How much power can a Midget rear end take?

How much horsepower can a stock MG Midget rear end take before it comes apart? Are there any easy, cheap rear end swaps for the Midget?

Word on the street is ~100hp. I put 120hp from a 12a through mine with not so sticky tires for a while. I'd say I punished it and it seemed to be ok.

I wouldn't put more than maybe 100hp through it and expect much durability though. There are parts to make them handle more though, they cost $$$.

The closest to a cheap simple rear end swap is a 1st gen RX-7 axle narrowed. Unfortunately unless you want flares like me, EVERYTHING is to wide for a midget, so you will have to narrow all axles. I said screw that and decided to widen the car. Your call.

@ 90-ish I've twisted an axle or two. The diffs don't seem to be the problem so much as the splined area where the axle meets the diff.

In reply to nocones:

If you're narrowing the axle, why does it really matter what the donor vehicle is, within reason? I mean, Pinto 8" seems like a great smaller axle for an application like this once narrowed properly, just as an example.

pres589

That is a good point. It really doesn't. I just know that the RX-7 axle is popular for midget people for whatever reason.

If your going to pay to have one narrowed I'd chose the one with the best assortment of LSD options, ratios, and brakes that isn't grossly oversized for you application.

How much would it cost to have a rear end narrowed?

If the answer is MGB, let me know. I have the rear axle from one that I want to make go somewhere else.

I thought I heard somewhere about someone putting S-10 or maybe Ranger rear ends in these... I could be wrong though.

If it were me I'd go with a toyota "T" code aka 10 bolt rear from 70-80's corrolas and celicas. Why? They take loads of power. The're front loading (mini 9 inch ford type) There's aftermarket support for axles in diffrent widths (axles come in three sizes with 6 inches of spline cut off what to don't need) There are full floater kit availible! (www,dwarfcarproducts.com) Theres 7 ratio's availible from factory 330 to 430 Retubing a factory housing with DOM tubing is around $300

The Midget I had with a 1600 Fiat engine used to consume rear axles at a regular rate.

The RX7 axle seems to be a compatible axle. Not sure what all is involved in shortening them. I suspect ratios, lsd and disc brakes are going to be factors. Weight also is bound to be lower with the RX7 part.

I'm building a bugeye, and used a mid 80's toyota VanWagon rearend. Narrowing, resplining axles, and a TruTrac installed and set up-$900 . I feel I got an exceptional deal from the local 4X4 shop here in Mid TN. The chunk is the same as late IFS toys front diff, and 2X4's rear, so lots of ratios available, but I figured the stock 4.10 gearing was good. All that said, unless you plan for mucho power, the rx7 looks better to me (Lighter, stock brakes would be fine)

I broke 2 or 3 axles with my ~90 hp 1275 before swapping to 4age 20v. I think the easiest and most documented is the rx-7 rear- no pinto due to weight and the availability of rear discs. The rx-7 has many rear diff ratios, many lsd options, and are really strong. You can find documentation on the interwebz if you look hard enough. I got a quote for around $300 to have it narrowed.

Me? I fabbed a bolt-in miata based independent. PITA.

Go with the rx-7 and you won't be disappointed.

Which generation RX-7 first or second or does it matter?

I'm sorry, I read the thread title and instantly started cackling like a middle school boy.

^--what he said.

Car people: the only people who don't laugh when you say, "I spent Saturday night at the drags and ended up blowing a tranny."

This thread title should be added to this list.

In reply to 96DXCivic: First. Second gen is independent. You'll want the GSL-SE if you want disc rear brakes. You'll have to have the bolt pattern re-drilled to 4x4" if you want to retain MG wheels. I think board regular Brian Kraus used the RX7 rear. http://www.britishv8.org/MG/BrianKraus.htm Another: http://the-mite.com/mite22.htm

What exactly does narrowing a rear end require?

In reply to Teh E36 M3:

I have knock-offs on both cars so I doubt I will be keeping the stock wheels.

"the mite" site is pretty thorough on that subject. that link shows a pretty comprehensive narrowing. Otherwise, there are shops that will do it for you.

slefain wrote: I'm sorry, I read the thread title and instantly started cackling like a middle school boy.

+1

The SCCA FP & GTL cars are probably putting 140-150 crank HP through them without too much trouble.

However, you need $600 worth of comp axles & $600 worth of double bearing rear hubs to make them work. (plus a rear disc conversion if you dont want oily rear brakes).

KJ

In reply to Teh E36 M3:

Thanks for the link looks like there is a lot of good info there.

I've read it all before, but I did just spend the last hour looking through it all again. My site and build aren't nearly as good, but take what you will:

www.home.earthlink.net/~roethler www.picasaweb.google.com/brust.roethler

96DXCivic wrote: What exactly does narrowing a rear end require?

About 6 miles of walking three times a week, along with a sensible diet...