clarkspeed

Please spend your money wisely. Safety, reliability, and driving skill are more important than the latest suspension. Is your car safe enough? It must protect you so you can come back to the track again and again. Is it reliable? Paying for 1-2 days of track is expensive and you don't want to be sitting on the side, or worse, on jack stands in the garage at home. Professional driving instruction can cut many seconds off lap times and is much cheaper than a new suspension or engine. Just let a fast guy drive your car if you don't believe it. Your initial goal should be getting the most quality track time, you can worry about go fast parts later when you damn sure what will help you.

Balanced Performance should be able to help you.

I dont recommend shifting at 120mph. The CD alone will wipe 10-15 mph off combined with a poor 5th ratio will put you in a hole. Your options are to find a better 5th gear box, change gearing where you shift to 5th at lower speed, or change gearing so you can stay in 4th. With a $5k budget you might get into a used Jerico 4sp with convert parts from Taylor. Or convert a WC T5.

Depends on a lot of things. Tire size, diff ratio, top speed at track, RPM's in important corners at track, power of engine, how hard and fast you want to shift, Availability of parts, and finally, how much you want to spend. For example, that ZX tranny you listed above is a good compromise, but if your gearing and track requires you to shift to 5th at 110+ mph, it sucks.

What happened to the LS? I know that was not a mild build up. Did you do a post mortem?

We run both Centerforce and ACT with no problems. Duragg, you might want to reconsider the Accusump even if it's not feeding. I lost an oil pump at Road Atlanta and did 3 laps with low to no oil pressure to finish race. No damage on tear down. Plus I like looking down at the direct pressure gauge when my dash gauge/sender looks funny.

Good luck with the machine work ahead of you. Hope the casting is sound. We've been working now with 3D printing the tooling in metal (smaller stuff) for investment casting cores. Technology is moving fast.

Derek you have been busy!

I don't have a Rebello or a 3.2L but a lot depends on your compression ratio and gas you will run. Either way, I prefer running an Accusump if you have any sort of sticky tires on there. Good luck with the carb settings.

Come to the season ending HSR race on December 3-7 at Sebring and watch 3 to 5 Z cars tear it up with some vintage Porsche, Jaguars' and Fords. This year celebrating the 50th anniversary of the Mustang. Driving a Z car makes you a VIP and you are welcome to park along side our S30 Motorsports trailer in the infield and talk about Z cars all day. http://www.hsrrace.com/2014_Events/Sebring/2014SebringHistorics.html

Everything Tony said, and he said a lot. I will add the NISMO gasket just happens to be 0.6mm which is .023", which just happens to be lower clearance limit recommended by 1fastz and others on this forum. I can also say from experience if you spin a rod bearing with this clearance the piston will hit something.

Some interesting comments here. Dan I'm probably not too far off your set up, and I keep my RC's in the 2-3" range, higher in the rear. I'm not lifting a front wheel but very close to doing so. I know that 4 wheels planted on the ground is desired for faster cornering speeds, even when dirt track racing, but trading some of that front grip for rear traction really helps a Z car if you have some HP to put down and are pushing a Quaife. Call it an old school set up and I know a few other fast guys that run this way. As always, Cary has some good insight and probably has the correct recipe for getting traction AND maximizing cornering grip. I can only say what worked for me and I don't run any real aero. I may be at a bigger disadvantage, I just discovered my rear strut housings that came with the car were cut 1" too short. I don't have much travel at all to max droop. I think we are all in agreement that you shouldn't tune this with a sway bar. A 1" solid bar on the front with no rear bar should be a recipe for serious understeer. When removing the rear bar, I caclulated the reduction in rear stiffness and then sized the front bar for the same reduction. Came out almost perfect balance. Are you running a Quaife? Yes when it drops it feels just like a clutch slip and takes a second to catch up, which seems like minutes when someone is on your bumper. Very uncomfortable. I'm sure you want it fixed right now. I agree with Cary, you may be a little off on RC's but I can't say that would cure your problem. Just guessing and assuming you have stock based components, I think your rear RC is probably 3-4"+ and front is JUST about ground level. I don't really like to go that low on a strut suspension. I put together a chart of control arm angle vs. RC height for my car. I set my front RC's (ride height) with a digital angle gauge on the CA.

When you are running relatively stiff springs, controlling body roll with ARB's is not so important. You really only need the bars to balance Front and Rear moments (understeer/oversteer). So if you removed the rear bar, it shouldn't take to much stiffness in the front bar to balance out. I reduce front bar stiffness until I get some good oversteer and then put one adjustment back in. In Mark Donahue's Unfair Advantage he talks about setting up his cars by changing spring rates with no ARB. He only adds the ARB so he can fine adjust at the track. And if you notice most pro level cars run pretty light bars. On track it is very important to rotate the car and get on full power as soon as possible. If you are having problems like you describe, reducing rear spring rate should help plant the rear. But there are other factors involved like tire size and stiffness so it's hard to say what spring rate will work. But I know plenty of other fast Z's that run a large delta between front and rear rate. You just have to try and see what works for you.

If you are double adjustable try softer compression. Then try softer rear springs. 325 or even 300. Very small front ARB. Thats what it took to get mine to hook up. I run a Quaife and when you lift a tire you instantly loose 1 - 2 seconds. I still have to be careful over curbing. Nice Aero.

I used a more simple and elegant design that I blatantly lifted from this website. I slightly modified Tube80's design using a stock control arm from page 4 of this old rear control arm design post. Used a 3/4x5/8 rod end for the forward one. I recently sourced some oil impregnated bronze bearings for the inner pivots instead of polyurethane which falls apart if you get oil on it . Works well and my rear RC is where I wanted it anyway. Being able to adjust rear toe transformed my car, it went from a darty unstable handful at 120+mph to rock steady at 140 on the banks of Daytona with one hand out of the window waving to the crowd. http://forums.hybridz.org/topic/62776-yet-another-rear-control-arm-design/page-4?hl=%20rear%20%20control

The Bilstein P30’s work ok with the stock valving. I ran a couple races with them before I had them revalved. I really liked the “feel” of them which is purely related to their low speed performance in transitions. I initially had them revalved 100/300 which was too stiff and killed the transitional feel of the car. I then worked with a Bilstein engineer to revalve again based on my measured data. Turns out my current valving is not too far off the stock numbers. My car weighs 2450# wet with me in it. I think if you were around 2100-2300# the stock valving would be really close. My comments are for road racing of course.

Funny thing is once you paint it all, no one really notices they are gone. It will look like it was meant to be that way.

I know the guy that bought the first one and has raced it extensively with no problems that I know of. Larry is also on this forum maybe he will chime in.

I removed them on a race car with full cage. 12lb sounds about right. Makes a lot of room for other stuff like electronics.

Keep us updated Mike. That car is sick! Would love to watch it run.

Depending on what cam you have you may be chasing the fuel values. Under WOT you may find a spike at 2500-4000 rpm where the engine wants a lot more fuel under load. To counteract this with SDS I had to create a rich condition before the spike and then pull it back out after the spike.

Interesting article and a compelling argument for motor in wheel. I would believe no degradation in ride quality but performance is another story. I doubt you will see a F1 or LeMans prototype putting their motors there. 2 lbs of unsprung weight may not be noticed by most, but 2 lbs off unsprung rotating mass is heaven.

I'm not familiar with the MM rear brakes. Sounds like weight was considered. I agree that the ARZ kit is a great deal. You cant duplicate for less. But I do think you can have too much heat sink. Its just more unnecessary weight. A move from 12.19 x 1.25 rotor to a 11.75 x .810 saves 2 lb.

Wow, 13" rear rotor, really? I've taken rotor temps at the track and could not imagine ever needing anything close to that, especially on the rear. I think you may be missing my point, nothing wrong with upgrading brakes IF YOU NEED TO. But if you are going to spend $700-800 on an axle, why is giant better than just a little bigger? All those big brake kits sold could be even lighter if sized more reasonable. Every pound counts out on the corners.

Nothing wrong with insurance. You could put in a 500lb Nascar cage too. Those giant rotors are just not worth the unsprung weight gain for me.