Written by Mike Napurano, Member 1 Applies to the following vehicles: 1997-2003 Grand Prix Created 5/19/1999, Updated 3/25/2003
Write-Up Rating Rated by 11 members
Well, here you go! You've been wanting some nice replacement struts for your Grand Prix? Well, here is an upgrade you can do. If you have all the tools, do it yourself, cheap! Otherwise, pay a friend/shop/etc to do the mods for you.
It took about 2 hours to do the modifications and alignment. I expect a person/shop doing it for the first time will take more like 3 hours or so if you have all the needed tools in one place.
FYI: This is currently a front strut upgrade
Special thanks to John Paul Hudson for the method, idea, and doing it on my car! JP has been competing with this setup in SCCA Solo II competitions for a while, and really annoying the Porsche 968's and BMW M3's (grin)!
One obvious recommendation, if you don't already have them, is to put on Eibach or other performance springs with this upgrade.
Okay, so what do you need? Well, below is a list of most of the parts and tools.
(2) Koni Strut Inserts
(3-way adjustable: Firm, Medium, Soft) -- Koni part number 8641-1287 (Made as inserts for the '95 Taurus SHO) [Rear strut is part number 8641-1323 (Used to be 8641-1270)]
I picked these up for $277 delivered ($122 ea) with 2nd day shipping from ASI/RD Enterprises.
Good power/air drill
Heavy duty tube cutter
(2) 2" heavy duty exhaust clamps
Click on any of the pictures below for a close up.
Preparing the car for the operation.
I'm assuming you know how to get the struts out, since this is a pretty
straight forward process. This is a shot of the stock struts out of the
Remove the top of the strut and springs (as if you were going to replace
the springs). The strut is then put into a vise. JP is pointing to
the area that will be cut by the pipe cutter in his hand. You will cut
about 3/4" below the lip of the strut.
You can see that the strut is now cut. You can now remove the old
strut "guts" from the strut assembly and dump out the oil.
With the "guts" removed and out of the way, you now want to take your air saw
and cut out a notch on each side of the strut, approximately 1 1/4" long, and
about 1/8" wide.
Here is the opposite side getting cut.
Finished with the cuts.
Invert the strut and put it back in your vise. You can now see the bottom
of the strut housing.
Take one of the new strut assemblies and use your air grinder to grind off
the paint around the lower nipple of the strut.
Here you can see the strut after sanding off the paint. You want to do this
to give yourself clean metal for your welding later.
Use your drill and/or air saw to cut out the bottom of the stock strut
assembly. You want to cut a hole that is just big enough for you
to be able to drop the Koni into (the area you sanded the paint off
of). After it's drilled out, rinse out the housing (oil works well) and
dry it off.
Put the strut assembly right-side-up into your vise. Drop the Koni
insert down into the strut assembly. Then take your exhaust clamp and put
it over the strut assembly as shown. Use an air wrench to tighten down the
clamps. This will pinch the stock strut assembly (from those cuts you made)
down around the new strut insert.
Go to your welder and weld the bottom of the strut to the strut housing.
This shows you how/what you should be welding (grin). This is obviously
a post weld shot.
Put your spring and the rest of the strut assembly back together.
Here's a shot of JP'slittle tool bench. If you have
one of these, you should have all the tools neccessary to do the job (grin).
Re-install the strut assembly back into the car. In this picture you can see the little bit of evidence that the car now has Koni's (the school bus orange strut housing).
That's basically it! It's actually a pretty simple and straight forward process
(for those mechanically inclined of course). After this, go for a test drive
(I recommend using the firm setting for your first ride!).
After your test drive, the next step is to have an alignment done. My car wasn't
out much at all, but better to be safe!
Below is a few shots of me and JP's car after we finished up in the shop.