Triumph Sports Cars

I'm beginning a 302 with a T5 conversion of my 1971 TR6. The plan is to use a crate engine listed at 340 hp. I'm not sure how much torque that equals at the wheels. I'm wondering if I really need to put in a Ford 8" rearend like so many people used. Can the stock differential take it?

I'm a middle aged guy with no aspirations for burnouts so we are really talking about high acceleration loads between second and third gear.

I'd rather make the switch now that the body is off but I don't want to spend the money, lose the handling advantages of IRS, or have the bolt pattern on the rear wheels differ from the fronts.


Thanks,

George

I can't answer your question but I can give you some perspective. I've run a high powered engine in front of a stock MGB axle for years, with limited incidents of wheelspin but frequent power applications at speed and my experience was that although the axle did not break, it wore much more quickly than I would have expected. Look at Calvin's build. Also in the MGB section the 340 thread has a good analysis of various differentials both for IRS and otherwise.

JB

Hi George,

You could do a bolt in R200 differential from Richard Good which would keep your IRS suspension. It is what I'm using in my build. When my build gets on the road, should be pushing close to 420 rwhp. I'm with you in not doing burn outs or drag racing, more like spirited driving and some auto-X. My build is here..[forum.britishv8.org] You will need to look on the first or second page for some photo's of the R200. Richard Goods website for R200 diff [www.goodparts.com] for axels [www.goodparts.com]

The stock differential could take some but you won't be happy with it in the end unless you get better guts in there.The differential will start to make noise. I believe Ken Schmidt used an up rated TR6 diff in his TR6. [www.britishv8.org]

The R200 LSD that I'm using is out of a Nissan Q45 which is a fairly heavy car with close to 300 HP. They have use R200 long nose differentials in drag cars and put them through a beating.

Some have used Corvette differentials like Jim Prettyleaf. [www.britishv8.org] Would take more fab work here.

Ken Percival TR6 has a 289 Ford engine. He was runing his stock diff and just changed over to the R200. When he took out his stock diff, the pinion bearing was going out. He said he was very careful with it, not to abuse his diff.
[www.britishv8.org]

I believe Rob F is building his mgb with a 302, using custom made IRS using a R200s diff also
[forum.britishv8.org]

Hope this helps some with your end results, and good luck with your build.

Maybe some others will chim in!

Calvin

Stock dies right around 200hp.

RGs bolt in is a short nosed R200.

Rather than type or cut and paste, just read this.

[forums.hybridz.org]

The pertinent piece is here:

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.

It'll answer any questions about the R200/230 and any of the others in that series.
I personally wouldn't put a solid axle in.
If you want to do that buy a TR8 or an MG.
Both come that way, and the conversion cost is way lower.

If you are putting a 300+hp engine in please please please budget to change the halfshafts and rear hubs also. They are absolutely not up to the job.



Edited 1 time(s). Last edit at 02/08/2010 09:42PM by alana.

>If you are putting a 300+hp engine in please please please budget to change the halfshafts and rear hubs also. They are absolutely not up to the job.


Thanks guys; your replies answer all my questions. I'm still reading my way through Calvin's long thread. It seems we are pretty lucky to have Goodparts.

I've never worked on a rearend. How hard is it to install all these parts?


George

It all bolts in.
Put a jack under the diff before you drop it. It's a lot less painful than dropping it on yourself.
Trust me...