Guest sector Posted February 22, 2003 Share Posted February 22, 2003 Hey guys, Just wondering how many GTO owners have put coilovers on in place of sectioning the struts? If you did use coilovers, were you able to lower the car enough to make up for the weight loss? I am trying to decide if I need to just use coilovers or section the struts with coilovers? John Washington do you have any advice on this setup? Any help you guys can provide will be appreciated. Thanks in advance- Brian Quote Link to comment Share on other sites More sharing options...
Guest nezzie76 Posted February 22, 2003 Share Posted February 22, 2003 I have coilovers on mine, and I also sectioned the struts 2 inches too. When I put the coilovers on, it dropped it about 2 inches, but since the top was missing on my car it rose up even more, so the 2 inch drop wasn't enough. That's why I decided to section them too. I have to run the coilovers up a bit, maybe around an inch and the ride height is about right on my car. Quote Link to comment Share on other sites More sharing options...
Guest sector Posted February 22, 2003 Share Posted February 22, 2003 Nezzie, What cartridges did you use for the front and rear struts for the 2 inch sectioning? Also whose coilovers did you use? Thanks, Brian- Quote Link to comment Share on other sites More sharing options...
Guest nezzie76 Posted February 22, 2003 Share Posted February 22, 2003 I used the strut cartridges of a volkswagon GTI for the front, and I used the ones from the front in the back. They ended up working out fine. I used Ross Corrigan's coilovers. Quote Link to comment Share on other sites More sharing options...
Guest sector Posted February 22, 2003 Share Posted February 22, 2003 Thanks for the advice. Brian- Quote Link to comment Share on other sites More sharing options...
Guest Skillet Posted February 22, 2003 Share Posted February 22, 2003 Nezzie, Thanks for the details on your struts. I have just sent in my money to John for a VR kit (layaway). I have one question for you, what year Volkswagon GTI front struts did you use. I am planning on going with Tokico Illumina's. If you happened to have used the Tokico adjustables yourself, do you have the part numbers & any feedback on the ride quality. Also, what springs rates did you go with through Ross? I am going to put in a 350 (per JTR specs) with aluminum heads, intake, waterpump, etc and move my battery to the back. Any feedback on the springs? Thanks, Chris Larson Quote Link to comment Share on other sites More sharing options...
Wagz Posted February 22, 2003 Share Posted February 22, 2003 I'm putting a VR kit on my '71 240. I am sectioning my struts 2" as well. The Tokico Illumna part # I have on the shelf are: BZ 3099 - Front BZ 3016 - Rear I am using 200# springs all the way around. Quote Link to comment Share on other sites More sharing options...
Guest Skillet Posted February 23, 2003 Share Posted February 23, 2003 Marc, Thanks for the info. I noticed that your stuts are different for the front and rear. What is the difference? How did you select these struts? BTW, your website is great!! You are doing everything I have been planning on doing. I will visit this site often to help me get through my project. Thanks!! Chris Quote Link to comment Share on other sites More sharing options...
Wagz Posted February 23, 2003 Share Posted February 23, 2003 Chis - In stock form the rear cartridges are about 1.5" longner than the fronts. When I bought my coilover kits and the cartridges, I told them how far I was planning on lowering the car and sectioning the struts. Basically, they just sent me cartridges 2" shorter than stock lengths. I got my stuff from Dave Turner Motorports in Cali. That was before I heard of Ross Corrigan and Mike G. (SCCA). I think their prices are better than Turner's and they both have excellent reps with the guys on this site. I've bought brake upgrades from Mike and I plan on purchasing some stub-axles from Ross. Thanks for the compliments on my site. About the only thing that gets less attention than my VR project these days is the website. One of these days I'll get both projects kicked into high gear. Quote Link to comment Share on other sites More sharing options...
Guest nezzie76 Posted February 24, 2003 Share Posted February 24, 2003 I may be wrong, but I think that the GTI inserts are the same for the years. I think I told them something from the mid eighties. I went with 150lb rear and 175 front. The car sinks too much with them in the rear, so go with 200 or so. I had my fiance riding with me yesterday and she was unhappy that the car wasn't bottoming out on the inner wheel wells until she got in , so if you don't want an unhappy woman you'd better go with the stiffer springs. Quote Link to comment Share on other sites More sharing options...
boatbum Posted February 24, 2003 Share Posted February 24, 2003 For my front I am using cartridges from a 300zx - they are about 1 1/2" shorter than the stock and look to fit better than the GTI. Planning on putting them in this weekend so I'll let you know how they work. Teo Quote Link to comment Share on other sites More sharing options...
Guest sector Posted February 25, 2003 Share Posted February 25, 2003 Teo, I am doing a 280 as well, are you using the 300zx in both the front and rear or just the rear if not what else are you using, and are you lowering the car 1.5 front and back? Thanks, Very interested in hearing how your swap goes. Quote Link to comment Share on other sites More sharing options...
boatbum Posted February 25, 2003 Share Posted February 25, 2003 Sector, For the front: sectioning the strut casing about 1.5" and using '86 300zx struts (front). The 300zx strut is more like the 280 and shouldn't require a custom bushing. I will then use lowering springs and this should sit the car about 1.5-2" lower overall. For the rear: I am replacingd the larger strut isolators with a pair of the shorter front isolators (bought from Dannys Datsuns) This allows me to use the same 280 rear struts and when combined with lowering springs sits the car about 1.5-2" lower. Should be ok - It is so cold here in MN that even the heated garage where I have my project is cold. I can't wait til I move everything to FL and then can work on it at will. Teo Quote Link to comment Share on other sites More sharing options...
Wagz Posted February 25, 2003 Share Posted February 25, 2003 Teo - With the lower overall weight of the car after removing the top and replacing fenders with fiberglass, do you think that your car will sit low enough to look right in relation to the wheels? In talking with Nate (Nezzie76) I thought he told me his car didn't sit low enough and he ended-up having to section his struts to get the correct ride-height. Just curious. I'd like to know what John Washington's thoughts are on the need for sectioning. -Marc Quote Link to comment Share on other sites More sharing options...
boatbum Posted February 25, 2003 Share Posted February 25, 2003 Marc, I plan on sectioning the struts around 1.5" It will definitely be needed. The car is right about 2" too high but I don't have my new wheels on yet. The plan is that my wheels will be on this weekend and I will adjust accordingly. I think either way - you will need to section or go with coilovers. The reason I went with the front 300zx struts is that the end is more like the 280 but is also about 2" shorter and doesn't require the mods and customizing like the GTIs. Teo Quote Link to comment Share on other sites More sharing options...
John Washington Posted February 25, 2003 Share Posted February 25, 2003 Thanks Wags, for letting me know about the thread. I saw it early on and meant to reply, but have just been buried! Adjusting front suspension ride height on a Z or Z-based car. 1. Sectioning the struts really is essential. Without it you simply can't lower the car enough without getting down to a point where you still have reasonable suspension travel. 2. 300ZX (third gen) shocks are not only shorter by about 1.5", but they also have the same threaded piston rod (upper end) as the first gen cars.Therefore, you can use them without modifying the strut insulator (top hat). With the GTI struts you have to drill them out. It can be a pain, plus it makes it harder to tighten or loosen the top nut. The GTI piston has a round threaded section, whereas the Z has a "D" shape that prevents the piston rod from rotating. 3. Coilovers are the way to go. I had some made locally but it was a pain; so much so that I'd recommend Ground Control in spite of the expense. I'd be interested to hear what everyone is using in this area. Coilovers will give you adjustability in ride height that will help you trim out the rake of the car just the way you want it. 4. While you have everything apart, drop the cross member and relocate the inner pivot point a la the JTR V8 book. This will eliminate the annoying bumpsteer that was built into the Z to help compensate for overly soft suspension, I suspect. What's bumpsteer? The annoying tendency of the car to follow the ruts in the road or pull to the side of a bump if you only hit it on one side. It's due to the tie-rod arm and control arm not being parallel. Re-locating the pivot point will cure it. 5. Install "bump steer spacers." Why the quotes? That's not really what they are, but it's what everyone calls them. They are spacers that go between the bottom of the strut and the ball joint. What are they really? "Camber curve correctors." My term. Copyrighted. Use it and you have to pay me:) In essence, when the suspension height is stock the ball joint translates outboard with increasing bump load. This makes the camber more negative, i.e., the top of the wheel leans more toward the center of the car. The more negative the camber, the better the bite from the tire, which is exactly what you want when you load that side (the side on the outside of the turn). At some point when loading the suspension, the control arm goes from a normal drooping (toward the outboard side), to horizontal and eventually above horizontal. When this happens, the ball joint starts coming back toward the centerline of the car, decreasing camber and causing the front of the car to "wash out" (understeer) in hard corners and especially under braking (which transfers more load toward that critical outboard tire). So, if you graph (I'm the self appointed king of analogies and visual aids) the camber versus loading, you see the camber start out at some negative value, go through zero (corresponding with horizontal control arm position) and start to become positive again. When driving a stock Z under normal conditions you'd never get it loaded far enough to get the control arm significantly above horizontal. However, when the car has been lowered the entire "camber curve" from the above referenced graph is artifical shifted toward the positive camber area. That is to say the closer you start out to horizontal on the control arm the easier it is to get into the wrong part of the curve. Imagine that if you started out with the control arm exactly horizontal, it would only take a minute amount of loading to start decreasing the camber. The camber curve correcting spacers push the control arm back to something more like a stock location, and therefore depress the camber gain curve back into a more desirable region. "How come I've never heard of this before, and why don't the racers do this?" I've heard that question, too. The answer is that most of them run such stiff springs and shocks that you don't have much movement on the camber curve. In essence the camber becomes fixed. The downside is loss of that all important suspension travel and it's little buddy "ride quality." In a racecar, neither is that important. I have some really nice billet CCCs that I never properly marketed. If a dozen of you guys would buy them from me it would pay for my time in posting this info. I'll try to get a picture up on the website when I have a chance. Some parenthetical comments: While you have everything apart, it's a good idea to do the suspension bushings. The steering rack in particular can cause irritating mystery problems that you won't figure out until you have a friend turn your steering wheel while you watch the rack move back and forth 1/4 inch relative to its mounts...or until you listen to me and just do it Also, you may as well change out the brakes. The JTR-suggested Toyota 4-piston conversion is a pretty good one. I think I have one of those in a box here somewhere I'd make someone a deal on. It's a little heavy compared to "real brakes." I hate to admit it and many of you probably hate to hear it, but our good friend at "the other Z place in Arizona" may have the best setup for that. If you just can't stand him so badly that you wouldn't buy a $20 bill from him for $10, let me know. I may have some inroads to some alternate sources, but don't have the time to invest in exploration without pretty promising prospects of selling some. Be very conscious of the bottom of your car. There should be nothing hanging out below the "frame rails." This becomes even more critical with decreasing ground clearance (duh), but you'd be surprised how many aftermarket headers dump out an inch below the frame rails. I call these headers "speed bump feelers." Make sure whoever does your exhaust work from that point back understands the concept as well. This is especially important with V8 cars. Not only will this stuff drag, scrape off that pretty JetHot coating, and tear up the exhaust, it will also loosen your exhaust manifold studs (or break them) and potentially ruin the gaskets. Also, I have had much better luck with graphite gaskets than anything else. They are a lot more expensive than paper, but it's a relative thing...relative to how CHEAP the paper stuff is. I hope this helps! Quote Link to comment Share on other sites More sharing options...
Guest sector Posted February 26, 2003 Share Posted February 26, 2003 John, As always, and I speak for the group, THANK YOU. Your insight into these cars is invaluable. I for one can not wait to have my car ready to purchase a kit from you. Hopefully only one more year, until the car is ready. Have you had a chance to update the installation manual? I have an older version and was wondering if there have been any changes? For instance the new bolt on cheek panels. Anyways I just wanted to say thank you and please let any of us know of anything you happen to have laying around you are wanting to get rid of, I am sure one of us in the group would love to have it. I can't speak for everybody but most of us on the thread either have or are going to get ross c's or scca's coilover kits vs. ground control. One other question is for the rear struts, do you just use the front struts and section accordingly as in most of the other swaps, or use the 300 struts in the rear as well. Thanks for taking the time out of your schedule to help. Brian Quote Link to comment Share on other sites More sharing options...
Wagz Posted February 26, 2003 Share Posted February 26, 2003 I just wanted to echo Brian's comments. We alway appreciate your insight John! I am also wondering about an updated install manual. I bought mine a few years ago and have the same question about the update cheek panels. I'd gladely buy another if there is any new info. Quote Link to comment Share on other sites More sharing options...
Guest Skillet Posted February 26, 2003 Share Posted February 26, 2003 John, Wow! What an excellent reponse. Thank you!! I have read about bump steer for years and never really understood it until now. I too would like to know the answers to the questions that Brian asked. When you say 300ZX (3rd generation), do you mean the 90-96 cars or the 3rd generation being the 300ZX (late 80's)? Also, I recall reading that you fabricated some thick "bump steer" spacers (CCC's) and preferred the 3/4 inchs spacer supplied by MSA and others. Are the ones you referred to in this post different that the spacers currently on the market? Last question, I want to make sure I understand this correctly, you recommend doing BOTH the front control arm realignment (per JTR) AND the use of the CCC spacers? Thanks again John (and everyone else!), Chris Larson Quote Link to comment Share on other sites More sharing options...
John Washington Posted February 28, 2003 Share Posted February 28, 2003 As usual, thanks for the kind responses, guys. I've been prefacing all my stuff with "I'm not an expert" lately, and when I realized I didn't on this one I was holding my breath in hopes that some more knowledgeable person wouldn't say, "You're an idiot." I really need to update the installation manual. Unfortunately, it's not in the cards for the short term. However, I've been pretty good about going through it step-by-step with new customers when they take delivery, to make sure it's all fresh in their minds when they begin, and that they have the latest info. I did post a photo of the new cheeks at http://www.kitcarz.com/newcheeks.htm I also summarized all this suspension stuff at http://www.kitcarz.com/suspension.htm along with a photo of the camber curve correcting spacers. In there I answered the question about the rear suspension, and whether to use both the JTR cross member mod AND the camber curve correction (Yes). I put some links there that you will find useful, too. One of them is to a thread between Pete Paraska and Marc Sayer that is particularly helpful. Chris, when I refer to "third generation Z" I mean 84-89. Let me know if you have more questions! Quote Link to comment Share on other sites More sharing options...
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