Guest Aaron Posted October 18, 2001 Share Posted October 18, 2001 Ok, the roads here in the mountains of NE AL are terrible. If I remember correctly from the service manual that I used to have, the factory springs on a 280ZXT are 120# on all four corners. I would like to firm the ride up, but I do not want loose any ride height. Does anyone know of a stiffer spring that does not lower the car? Has anyone used the rubber inserts that fit between the coils to firm it up? Are coil-overs the only way? [ October 18, 2001: Message edited by: Aaron ] Quote Link to comment Share on other sites More sharing options...
Modern Motorsports Ltd Posted October 18, 2001 Share Posted October 18, 2001 If your springs are weak inserts aren't rec'd as they'll only stress the weak part more. TRW makes an awesome IMO rear pair of springs for a 280ZX (might not be designed for it but they do come up as listed for 280zx). I ran them for 5 yrs till I went coilovers to clear my 245s. They were definitely stiffer than stock and progressive. And only $55US/pair, I'd have bought them for twice that in a wink. Worked great with my BOGE strut cartridges. Up front, if you can find any low miles 2+2 springs they might be suitable....measure up your OE spring size & pass it on to me and I'll check out another idea I have. Quote Link to comment Share on other sites More sharing options...
Mike kZ Posted October 19, 2001 Share Posted October 19, 2001 Has anyone tried progressive, or variable rate springs? How do they work exactly? Do you need these springs in all 4 corners to work right, or can you just put some in the back? I'm looking at 130/250lbs HAL veriable rate springs for the back of my car. They say "that the lower spring rate helps allow the suspension to get weight transfer for a good launch off the line" Quote Link to comment Share on other sites More sharing options...
DavyZ Posted October 19, 2001 Share Posted October 19, 2001 Mike, the progressive rate springs get progressively stiffer the more that they are compressed. They have near stock "give" initially, so small bumps on the road are not teeth shattering, but when subjected to further travel as in performance driving, the stiffer portion of the spring shows itself and limits the amount of compression. Really cool idea. I'm considering them, but I think I'll just do coil-overs for more tire... Davy Quote Link to comment Share on other sites More sharing options...
Modern Motorsports Ltd Posted October 20, 2001 Share Posted October 20, 2001 Progressives are absolutely excellent IMO if they offer the range of rates and ride height you want. I loved mine, but I needed every 1/8" (literally, I'll have to post that inner tire to coilover clearance pic...<1/8") so finally went coilovers. They worked great on track as well. Swaybar kit eliminated my majority of body roll. Quote Link to comment Share on other sites More sharing options...
ZROSSA Posted October 20, 2001 Share Posted October 20, 2001 You can get coil overs that are progressive. they run two springs one is a hepler that goes coil bound after a certain amount of travel then the higher rate ones take over. The race boys have a lot of success with these but it takes a lot of testing to get them right. I am not telling you anything that you dont allready know though, am I. Douglas Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted October 21, 2001 Share Posted October 21, 2001 are there any places you might recommend that are good at helping you figure out what you need? Talking about progressive coilovers here... Quote Link to comment Share on other sites More sharing options...
Modern Motorsports Ltd Posted October 21, 2001 Share Posted October 21, 2001 Sounds like their might be some more diverse vendors in NZ or AUS? Afco only makes a few progressive rate coilover springs and from their pics they look like crap IMO. Several coils so tight like that are next to useless which makes me wonder at the seriousness of their design intent? See if afco (only NA retailer of progressive rate coilover springs...they have 3 options AIR and all 10.5" or longer) can tell the working range of their springs.....if not and you must have coilovers I'd select them on the softer end, 125/150 or similar......~$60@ for the springs to change later on. Quote Link to comment Share on other sites More sharing options...
johnc Posted October 22, 2001 Share Posted October 22, 2001 From a racing perspective, you have to be able to do a lot of testing and have good data acquisition to develop a progressive spring set up. I have yet to see a set of progressive springs that have a linear rate increase. Basically, they increase at a somewhat linear rate until they reach their designed coil bind for the softer part and then the spring rate is basically flat until full coil bind. One of the critical adjustments made to a race at each track is ride height. If I lower my car 1/2" in front and 1/4" in rear to get some additional rake, what is that going to do to my wheel rates as I use up that softer part of the spring? I will obviously hit the flat line spring rate sooner, but is that desirable? What if it isn't? Its so much easier to tune a race suspension with linear rate springs than with progressives. If you do need rising wheel rates (which is really what you should be meauring), then a rising rate suspension is a much better choice than progressive springs. Quote Link to comment Share on other sites More sharing options...
blueovalz Posted October 22, 2001 Share Posted October 22, 2001 quoteIf I lower my car 1/2" in front and 1/4" in rear to get some additional rake, what is that going to do to my wheel rates as I use up that softer part of the spring? How does lowering the car make the spring rate change (using up the softer part of the spring), or did I read this wrong? Quote Link to comment Share on other sites More sharing options...
Mike kZ Posted October 23, 2001 Share Posted October 23, 2001 These HAL's are coil over progressive springs sold by Jeg's. I'm going to try the 130/250 12" springs in the rear. They are $53.99 ea. Quote Link to comment Share on other sites More sharing options...
johnc Posted October 23, 2001 Share Posted October 23, 2001 It wasn't obvious in my post, but if I'm increasing rake I'm transferring more static weight forward. Let's say the corner weights are: LF - 580 RF - 550 LR - 540 RR - 530 If I add in 1/4" more rake then I move weight forward. The new corner weights might be: LF - 610 RF - 580 LR - 510 RR - 500 Because of the additional weight up front I've compressed the front springs an additional amount (and uncompressed the rear springs some amount). With linear rate springs that's not big deal. With progressives, it "might" be a big deal but you won't really know that unless you've done some testing. Quote Link to comment Share on other sites More sharing options...
Modern Motorsports Ltd Posted October 23, 2001 Share Posted October 23, 2001 quote: Originally posted by Mike kZ: These HAL's are coil over progressive springs sold by Jeg's. I'm going to try the 130/250 12" springs in the rear. They are $53.99 ea. Have you got PN's, any other offerings by HAL? Is that their full name? I'd have to make new coilover setups on my ZX to fit 12's I'm quite sure (Z's are more forgiving). Sounds like a great 'winter' setup for me to run. Quote Link to comment Share on other sites More sharing options...
Mike kZ Posted October 23, 2001 Share Posted October 23, 2001 quote: Originally posted by Ross C: Have you got PN's, any other offerings by HAL? Is that their full name? I'd have to make new coilover setups on my ZX to fit 12's I'm quite sure (Z's are more forgiving). Sounds like a great 'winter' setup for me to run. Ross, That's all they say is HAL, don't know if this stands for anything. 10" springs 122-10-140/250 122-10-225/475 12" springs 122-12-100/200 122-12-130/250 122-12-175/350 the last 6 numbers are the spring rates, and they are all 53.99 ea. Jeg's phone # is 1-800-345-4545 Quote Link to comment Share on other sites More sharing options...
Modern Motorsports Ltd Posted October 23, 2001 Share Posted October 23, 2001 Thanks Mike, just found some webinfo as well: HAL spring offerings. I wonder how their 'bulk' buy compares to JEG's pricing? Those 10" 140/250s would be right up my 'winter' alley Quote Link to comment Share on other sites More sharing options...
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