View Full Version : Chassis Stiffening

03-19-2017, 10:17 AM
Im in the process of building a 75 monte carlo into a autox/track day/ more or less a streetable race car. I built my own chassis stiffening kit for the center section and rear stub but what can I do for the front stub? I was planning on building a brace that ties the cross member to the frame horns but is there more I can do? I was going go as far as building bay bars similar to that of a circle track car but I dont have a full roll cage in the car. How far is too far and do you guys think what I have done is enough? Thanks in advance.

03-19-2017, 12:45 PM
Adding bars out in front of the cross member will do nothing. Trying to stop twist, without a good cage, is not going to happen. All you are doing is adding weight. Lateral stiffness can be improved with a good K-member design but, to improve torsional stiffness, you need to have a good cage that is triangulated down to the chassis and ties the front and rear suspensions together.

03-19-2017, 02:31 PM
Look at some of the frame brace kits that hpi,hellwig, speedtech etc have developed for 68-72 a body's. Being as your cars frame design is quite similar this would be something that you might want to copy for your own design

03-19-2017, 04:04 PM
Thats what i pretty much did for the center and rear stub. I built a coilover setup for the rearend so the rear stub is taken care of I was more concerned for the stub moving up and down as more than torsional. Thank you guys for all the tips! keep em coming! I want to be able to keep up with corvettes by the time Im done with with this!

03-19-2017, 05:11 PM
If you're corvette hunting .....next step cage

03-20-2017, 07:51 AM
If you're corvette hunting .....next step cage

Yeah I was afraid of that! Maybe next year then.

sam 74
04-09-2017, 03:39 PM
on my74 olds the biggest difference was made by the cage, i wouldn't build a car setup for road or auto X races without a cage.

05-11-2017, 05:28 AM
I went with the HPI kit and it turned out great.

05-11-2017, 05:41 PM
I really dig that crossmember setup! Pretty clean install as well!!

05-12-2017, 08:34 AM
Used the HPI on on my el-Camino frame- had to cut it up some since we used the factory boxed frame rather than the HPI boxing plates

05-16-2017, 11:58 AM
Although, a cage will add weight, the benefits of a cage is worth the added weight. You can always remove the added weight from other areas to get the weight back down to the pre-cage weight. Do not add a pre-fab off the shelf cage. You need to take it a reputable chassis fabricator not only for the chassis stiffness but, for your personal safety. A poor design installed cage can be more dangerous than no cage.

After you have the cage built to a standard such as, the SCCA specs, it would be best to have the cage inspected, by a licensed tech inspector/scrutineer and obtain a vehicle log book with that inspection so you won't run into a problem in the future.

05-28-2017, 07:22 PM
Thanks for all the advice! Im really looking forward to making this car fast! Looks like Ill have to talk to a chassis shop I know very well about putting a full cage in the old girl! Thanks again for all the great advice!