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Boy, this makes me want to try coil overs. I bought new springs in '15 from them and have maybe 700 miles on them. i debated on coilovers originality and I wish I would have.
Just curious why you don't coilovers? Clearly a better set up for any serious car tuner guy / racer if they know what they are doing.
1988 (my car) was the first C4 model year for the re-designed front suspension. Apparently, as a 1-year only change, my car has shock towers that are taller and narrower than other C4 models. To do coilovers it is my understanding that I would have to drill out all the spot welds and cut the shock towers off my frame, then weld on towers from a later model C4. I don't want coilovers that bad.
Besides, REAL Corvettes have transverse composite leaf springs, don't they?
I’ve got a brand new set of coilovers available. Also have a used set as well that need to be pulled off a car.
I have a VBP adjustable front spring (1074 lb-will have to double check the rating) that I may remove to convert to coilovers. I do prefer the composite spring. However, my 1992 now has a 9" solid axle (with colicovers). I would like to put softer springs in the front. How much and can you post a photo or PM me.
To the OP my spring is still on the car. Let me know if you may be interested.
Prefer k=1000 or less. PM me if you have one available.
How does the "K" number compare to N/mm number? I have a Vette Brakes front but it's only K=532 I'm not sure if it's softer or stiffer than my GM spring which is a rate of "130.6 N/mm" and a load of "13943 N"
This is a pic of the Vette Brakes spring (still in the car)
Conversion is: N/mm / 0.175 = lb/inch. 130.6 N/mm would be 746 lb/in.
I thought the stiffest stock spring was the Z51 / Z07 FHB code at 660 lb/inch.
Is there a three letter code on your stock spring?
My GM spring is an FHB code, Tommy Morrison Racing was supplied these for their ZR1 race team. They serial numbered each one and tested them for load and rate, kept the ones they wanted and eventually sold the remainders. I got mine way back around 2002 It was never used by them. So the numbers I have are written right on the spring in paint pen.
So what is the "K" number in relation to all this? My 532 K from Vette Brakes "seems" stiff but I don't know if it is or not
My GM spring is an FHB code, Tommy Morrison Racing was supplied these for their ZR1 race team. They serial numbered each one and tested them for load and rate, kept the ones they wanted and eventually sold the remainders. I got mine way back around 2002 It was never used by them. So the numbers I have are written right on the spring in paint pen.
That's interesting. As the OP wrote, the FHB is supposed to be a Z07/Z51/Challenge front spring, and they were nominally rated at 115.5N/mm (or 660lb/in). So that tells me they either bought a bunch of those springs off the shelf and tested each one to find the stiffest ones based on production variance (but that's a lot of variance!), or they somehow got some made that were thicker/stiffer and GM just labeled them with the same part number. Either way, they measured each one to find the ones they wanted to keep, and wrote the measured stiffness on each one, just like VBP always did.
So what is the "K" number in relation to all this? My 532 K from Vette Brakes "seems" stiff but I don't know if it is or not
It's just a matter of SAE vs metric units. The hand-written "K" rating on your spring is written in lb/in, whereas the factory ratings were in N/mm. As the OP noted, 130.6N/mm is the same as 746lb/in, so your GM spring is quite a bit stiffer than your 532lb/in VBP spring.
11-08-2018, 01:23 PM
