datzun240 Posted February 6, 2006 Share Posted February 6, 2006 I spent the last few days going through the hybridZ searches and just googling some stuff online, had a few questions thought some people mite be able to help me figure out. I have a 72 240Z (L28ET swap). My suspension on all four corners: Arizona Z car Coilover kit Eibach 8" springs (150F/175R) Poly Bump Stops Tokico Illuminas The problem I'm dealing with is a harsh ride quality. I dialed in some different settings w/ the illuminas and the best setting so far is 4 or 3 in the front and 1 in the rear. The ride quality is really bad at low speeds going over bumps, especially if they are consecutive bumps in the road. I was wondering if anyone had personal experience with what could be causing this type of problems in my suspension. I don't think that my spring rates are stiff by any means, but the free length is a significantly shorter than OEM. Also if my Lower control arm bushings are worn out, will that affect the lateral ride quality. btw: the issue is when driving straight, there are zero problems when going into turns. Thanks in advance. Quote Link to comment Share on other sites More sharing options...
Clifton Posted February 6, 2006 Share Posted February 6, 2006 I haven't run an 8" spring that soft but I would think it would coil bind on dips. What happens when you soften the struts all the way? Should soften the ride. Quote Link to comment Share on other sites More sharing options...
datzun240 Posted February 6, 2006 Author Share Posted February 6, 2006 When I set the illuminas to 1 in the rear its fine, but if i put it to 1 in the front, when the tires go over a bump, i can feel every part of that bump and in some cases (depending on the bump and the speed im traveling) my *** will leave the bucket seat. I've been testing different settings on the same street over and over again. Btw: The shocks aren't blown and I have tried a 225F/250R setup also with the same exact setup prior to the softer rates. Basically the same outcome, but the stiffer rates made it worse. Quote Link to comment Share on other sites More sharing options...
qwik240z Posted February 6, 2006 Share Posted February 6, 2006 I have MSA coilovers on mine with Eibach springs and Tokico 5 ways. I noticed the same harsh ride quality over anything but smooth road surfaces. I set the fronts to 2 and the rear to 1 and it was a little better. I repaced the half worn out Falken Azenis 195-60-14 tires with new 225-50-16 Pirelli P6000 tires and the difference is night and day. It is amazing how much smoother the ride is. The new tires are not as sticky as the Falkens but they are great for the street. I plan on getting another set of wheels and tires for track/autocross days. Quote Link to comment Share on other sites More sharing options...
datzun240 Posted February 6, 2006 Author Share Posted February 6, 2006 Yea I got brand new tires on mine. I linked some pictures to how the Z sits right now to give an idea of what it looks like. thanks to all who replied http://www.slackaz.com/images/QUICK/1.JPG http://www.slackaz.com/images/QUICK/2.JPG Quote Link to comment Share on other sites More sharing options...
260DET Posted February 6, 2006 Share Posted February 6, 2006 Spring rate should not be a problem. If there is sufficient and free moving suspension bump travel then shocks? Quote Link to comment Share on other sites More sharing options...
datzun240 Posted February 6, 2006 Author Share Posted February 6, 2006 I didn't really understand what you were asking in your reply. I will jack up the front of the car tomorrow and snap some photos of the suspension w/o a load on it. Quote Link to comment Share on other sites More sharing options...
Supra510 Posted February 6, 2006 Share Posted February 6, 2006 Like Clifton said I'm pretty sure what you are experiencing is coil bind. 8 inch springs at a given rate will bind before 10 inch springs at the same rate. When you get under the there check for marks on the coils where they may be touching, on mine it left a slight grey mark in between each coil. Anthony Quote Link to comment Share on other sites More sharing options...
datzun240 Posted February 6, 2006 Author Share Posted February 6, 2006 oh ok. I will check for that. Thanks for the input. Does anyone else have any other ideas? thanks in advance all. Quote Link to comment Share on other sites More sharing options...
260DET Posted February 6, 2006 Share Posted February 6, 2006 I didn't really understand what you were asking in your reply. I will jack up the front of the car tomorrow and snap some photos of the suspension w/o a load on it. Yes, it was a bit cryptic, basically you need to check that the suspension can move up sufficiently when you hit a bump. If it can then shocks are likely the problem. Quote Link to comment Share on other sites More sharing options...
datzun240 Posted February 6, 2006 Author Share Posted February 6, 2006 Yea... after awhile i figured out what you were saying. But shocks already are not part of the equation ne more. Right now I have to check tomorrow and see if im getting coil bind in a few ways. And if so, i mite have to do some swapping of springs. Quote Link to comment Share on other sites More sharing options...
fastzcars Posted February 6, 2006 Share Posted February 6, 2006 First a couple of questions. First, did you shorten your strut housings, if so by how much. Second if you didn't shorten you strut housingss did you just install the coilover kit and threaded down the lower spring perch. I can only assume things here. But if you didn't, and you lowered your car, your probably hitting your bump stops. You do have bump stops? There's still alot of info we need to know to help you out. I would suggest to wrap 1 nylon wire tie(zip tie) around the strut shafts on each corner. They got to be snug so to not slip back down the strut shafts and drive it around normally for a couple of miles. Then carefully raise your car and see how much the wite tie moved. That way you can see how much travel you are actually using. 150/175 are not that high of a spring rate, it's only 20% to 25% higher than stock. BUT the 8 inch length is probably too short. Your probably coil binding as well. Quote Link to comment Share on other sites More sharing options...
datzun240 Posted February 6, 2006 Author Share Posted February 6, 2006 I didn't shorten my strut housings. I did the basic remove the lower perch and use the stock weld. I am using the energy suspension bump stops. Yea after driving around about 75% of the roads feel ok, the other 25% of the time it doesn't feel ok. Its not to the point where i can't take it any more. Im gonna check tomorrow to see if i am coil binding. thanks for the suggestions. Quote Link to comment Share on other sites More sharing options...
CruxGNZ Posted February 6, 2006 Share Posted February 6, 2006 Sounds like you are bottoming the struts out or you have a coil bind issue. How much clearence do you have from the road to the bottom of the rocker panel? Quote Link to comment Share on other sites More sharing options...
tube80z Posted February 6, 2006 Share Posted February 6, 2006 A few ideas. Put zip ties on the shock shafts and a few of the coils and go for a drive. If you come back any of the zip ties are missing from the coils then you are probably binding the coils. Look for the zip tie on the shock shaft and if it is missing or burried in the bump rubber then you are probably bottoming. You might also check to make sure you have adequate shock travel and aren't bottoming the insert. That will probably require taking things apart and doing some measurement without the spring in place. Cary Quote Link to comment Share on other sites More sharing options...
datzun240 Posted February 6, 2006 Author Share Posted February 6, 2006 Yea that what I will be attemping this AM as soon as I get myself awake. Someone above also suggested the same thing. Im going to go ahead and take some pictures to better display what is going on. I have a few ideas of how to remedy the problem, but will put them up for question after I do a few things here. thanks for all the suggestions, will update soon. Quote Link to comment Share on other sites More sharing options...
tube80z Posted February 6, 2006 Share Posted February 6, 2006 I don't there's any real reason to take pics. You could do a simple measurement of how much shock shaft you have and compare that to when a 8 inch coil stacks or you can put on some zip ties and go for a drive. The symptons you describe are the classic "flat ride" problem. That is where you pick spring frequency to give a flat ride as you hit bumps at a set speed. Given the car is riding rough -- often a pitching issue and you sitffen the rear to compensate. That leads me to speculate something has suddenly gotten very stiff in the front. It's time to put down the keyboard and do some real work Cary Quote Link to comment Share on other sites More sharing options...
datzun240 Posted February 6, 2006 Author Share Posted February 6, 2006 Ok. So i took the Z out and i wrapped up some zip ties on equal distances on the coils of the springs. I took it out on the worst quality road i could find. Drove it up and down that street for about 10 mins or so and then took it around on the expressway. So I got back and checked the zip ties on the spring itself. There were no marks or scratches or signs of them touching @ all. All of them were good on all the corners. The zip tie wrapped @ the bottom of the strut shaft was @ the top though right underneathe the bumpstop. So there is where the problem is. LOL. That @ least narrows things down, but my options are limited. Besides sectioning out the strut housing, does anyone else have any ideas? thanks for the input. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted February 6, 2006 Share Posted February 6, 2006 Stiffer springs, sectioning the struts, combination of both. Quote Link to comment Share on other sites More sharing options...
mom'sZ Posted February 6, 2006 Share Posted February 6, 2006 I'm no engineer or a suspension expert but I thought I would relate some personal experience. I installed new strut inserts and ground control coil overs some months ago. My spring rates are slightly higher (225f & 250r I think, can't remember off hand). From my personal experience at low speeds (below 30 MPH) the ride is a little rough. Above thirty it become smoother. I think the reason for this is as follows. These are light cars. Spring rates in this range are kind of heavy for such a light weight car. I feel that below 30 MPH the forces on the suspension are not enough to deflect the suspension, in effect the suspension is solid. At those lower speeds you feel everything. Like another user in the forum said, you can even feel the painted stripes on the road. I like it, but this is subjective. What I feel is a 'sporty' ride, you may feel is harsh. Just a thought. Quote Link to comment Share on other sites More sharing options...
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