tube80z

Old tires can be used to work on balancing your setup but when the grip goes the car still feels good but goes slower. If you run a data logger you should be able to compare your lateral acceleration from when it was working better. If you don't data log I would recommend adding that to the must have column of stuff. From what you're writing it's clear to me that you need to be stiffer. That will reduce rebound requirements and you'll need less bar and let you run with lower roll centers. As far as how to go faster that is all about first principles. That is what are the terms in the equations of motions and their various forms. That is mass, center of gravity height, and grip (force). One often overlooked area that pays big dividends we have talked about from time to time is friction. The more you can remove from the parts the move equals more grip. Hope that helps, Cary

From your picture and the following description it sounds like you want flexibility in being able to have a non-zero toe curve and the ability to tune it by using spacers on the toe-control link. The only downside I see is if you stick to something similar to the reverse a-arm design in your diagram you give up being able to also adjust anti-squat and lift. This assumes you keep the strut and don't add an upper a-arm. Is this going to be a strut or an a-arm? The other thing to check is if this design is not as stiff as using a reverse a-arm. To check that on the car you use some method of pulling the wheels together with the vertical position locked. Then repeat by pushing. Then switch to pulling/pushing the same side wheel pair. This is a poor mans K&C rig and you can see camber and toe changes from force at the contact patch. I think you could do something similar in a CAD package to at least see what the forces were in the members. If no difference that's great. If you end up putting a lot more load on a single member or joint then you might have problems. Happy to see a more technical thread in this section. Cary

Looks really nice. Very, very jealous

A friend with a performance oriented street Z had 305s on the front and 315s in the rear. It drove fine on the street. It had power steering and that's probably going to be a requirement unless you can leave with a high steering effort. Cary

Square (all the same) or wider rear work fine. It's all in the setup if you're not matching the contact patch area to the weight distribution. Wider rear generally allows more throttle in a corner sooner and that gives a knock on effect down the next straight. It also depends a lot on the type of event you're doing. If the reaction stuff is a copy of the original IMSA items the rear was setup for 14 inch wide wheels. Cary

Lifting a front wheel isn't caused by the ARB. It's from being too soft in the rear or too soft all round. Personally I would look at a C6 vette for the ABS computer and tone rings. They are a generation newer than all the 240SX stuff. Teves sells a motorsport unit but it's going to run 5K or so. Bosch also has a motorsport ABS but it's probably closer to 20K installed. Cary

I like the air hammer for stub axles. For spindle pins a puller has worked better for me and I don't have to destroy the pin.

Lower the rear. Your RC is too high if I understand the control arm angle. You want to lower the end that needs traction unless you're hitting the ground and upsetting the cornering balance. For the really bad bumps add packers and tune the bumpstops. If you have a lot of lock on try and winding the wheel sooner or less caster to reduce cross weight change. For a fun afternoon put the car on scales, if you have them, and raise and lower each end and turn the wheels and watch the weights change. Change caster and see the difference. On our cars we often use a lot of caster to help low speed turn in. This can cause catch and release on corner exit as you unwind the wheel. Spacers to change the track that add more scrub will make this worse. Maybe a cool winter project would be a simple subframe in the rear and new arms that allow you to raise and lower the pickup points. I have some pics if you're interested. Cary

I may not be following all this but if you don't have enough rear droop travel you don't want to soften the rear. You need to stiffen it up. If you lower the spring rate in the rear you'll get more suspension travel used up from weight transfer. A lot of the hillclimbers in the NW used to soften the rear of the car so they would put down the power better. I have convinced a number of them to use much stiffer rates and it works. When you start using aero you also need to run stiffer and change your driving style to accomodate. To keep the splitter down and working harder to match the rear wing you can trail brake to the middle of the corner. Then onto the gas but you need a stiff rear end to keep the car from squatting too much and upsetting the extra grip you are getting from aero. If you watch classes with wings and splitters you'll see often see this. I think you'll find that the diff will be kept loaded this way too. Cary

Thanks, learn something new everyday. I dug out my old nissan comp catalogs and didn't see it listed. But clearly they are now available.

I'm pretty sure you can't get a 4:44 in a R160. I seem to recall only the 4:38 was available that was close. Or 4:62. I had a 4:44 but it was in an R190.

Wow, that's awesome. Thanks for sharing!

Take a look at a long shanked lug nut. That's what's used on a number of the plates now.

Thanks Gary, that's awesome. Now saving pennies

Not sure if it would help but there's also Evan's coolant. That might help if you need a higher delta in temp across the radiator. Cary

I heard 4500 is the new 2500

Thanks Gary. One more question. What happens if you release the wheel in a corner? Does it straighten out like manual steering or does it slowly move back like damped hydraulic steering? Cary

You really want a mount over the top as the diff tries to move up under acceleration. You could still do something similar but it would be better if one piece that connected to those tubes by dropping down. It probably could be fairly simple with poly bushes around the tube. You need to be careful that you don't make one end or the other solid when mounting the diff. Cary

Good to hear. I drove a Honda with EPAS and it sucked. The steering was numb to me. At low turning rates you could feel pulsing. Did you upgrade your steering joints to deal with the extra torque? That would be one concern using older parts with this. And my final question what amp range did you go for? Cary

Actually more distance is probably not that helpful. It allows more acceleration before impact. If you look at most new cars the interior has become cramped so that you don't have as much room to move before you touch the plastic. The key is to have something that spreads the load over a wider area. I have been looking closely at this for my new street car and haven't decided if I want to use structural foam in the roof rails or use tube that seats into the flat panel. I have already figured out you can run tubing inside the wheel well from the rocker up to the back of the fender top to complete the lower leg. Not really SCCA compliant but for a street car probably good enough. There are also a lot of clues to be taken from modern cars like the 3 series BMWs for how to reinforce the front end. And like Dan's cage you can do a cross bar the mimics what modern cars run under the dash. Cary

The pictures in the ebay ad show wilwood dynalite calipers. The front are 4 piston and the rear look like 2 piston. The AZcar photos shows wilwood superlite. It's a larger stronger caliper that has a larger pad. Make sure you're comparing apples to apples when you decide to buy. You can download the wilwood catalog to see the calipers these kits use and what options are available. Cary

I'm interested in the steering feel and how it operates when you let go of the wheel. In the ones I have driven they feel numb. I'm looking for the same feel as manual but with some assist and no damping when you release the wheel. Would love to hear thoughts on this. Cary

15x10s should easily clear with that on the front. I think mine are 3 or 3.5 on the backspacing. They have the bell but it does clear the AZ brakes but barely. Some wheels needed a small spacer and those may have been the 3.5s. It was a few years ago and memory isn't always the best.

A friend has had two of the AZ big brake kits and they fit under the 15x10 diamonds up front and the 15x14 diamonds on the rear. These are the 12.5 inch kits I believe. They had Superlite front calipers and dynalites in the rear. If you're looking at 6 piston calipers or 13.25 or bigger rotors I'm not sure. For Diamond wheels they often have an inner lip that will interfere if you try and run too much backspace. Luckily when this wide you often miss it. I have one of the 15x10s here if you want me to try and measure it or send pics.

Glad to see no one was hurt. I'm curious what cause the failure other than old age. I crack check mine each year when I'm running. So far I haven't found anything. My car generated 1.6 to 1.8 lateral Gs and I pound the FIA curbs. I don't torque my lugs as much but that's probably more to do with the brand. This probably isn't the problem either but how hot do your hubs get? I wonder if the spacer expansion could have worked against the hub. Like I said I'm totally guessing and this is just throwing another thing out there.