Jim Clark

Anyone try welding the Diff. in a 944 NA for track use?

38D

I'm not sure why you would want to weld up the diff in low horsepower car.

Alan Herod

Pesky, you should never question a racing legend.
Its the cheap approach to racing a low powered car that lifts a powered wheel while cornering. Many cars in the lower production classes of SCCA running with welded difs. When I raced a Bugeye I broke a lot of axles until I had the dif welded. Wheel lifted, tire spun, lost power, spinning wheel came down, and snapped axle. I had the dif welded on an IT car - a few problems - low speed push, and more difficult to move the car by pushing it.

Stuttgart

ahh.. the good ole "Lincoln Locker"

924RACR

Yeah, really... if you can't get the inside wheel to spin on an open-diff car - you're not driving it hard enough! I could regularly light up the inside on my racecar (with race suspension but stock motor) until I retrofitted a 951 LSD.

Sorry, can't provide any advice on welding the diff, though it's so cheap it's probably worth a try. Effectiveness may well depend quite a bit on where you run; would be more of a PITA on the tighter tracks, I think, but nice on the larger radii of bigger tracks...

ngoldrich

FWIW - I raced a high HP GT2 all season with a locked spool. I will be trying a guard clutch type diff after the Sebring race. The locker induces a tremendous amount of understeer and is incredibly hard on my front tires. The results may be different in your car, but I will be trying the reverse.

My guess is that a good limited slip with the proper locking ramps will be quicker in low power and high power applications. But I am no expert on the subject.

Norm

TREMPER

I ran a welded diff for five years in my 914-6. It helps keep the temperature down in the trans for there is less friction than a Quaiffe. The trans temp in a 914 runs about 340 deg F..moving to a locked rear dropped the temp to about 270..but there is a lot of understeer in tight corners..
Pete

ngoldrich

Pete,

How about adding more coolers and a trans pump and a clutch style diff. Maybe that will help both with temp & understeer.

Norm

TREMPER

Norm,
I had a poorly designed cooler system on the trans before we welded the spiders. I am going to a better diff this year so we will see how the temperature fairs. The locked rear also helped on breaking... allowing the rear wheels to brake evenly. Now I have a wing to help the breaking with better downforce. I liked the locked rear at fast sweeping tracks like Watkins Glen and Sebring (except for the hairpin), but lost out at tracks with tight turns like VIR and Summit Point.
Pete

GUMBALL

There is no inexpensive limited slip available for many cars, so the "only way" is to weld the spiders.
BUT, having run both a limited slip and a spool in both a Trans-Am Camaro and a Porsche RSR, I found that the limited slip is definately better...everywhere.

Jim Clark

I appreciate all the view points.
If anyone has a line on a LSD that's not going to cost more than my ITS car is worth, I'm in the market. I've worked quite a few locations for about six months looking for either a whole transaxle or just the LSD unit but have come up empty.
As for the under steer or push, I would suspect that with the 50/50 balance on a 944 and having the ability to get the car to turn, this may not be as much of a draw back as thought. As Alan stated, when the spinning wheel captures grip again the likely hood of snapping a half shaft, CV, or diff. is much greater. We ran a locked diff in an EP TR3 back in the late 60's and were just seeing if this trick was still being used today on the transaxles.

Thanks and would enjoy any feedback available.
Jim

Bill935K3

HI Norm, I’ve been biting my tongue RE your spool rear end and push problems, your too quick to be giving advice to!! Now that cats out of the bag I’m happy for you that you will not be burning front tires unnecessarily. See you at Sebring we should have a good race. Savino from CT has a new power plant and so due I.

ngoldrich

Bill,

I am really looking forward to Sebring. You and Savino are already wickedly quick. Why new motors ?

For Sebring I will still be running the spool. That wont change until after Sebring. My engine is also being freshened as we speak...

Will you be running the test day also ?

See you there.

Norm

ngoldrich

Bill,

One funny note - I won Watkins Glen only because of someone else's misfortune. Rick Deman had a small interaction with a backmarker, and then Savino ran out of fuel.

It was poetic justice that my next race was at Putnam and I ran out of fuel while leading the race.

I now have a larger fuel cell with a surge tank...

Thought you'd get a kick out of that.

See you @ Sebring...

Norm

Bill935K3

Hi Norm,
Savino grenaded his motor as he took the checked flag at Lime Rock. It was a 3.0, John Milledge is building him a 3.2 with all the cool stuff off his old one. I have been running an old CIS injected 3.4 with home made fuel enhancement. At 80 hours (real good service) the mushroomed valve guilds (we rolled the dice) let through too much heat. See attached photo. Unfortunately I was leading the VIR enduro at the time, we are going to real computer controlled injection. I hear DeMann sold the GT2 and got a used GT3rs. If he dropes a TT motor in it we are in for it. I ran against a guy named Jim at Mosport who dropped a TT in a late cup car (ABS and the latest suspension) we split the weekend he took the sprint and I won the enduro. See you down south!!!