David N

I've discussed my disappointment with KBDDs before, along with the rattling problem I suffered on the passenger side LCA body mount. I just picked up my car from a very very expensive/skilled performance shop. They removed my KBDDs and installed in their place SLP SFCs which were welded in. I didn't have a chance to take any photos (but in a month I'll have my Prospeed brakes and a custom 6-pt. cage installed, I'll take some then) but you could never tell any other SFCs had been there before. In addition, the SLP SFCs were installed so nicely they look like they were installed at the factory. Also, they had to R+R the right LCA mount. Due to the crappy slot design of KBDDs around the rear LCA mounts became distorted in this area. No amount of overtightening or loosening the LCA bolts prevented rattling from happening. This is now fixed.

As for the comparo. With the KBDDs there was definitely an improvement one could notice compared to stock. But it wasn't as much as I had expected particularly in up/down bending along with reinforcement of the rear chassis. Compared to the rigidity of my '91 GTA which has two sets of SFCs I was really disappointed. Frankly I had expected more but maybe my expectations were unrealistic. According to most posts KBDDs are as good if not better than SLPs. Now that I had my first two drives I have to say they're wrong. The improvement of the SLPs over the KBDDs was larger than the KBDDs over stock! In particular bending, the rear LCAs are way better reinforced than before (yes, you can feel it), and when I hit bumps a more solid thunk is heard. My expectations were met and therefore had been realistic. KBDDs didn't deliver the amount of solidity I wanted. For 10 pounds extra weight you get a lot of extra rigidity you can feel and hear.

And one can explain it simply: the tubing of the SLPs along the pinch weld are 2x3 and once they bend in towards the front subframes 2x2. KBDDs are 1x1 so the cross sectional area of the SLPs is 4-6x larger and this is a difference you can feel. Also, the reinforcement/attachment points around the LCA mounts. The shop found the design to be superior (as do I) and much easier to install without distorting the LCA mount.

I'm hoping I can convince anyone about to make the mistake of buying KBDDs to reconsider. I didn't buy SLPs SFCs in the first place because they have a deservedly poor reputation. But their SFCs are an exception to that rule. Avoid my costly mistake.

I just can't get the grin off my face. I'm really satisfied and wish I had done this earlier.

mjf454

Nice write up on the subframes. Good luck with the prospeed kit. Mine was orderd months and months ago, and i am still waiting. prospeed

David N

I heard that Prospeeds service was slow at best. I bought my set used. I won't know until the shop cleans them up whether the rotors or anything else has been abused but I couldn't find any cracks when I inspected them.

Viper

iTrader: (6)

I'll throw out something else.

I had SLP SFC's since early 2000, bolt-on.

Loved them since day one, and the bolts never came loose.

This year I had them welded in.

And they are even better than just the bolt-on. Much more rigid.

So even though I'm a proponent of the bolt-on, I recommend getting the SLP's welded in.

FWIW

mjf454

I am glad you got the prospeed kit used, otherwise you would be in the same boat i am in.

Gary Z

David,

I have been reluctant to have SFCs installed because I don’t know what shop to trust. Your story gives me the impression that you are as particular as I am. I am in the bay area and would appreciate knowing what shop you found.

Thanks, Gary