74_5.0L_Z Posted October 16, 2002 Share Posted October 16, 2002 On May 27 I wrecked my 5.0L 260Z. I demolished the front unibody. The car was completely rust free so I cut the car at the firewall and have started to build a full chassis and cage. I am using all the suspension parts that I already have; therefore I am building the chassis to use the stock suspesion attach points. I have already installed a full frame 2.5" square that extends from the rear subframes all the way forward. I used the frame drawings in the Nissan 260 manual to establish the crossmember attach point. Last night, as a final check before building the front cage section, I dummied up the front suspension to check alignment. The front crossmember appears to be too far back. I have double checked all my measurements against the frame drawings, and they agree. This morning, I checked the 280Z drawing and see that point B is given a dimension of 12.88 as compared to 11.3 on the 260Z drawing (this difference would seem to put the crossmember where it belongs). Pete, I know you built front frame rails. Where did you place the rear bolt of the front crossmember relative to the firewall. On the drawing the firewall has a dimension of 54.5. Can someone pleaes measure from the vertical portion of the firewall to the rear bolt of the front crossmember and give me the value. Thanks to all in advance, Dan Quote Link to comment Share on other sites More sharing options...
Mike kZ Posted October 16, 2002 Share Posted October 16, 2002 You may be right to go with the 12.88 measurement. The 260Z model changed in mid year from early 240Z bumpers to 280Z bumpers, I'm sure all measurements also reflect the 280Z. So you may have 280Z specs. Quote Link to comment Share on other sites More sharing options...
Jeff Posted October 16, 2002 Share Posted October 16, 2002 Dan, Is yours an early or late 260? I have an early 260 that I can pull the measurement on. It is a bare body shell up on a rotisserie so measuring is very easy. You are more than welcome to come by some time if that would help. I'll measure it tonight and let you know. Quote Link to comment Share on other sites More sharing options...
74_5.0L_Z Posted October 16, 2002 Author Share Posted October 16, 2002 My car is an early 260Z. It had the narrow (240 style) bumpers, and turn signal placement. Further, I always thought the crossmember, T/C rod, and sway bar were interchangable between the 240 ,260, and 280. I believe the 280Z drawing may be correct, and the 260Z drawing has an error. I need to be correct on this because my engine is insalled on plates that are referenced to the crossmember position. If I get it wrong, my engine position will not be the same as it was. I dont want to have to modify my exhaust, driveshaft, and steering link. Thanks, Dan Quote Link to comment Share on other sites More sharing options...
pparaska Posted October 16, 2002 Share Posted October 16, 2002 Dan, sorry to hear your baby got bent, but it sound like a 6-Million Dollar Man rebuild project is in the works - "We can make it better, stronger, faster" I'll check my car and see where the X-member mount hole is relative to the firewall vertical plane. BTW, you might want to think about moving the crossmember and maybe the T/C rod bracket forward relative to the strut top mount to gain some caster. Quote Link to comment Share on other sites More sharing options...
74_5.0L_Z Posted October 16, 2002 Author Share Posted October 16, 2002 Thanks Pete, Jeff, Mike Pete I thought about moving the crossmember forward, but decided against it because I don't want to modify my driveshaft or exhaust. I am moving the T/C mount up 3/4" and out 1/4" to match the JTR mod of the front crossmember. I am also going to a heim joint and clevis rather than the stock T/C box and bushings. I am going to use the Ground Control caster/ camber plates, and I am considering moving the strut upper mount back to gain some caster. Dan Quote Link to comment Share on other sites More sharing options...
Guest AlsoRanFPrepared Posted October 16, 2002 Share Posted October 16, 2002 Just a consideration... I was looking into using the "stock" attachment points on my tube framed E-Modified car and eventually decided to go with a SLA setup. Since you may already be tubing the front end it may actually be easier to design a SLA than to recreate the stock front attachments (depends on how much of the strut towers were thrashed). Just some food for thought. -Mark Quote Link to comment Share on other sites More sharing options...
74_5.0L_Z Posted October 17, 2002 Author Share Posted October 17, 2002 I am starting from scratch from the firewall forward. The front frame and struts were wasted, but the car was perfect from the firewall back. I cut the entire front off at the firewall. I have to reconstruct all the front attach points including the top mounts for the struts. I already have all the lower points established (assuming I get the correct placement of the crossmember holes). SLA? Single Live Axle? Thanks, Dan Quote Link to comment Share on other sites More sharing options...
Jeff Posted October 17, 2002 Share Posted October 17, 2002 Sorry Dan, I went to the track last night and forgot to measure when I got home. I made myself a note and will measure tonight. Quote Link to comment Share on other sites More sharing options...
Guest AlsoRanFPrepared Posted October 17, 2002 Share Posted October 17, 2002 Sorry for the acronym. SLA stands for short-long-arm. It is a dual A arm configuration that allows for a better camber curve which allows the tire to remain at a better angle to the road when the body rolls. It is a better system from a handling standpoint. It also has the potential to reduce the unsprung weight of the front suspension whch is also beneficial to handling. -Mark Quote Link to comment Share on other sites More sharing options...
Jeff Posted October 17, 2002 Share Posted October 17, 2002 From the centerline of the crossmember rear bolt hole to the vertical plane of the firewall is exactly 20" on the drivers side of my car. I transfered the mark to the top of the frame rail and measured back to the firewall. Hope this helps and good luck with the project. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted October 18, 2002 Share Posted October 18, 2002 I checked my 71 240, on the passenger side projecting from the verticle portion of the fire wall straight down, then forward to the rear x-member bolt center, I had 19 7/8 inch. Chris Quote Link to comment Share on other sites More sharing options...
74_5.0L_Z Posted October 18, 2002 Author Share Posted October 18, 2002 Anyone get a measurement yet? Quote Link to comment Share on other sites More sharing options...
74_5.0L_Z Posted October 18, 2002 Author Share Posted October 18, 2002 Thanks Guys, By your measurements, the dimension on the Nissan 260Z drawing is ~1.5 inches wrong, and the 280Z drawing is correct. I did consider going to a nonparallel, unequal length double wishbone suspension. Never heard it called SLA. However, I already have the complete adjustable coilovers, camber plates, konis, and Outlaw Brake setup, and wanted to reuse them. Dan Quote Link to comment Share on other sites More sharing options...
peej410 Posted October 18, 2002 Share Posted October 18, 2002 if youd like to go to the double wishbone setup id be more then happy to purchase all of the parts that you cant use even the brakes. As long as your not asking more then what they were new i was also considering this and i found a great website for parts if your interested http://www.cmwraceparts.com/ go to the online catalog, they have prices listed their prices are fantastic and if u click on the little camera of each product they have pictures up too goodluck - pete Quote Link to comment Share on other sites More sharing options...
ZROSSA Posted October 19, 2002 Share Posted October 19, 2002 I was always under the impression that a sla set up was a bit of a band aid to use when you couldnt run long wishbones. Audi, Honda, Aussie ford falcon all us this set up. It basicly means you can get performance of a wishbone set up in the spave of a strut. Douglas Quote Link to comment Share on other sites More sharing options...
pparaska Posted October 28, 2002 Share Posted October 28, 2002 Sorry it took so long. I just confirmed that the rear crossmember bolt is very close to 20" from the vertical portion of the firewall on my 73 240Z. Quote Link to comment Share on other sites More sharing options...
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