Merkur XR4Ti ??

[ih8hardtops]

Hi everyone. I'm new here and I'm in southern Ontario Canada. Lately I've had the urge to build my own roadster. I got pretty excited when I learned that a North American Merkur xr4ti could possibly be used for the build (I think) My son has one that we're pulling the 2.3 turbo motor out of for his project, but he doesn't need the rest of the car. We also have an extra engine (unknow condition internally).
So what I have kicking around is this,
-basically entire xr4ti (alloy wheels, T9, Koni suspension, etc)
-MG Midget seats
-autometer speedometer
-gauges
-enough tools
After I do a little more research, it looks like I may take the next step and order the book. Is the Haynes manual the one that would fit my build the best??
Thank you very much, and
MERRY CHRISTMAS.
Jeff

[alga]

Welcome to the forum! By all means use it as a donor. And do get the Chris Gibbs book. Essentially, you'll use the front hubs, transmission, diff, driveshafts, rear hubs, steering shaft from the Merkur. They're getting rare in Europe too, so having one at your disposal across the pond is a chance that's too good to miss!

[ih8hardtops]

Originally Posted by alga

Welcome to the forum! By all means use it as a donor. And do get the Chris Gibbs book. Essentially, you'll use the front hubs, transmission, diff, driveshafts, rear hubs, steering shaft from the Merkur. They're getting rare in Europe too, so having one at your disposal across the pond is a chance that's too good to miss!

Thanks Albert. I looked at your build. Nice job . Sure wish I could read it.
Jeff

[XR4BILL]

Hi Jeff, my name is Bill, and I live in Calgary. I am getting the parts together to hopefully start building in the New year. My base will also be the XR4Ti.

cheers,

Bill.

[ih8hardtops]

Originally Posted by XR4BILL

Hi Jeff, my name is Bill, and I live in Calgary. I am getting the parts together to hopefully start building in the New year. My base will also be the XR4Ti.

cheers,

Bill.

Hi Bill, Noticed in another post that you are pretty familiar with xr's. Do you have an opinion about the durability of the T9 and the xr's open rear end? I'm kind of considering maybe just biting the bullet and going with a T5 before I build an entire car around a T9. I also have a GM 10 bolt posi rear in the garage I could use (currently 2.73 ). Thanks and Merry Christmas
Jeff

[snapper]

Do have a good hard look at the gear ratios in the gearbox's.
The T9 box has better ratios than the MT75, the T9 from the euro V6 engine cars a bit better than the 4 cylinder cars but I don't know what the Merkura ratios are. The T5 which Europe knows as the one fitted to the Cosworth Sierra has the best ratios available and is the strongest of the gearboxes, I believe it was fitted to the Mustang over there.
It's all about first gear, MT75, 3.9. T9, 3.6. V6 T9, 3.3. T5, 2.9
Then look at tyre/wheel sizes and the Differental ratios, in the Euro Sierra we have 4 available ratios although there are more available
3.9, 3.6, 3.3, 3.14, in 7" & 7 1/2" crown wheel, push in or bolt on shafts and some with Limited slip (locker)
As a general rule the 3.9 & 3.6 are best for Haynes with car engines and the 3.3 & 3.1 better for bike engines

[AshG]

google translate works quite well on alga's build diary

http://translate.google.co.uk/transl...f%3D2%26t%3D14

[twinturbo]

Type 9 will be fine in most applications, it has less weight to get moving than in a sierra so the strain on the box is significantly less.

Basicaly you should be able to use the same components as any other sierra ( except 4x4 models ).

Your MG seats are probably no use though.

TT

[alga]

Originally Posted by twinturbo

Type 9 will be fine in most applications, it has less weight to get moving than in a sierra so the strain on the box is significantly less.

Hmm, I think the strain on the gearbox depends on the power (torque * rotational speed) being transfered though it, not the weight being moved or anything else. The torque, though, is limited by the grip of the rear tyres, which is directly proportional to the weight on the rear axle. I wonder, what is the practical limit of torque/power that can be put down on the Roadster with semislick tyres like R888?

It has been discussed several times on here that 160-180 bhp is the limit for a Seven type car beyond where there are diminishing returns from extra power. Perhaps that is the limit of typical road tyres with the roadster's weight?

[alga]

Originally Posted by ih8hardtops

Do you have an opinion about the durability of the T9 and the xr's open rear end?

The Sierra's standard diffs are said to last forever and deal with a lot of power withouth any problems. The only reason to use a different diff is if you want an LSD.