Kubs Posted September 12, 2011 Share Posted September 12, 2011 I have a question regarding the factory leaf springs in my C4 Corvette. The stock spring is worn and starting to delaminate. Do I have to replace the spring with another used OEM spring or can I get a NEW spring from an aftermarket company like VBandP in the same OEM rate as the old one, or will that cost me 2 points? Quote Link to comment Share on other sites More sharing options...
jimbow Posted September 12, 2011 Share Posted September 12, 2011 I forget which year your corvette is, but I'd research the stock spring rates available in your year range (update, backdate rule). Then a non-adjustable VBP spring with that rate would be the non-oem replacement part that performs the same function and has the same specs as original. I'm keeping a folder of anything questionable like this (so far I think it has one useless page since I went with a reclass from greg). That way if a competitor says "Hey thats an aftermarket spring!" you can pull out all the paperwork to show its a replacement part. I can't recall if we can get new ones from GM, but any info on that helps as well. Quote Link to comment Share on other sites More sharing options...
kbrew8991 Posted September 12, 2011 Share Posted September 12, 2011 I'd look carefully at how "OEM part" is definied - I want to say there's some allowance for aftermarket parts that perform the same, but I'd want to know the exact verbage of the rule and how this alternate part stacks up to the actual OEM part before I spent any money. Quote Link to comment Share on other sites More sharing options...
Kubs Posted September 12, 2011 Author Share Posted September 12, 2011 My car is a '90. I have a print out of the available rates and spring options for the C4. The '84 base model had the stiffest rear springs, but one of the softest front springs. I think I would just stick with the base FE1 springs that my '90 originally had. The only thing I can think of is the VBP springs have less arch to them to lower the car a little. I think this would make the spring a 2 point mod. Ride Height adjustment is in the free mods list but Im sure that refers to the factory range of adjustment, and the C$ has no adjustment for the front anyway. Quote Link to comment Share on other sites More sharing options...
TurboShortBus Posted September 13, 2011 Share Posted September 13, 2011 I can tell you from experience that it will be better to just get another OEM spring if you want to avoid the points. Along similar lines, a couple of years ago, I was looking to replace the Flowmaster mufflers that came on my Mustang with OEM mufflers in order to get +2 points back. I couldn't find any that weren't rusted out (and new ones were something like $400 per side from the dealer), so I submitted several OEM-style replacement mufflers to Greg for his review. Unfortunately for me, this didn't fly, and they would not pass as OEM replacements. Greg and I also assessed +2 points to a PTE Miata during an inspection at the Championships yesterday, as his muffler was not OEM but didn't appear to be a "performance" part, either. But, since you mentioned that the aftermarket springs would lower the car (although keeping a similar rate), the points would definitely apply. Mark Quote Link to comment Share on other sites More sharing options...
Kubs Posted September 13, 2011 Author Share Posted September 13, 2011 I can tell you from experience that it will be better to just get another OEM spring if you want to avoid the points. Along similar lines, a couple of years ago, I was looking to replace the Flowmaster mufflers that came on my Mustang with OEM mufflers in order to get +2 points back. I couldn't find any that weren't rusted out (and new ones were something like $400 per side from the dealer), so I submitted several OEM-style replacement mufflers to Greg for his review. Unfortunately for me, this didn't fly, and they would not pass as OEM replacements. Greg and I also assessed +2 points to a PTE Miata during an inspection at the Championships yesterday, as his muffler was not OEM but didn't appear to be a "performance" part, either. Thanks. This was kind of my thinking. I have room to use the 2 points so its not a big deal, but if I was able to save them and try something else I was going to. But, since you mentioned that the aftermarket springs would lower the car (although keeping a similar rate), the points would definitely apply. Mark Yeah Im not sure if all of their springs do, but I dont want to be called out on it. I will just take the points and get whatever rate I want. Quote Link to comment Share on other sites More sharing options...
jimbow Posted September 13, 2011 Share Posted September 13, 2011 I can tell you from experience that it will be better to just get another OEM spring if you want to avoid the points. Along similar lines, a couple of years ago, I was looking to replace the Flowmaster mufflers that came on my Mustang with OEM mufflers in order to get +2 points back. I couldn't find any that weren't rusted out (and new ones were something like $400 per side from the dealer), so I submitted several OEM-style replacement mufflers to Greg for his review. Unfortunately for me, this didn't fly, and they would not pass as OEM replacements. Greg and I also assessed +2 points to a PTE Miata during an inspection at the Championships yesterday, as his muffler was not OEM but didn't appear to be a "performance" part, either. Thanks. This was kind of my thinking. I have room to use the 2 points so its not a big deal, but if I was able to save them and try something else I was going to. But, since you mentioned that the aftermarket springs would lower the car (although keeping a similar rate), the points would definitely apply. Mark Yeah Im not sure if all of their springs do, but I dont want to be called out on it. I will just take the points and get whatever rate I want. Thats a good plan, I forgot the spring had less arch. That makes it different from the OEM part and costs points. So get the spring you want in the fron and rear! its the same 2 points. Quote Link to comment Share on other sites More sharing options...
Varkwso Posted September 14, 2011 Share Posted September 14, 2011 Dumpster diving is a TT and vintage racing tradition since most base model stuff was tossed long ago. Shocks, springs, sway, brakes and exhaust come.to.mind. Any aftermarket spring will probably cost you points. Quote Link to comment Share on other sites More sharing options...
jimbow Posted September 14, 2011 Share Posted September 14, 2011 Since we are talking about springs and I already have to take the 2 points because mine are not the ones found on the FE1 suspension. I have a question - if I pull the spring and change the center shim stack and trim the center rubber to drop the nose of the car a little bit is that any additional points? I should know the answer, but I don't have the rules with me here at the center of the universe (Cedar Rapids, IA) Quote Link to comment Share on other sites More sharing options...
Kubs Posted September 14, 2011 Author Share Posted September 14, 2011 No. Ride height adjustment is free within the factory settings, plus if you are already taking points for springs you can pretty much do anything you want to them (except go from leaf to coil). Quote Link to comment Share on other sites More sharing options...
kbrew8991 Posted September 15, 2011 Share Posted September 15, 2011 be careful with how that ride height free mod is worded... Quote Link to comment Share on other sites More sharing options...
Kubs Posted September 15, 2011 Author Share Posted September 15, 2011 be careful with how that ride height free mod is worded... I take it that it is within the factory range of adjustment. If you have to modify the spring itself or how it mounts to lower the car its +2. Quote Link to comment Share on other sites More sharing options...
jimbow Posted September 15, 2011 Share Posted September 15, 2011 No. Ride height adjustment is free within the factory settings, plus if you are already taking points for springs you can pretty much do anything you want to them (except go from leaf to coil). Its a toss up between going coil overs or A6 tires. My reclass is TTB, TTB* or TTB**(Have to have enough points to run in TTA to use this HP) I like the idea of coilovers - but I don't want to mess with the infinite adjustability Hope you come play in the south east one day! Quote Link to comment Share on other sites More sharing options...
Kubs Posted September 15, 2011 Author Share Posted September 15, 2011 Its a toss up between going coil overs or A6 tires. My reclass is TTB, TTB* or TTB**(Have to have enough points to run in TTA to use this HP) I like the idea of coilovers - but I don't want to mess with the infinite adjustability The only thing you really gain with coils is adjustability. The leaf spring setup is a great design and also acts as an anti-roll bar also. If you are tight on points go A6s for sure. They will give the bigger gain. I am working on a mount design to get the OEM style front springs (huge arch) lower and have better adjustability. Ill send you some pictures when I finish it. Hope you come play in the south east one day! Road Atlanta is on my list!! I need to get the car done first, which on my budget is taking for-ev-er! Quote Link to comment Share on other sites More sharing options...
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