johnc Posted December 5, 2007 Share Posted December 5, 2007 Careful there Pete. John knows his road racing, and had an INSANELY fast 240z that didn't have subframe connectors at all. Don't poke the bear in the eye with a stick... I wish my Z did have SFCs but the class rules I built the car for (SM2) didn't allow weld in SFCs. Later, when I starting racing NASA U3 I focused my efforts elsewhere for chassis stiffening. Ultimately I would have put in a full cage before I went with SFCs because the S30 chassis really benefits from a cage - far more then what just a pair of SFCs provide. But, given that most everyone's car here is a street car and a cage isn't a good idea on the street, SFCs do a good job stiffening the chassis. An X brace in addition to SFCs, as I've said before, will just add weight. The center part of a Z chassis doesn't twist in a way that an X brace will help, once SFCs are installed. What the S30 chassis need badly is upper level reinforcement at the firewall and the strut towers. Connecting the front strut towers, upper firewall, and rear strut towers together does wonders for this 35+ year old chassis. Quote Link to comment Share on other sites More sharing options...
Wedge Posted December 20, 2007 Share Posted December 20, 2007 I dont want to be a noob but does the bad dog frame rails are just welded over the old ones ? Quote Link to comment Share on other sites More sharing options...
Guest TeamNissan Posted December 20, 2007 Share Posted December 20, 2007 I dont want to be a noob but does the bad dog frame rails are just welded over the old ones ? Yes, search there are threads that talk about them. Quote Link to comment Share on other sites More sharing options...
Wedge Posted December 20, 2007 Share Posted December 20, 2007 I got that thread while searching pardon me for asking here i just wanted to be sure the information i read was what i understood . Quote Link to comment Share on other sites More sharing options...
crazy280 Posted December 28, 2007 Share Posted December 28, 2007 I don't think it would hurt to put some holes in them. You guys are acting like he was gonna drill holes into the stock subframes or something. Remember, the car never came with SFC's, so no matter what he does to them they will still be an improvement over stock. That's just my oppinion of course Quote Link to comment Share on other sites More sharing options...
JMortensen Posted December 28, 2007 Share Posted December 28, 2007 I don't think it would hurt to put some holes in them. You guys are acting like he was gonna drill holes into the stock subframes or something. Remember, the car never came with SFC's, so no matter what he does to them they will still be an improvement over stock. It would take some analysis to truly figure out how much of a difference the holes would make, but your idea of "anything more is better" isn't really very sound. If drilling holes so weakens the connector that it doesn't do anything useful, then you're better off not having it at all if for no other reason than just that it is dead weight being carried around. Unfortunately testing these things is a real PITA, so I doubt we're going to get a good answer as to it's effectiveness one way or the other. Quote Link to comment Share on other sites More sharing options...
Pete Sprenger Posted December 29, 2007 Author Share Posted December 29, 2007 John C. Wrote: "I wish my Z did have SFCs but the class rules I built the car for (SM2) didn't allow weld in SFCs." I just downloaded the rule book for 2007 from the SCCA web site and reviewed the rules for SM2 and they say that subframe connectors are legal in SM and SM2 as long as they only run front to back and do not have any kind of X bracing. 16.1 paragraph G states: "Subframe connectors are allowed, but each connector must be attached individually without any lateral components attaching the two longitudinal frame rails. Subframe connectors may be bolted or welded. SP allowances which authorize unrestricted mounting of suspension components do not permit the incorporation of non-SP-legal subframe connectors into the mounting scheme for a Street Modified vehicle." Doesn't that mean we can use these BD SFCs in SM2? Pete Sprenger 1972 240Z Quote Link to comment Share on other sites More sharing options...
johnc Posted December 29, 2007 Share Posted December 29, 2007 Weld in SFCs were allowed in SM back in 2005 or 2006. I built my car for the class in 2001. Quote Link to comment Share on other sites More sharing options...
crazy280 Posted December 29, 2007 Share Posted December 29, 2007 It would take some analysis to truly figure out how much of a difference the holes would make, but your idea of "anything more is better" isn't really very sound. I never said "anything more is better", please don't misquote me. What I'm saying is, in this instance the SFC's will still add stiffness to the car, even if he puts some holes in them. Chamfered holes in chassis reinforcements is common for race-prepped cars, even without a full cage. If he was going to drill out existing, stock chassis components, then there might be a safety issue, but in this case its fine. Just don't go drill crazy and turn them completely into swiss cheese! 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.