JMortensen

This is one of the most commonly asked questions asked here and it is also a tough one to answer, due largely to the varied usage of our cars. From the factory the only adjustable alignment angle available is the front toe. One of the main features of a high performance suspension is the ability to adjust the suspension angles, so as the stages progress the adjustablity increases. IF YOU INTEND TO RACE YOUR CAR, GET THE APPROPRIATE RULEBOOK BEFORE YOU START ANY MODIFICATIONS TO MAKE SURE YOU REMAIN LEGAL!!! REFURBISHING A STOCK Z CAR If the car is a street driver and the intent is to have a cushy ride, it may be that a simple refurbish of the stock suspension is all that is necessary. A typical rebuild of the stock suspension will include: 1. New outer tie rod ends 2. New ball joints 3. New rubber bushings and steering coupler 4. Repack/retighten front wheel bearings 5. Replace rear wheel bearings if needed 6. New shocks (KYB GR2, Monroe, etc) 7. New springs OEM replacements and slightly stiffer Euro springs are available from http://www.courtesynissan.com These few things will restore the ride to close to factory stock. MODIFYING A Z CAR FOR BETTER HANDLING If the goal is to stiffen up the car for better handling, then a lot more can be done. I'm going to attempt to show "Stages" of modifications. These are loose guidelines and parts can be mixed and matched, but these are what I feel are typical mods on the Z's that I've come in contact with over the years. STAGE 1 replaces all old parts with stiffer components. This will give you a firmer sporty ride. 1. New outer tie rod ends 2. New ball joints 3. Polyurethane bushings 4. Repack/tighten front wheel bearings 5. Replace rear wheel bearings if needed 6. Aftermarket front and rear swaybars 7. Lowering springs (Eibach, Suspension Techniques, Tokico, MSA, AZC) 8. Aftermarket shocks (Tokico HP, Tokico Illumina, Koni Red) 9. Bumpsteer spacers STAGE 2 is similar to Stage 1 but starts to allow adjustment of alignment angles. 1. New outer tie rod ends 2. New ball joints 3. Polyurethane bushings and Gmachine control arm bushings and TC rod kit (these allow camber adjustment front and rear and also toe adjustment in rear) 4. Repack/tighten front wheel bearings 5. Replace rear wheel bearings if needed 6. Aftermarket front and rear swaybars 7. Lowering springs (Eibach, Suspension Techniques, Tokico, MSA, AZC) 8. Aftermarket shocks (Tokico HP, Tokico Illumina, Koni Red) 9. Bumpsteer spacers STAGE 3 takes adjustability a step further. 1. New outer tie rod ends 2. New ball joints 3. Polyurethane bushings and Gmachine control arm bushings and TC rod kit (these allow camber adjustment front and rear and also toe adjustment in rear) 4. Repack/tighten front wheel bearings 5. Replace rear wheel bearings if needed 6. Aftermarket front and rear swaybars 7. Coilover spring conversion to 2.5" springs. Street springs generally under ~250 in/lbs. 8. Aftermarket shocks (Tokico HP, Tokico Illumina, Koni Red) 9. Bumpsteer spacers 10. Biscuit style bolt in camber/caster plates (EMI, DP racing) 11. Strut tower bars front and back, preferrably triangulated to the firewall in front STAGE 4 1. New outer tie rod ends 2. New ball joints 3. Adjustable control arms (Modern Motorsports, AZC, Z Select) 4. Repack/tighten front wheel bearings 5. Replace rear wheel bearings if needed 6. Aftermarket front and rear swaybars 7. Coilover spring conversion to 2.5" springs. Street springs generally under ~250 in/lbs. 8. Aftermarket shocks (Tokico HP, Tokico Illumina, Koni Red), might be thinking about sectioning strut housings and getting appropriate shorter shocks to fit at this stage 9. Bumpsteer spacers 10. Biscuit style bolt in camber/caster plates (EMI, DP racing) 11. Adjustable TC rods (TTT, AZC, Z Select) 12. Strut tower bars front and back, preferrably triangulated to the firewall in front 13. Roll bar STAGE 5 - at this point you're pretty much race only 1. New outer tie rod ends 2. New ball joints 3. Adjustable control arms (Modern Motorsports, AZC, Z Select) 4. Repack/tighten front wheel bearings 5. Replace rear wheel bearings if needed 6. Aftermarket front and rear swaybars 7. Coilover spring conversion to 2.5" springs. Springs generally over ~250 in/lbs. 8. Aftermarket shocks in sectioned strut housings(Koni 8610-1437RACE single adjustable, Koni 8611-1259 double adjustable, Ground Control Advance Design, Bilstein Sport VW non adjustable P30-0032) 9. Bumpsteer spacers 10. Cut to fit camber plates (DP racing, Carrera, Ground Control, AZC, TTT) 11. Adjustable TC rods (TTT, AZC, Z Select) 12. Strut tower bars front and back, preferrably triangulated to the firewall in front 13. Roll cage with tie ins to front strut towers Above and beyond Stage 5 you get into modifying the chassis itself to allow for modification of the suspension pickup points. There are also people who have adapted suspensions from entirely different cars into the Z chassis. We've had members install 240SX IRS, Corvette C4 rear suspensions. Also for drag racing there have been quite a few "backhalves" where the entire rear section of the frame is cut off and a new frame built in the rear to allow installation of a solid rear end. Popular choices seem to be Ford 8.8 and 9 inch and Chevy 12 bolt rears. Front suspension swaps aren't as popular as of yet, but many GT2 Z racers have fabricated their own SLA (short and long arm) front suspensions. Modifying your suspension is potentially dangerous and you do so at your own risk.

Out of curiosity, is that a long nose R200 or short nose? I'm thinking long nose since they have the R160 and R180 in their other models...

Sounds like ignition module to me. Does it run again after sitting for a while, then do the same thing again after you've driven around a bit? That would be classic module failure.

That looks like it could be an extremely fast Mustang. Not sure what the issue is with the setup, but man was that pretty funny to watch him lose it that many times... thanks!

I used the BG additive for years and thought it worked really well, but then I found SWEPCO 201 and was sold on that. It seemed to keep the LSD smoother longer than the BG stuff. In my mind this meant the BG additive was "breaking down" faster. Don't know if that's the case, but that was my thought process. I changed out the SWEPCO about every 3 months, when it smelled burnt or when the LSD started to whine, but at that time I was autoxing every month and only doing a couple track days a year, so I wouldn't have been going through it as fast as John or Keith.

The factory strip has the gap in the middle of the bottom. Just cut it a little long and then shove it in there.

John didn't you say previously that you've seen over 300 degrees on yours? Mayolives, are you running the finned cover on that diff? That might help a little bit if you aren't already doing it.

Sure. They're on your side of the country so it will probably be a week at least.

I agree with Tom, the MBA will give you FAR more options in life than the trade school diploma. Get the important stuff done first, then if you want to screw around at the tech school go do that later. Don't get me wrong, I think it's admirable to want to do the trade school, just maybe not as important in the big scheme of things. I know several people that went to UTI in Phoenix, and the reviews were mixed. Regardless, none of them came out of school and got a really good paying job. Don't know any MBAs, but I'm guessing the starting pay for that degree is a little better than $9/hr...

I went ahead and ordered these suckers up. Weird too, because the sizes are 2.310 and 1.925. I ran out and measured my G Machine bushings and they are 2 3/8" and 1 7/8" so the length of the sleeves is damn near perfect too. I got the units with the monoballs just cause I figured that would be easier to mock up. I'll have to take a look at the monoballs themselves and see if I really want to run them or if they should be replaced with something a little better before the car hits the track.

If that's the case, then this might just be the answer. Some minor machine work on the threaded tube ends and some fairly simple welding, and that should be it...

Actually, the sleeves wouldn't really need to be welded in. If you could find a piece of tubing that had the same ID as the holder's OD, that could be cut in 1/2 lengthwise and that piece could be welded in, and the other half used to make the strap. Then the whole thing could be taken in and out. Furthermore, by moving the threaded tube ends in to the right spot, the holders could be used as is with no needed mods to the bushings and all of that.

Thanks Cary, I found those parts! http://www.stockcarproducts.com/susp3.htm I called SCP and they said OD was between 1 3/4 and 1 7/8. I know the stock bushing is 1.580, so that should mean that there is enough meat on there to turn it down on a lathe, which gives the lips front and back to hold the sleeve in place. The issue is -- HOW DEEP IS THE SNAP RING GROOVE??? If it is too deep then when the housing is turned down there might not be enough meat there. I don't see another way around that snap ring groove issue, unless the frame were hacked to to allow the full size monoball holder to be installed, then the whole thing could be welded in place. Hey, that might not be such a bad idea!!! The issue then becomes one of changing the monoballs. If the 3/4" stud idea that Terry had was used, then I don't think the monoballs could ever be changed. I suppose if this concept was married to the 5/8" tube adapters, maybe bolts from the outside could be used. And THAT seems like it might just be a viable solution... So to recap. Cut then ends off of the control arm. Get 4 more 5/8" threaded tube ends. Turn the tube ends down to .75 OD, weld into the control arms. Cut frame rails to install monoball holders. Make new straps to hold down the monoball holders, and weld it all together into the frame (I guess in the back this will be more modification to the bushing clamps on the rear toe adjuster). Run 5/8" bolts through the rod end reducers (already part of the monoball holder assy sold by SCP). Also their monoball holder part has a shaft length of 2.5", so that might need to be cut down, but cutting the monoball holder and the bushings down to the correct length should be pretty simple I think... Am I onto something... or on something???

To add to naviathan's suggestion 99% of the time if you get a ZX dizzy it's going to be in need of a rebuild. It's pretty easy to do, but the vacuum advance in those things breaks and can lead to all kinds of other issues, like spinning parts hitting stationary parts inside the distributor. If you were going with ms, I'd just go with a crankfire setup and remove the distributor completely. That's really the best upgrade to a distributor issue.

Damn I love your illustrations Terry! Measuring on the rear strut sitting next to my desk here, it looks like there is about 5.5" from the spindle pin hole to the flange for the wheel. That coupled with the wheel offset should tell you where C is, correct? The rod end holes were 7 1/8" apart, I remember that. The center of the front inner bushing to rear inner bushing is ~18" and the distance from the inner pivot to the outer is ~14.5". I think that gives all the values needed, except the shape isn't a perfect isosceles triangle, don't know if that messes up the ratios or not.

Wow, that was a combo of severe bumpsteer, a way loose Porsche, and a driver with some huge cajones.

If you want it lowered, I'd get some lowering springs, then don't cut them when you install them. Tokico, Eibach, Suspension Techniques, Motorsport Auto, and Arizona Z Car all have springs for the Z. Take your pick. You should install bumpstops as well if you don't have them. If you still feel the car is too high, then you should section the struts (read the FAQ about sectioning struts to find out more about that).

I should state again for the record that I really suck at math, but I thought that the diagram of the forces and such from post #73 was saying that the farther the rod ends are apart the less load they take, and the rod ends are definitely farther apart on the inside end of the control arm than the outside end.

The only thing I can think of that fits your description is one of the firewall mounted monoballs that would be used for a steering shaft. There are some on this page: http://www.stockcarproducts.com/steer5.htm Are you referring to something else? If there is such an animal and it has a 2" OD that might save me a lot of trouble...

A sleeve? How would that work? I could see a 5/8" threaded end with a 3/4" OD sliding into the arm, is that what you meant?

All I can tell you is that I've torn up a couple radiators in my car, and that happened from chassis flex. The chassis flex comes from the struts with maybe a little more from the sway bar. It should be possible to brace the strut towers enough to stop that flexing from happening, but until that is actually accomplished, the core support is definitely structural. You've got the upper and lower frame rails to deal with on a Z, and they're very long, so any flexing going on is magnified out at the end there. I think what you're looking at doing CAN be done right, but it's going to require one hell of a strut tower brace, and I'd strongly suggest some kind of lower bar to tie the bottom together.

Just had an idea on the inners. I went and checked and the tube that connects the front to the back is almost exactly 1". I measured 1.005" but there is paint on mine, so it's REALLY close. So the thought is why not cut the end off of the control arm, then cut one more inch of the round tube out, and weld another couple of these tube ends in? This would leave a 5/8" threaded hole into which a 5/8" bolt could be inserted from the outside. The benefit to using 5/8" here would be that a smaller 5/8" monoball could be used on the inner pivot and there would be a LOT more meat around the monoball used in the original sleeve type of design we were talking about in the beginning of this thread. As has been discussed the outer heims joints are going to take more load than the inners, so size of the joints shouldn't really be an issue. Might not be worth the extra hassle, except that the sleeve part could again use a snapring to hold the monoball in, and there wouldn't have to be two halves that come together to hold the bearing.

Yes it matters. No, the springs won't bind if you get the right springs. Lowering a car DOES NOT reduce the travel. Sectioning a housing does not reduce the rebound. It reduces the starting point. If you have a fender height of 25 inches and you section the struts to reduce that height to 23 inches, you still have the same amount of bump and rebound travel as you would at the 25 inch height. That's why sectioning is better than cutting springs. With cut or lowering springs you lose bump travel, but keep the rebound. With the TTT piece you lose bump and rebound.

Why not spin the L28 faster? They have the almost identical cams, and it's not going to shake the L28 to death to get the extra rpms. Probably has to do with the crappy stock induction system. I'd be absolutely shocked if an L28 with SU's didn't put out significantly more hp than an L24 with SU's.