What weight Mono Spring???
Thread Starter
Instructor
Joined: Sep 2001
Posts: 208
Likes: 8
From: Grand Ledge MI
What weight Mono Spring???
I'm thinking of replacing my mono spring simply because it's over 30 years old. I want to go composite because of its weight. What do you guys recommend as far as spring weight? 300, 310, 315, 330, 340??????
Le Mans Master
Joined: Aug 2000
Posts: 6,273
Likes: 14
From: Austin TX
Re: What weight Mono Spring??? (68ragtop)
I have used both the TRW 315 and the VB 320 and 340. The TRW has a very different ride quality - it seems much smoother. The VB responds quickly- quickly enough to be bouncy.
For street use, I recommend the lower rate TRW. For more aggressive use, the VB would be good.
In either case, shock selection is very important. After trying several combos, I am now using Bilstein Sports. Just right........
BTW, Paul Lisinsky of VB will tell you that 80% of C3 ride quality comes from the rear spring.
For street use, I recommend the lower rate TRW. For more aggressive use, the VB would be good.
In either case, shock selection is very important. After trying several combos, I am now using Bilstein Sports. Just right........
BTW, Paul Lisinsky of VB will tell you that 80% of C3 ride quality comes from the rear spring.
Race Director
Joined: Aug 1999
Posts: 11,121
Likes: 672
From: SE Pennsylvania
St. Jude Donor '03 thru '26
Oldtimer
Re: What weight Mono Spring??? (68ragtop)
I changed to a 310 Lb TRW spring in my 79, they recommend changing to a gas shock to go with the spring. I can personaly say that the change is one of the best things for the ride in a C-3.
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Pro
Joined: Jan 2002
Posts: 534
Likes: 0
From: FL
Re: What weight Mono Spring??? (68ragtop)
Depends on what you like. Me, I like my car to corner stiff and flat. No side effects to violent maneuvers. I bought my car with the Gymkhana steel spring for that reason.
Some years ago I decided to upgrade to a VB&P fiberglass monospring... I did my homework and bought a 400 lb unit (they offered 360 and 420, and I had them test several until they found a 420 that was reading a tiny bit light). I've never been unhappy with the choice.
Here's the whole suspension I drove for years in a nutshell:
400 lb single mount rear monospring.
Carrera shocks in the rear.
Poly bushings everywhere.
3/4" rear sway bar with Delrin (hard) bushings and adjustable links, cranked nearly tight.
Front coils were 550 lb Gymkhana.
1 1/8" front sway bar with poly bushings.
Koni adjustable shocks in front, 3/5 of the way set to stiff.
Now I'm in the midst of replacing the front coils with the VB&P front dual mount monospring. Here's hoping I can make it at least as stiff as those 550 coils.
-Noel
[Modified by Noel Carboni, 3:22 AM 3/28/2002]
Some years ago I decided to upgrade to a VB&P fiberglass monospring... I did my homework and bought a 400 lb unit (they offered 360 and 420, and I had them test several until they found a 420 that was reading a tiny bit light). I've never been unhappy with the choice.
Here's the whole suspension I drove for years in a nutshell:
400 lb single mount rear monospring.
Carrera shocks in the rear.
Poly bushings everywhere.
3/4" rear sway bar with Delrin (hard) bushings and adjustable links, cranked nearly tight.
Front coils were 550 lb Gymkhana.
1 1/8" front sway bar with poly bushings.
Koni adjustable shocks in front, 3/5 of the way set to stiff.
Now I'm in the midst of replacing the front coils with the VB&P front dual mount monospring. Here's hoping I can make it at least as stiff as those 550 coils.
-Noel
[Modified by Noel Carboni, 3:22 AM 3/28/2002]
Le Mans Master
Joined: Jul 1999
Posts: 9,206
Likes: 17
From: Sewell NJ
Re: What weight Mono Spring??? (68ragtop)
I've had a 340 lb. TRW on my 74 for over ten years and have never regretted it. Most fiberglass springs ride a little bouncy just because of the nature of the composite. You should look into a good set of shocks to go along with the new spring. Vette Brakes sells KYB shocks that are specifically valved for composite springs. I wouldn't go any lighter than a 340 lb. spring or your pipes may start to bottom.
Racer
Joined: Apr 2000
Posts: 499
Likes: 0
From: Kristiansand
Re: What weight Mono Spring??? (68ragtop)
There was a lot of discussion on breaking fiber springs here earlier.
I made a survey at my site and although there are not many entries, at least it's zero on broken TWR's. Seems like a good choice.
I made a survey at my site and although there are not many entries, at least it's zero on broken TWR's. Seems like a good choice.
Le Mans Master
Joined: Jul 1999
Posts: 9,206
Likes: 17
From: Sewell NJ
Re: What weight Mono Spring??? (Ingar, Norway)
I agree. I posted exactly this is another topic. When I bought my spring from VB&P they hadn't started selliing their own composite springs but offered the TRW spring. In all the years I've had mine I've never heard of a TRW spring fail but I've heard of a lot of problems with the VB&P springs. The TRW spring is shaped much different than the VB&P and is quite a bit wider at the end where it supports the trailing arms.There's only a few dollars difference in the cost of the two springs but I think in the long run the TRW is the bargain.
Burning Brakes
Joined: Jul 1999
Posts: 1,013
Likes: 0
From: Austin TX
Re: What weight Mono Spring??? (vettfixr)
I think the spring rate choice is a bit car dependant.
I was running a 360# for awhile, but the car was very bouncy...I wound up buying a 315# from Zwede and it made a big difference for me...the car acrually has a ride now!!! I'm running the KYB GR2 shocks that are valved for the spring.
So the reason I think the spring rate is car dependant, has to do with the weight or your car...I have a light car, ~3100 with a little less than half of that on the rear. If you have a heavier car you will need a heavier spring than I did.
My car actually rides better with a full tank of gas...this probably gets me close to a 50/50 front to rear split too.
I was running a 360# for awhile, but the car was very bouncy...I wound up buying a 315# from Zwede and it made a big difference for me...the car acrually has a ride now!!! I'm running the KYB GR2 shocks that are valved for the spring.
So the reason I think the spring rate is car dependant, has to do with the weight or your car...I have a light car, ~3100 with a little less than half of that on the rear. If you have a heavier car you will need a heavier spring than I did.
My car actually rides better with a full tank of gas...this probably gets me close to a 50/50 front to rear split too.
Le Mans Master
Joined: Jul 1999
Posts: 9,206
Likes: 17
From: Sewell NJ
Re: What weight Mono Spring??? (StingrayRacing)
Agree. I think the 360 spring would be too harsh for everyday street use. I think the key to your combo is the KYB GR2 shocks. They probably allow your 315 spring to act more like a heavier spring under load by controlling the motions better. My 340 spring will get bouncy with a light load of gas but I think it's because I'm using the regular KYB shocks. That's all that was available 12 years ago when I changed them. Maybe I'm due for an update. Yeah, that's what I need, more mods. :jester
Safety Car
Joined: Aug 2001
Posts: 3,892
Likes: 13
From: Pettis Performance 565 with two stages of Nitrous Supply nitrous 1.082, 4.61 at 155, 7.17 at 192
Re: What weight Mono Spring??? (vettfixr)
I have a 360 spring and it is too bouncy, to the point I thought I did something wrong installing it. I got it because of the power my motor makes, close to 730HP on the NOS. I thought I had to step up to a heavy spring, maybe I did not need to.