Q45/IRS.

[roverman]

POP HOT RODDING, 6/09, page 30. They briefly mention using an Infinity centersection mated into 280 Z, IRS. Anybody have info on this diff"?  Should take more HP. than Series II/RX-7. Suggestions for suitable, OEM. 5/6 spd. transaxle using 500-600HP., in smallish roadsters ,like JH. or MGB?  Thanks, roverman.

[74ls1tr6]

Hi Art,

Here is some information I found awhile back when researching for my ride. I'm using the Q45 R200 LSD 3:54:1 ratio diff in my build. Using Porsche CV axles. If the R200 breaks, I would adapt the R230 in there, or replace the CV axles.

http://forums.hybridz.org/showthread.php?t=114798

[roverman]

Calvin thanks. So the R230 is stronger? Any other ratios avail.? Ring gear dia. or feel for HP. it will stand?  Art.

[74ls1tr6]

Art,

 The R230 came in 3.54.1 and 3.69.1 . There may be more ratios.

This was taken off the link above....below

The torque capacity of the shortnose R200 should be equivalent to the R200 longnose, which means it can handle a lot of abuse. 400 lb/ft should not be a problem with the R200 shortnose, and it will probably hold a good amount more if the VLSD is used. There is apparently another model of the R200 shortnose which has 5 bolt output flanges on the sides of the diff. This model should be avoided, since the CV adapters we have available use the 6 bolt flanges.

The R230 is bigger than a 9" Ford differential, so we're talking HUGE torque capacity here. I suppose we'll have to wait for someone to break one before we'll know for sure.

[BlownMGB-V8]

Art, the series number stands for the ring gear diameter in metric. So a 230 is about 9". A bit largish. A 200 is just a little under 8" and may or may not stand up to the horsepower levels you propose. By contrast the MGB ring is around 7-7/8" IIRC and good for up to around 300 hp max. The 8" ford axles seem to be standing up rather well behind 302 SBF engines of up to 375 hp factory rating. The Dana 44 is about an 8.4" ring and good for 500 hp. (Jag IRS) To me this seems the best compromise for the MGB. It's really too bad Nissan did not see fit to produce a 215 series diff. That would have been ideal. However, in some applications smaller ring gears seem to be holding their own and hopefully Calvin's will be one of those. It's really too pretty to go changing it!

Jim

[roverman]

Thanks guys. I have a 4.10-posi, Series II, Mazda modular set-up but I don't trust it for those power levels.Road racers claim to be putting up to 500 hp. thru them, using a cooler. I'm thinking the're not getting the shock loading of other forms of,"spirited driving".  I would like to hear of an OEM. 5/6 spd. transaxle that would handle 600 hp. ,with a cooler, in a 32V/4.6L, Jensen Healy. suggestions anyone?  roverman.

[rficalora]

Probably depends too what you'll be doing with the car Art.  Unless you have really sticky tires & are dumping the clutch the tires will break loose way before the diff sees all the torque the motor could throw at it.

[roverman]

All true. Thats why I believe the Mazda set-up is well suited for my MGB build. No drag racing but oooh so good corner burnin. So I'm still gonna need a savy transaxle for the Healy. Thanks, roverman.