CNC made aluminum Uniball rear suspension system

[kendy]

Ok, can you tell me which type of QA1 i should buy? And which springs?

[-Alex-]

QA1 Promastar, single or double adjustable. Dont know the exact lenght, you have to measure it. Stock irs shocks are about 11"-16".


Use around 350-425 lbs springs with stock weight drivetrain and mild engine, more hardcore motor etc maybe 450-550 lbs springs.


On steel irs arms you might have to drill another hole to the arm, see here:

http://www.germanlook.net/forums/sho...&highlight=QA1

Here are QA1 shocks on aluarms at Humbles car:

http://www.germanlook.net/forums/sho...t=7848&page=19

[kendy]

thanks, it helped me

[owdlvr]

Hmmm..seems my post from earlier today didn't work out. QA1 has changed their part numbers in the past year. The "popular" QA1 shocks on this site are the following:

DS402 - Single Adjustable Shock
DD402- Double Adjustable Shock

They use 2.5" springs, and you'll find that the spring interferes with both the stock shock mount and the CV Joint. Best solutions (IMHO) are to make new lower shock mounts and use Motorsport CV Boots. For the motorsport Boots I used GKN part number MSJ6002 (Type1 CVs):




For the lower shock mounts, I'd go with something fully custom build/welded as opposed to modding the factory mounts. I started with modding the factory mounts and so much is cut away its arguably not strong enough or safe.


-Dave

[Wally]

Doesn't have QA1 have 2,25" springs and perches? I even run 2.25" on the front (other brand).

Do you only run 300lbs springs on the rear? I started with that on the front and now run 400 already there...

[kendy]

hi freaks

so - if i choose DD402 should i use 9 or 10" springs? and fx on autofabcart are:

http://autofabcart.net/search.aspx?f...lse&category=4

350 lbs? 400lbs? i have vw1302 and 2028 engine

[owdlvr]

QA1 told me they only ever offered these with 2.5" springs, though someone posted up that their set was using 2.25" springs. QA1 said I could lathe down the perches (They don't sell a 2.25" set for these shocks) but when I did the math there would be so little meat left on the threaded perch I decided against it. The 300lb springs were used for testing/fitting only, as soon as the engine went in I moved to 550's.

9" springs will be a better choice, or even an 8". I'm using 8" 550lbs out back with my 1302. With the 8" length I can swap out the springs without having to remove the axle or anything else. The 9" springs I have just *barely* pop on without issues. I think if they were stiffer then 300lbs I'd have difficulty for sure.

-Dave

[Wally]

Yeah, 550's sound about right.

[kendy]

ok, i ordered 550 lbs

[-Alex-]

550 sounds a lot, but i havent tried yet coilovers at back. Mendeola uses most of the time at their rear kit 450lbs springs.





Does it just look like that with aluarms there is more room between coilover and CV joint boot, or is there?

[kendy]

so..i changed order for 500 lbs

[owdlvr]

Originally Posted by -Alex-

550 sounds a lot, but i havent tried yet coilovers at back. Mendeola uses most of the time at their rear kit 450lbs springs.

Two things to consider: The kits used in their photographs are for a fiberglass speedster kit which is considerably lighter. Their shock mounting points are changed and thus the leverage ratio is likely different then our (typically) stock mounting points.

With stock shock mounts a 300lb spring will have the suspension sink to 1/2" off the bumpstops with just a body & transmission. No glass, no motor. 550lbs rides well, slightly stiffer then stock, and still requires preload to adjust the ride height with a complete car.

-Dave

[Wally]

Good info Dave and nice pictures Alex!
Kendy, I think you should probably get used to the idea that a completely modified suspension with coil-overs is just not exactly right the first time and needs adjustments to work as well as you anticipated when you wanted to change from stock.
Buying more then one set of springs is part of that adjustment I think. I ordered an extra set of springs (they don;t cost much btw) two years in a row and I think I have it set now. Sometimes you also need to get used to new springs a little. I changed over back and forth a few times and got a feel for what works best better now.
With a 40/60 weight ditribution (guesstimate) I guess for my car a 600lbs spring theoretically sounds best with my 400lbs front springs, but you never know till you try it. For now, I seem to overpower the 25.5mm rear torsion bars with drag starts. Each application is different is what I am trying to say and multiple sets of springs might just not be avoidable.

[Wally]

Originally Posted by -Alex-

Does it just look like that with aluarms there is more room between coilover and CV joint boot, or is there?

Alu arms are wider in general as you know, but the CV sits even further in the arm, making the shaft itself relatively longer then the increase in track width would suggest. Hence never a clearance problem with the CV boot.

Nice set-up BTW. Who's (german) car is this? I would like to see where he has mounted that sway bar and who's coil-overs thos are.

[-Alex-]

Don't know that car, i have had that picture few years. I remember that you have aluarms also, what lenght shocks are you using?

I havent yet bought rear shocks, just today got hubs and hats anozied to black, they are awesome. Now sawing for the transaxle.