What's better for road racing?

A posi or a locker? Either an eaton posi which will cost more ( including the gears and install kit) or a lockright automatic locker? I have 273 gears right now and I plan on putting in an overdrive 200 4r in the future so I just don't know what all I need to do. Will the gears be to tall for the 200 4r? Can I still do a burnout with that auto locker?

 

For actual road racing, a true posi is going to be superior. Sometimes the auto lockers can be unpredictable locking and unlocking in cornes, which is not what you want on the track.

 

A 2.73 and a 200-4r is a total mismatch. Road racing with an automatic is not a great idea.

 

I probably should have said road racing down the highway. I really don't want to do a lot of fish tailing when I take a hard turn.

 

Ah, big difference, lol! :laugh:

On the street, a lunchbox locker, or auto locker should be fine. And I agree, that's WAY to high a gear.

 

The beauty of a 200-4r is that you can run up in the 3.23-3.42 range and it'll keep you nicely in your powerband on most cars.

 

I'll have to think on it, cuz If I go with the eaton posi then I have to change the gears but if I go with the auto locker I don't have to change the gears.

 

If I do change gears I'm thinking of going with the 373 ratio.

 

Most of us use the 3.73 with a 200-r4 if using a performance cam. 3:55 works well with smaller cams.

 

possibly 3 posi units to consider depending if you have a 12bolt or swapped in 9in

one will be the wavetrac...supior to every posi out there...but pricey ..you can get this for ford 9 in 31 and 35..and 12bolt for 35spline

second would be detroit tru-trac.. you can get this for all axles

3rd would be the ford trac-loc if for somereason you wanted a ford unit in your 9in..

these are all torsen type posi units

 

ps scratch the ford trac loc..its not the same as the other two ive mentioned..as it has clutches

 

I put a powertrax locker in my carrier last summer. Just remember to buy the Richmond cross shaft like they recommend or they will not warranty the unit if it fails. I haven't had any problems with mine.

I've been looking at going with a 2004-R and i agree, your rear end is gonna be REAL tall. We're talking 100mph cruising in the powerband. :TU:

If you go with the trans swap, you may as well go with a "real" posi carrier and install a 3.73 ring and pinion.

 

iF YOU HAVE A 10 BOLT 8.5 you will not need to swap out gears to get a EATON limited slip differential posi unit. 2.73 -5.57 are all on one carrier.

12 bolt chevy you would need to swap out the carrier and even then I have 2 series posi unit that is a factory eaton for that 12 bolt rear also. SO that should not be a concern to worry over.

THE TRUE TRAC is a MUCH better way to stop the fish taling you might have with performance curve driving. Ok? Jim

J D

 

It's a chevy 8.2 rear end. I wish I could get the truetrac but they don't make it for the 8.2.

 

Yeah, that's something I gotta fix also. I swapped in a 200-4R late last summer but left my stock gears alone; I'm guessing they are 2.73 also. It feels like I can go 200mph down the highway!

I'd go with a posi over a locker personally.. something else I gotta put on my list!

 

Brand new Nitro Eaton clutch unit 389.00 DONE.

400# preload
Carbon fiber clutches
Hardened spider gears

13.50 shipping to all 50 states with out the original box.

With the original box will have to run a zip code through the fed ex ground computer.

Jim

 

Jim is that one for a chevy 8.2? I'll buy that off of ya asap when I get the money. That the best price I've seen:eek2:
And I'm thinking of 373 gears but I hear that 355 will work better for a stock engine. What's your opinion on that?

 

gear choice is a choice better made by what your car will be doing more of. Highway track time light to light action
It will also be persuaded by the small or large cam shaft overlap steeper gears will be needed for a long duration cam as its power band and optimal rpm range is higher which means you need to keep the rpm in that optimal range for driving.
Tire size again will affect the ratio output the rear can supply. smaller tires tend to raise the rpms larger diameter tires will lower the rpm ratio.

finally torque converter stall another reason in picking the correct ratio to keep it in a locked up state when normal driving range. IE if you have a 3000 stall and you car / engine cruises at 2000 rpm on the freeway, your converter is eating gas and creating heat form excessive slippage because the motor is not putting out the RPMs to keep it close to its lock up stall speed.

SO all these things help pick the right ratio for your car.

With the overdrive 200r4 373 with 26" tall tires and 2000 -2500 stall will be a great street strip combo that will please MOST Guys with some Muscle.

IF you like the freeway seen more and go further distances 3.42 / 3.55 will be a better choice and still give you the low end pull for lively driving.

Jim
J D

 

That first option is what I'll probably be going with.

 

Thanx for the posi I'll let ya know when I get it installed.