Lets talke gearing... wasn't using 5th at VIR at all.

[Gatorac]

Originally Posted by NZGTRA17

Jim,
not sure that RA cars had an open diff from the factory. Mine came with a True Trac LSD and the optional 3.5 gears. The True Trac acts like an open gear set if you lift a wheel and turn it but when torque is applied it is a very efficient LSD unit that is perfect for our low C of G cars.

Kel.

How could one tell if it is a true trac diff? Mine acts like an open diff when on the lift but I have never had an issue with one wheel spin on the track.

[Cobra4B]

^ I think that's how they work... when in the air they act like an open diff, but when torque is applied they function.

[Cobra4B]

Allright we're having 3.89 gears put in... she needs it anyway as the current gear set howls when hot.

[eric1h]

Originally Posted by Cobra4B

Allright we're having 3.89 gears put in... she needs it anyway as the current gear set howls when hot.

let me know how that goes and what the cost is, i want to go that route as well.

[Cobra4B]

The gearset from Richmond Gears is ~$230, the install kit w/ shims etc. is ~$120, and it's about 5 hours of labor = ~$800 out the door.

The gear calculator I found online says the car will go 151 at 6500 rpms w/ the current wheels/tires on it. That should be plenty for any track on the east coast I'll run. My Z06 would just nip low 150s w/ 500 horse and no extra aero. I'd guess the Panoz is doing around 140 on the straights.

[Panoz Paul]

Good Morning ... Question ... With the Richmond kit ; are the GT-Ra's pinions 28 or 31 spline ... The car is now in storage ; starting next race seasons parts wish list ; Dear Santa ( my wife ) ... lol Thanks / Paul ...

[PanozDuke]

Originally Posted by Panoz Paul

Good Morning ... Question ... With the Richmond kit ; are the GT-Ra's pinions 28 or 31 spline ... The car is now in storage ; starting next race seasons parts wish list ; Dear Santa ( my wife ) ... lol Thanks / Paul ...

Paul,
If you are doing a gear change, the axle spline count doesn't matter as you would retain the same third member. If you are planning on changing the carrier to go to a different traction control, then it matters. I think they are 28 spline, but I can not find the reference for that opinion. Jim Pomroy (Gatorac) can give you the definite answer since his is apart now see the tread on carrier bearings.

Mike

[Racer9007]

If you have a GTS you need to have a gear set that is machined for the TEX racing internal pump. Also I highly suggest having it REM finished, they run longer and cooler. Also check out Ebay, there are a lot on NASCAR take out third members that are sold as new spares that are complete and ready to go with internal pump.

[Gatorac]

Originally Posted by Panoz Paul

Good Morning ... Question ... With the Richmond kit ; are the GT-Ra's pinions 28 or 31 spline ... The car is now in storage ; starting next race seasons parts wish list ; Dear Santa ( my wife ) ... lol Thanks / Paul ...

28. I'll post all that I have learned about the diff in these cars once the project is complete and working. I am swapping gears and replacing bearings.

[Panoz Paul]

Greetings ... Is there any concern about 5th gear ; an over-drive ratio ; being loaded as a power gear w/ the lower diff ratios ... I know the Tremmec 3550 is very strong , but I thought its a worth the question ... Thanks / Paul W.

[NZGTRA17]

Originally Posted by Panoz Paul

Greetings ... Is there any concern about 5th gear ; an over-drive ratio ; being loaded as a power gear w/ the lower diff ratios ... I know the Tremmec 3550 is very strong , but I thought its a worth the question ... Thanks / Paul W.

The OEM torque rating that applies to the 3550 (375 or 400 ftlbs? as have seen varying numbers quoted) allows for the 5th gear situation so no issue due to just 5th that I am aware of Paul. Later variations of the 3550 such as the TKO 500 (500 ftlb rating) & 600 (600 ftlb rating) have uprated shafts and gear sets to handle teh additional torque. The cases and basic internal design is exactly the same as the 3550.

As changing the rear end ratio is after the gearbox it does not put additional load on the gearbox components unless you put sticky drag slicks on and are doing 5000rpm+ launches and then the load transfers back. Conversely low 1st gear ratios inside the gearbox (i.e. high numerical such as 3+:1 1st gear) normally result in higher gearbox loads (gears shafts etc) and lower OEM rating figures.

Kel.

[Wess-RA]

Has anyone run a cooling duct to the rear diff oil cooler? It would seem to be a good idea as there is no real airflow going to the cooler. Any suggestion on where to put the intake?