track after a gardening event.

All in all it will come down to the lap speed target you intend to run for 12 hours. I think a quick but smooth and trouble free pace with less shifting will net you a better result than a lot of unnecessary, frantic gear-changes, zinging the motor and the potentially higher chance of gearbox/motor failure (missed shifts).

Didn't Mario Andretti set the lap record with a MK2 using 3rd and 4th at Le mans?

 

[Julian]

Re: Audi 016 goes Bang!

Interesting. For my purposes a lot of events are either hillclimbs or quite short tracks, where I'm lucky to get out of 3rd gear (assuming 3rd runs to around 150 kph). So for me, short gearing is fine. For the 5 or so events I did manage to compete in last year the 016 short gearing was fine, except 1st gear was only good to get off the line under part throttle. See videos I've posted on youtube for what it looks like from inside and out. Mind you, car was down a little on power for those videos compared to now, and not reving to 7000 rpm. Given that the motor power is still going up at 7000, I need to rev it. Maybe some longer intake trumpets and cam advance by say 2 - 4 deg is an option in the future to shift the powerband down a few hundred rpm.

Looking at a common non turbo G50 box G50-01, G50-03(the most likely option) with my 275 x 45 x 17 rear tyres I get following gear speeds at 7000 rpm (all in km/h):

1st 71
2nd 121
3rd 177
4th 230
5th 287

Which to me seems like a reasonable compromise between short gearing I'd like, plus allowing each gear a bit of time to load up the motor, instead of constantly changing gears.

Anyways, talk is cheap, I need to look at my budget!

Cheers,

Julian