pjo046 Posted January 12, 2006 Share Posted January 12, 2006 I am going to install a L28ET in my 1970 240Z, and I am hoping for 400rwhp and as much torque as I can get with it. I have searched a lot, and read many posts both here and on zcar.com regarding this. I know the chassis will need to be reinforced in some way. But I don't want to install a complete roll cage, as this is going to be a street car with much comfort. What I have done so far is: - I have connected the subframes - I have installed baddogparts' 240Z frame rail bars over the existing(completely rust free) frame rails. - I have stitchwelded along most of the seams underneath the car - I have bought a pair of strut tower bars of ebay, just like the ones MSA sells. I know it would be better with TEP's strut tower braces, but I found that out after I had bought the pair I have now. Is it a necessity to swap to the TEP style braces? Also, how does that front brace mount to the firewall? Is it welded in place and thus a pain in the *** to remove? So do you think I will be needing more reinforcement than what I have already done? An important thing to remember is that I will be using an open R200, and only run 225 widht tires front and rear. So that means that when huge torque is applied, I'll get wheelspin instead of chassis-warping. Right? So far I have thought I would be ok, but the more posts I read regarding this, the more doubt I get. I was thinking about getting a rollbar of some sort. Will this improve things? Any suggestions as to which to get? How about the one MSA sells? Quote Link to comment Share on other sites More sharing options...
johnc Posted January 12, 2006 Share Posted January 12, 2006 What you've done to date will help the car. A wedled in roll bar helps stiffent the rear of the a lot. The bolt-in roll bars offered by MSA are more a safety items and don't do much to stiffen the chassis. Quote Link to comment Share on other sites More sharing options...
pjo046 Posted January 13, 2006 Author Share Posted January 13, 2006 Hmmm. Well, I'll at least continue to stitch weld every seam on the car. I must admit, that at first I did some seam welding under the car, before reading about the stitch weld process here. I seam welded the sub-frame connectors in place, and I also seam welded the frame rail bars from Baddogparts. Have I messed everything up doing this? Well, I know I have, but I mean, will this put too much stress on everything, causing something to crack? Quote Link to comment Share on other sites More sharing options...
Mikelly Posted January 13, 2006 Share Posted January 13, 2006 Obviously stitch welding is the best way to do it. But seam welding is better than those spot welds and seam sealers used at the factory. I'd just continue on with stitch welds from here forward. Mike Quote Link to comment Share on other sites More sharing options...
pjo046 Posted January 13, 2006 Author Share Posted January 13, 2006 Thanks! Quote Link to comment Share on other sites More sharing options...
Ed260Z Posted January 13, 2006 Share Posted January 13, 2006 Sounds like you've done just about everything you need to do. You probably won't need the roll bar to stiffed the chassis, but it wouldn't hurt. If you decide to get a bar make sure it's a weld in piece, a bolt out won't do much for you. Quote Link to comment Share on other sites More sharing options...
dj paul Posted January 13, 2006 Share Posted January 13, 2006 you could get one that bolts in and then weld 2 bars to the strut towers in a triangular fashion from the center bar of the roll bar and then get a bolt on rear tower brace to make it fully triangulated. that would prob be easiest. let me know if this is a good/bad idea because im going to do it soon. lol. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted January 13, 2006 Share Posted January 13, 2006 you could get one that bolts in and then weld 2 bars to the strut towers in a triangular fashion from the center bar of the roll bar and then get a bolt on rear tower brace to make it fully triangulated. that would prob be easiest. let me know if this is a good/bad idea because im going to do it soon. lol. One problem with this idea is that you now have 6 attachment points. So if you have a 6 point limit to the cage in the class you're racing in, you've already used them all up. May not be a problem for you, but I thought I'd point it out anyway. Quote Link to comment Share on other sites More sharing options...
dj paul Posted January 13, 2006 Share Posted January 13, 2006 oh ok. but besides that would that be a good idea? im going to look at scca rules for the class i would most likely be in. and see what the limits are. im not sure what a twin turbo 240 with a 280zx motor would be in. would that put me in a class that i would be the lowest in? Quote Link to comment Share on other sites More sharing options...
JMortensen Posted January 13, 2006 Share Posted January 13, 2006 I don't think there is a class for you in SCCA road racing, but maybe you'd fit in autox in a Mod class. For those classes I don't believe there is a limit as to chassis attachment points. So you should be good to go. I didn't understand your last question, but you will probably be slowest in a Mod class. They're extremely fast purpose built race cars. You can download the rulebook from the SCCA website. Quote Link to comment Share on other sites More sharing options...
74_5.0L_Z Posted January 14, 2006 Share Posted January 14, 2006 Have you checked out the new XP class in SCCA. This looks like a perfect fit for our Hybridz cars in national level autoX. Quote Link to comment Share on other sites More sharing options...
pjo046 Posted January 14, 2006 Author Share Posted January 14, 2006 Thanks for hijacking my thread... Hehe, just kidding! Anyways, do you know where I can get hold of a weld in roll-bar kit for the 240Z at an affordable price? Quote Link to comment Share on other sites More sharing options...
tube80z Posted January 14, 2006 Share Posted January 14, 2006 Have you checked out the new XP class in SCCA. This looks like a perfect fit for our Hybridz cars in national level autoX. It's interesting but unclear to me if you can be semi-tube like the front of your car. I know you can't molest the firewall. Cary Quote Link to comment Share on other sites More sharing options...
dj paul Posted January 14, 2006 Share Posted January 14, 2006 the rules state that there must be a protective barrier from fire/ etc so i believe if we found a class that allows are motors with our mods we should be fine. the main thing in their concern is safety. for the cages i just did a google search http://www.advancedautosport.com/cages.htm pdk also specializes in it http://www.pdkfabrication.bravepages.com/ there were a few more that ive found before. it was a major one like jegs or something. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.