44 replies to this topic

[turbotory]

Has anyone fitted coil overs to there lx , I recently bought a kit from Mc Donalds bros in Melbourne just
Wondering if I will need an engineer cert once its fitted
And how much of an improvement over standard set up are they .

[myss427]

I have the fronts coilovers (QA1) and no you don't need an engineers as a lot of cars come standard with coil overs. So long as they mount in the standard position with the same spring location you are ok, that what I was advised.

[ls2lxhatch]

Arguably the lower spring mount has changed on the coil-over so it could require engineering.

 

The only real advantage you get from fitting the McDonald Bros (QA1 Pro Coil) coil-over shock setup is ride height and shock adjustment.

 

As far as performance goes the QA1 Pro Coil coil-over shock setup has no advantage over an equivalent quality shock and spring using the factory setup. 

 

The biggest problem with the QA1 Pro Coil coil-over shock setup is finding springs with a suitable height and spring rate to suit a Torana. Last time I checked McDonald Bros were supplying 250 lb/in or 350 lb/in springs which you then cut to suit the Torana. The standard Lovell V8 springs are 650 lb/in.

 

The reduced height available for the coil-over spring would probably make it impossible to fit a spring with a rate suitable for track work..

[turbotory]

The kit is for a hq but will fit an lx torana I was told I had to cut the front springs to suit the rear set up will not be mounted in the original position so I guess I will need an engineers cert for that .
Thanks for your response

[ls2lxhatch]

I doubt an engineer would pass the cut front springs if they saw them. The spring tower in the Torana is designed for a flat top spring, the cut springs will have a pigtail top.

 

I have found a flat top spring available in 375, 500, 600 and 700 lb/in that may be suitable for QA1 Pro Coil setup in a Torana. I have a 600 lb/in spring to test but I have not had time to put the car together to see how it will sit

[myss427]

Mine sits perfectly with the springs, ride pretty good and yes you need the spring with the flat top, -2 at the end of the number if I remember. I have the 350 springs, with the alloy engine its about the same weight as a 308. if I went 250's I probably have a bit more adjustment but tyre is just below flair and I like the ground clearance I have.

[Uncle Chop Chop]

I doubt an engineer would pass the cut front springs if they saw them.

If you cut a spring and it had the same amount of coils as a standard spring after the surgury, that should be fine. Reducing the number of active coils is illegal.

[ls2lxhatch]

The factory spring is flat at the top and has a pigtail at the bottom. If you cut a factory style spring at the bottom you still have a pigtail so it will seat in the lower control arm.

 

The QA1 Pro Coil spring is flat at top and flat at the bottom for the shock. The spring that McDonald Bros supply is too tall for the Torana so it needs to be cut. If you cut the spring you will end up with a pigtail which the engineer should knock back.

Edited by ls2lxhatch, 27 May 2013 - 10:16 PM.

[ls2lxhatch]

The QA1 Mustang spring is the only option I have found off the shelf to suit a Torana with QA1 Pro Coil Shocks.

 

The 600 lb/in and 700 lb/in springs would the two options depending on preferred ride height and engine weight.

http://www.qa1.net/s...-system-springs

 

The Lovells Standard Torana spring rates can be used as a guide to what spring rate you should be looking for.

 

Lovells Standard Torana Springs
Standard 6 cyl spring range 590 lb/in
Standard V8 spring range 760 lb/in

 

V8 Track cars run 850 – 1000 lb/in

 

I bought the Mustang 600 lb/in springs to suit a LS2 with my preferred ride height, on paper they work out about right. I won't know for sure until the car is finished.

 

I know of a hatch with a BBC that is using the 700 lb/in springs, they were happy with the ride height.

Edited by ls2lxhatch, 10 December 2015 - 03:39 PM.

[Bigfella237]

One thing I've always wondered with those QA1 front springs is, being different diameters top & bottom, does that have a "progressive rate" effect?

 

Also, I just went to the McDonald Bros website and they don't seem to list QA1 coilovers any more? The only brand I can find is Viking...

 

[Bigfella237]

That's the sixty four thousand dollar question Daz.

 

I would assume their custom lower control arms would be designed to take the load...

 

 McDonald Bros LH-LX Tubular Lower Wishbone.jpg   37.09K   13 downloads

 

...but personally I hate the idea of the vehicle's weight being supported by two small lower shock mount bolts each side.

Edited by Bigfella237, 10 December 2015 - 06:14 PM.

[Bigfella237]

At the very least I'd like to see the shock located on top of the control arm so the bolts are only locating it and the weight is borne by the metal arm, this wouldn't really make any difference to fitting as you can't remove a coilover shock without relieving the spring tension anyway like you can with a regular OEM-style shock.

[Bigfella237]

While we're on the subject, anyone know if our LCAs are interchangeable with the early Camaro stuff from the US (I know the ball joints are the same)?

 

I've seen some really beefy-looking tubular Camaro arms available...

 

[Bigfella237]

I'll have a search around to see if I can find a technical drawing of the Camaro arms to compare to ours, they look very similar although the bump stop and swaybar mounts are different?