GrommitZ

Ha! The reminds me of a Dave Grohl interview where he talks about trying to drive down to LA with Kurt Cobain in Kurt's Datsun B210. They were frantically trying to get to the LA recording studio to lay down tracks for what would become their breakout album, but the B210 kept overheating. http://www.youtube.com/watch?v=4aHCUjY7E4k&mode=related&search=

Hi Greg, I didn't give a preference because I haven't optimized either setup yet to make the comparison fair. If you track your Z, I recommend trackday pads. OEM pads will fade and shudder. Yes, I don't know of off the shelf trackday pads for the s12 + 8 vented. The rx7 pads I mentioned above will need a little modification. I currently have only the outboard pads on. The inboard one's will need more grinding before I use them. I'm using the rx7 Hawk HP+ for the s12 + 8 vented and tried the Satisfied gs5 pads with the s12w's, though the gs5's are no longer available for the s12w's through tirerack. Both pads work much better than oem. Some complain of excess noise and rotor wear with the HP+. I notice only minor noise, but I'm only using the outboard pads right now. The rotors do wear, but have worn smoothly. As for the spacer, I'm using the 280Z hub on my 240Z strut. I prefer the 280Z hub because it uses a thinner spacer than the 240Z hub. I'm not sure what differences there are between the 240Z and 280Z struts. I'm using a .355 " spacer, but I still strongly recommend that you mock up your setup with washers first and measure them. My caliper barely clears one of my rims. A wider spacer would be safer because you can always turn it down if you need to instead of starting over. I'm happy with my S12 + 8's, but I liked the s12w's too. Again, I've been making so many changes between track days that I can't come to a firm conclusion between the two. Based on pad availability, the s12w's might be better. Based on balance with the stock rear drums, the s12 + 8's might be better. I had fewer lockups with the s12 + 8's, but that could be because of my pads, tire pressures, track conditions, experience with the setup...etc.

Did you bleed directly from the master cylinder yet? Air gets trapped in there often.

It sounds like you were pumping air into the master cylinder, not sucking it out. Could you have hooked up the vacuum pump incorrectly? That would explain how brake fluid got into your booster, which usually only happens with an old master cylinder with bad seals. The firmness you now feel is probably because you lost the rubber reaction disk inside the brake booster. You'll probably have to remove the booster to shake it out. Don't feel bad. This stuff happens. Ask me how I know. The best thing is to take a break and come back later.

Ditto. I like the mash potato's idea too. You'll laugh about this someday.

Nice!

Sorry to hear about your problems. I'm sure this will help others to learn from your experience.

I'm using the s12 + 8 vented calipers so (2) 1986-88 Toyota 4X4 4 cylinder pickup with vented rotor, front calipers marked ‘S12+8’ (2) 1984-85 Nissan 300ZX front rotors 4 X 4 1/16†bolt pattern are true. You should mock up your new setup with washers and measure your hub and new rotors to determine your spacer dimensions. Some people need a wider spacer for better wheel/caliper clearance. I'm using a 280z hub on 240z axels. My spacer width is .355 " just like danman's, but wheel clearance with one set of rims is almost paper thin. Note that when the braking system heats up, the wheel and caliper can start to rub even though it doesn't when cold if clearances are too tight. Also note that I have never mounted new rotors where the clearances would be tighter. If your going to make spacers without mocking up first, I would error to the wide side. You can use thin washers for mounting the calipers, if there is rub with the rotor. I swapped out the s12 + 8 vented calipers with my friend's s12w's for a day without any rubbing issues so the offset between the two calipers is pretty close. I swapped calipers because the track pads I ordered ended up being for the s12w instead of the s12 + 8. I searched but could not find someone who has off the shelf track day pads for the s12 + 8's. I found a pretty close fit using pads for a second gen rx7 with the sport suspension(different caliper from the regular suspension). It requires a little modification to fit. The s13w's require more mods from what I've read here. The s12w's have enough leverage for me when using the 15/16th master cylinder. For my s12 + 8 vented's, I prefer the extra leverage of the 7/8th mc even though pedal travel is a little longer.

Where's the mouse trap?

According to my Haynes manual, the VIN doesn't match the 280ZX format of XXXXS130XXXXXXX, where every X stands for a specific option on the car. Note that some X's could be blank or 2 letters, depending on the option.

Sure thing! Edit: Practice over for today.

https://www.iseesports.tv/indy/secure/player.aspx?sid=32276

It's pretty easy compared to what most people do. Do you have a bearing grease packer? You should put in a new cotter pin. The the worst case, it can be the only thing keeping the wheel on the car.

I still think it's air in the master. I had a very similar problem. Brakes were good in the morning, but the pedal started sinking in later sessions to the point where the brake warning light came on a couple of times. Like you, pumping once or twice before the turn brought them back up. I bedding the brakes in thoroughly and rebleed them several times before the night before. I was bedding them in to hard, heating the fluid, and thus needing to be bleed. The day after, I carefully bleen the master and got the pedal height much higher and firmer than I ever did before. It required the right touch for bleeding the master. I did not get to retest that setup though. Hope this helps.

If you pedal sinks under normal driving conditions, you probably have a cylinder leak. If you haven't overhauled all your cylinders in a while, rust can get lodged between the seals, especially under extreme conditions. The master cylinder can be difficult to bleed. Open and close the bleed valve quick and far enough to get the air out. My pedal tighten considerably after finding the right touch to bleeding the master. That said, I had a similar problem as yours. ThunderHill is hard on brakes. Have you bleed your brakes after your track day? I'm guessing you boiled your fluid even with all your modifications. Brake ducts and heat sinks are next on my list.

Here's a quote from Mikelly: Here's the deal... We've set up a HYBRIDZ only sub-category. We want to protect th data to insure out members have access to the data FIRST before it gets to far... To initiate a request to join: Click on your User Control Panel (User CP) in the upper left menu bar. Scroll down the left hand menu under Miscellaneous select Group Memberships You will see the “AeroTech†group listed, select the radio button on the right that says “Join Group†and then click the “Join Group†button. Type in the Reason for your request if you feel like it then click the “Send Request†button. You will have to wait until one of the admins approves your request before you can access the new Forum. You must have been a member here before May first 2007 to have access to the sub-category! On Turn 9, it actually turns left after the top of the hill as well. I've had trouble too slowing for turn 9, especially in the afternoon when you're driving straight into the sun.

Mine Xenon's warped too, but I plan to reinforce it while adding coverage at the same time. How about adding a chin?

Awesome! ....considering you also have a 9to5. I hope you'll have pics and/or video for us. Great Job!

Join the aero group. It will give you some other ideas that you'll want to consider. Turn #9 is tricky. Are you using the water tower on the hill, south of the track to help guide you over the top? You need to go pretty straight over the top of 9 to the bottom of the hill.

Sounds mean OTM! Did you check the position of your oil pump/distributor shaft? It should be clocked at 11:25 am/pm, not aligned with the distributor bolts. This would be slightly clockwise of the the line that the two distributor mounting bolts make. Can't wait to see it on the road.

Miata. Fun University.

Congratulations! Nice job!

One source of high pressure air is just in front of the windshield. You can see the yarn is some of the photos drops into the windshild wiper grill. I know there's one post about overheating at speed caused by a rear hood cowl. High pressure air in front of the windsheild slows flow through the radiator enough to raise engine temps significantly. The problem was solved by moving the vents closer to the stock outboard locations. Maybe this answers the low 15mph radiator exhaust flow. With a couple of the test cars having hood latch problems and that there are small passages from the wiper area to under the hood, I think future tests could make sure the rear of the engine compartment is sealed as well as the front. I know it's being debated whether or not negative engine compartment pressures can be acheived, but it looks to me that efforts to reduce pressure will not only help with down force, but with drag by increasing the pressure differential between the front and rear of the radiator, thus allowing for a smaller mouth opening.

To remove the gauge. You don't have to remove the whole dash, just the center air/heat/fan panel. To remove it, you have to remove your stereo, the four phillips screws in the corners and disconnect the 4 wire control cables under the dash. There are 2 on each side. I just replaced my gauge and it fixed the exact same problem you have, so it must have been the gauge's voltage regulator, not the one by the alternator.

It looks like the 16" Panasport rims with larger tires in case 5 and 6 are responsible for most of the increase in drag up to that point. I know wheel width can add considerable drag, but maybe the higher ride height allowed more air to flow under the car too.