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Coilovers / Spring Rates - Need Advice!

carcrobatics

carcrobatics

New member
Hello all, I'm about to bite the bullet on some coilovers for the FRONT ONLY. Reason being my B+G Spring + KYB AGX setup has a bit of sag in the rear. To be specific, I have a two finger gap in the front and one finger in the back. This picture below shows the difference pretty well. If you have trouble seeing you can zoom into your browser window by holding down the control button and scrolling at the same time, though I'm not sure that works on all browsers/computers.



So basically I'm going to drop the front down to a one finger gap to match the rear perfectly. I've never been on coils in these cars and I'm not sure what spring rate I should be running for this low of a drop. I know most people run 350# and higher to avoid bottoming out all the time, but I'm not sure how low they run their cars or what struts they use either. I'll be going with KYB AGX struts, and I'll probably be running them on the stiffest dampening setting at all times like I am now. Since I am only doing the front, I want to go as low as possible on the spring rate to match my B+G rear spring rate as well as possible for more even handling vs having understeer everywhere. Any and all advice is welcome. I know these cars aren't incredible in the handling aspect so you don't have to tell me that, if I have to run a high spring rate I'll probably just get a real stiff rear sway bar to even it out as much as I can.
 


i would get gr-2 with something a little heavier than 350. at 350 you will still bottom out ALL the TIME
 
The larger problem will still be the mismatch between the coil spring rate and the dampening rate of the strut... They need to be matched in order to work correctly. In other words, the GR-2's are not the answer. It may work for a little bit, but will wear out and leave you wanting more... Proper investment in coilovers and matched struts will run ya around a grand for the front alone.
 


What are your expectations of the GR-2's? You do know they're only a slight upgrade over stock... Do you honestly think $120 struts are going to perform?

If your are serious ​about wanting coilovers you should be looking at MonoTube struts like Bilstiens and having them valved to match the rate of the springs. You'll still have another issue that the height of the strut rod will be too tall as you're using lowered springs lol... But you wanna gangster the ride, go ahead, it'll still work... Lol, but don't think that GR-2's and a stiffer rear sway will fix anything. Sorry : )
 
I'd say most people blow the struts because of the compressed strut travel once you press hard enough on the lower limit of rod stroke it will blow the strut quickly.

The bisteins had way more to work with in stock form as far as rod length being shorter. They are still holding up with my 350# setup.
 


91parkave said:
I'd say most people blow the struts because of the compressed strut travel once you press hard enough on the lower limit of rod stroke it will blow the strut quickly.

The bisteins had way more to work with in stock form as far as rod length being shorter. They are still holding up with my 350# setup.
Click to expand...

Could you link me to the struts you're talking about?
 
coolone said:
What are your expectations of the GR-2's? You do know they're only a slight upgrade over stock... Do you honestly think $120 struts are going to perform?

If your are serious ​about wanting coilovers you should be looking at MonoTube struts like Bilstiens and having them valved to match the rate of the springs. You'll still have another issue that the height of the strut rod will be too tall as you're using lowered springs lol... But you wanna gangster the ride, go ahead, it'll still work... Lol, but don't think that GR-2's and a stiffer rear sway will fix anything. Sorry : )
Click to expand...

For the last time, I'm not running gr2's...
 
coolone said:
What are your expectations of the GR-2's? You do know they're only a slight upgrade over stock... Do you honestly think $120 struts are going to perform?

If your are serious ​about wanting coilovers you should be looking at MonoTube struts like Bilstiens and having them valved to match the rate of the springs. You'll still have another issue that the height of the strut rod will be too tall as you're using lowered springs lol... But you wanna gangster the ride, go ahead, it'll still work... Lol, but don't think that GR-2's and a stiffer rear sway will fix anything. Sorry : )
Click to expand...
although you are right, that would require a ridiculous amount of money.
 
BlackFlag said:
350# with gr-2s.
i have a .5" fender gap.

Agxs are known to blow just as fast as gr-2s. THAT is why i wont spend the money
Click to expand...

Besides the obvious difference in cost, don't the agx's handle the springs better?

I'll be lowered at a 1in gap. But that probably doesn't matter too much.
 


coolone said:
Bilstein Shocks for a 2000 PONTIAC Grand Prix including GXP

the Sport version
Click to expand...

That site is wrong.

Bilstein does not sell B8's for the W body.

They sell comfort and heavy duty valving B6's.

B8 is designed for lowering springs, typically work well with the H&R springs. Namely they have a slightly shorter rod, say 20-40 mm.

If you're serious about Bilstein coilovers, fill out this form: Fat Cat Motorsports - Consultation form, new monotube suspension, shocks and coilovers

But note it's going to cost you $50 for consultation, and the coilovers will be somewhere around 2500. Maybe.

I bought KYB Sports for my car, I really hate them. I'm contemplating going that route, at least for the front.

The other option would be to buy a set of bilsteins, and have them valved by a local shop, and put them together yourself.

Also bilstein offers revalving and shortening of the rod.

Expect to pay 70-150 for valving per shock, 50-80/per for shortening IIRC.
 
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