Has anyone done this? Pics would be great! I thought to put a Sierra IRS in the car but wanted to see if other have done this modification before.

I'm new here.....a proper introduction to follow.

I own a 1976 Capri II with a 300HP turbo 4 on the other side of the pond.

 

Hi

I am taking it that by IRS you mean Independent Rear Suspension. The answer to your question is a yes and no. For starters if you REALLY want to fit back end off a Sierra into a Capri you could do it (if you're into good welding n stuff) however I do not recommend it, because it won't handle as good as you might expect. You might end up making your Capri handle like a pig.

If you're looking to improve the handling of your nice 300 BHP baby there is other routes you can try depending on your budget.

First Step Starting from the most economical one, a good set of single leaf springs off a 3 litre MK3 with polyurethane bushes and A frame arrangement will drastically improve your handling. If you got some more cash there are some coilover kits which can be mounted on to your existing rear dampers but this does not mean that you will eliminate the leaves. I know of some people who tried it. The only effect they got is harder suspension at the back thats all. This would help relocate the axle under heavy cornering and would eliminate some other axle movement.

Second step up (if you got some more cash to spare that is). You can put in some nice adjustable shockers from GAZ (which are currently installed on mine) and they are good value for money.

Third step, if you're into drag races and stuff like that (so racing on a straight track). I DO NOT RECOMMEND that you remove the live axle because it is far better on the straights than the Sierra item. However if you want to keep the Capri's axle from twisting upwards due to the high torque, you can put in some lifters OR an Air suspension system which locates between the live axle and the chassis. Lifters can keep the axle fixed from twisting, but will also harden the Capri's ride completely. The advantage of air suspsnsions is that you can fill them up with air(through some motorized air compressor) stiffen the back end as much as you want, race a couple of times and then release the air again thus getting all the soft ride back again.

Fourth step if you REALLY like your Capri and you have some extra cash to spare I recommend that you talk to Ric Wood (these may be found at http://www.ricwood.com/capri.htm). These guys specialise in Capri performance as well as handling and they did some quite nice jobs out there. They will typically turn your Capri into a proper race car and optimise it for maximum handling. It won't be cheap but its good value for money.

I hope that thie post was of help to you. Feel free to take a look at my build

Cheers

 

First step is done. 4 leaf spring set from a US supplier by the name of Team Blitz. The car has a full poly bush kit.

I guess the second step is done too. Koni yellows

I guess my motivation for this is a bit of wow factor. I know I could build a fairly indestructible rear axle with a pan hard bar for lateral movement.

The car is not a drag car. It's a street car that will eventually do some fun time road racing and autocross. Nothing serious or overly competitive. I've been to the 1/4 mile track with it but it's not really my thing.

 

ok then ... I guess you should opt for a the Air Suspension and the Quaife LSD with ATB if you have a stock axle.... This will improve your stability as discussed earlier ...

 

IRS in a capri will look really odd theres a cortina MK3 on youtube with this see it and you will understand

IRS is not as good at launching as a live axel which is well set up

Paul

 

 

If you don't mind a bit of fabrication then fitting a WRC full cradle is an option and MK Motorsport thinks he has reduced the cost of producing them, he can sell the mounts as well for the pick up point on the car, this allows you to mod it to run any diff that you want (my choice would be ally one from USA spec muscle car) We are fitting the cradle to my car at the moment and you can make the track any width you want and place the geo pretty much where you want it etc.

I would have thought a well linked live axle can be made to handle really well?

 

 

You can have them made as narrow track, I may be taking a bit of width out of mine as my car is a Pug 205 with wide arches, that is still a bit narrower than an escort WRC car.