What HP level requires transmission upgrades?, I have 200 HP to the wheels, what do I need? Options

[Charles Freeborn]

Thanks for the great replies everyone!

Seems like the 901 should last a while with the right upgrades.

Love the gear ratio chart @slivel!

I plan to run the same cooling pump and radiator that were in the car when I got it.

Adding a spray to the diff seems like an easy upgrade and maybe a couple more, like 3rd, 4th, 5th gears.

Do most people use -10 AN lines?

If I use the billet intermediate plate, do I need to reset the pinion depth? That is a big question. If not, then I think it is a no brainer to get it.

Maybe the 108mm CVs from the 930 are overkill? Maybe the 100mm CVs would be enough?

John

In answer to the billet plate question, yes and yes. The intermediate plate takes a lot I of abuse as the thrust is directed at it. The billet upgrade is very worthwhile for that as well as having a superior (and new) int main bearing retainer. It is also wise to drill out (ideally on a milling machine) the case and use through bolts and Jet nuts as the threads in the case are also stressed.
As for gear lash set up; yes. The int plate swap is a complete tear down so all the tolerances will need to be checked and likely reset. Get used to doing this regularly. Nothing beats up gears of any kind more than excessive lash.
Traveling at the moment but will post pics of my rebuild when I get home.

[campbellcj]

My experience has been similar to above. My box had been built by John W at Ottos many years ago and was behind a relatively low torque 2.2 at first, then the significantly stouter 2.7. It has a 904 mainshaft, oiling mods, billet int plate, guard TBD and short gears.

By the last couple track events I did it was really shot including the R&P, several gears, synchros and various other bits. All freshened-up now including new clutch & flywheel, intermediate plate, and rebuilt diff as well but I still have no cooler on it. I actually have one in a box taken off a retired POC 914-6 racecar, but haven't pulled the trigger on the install and am not sure how much fab is entailed. It's definitely on my list as I don't want to have to rebuild that extensively again anytime soon (ever) and this car sees significant heat loads - high RPM in desert conditions.

In terms of the intermediate plate, my old one (Weltmeister) apparently had no bushings/bearings and was showing some galling, and also may have had some heat deformities, possibly was the culprit of the thing jamming in 4th prior to being replaced. The new one is bushed. Anyone have experience or thoughts on that?

[Charles Freeborn]

My experience has been similar to above. My box had been built by John W at Ottos many years ago and was behind a relatively low torque 2.2 at first, then the significantly stouter 2.7. It has a 904 mainshaft, oiling mods, billet int plate, guard TBD and short gears.

By the last couple track events I did it was really shot including the R&P, several gears, synchros and various other bits. All freshened-up now including new clutch & flywheel, intermediate plate, and rebuilt diff as well but I still have no cooler on it. I actually have one in a box taken off a retired POC 914-6 racecar, but haven't pulled the trigger on the install and am not sure how much fab is entailed. It's definitely on my list as I don't want to have to rebuild that extensively again anytime soon (ever) and this car sees significant heat loads - high RPM in desert conditions.

In terms of the intermediate plate, my old one (Weltmeister) apparently had no bushings/bearings and was showing some galling, and also may have had some heat deformities, possibly was the culprit of the thing jamming in 4th prior to being replaced. The new one is bushed. Anyone have experience or thoughts on that?

I have it on rather good authority that the Intermediate Plate made for and sold by California Motorsports is of good quality. https://californiamotorsports.net/collectio...ermediate-plate

[campbellcj]

I have it on rather good authority that the Intermediate Plate made for and sold by California Motorsports is of good quality. https://californiamotorsports.net/collectio...ermediate-plate

I hope so - that's the one I just got! (IMG:style_emoticons/default/driving-girl.gif)

[campbellcj]

(IMG:http://www.914world.com/bbs2/uploads_offsite/live.staticflickr.com-21-1666631352.1.jpg)