TRW spring special installation and mods
Thread Starter
Melting Slicks
Joined: Feb 2003
Posts: 3,053
Likes: 4
St. Jude Donor '03,'11
TRW spring special installation and mods
I was given a TRW "high rider" spring for Christmas from MidnightBlueL82. For those who don't know already, most of the guys that have installed these are unhappy with the rear ride height running 2 - 3 inches higher than the stock 27 inch fenderwell height.
I installed it in the car and the ride height is acceptable after special installation and mods. I am not recommending that anyone duplicate this, just providing FYI.
I installed the spring without the upper spacer ie. the fiberglass actually touches the differential cover. That saved an inch. I'm also using 8" bolts but was uncomfortable with how close the spring ends were to the sidewall so i cut the spring end shortening it by 3/4 inch.
The 330 pound spring is way way softer than my 5 leaf steel. The car acually squats when you goose it from a standing start. I'll let you all know how it works out for me in the long run.
I installed it in the car and the ride height is acceptable after special installation and mods. I am not recommending that anyone duplicate this, just providing FYI.
I installed the spring without the upper spacer ie. the fiberglass actually touches the differential cover. That saved an inch. I'm also using 8" bolts but was uncomfortable with how close the spring ends were to the sidewall so i cut the spring end shortening it by 3/4 inch.
The 330 pound spring is way way softer than my 5 leaf steel. The car acually squats when you goose it from a standing start. I'll let you all know how it works out for me in the long run.
Le Mans Master
Joined: Mar 2004
Posts: 7,502
Likes: 1,510
From: Little Rock AR
Now you just need some Bilstein shocks to get rid of the dreaded "bouncy" rear. 
I used factory shocks for a little while and it did seem softer with the fiberglass spring. It is totaly different with the better shocks. I would install them right away if I ever did another Vette.
-Mark.
I used factory shocks for a little while and it did seem softer with the fiberglass spring. It is totaly different with the better shocks. I would install them right away if I ever did another Vette.
-Mark.
Race Director
Joined: Jan 2004
Posts: 18,191
Likes: 145
From: Snake handler
I would be concerned about losing the rubber spacer inbetween the spring and the diff. The reason is that it will cause the spring to crack. I also keeps the bolts from putting too much pressure on the spring - also a cause of cracks. My TRW sits too high too.
I've heard of a more radical mod where you remove the rubber donuts from the crossmember and replace with 1/4" steel - this eliminiates the slop caused by the rubber bushings by attaching the crossmember directly to the frame and buys you about an inch and three quarters. Combined with a longer spring, you can get the rear down. (oh, and you need a spacer for the camber rods and you need to re-position the uppoer shock mount holes)
I haven't done this because it sounds like a royal PITA.
Anyone else heard of this?
I've heard of a more radical mod where you remove the rubber donuts from the crossmember and replace with 1/4" steel - this eliminiates the slop caused by the rubber bushings by attaching the crossmember directly to the frame and buys you about an inch and three quarters. Combined with a longer spring, you can get the rear down. (oh, and you need a spacer for the camber rods and you need to re-position the uppoer shock mount holes)
I haven't done this because it sounds like a royal PITA.
Anyone else heard of this?
Thread Starter
Melting Slicks
Joined: Feb 2003
Posts: 3,053
Likes: 4
St. Jude Donor '03,'11
Originally Posted by pjmonfre
I would be concerned about losing the rubber spacer inbetween the spring and the diff. The reason is that it will cause the spring to crack. I also keeps the bolts from putting too much pressure on the spring - also a cause of cracks. My TRW sits too high too.
I've heard of a more radical mod where you remove the rubber donuts from the crossmember and replace with 1/4" steel - this eliminiates the slop caused by the rubber bushings by attaching the crossmember directly to the frame and buys you about an inch and three quarters. Combined with a longer spring, you can get the rear down. (oh, and you need a spacer for the camber rods and you need to re-position the uppoer shock mount holes)
I haven't done this because it sounds like a royal PITA.
Anyone else heard of this?
I've heard of a more radical mod where you remove the rubber donuts from the crossmember and replace with 1/4" steel - this eliminiates the slop caused by the rubber bushings by attaching the crossmember directly to the frame and buys you about an inch and three quarters. Combined with a longer spring, you can get the rear down. (oh, and you need a spacer for the camber rods and you need to re-position the uppoer shock mount holes)
I haven't done this because it sounds like a royal PITA.
Anyone else heard of this?
Race Director
Joined: Jan 2004
Posts: 18,191
Likes: 145
From: Snake handler
Originally Posted by turtlevette
I have put the aluminum disks in from VBP but it doesn't change the rear end location vertically. I would be interested to learn more about the mod you speak of.
I don't know much about the mod but it sounds interesting.
Melting Slicks
Joined: Jun 2003
Posts: 2,802
Likes: 241
From: Niles, MI
IMHO the best mod for the TRW design spring is this:
1. Place it in an open area away from any buildings.
2. Pour 1 gallon of gasoline over it.
3. Toss a match and run away like crazy.
4 Call VBP and order one of their springs.
Seriously, John Greenwood describes how to lower your rear end about 3/4" in the VIP article. However this does nothing to get your halfshafts back in the proper orientation. Your halfshafts should be level or slightly inclined at the center. 10" bolts aren't the solution either. You need a spring with the proper arch.
1. Place it in an open area away from any buildings.
2. Pour 1 gallon of gasoline over it.
3. Toss a match and run away like crazy.
4 Call VBP and order one of their springs.
Seriously, John Greenwood describes how to lower your rear end about 3/4" in the VIP article. However this does nothing to get your halfshafts back in the proper orientation. Your halfshafts should be level or slightly inclined at the center. 10" bolts aren't the solution either. You need a spring with the proper arch.
