Guest zfan Posted February 28, 2006 Share Posted February 28, 2006 Well it is time to purchase my rear coilovers for the 240Z. I have rolled the fender lips and will be running 16x8 rims with 255/50-16 Mickey Thompson drag radials. I think I will need to run the shorter 8-10" springs with a 225-250 spring rate. I think the shorter spring should help with clearance issues. Does anyone have a set up simular to what I am going to be running? I want to do this with as little screw ups as possible. Don't laugh! Seriously, is there one brand Coilover anyone recommends over the others and what strut would you recommend while I am at it. I have some concerns regarding running the Tokico Illumina's as several folks here say they will go "BOOM" with a 250 spring rate. Thanks for any help/imput you can give. Mike Quote Link to comment Share on other sites More sharing options...
JMortensen Posted February 28, 2006 Share Posted February 28, 2006 I'm running a 250/45/15 tire, 23.5" tall, 8" rim, my fenders are not rolled. I use 10" coilovers, not the shorter 8", and I have 250 in/lb springs in back with Tokicos. Suposedly the 250's in an 8" length have binding issues, but maybe you could run a longer bumpstop to prevent that from happening. Haven't blown a rear strut yet in ~8 years hard usage including 5 seasons autox and a bunch of track days. I did blow a front (200 in/lb in front) running over curbs at the road course, but it had nothing to do with the spring rate and the other front is fine years later. The tires are about 1/4" away from the adjusting nuts on the coilovers, and probably 1/2" away from the fender lip. I ordered the wrong size wheels and I had to space the wheel out with a 1/4" spacer, but if you do it right you definitely can get them stuffed in there with no issues. Don't ask me what my backspace is, I don't know and I'd hate to give you the wrong info... Ground Control/Modern Motorsports coilovers are supposed to be slightly higher quality than the rest. I don't know that it matters that much though. Quote Link to comment Share on other sites More sharing options...
fastzcars Posted February 28, 2006 Share Posted February 28, 2006 I think you'll be squeezing the tires a bit to fit on a 8 inch rim, but each tire manufacturer is different. they are NOT all the same physical size, even if they have the same size written on the side wall. Try going to the "TireRack" website and you'll see what I mean. They have all the actual tire diminssions listed. As far as the wheel offset, reletive to the coil spring size, the 8 inch rim with a 5 inch backspace has about 1 inch of clearence on the inside from the tire to the coilspring. It's when you try to squeeze a 9 inch rim in the rear is when you run into trouble with the clearences. That's the reason for the very short 8 inch coilspring. We're trying to get the bottom coil adjuster to be above the tire, to gain inside tire cleareance. So I wouldn't worry about it in your case. A 10 inch spring will clear fine. Now as far as coil spring rates that's still another story. There are alot of variables. I'll let other's here with MUCH more knowledge answer that one. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted February 28, 2006 Share Posted February 28, 2006 fastzcars is right about squeezing the tire on the rim. I really wanted to run a 10" rim but didn't want to flare the car and the tires were cheap, so I forced them onto the 8" rim. Probably doesn't matter so much for drag racing, but that really is too wide a tire for the optimum handling on that rim. Quote Link to comment Share on other sites More sharing options...
Clifton Posted February 28, 2006 Share Posted February 28, 2006 You can fit a 9" wheel without flares. I run 8" springs 250f/280r. No problems. Quote Link to comment Share on other sites More sharing options...
Guest zfan Posted February 28, 2006 Share Posted February 28, 2006 Thanks Guys. I am only following Mickey Thompsons recommendations for the rim size. They say to run an 8" rim but I guess I could go with a 9" rim as well. The car is a drag/cruise car with some twisties every so often. I have other wheels and tires for that of course. Mike Quote Link to comment Share on other sites More sharing options...
jt1 Posted February 28, 2006 Share Posted February 28, 2006 I've been running the Illuminas 4 yrs with 250F/275R, lots of track days, with no problems with them. John Quote Link to comment Share on other sites More sharing options...
Guest zfan Posted March 1, 2006 Share Posted March 1, 2006 I spoke with the Guys at Ground Control directly. They recommend a 10" spring and not the 8" though they never gave me a definent reason why 10 over 8. Is there anything else I should look out for before ordering. I am new to the coil over stuff but have completly rebuilt my Z's suspension and brakes with upgrades included. Wish I had just done the coilovers to begin with instead of the whole struts and springs thing. Oh well, it will be good for someone else when I sell my old stuff. Mike Quote Link to comment Share on other sites More sharing options...
2126 Posted March 1, 2006 Share Posted March 1, 2006 Food for thought......If your going the route of coil-overs, you may consider the addition of adjustable camber plates as you will most likely be changing your ride height and will want to be able to change the camber settings. The camber plates that require modifying the strut tower, to mount them, are certainly better (but a little more expensive) than the unit that have multiple fixed adjustment and require no strut tower mods to install. GC offers both types. Quote Link to comment Share on other sites More sharing options...
Guest zfan Posted March 1, 2006 Share Posted March 1, 2006 Do I have to use camber plates? I am looking at straight line performance and cruising mainly. Besides that I am on a pretty tight budget. I was hoping to put Tokico Illuminas on all four corners and the camber plates will foil that plan. The only reason I am going to coilovers is for rear clearance issues. Mike Quote Link to comment Share on other sites More sharing options...
Clifton Posted March 2, 2006 Share Posted March 2, 2006 You don't have to. I don't know how much power you are putting down but negative camber doesn't help straight line traction. The more you lower the rear the more neg camber you'll put in it. IF you have c/o's you could avoid going to low. Do I have to use camber plates? I am looking at straight line performance and cruising mainly. Besides that I am on a pretty tight budget. I was hoping to put Tokico Illuminas on all four corners and the camber plates will foil that plan. The only reason I am going to coilovers is for rear clearance issues. Mike 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.