Rear suspension upgrade advices

[CLV8]

Hello.

Any of you already upgraded rear Jag suspension ?

I'd like single adjustment coil overs but don't know what to choose ? manufacturer ? reference ?

Thanks for your help.

OliveR

[strictlypersonl]

Which rear suspension do you have?

Jag in Jaguar subframe (very early cars).
Jag in tubular ERA subframe?
ERA rear suspension (outboard brakes).

[CLV8]

I have a Jag in Jaguar subframe so early car.

Thanks.

[Unique427]

I have BB Ford with Jag rear very similar to ERA.

Front: (2) QA1 Proma Star DD404 (dual adjust)
Rear: (4) QA1 Proma Star DD403 (dual adjust)

Link to expanded description:
https://www.summitracing.com/parts/qa1-dd403

Spring Rate Front: 350
Spring Rate Rear: 300

Adjustment knobs on bottom so compression/rebound
can be set for conditions on all (6) coilovers in 2 minutes.

Car tracks true and not a harsh ride at all.

Hope this helps a little.

[CLV8]

THANK YOU VERY MUCH for your detailed information UNIQUE427 !!!!

I'm going to ordered the reference you sent.

[Unique427]

Originally Posted by CLV8

THANK YOU VERY MUCH for your detailed information UNIQUE427 !!!!

I'm going to ordered the reference you sent.

Je vous en prie Monsieur.
Bonne chance.

[strictlypersonl]

The stock Jag rear dampers:
13.3" extended
10.3" compressed

The QA1s:
15.0 extended
11.1" compressed
At full droop, you may get universal-joint binding.
You will lose approximately 1.5" of compressed travel from ride height.

If they worked on the Unique, it might be that their top mounts have been raised.

[Unique427]

Originally Posted by strictlypersonl

The stock Jag rear dampers:
13.3" extended
10.3" compressed

The QA1s:
15.0 extended
11.1" compressed
At full droop, you may get universal-joint binding.
You will lose approximately 1.5" of compressed travel from ride height.

If they worked on the Unique, it might be that their top mounts have been raised.

Would this solve any potential issue?

QA1 DD401 & DD402
14.0" - Extended
10.125" - Compressed

Reference Info here:
https://www.summitracing.com/parts/qa1-dd401

[strictlypersonl]

Originally Posted by Unique427

Would this solve any potential issue?

QA1 DD401 & DD402
14.0" - Extended
10.125" - Compressed

Reference Info here:
https://www.summitracing.com/parts/qa1-dd401

Yes. Those seem to be size-compatible.

[CLV8]

Thanks to both of you for your help !!!

[EM-0785]

You mentioned you want single adjustment coilovers. If so, the QA1 part number scheme has the same numeric portion but with the letters DS in front for single-adjustable (DD for double-adjustable).

QA1 tech support can also walk you through the decision point considerations to verify in your application if helpful (measuring, end types, spring length, axle weight, etc.). Best of luck. Brent

[CLV8]

Originally Posted by EM-0785

You mentioned you want single adjustment coilovers. If so, the QA1 part number scheme has the same numeric portion but with the letters DS in front for single-adjustable (DD for double-adjustable).

QA1 tech support can also walk you through the decision point considerations to verify in your application if helpful (measuring, end types, spring length, axle weight, etc.). Best of luck. Brent

THANK YOU VERY MUCH FOR THE ADVICE Brent !!!

I've placed my order 2 days ago with Double adjustment QA1.

[EM-0785]

Originally Posted by CLV8

THANK YOU VERY MUCH FOR THE ADVICE Brent !!!

I've placed my order 2 days ago with Double adjustment QA1.

You bet! I’m glad to hear your selection and ordering seems to have progressed positively. May your install and tuning/drivability work smoothly as well.

I too have the QA1 double adjustables and have been very pleased with them. Felt like a whole new car.

Best of luck! Brent