RebekahsZ

Feedback from commute to work. Pull to the left is less noticeable, but likely only due to less aggressive pad compound. However, the pull is still present in spite of replacing the rotor. I plan to try the gauges as originally discussed. I have a tracking number for a new caliper that should arrive next week. Car has to be on a trailer Thursday night ready to race....midnight oil.....argh...I guess "that's racin'." I am taking advantage of the delays to ready other aspects of the car. Checked temperature of rotors. Drove down long straight road, stopped using parking brake and checked rotor temp: cool to touch (cooler than my seat covers!). Did done hard(er) braking on way home and checked rotor tenp with I/R thermometer: 132 degrees both front rotors. Wish I had tried this before changing rotors. I'm just looking for something definitive.

The first cable I ordered for the truck came in today-too short! I changed the Z's brakes from my road race kit to my street kit. Played with ride-height some more and changed the oil on both the Z and the truck. The list is getting shorter.

Burned the midnight oil to make some progress. As I drove the car around town for the past 2 day, I noticed that there was a noise coming from my right wheel on slow right and left turns. The sound was similar to the noise that Chewbaka makes when trying to get Han Solo's attention. Well, I've decided that the left rotor is warped. How is it warped-I dunno. But-I have a set of street rotors and pads, so I swapped those on all 4 corners. Prior to that, I though perhaps that left caliper was not releasing, so I cracked a bleeder and the noise didn't change or go away, so I don't think that is it... There was no visible runout on the rotor, so I'm not counting my chickens until I drive the car tomorrow and do some high-speed stops. I wanted to put a dial indicator on the system to check for runout, but I couldnt figure out where to mount the magnetic base, so I said F-it and changed all the wear items over to my street stuff.

No. Throttle cable broke in my truck, so I'm driving the Z to work while awaiting parts for truck. One broken vehicle at a time.

I don't run Cheauered Flag (CF) CVs. I run Z31 CVs with CF adapters and stubs. If CF winds up making the chrome moly kit with 930 CVs I might buy some. But, 930 CVs are a little harder to work with than the Nissan CV system. I don't like Wolf Creek CVs because you can't inspect your fasteners.

I'm all over this! Great work. I just won a model A off eBay, so our shops are even more similar. I will want to copy your accessory setup when I build a turbo motor. Thanks for such a great post!!

Driving the Z to work for the rest of the week. Throttle cable snapped in the truck. 10 days to race day......

You won't believe this: The throttle cable on my LS-swapped S10 daily driver/tow vehicle failed today. So I swapped on my street tires and will daily the Z this week while figuring out what to replace my throttle cable with. The Z continues to be the most reliable car in the stable. Using theocracy car to get parts for the shop truck.....10 days 'til race day.

I wonder if there is room in the tunnel for that? Might have to do some cutting and welding. That would be super sweet if there was clearance for that. Beautiful part. Following with goal of learning.

Maybe next year. One variable at a time so I can learn. I have to put window tabs/straps on this winter, so I want to wait to avoid a placement conflict. Pray for no wind, so the research can have meaning. I want a dead-still race day (wind wise that is).

I'm just trying to think thru it instead of "parts swapping." The brakes are getting hot on both sides, although I didn't put a pyrometer on the rotors like I should have.

Anybody ever use a gauge like this to try to sort out a brake-induced pull to one side?

Here are some pics that show the past 2 weekend's progress in prep for the GA 1/2-Mile and Ohio 1-Mile. Before I started all this, the car pulled alternately to one side with braking. Now it is consistently pulling left. No air in fronts and firm pedal. Gonna play lip-service and bleed rears next. After that, I'm gonna re-build the line lock. It is where my front brakes split from a single line leaving the master into 2 lines, a left and a right. Maybe the O-ring has broken down (?).

See you in April at Z Attack!

My understanding is that a wing causes downforce and that a spoiler reduces lift. Class rules forbid a wing. I wanna say that the old S30 wind tunnel data showed 70# of lift (on the rear axle) at 80mph. If the car weighs 2400 and half of that is on the back axle, without a wing, the most you can make the rear axle see is 1200#. Using the term downforce suggests that one could make the rear axle see more than 1200. I'm pessimistic. Rear springs are 400#. Feels good.

I have drilled my rear deck to accept 2 different spoilers: a small version similar to the BRE/factory/432 style and a larger version that I think was manufactured by ZCC-JDM. I've got them set up so that I can swap them fairly fast (depending on how fast I can find each screw I drop in the grass or under my workbench). I wish I lived closer to the A2 wind tunnel, because I'd probably rent a session if money were the only restriction, but I'm also restricted by time and distance. So...I'm hoping for low-wind days at the GA 1/2-Mike and the Ohio Mile (and a consistent driver), so I can report back to the forum about how these spoilers (to include no-spoiler) affect top speed and subjective "stability." Here are some pics to whet your appetite.

It's 9/10 about the engine. Most guys never get to that 9/10, so it's hard to find practical experience regarding that last 1/10. Lots of theorists, but not many guys with a working, practical knowledge. So, theorists spend a lot of time on low-yield projects rather than taking on the high-yield tasks first. You've moved into the Twighligt Zone of aero and it's a lonely place.

Welcome to the "low life!"

Impact and wear are the enemy. On an open R-whatever, the cross shaft wears and allows the spiders to get out of alignment and they they get into a locked (like a vice) configuration and one wheel stops turning and an axle snaps, then the car will at least roll again, but not move under its own power (cause the open diff just free-wheels). Automatic trans is much much more gentle on the driveline than a manual trans because you can load the driveline by foot-braking, thereby pre-loading the driveline and removing much of the slack and associated impact from the system. Add a trans brake and you can expect the reliability of a manual trans again. Go to a Powerglide and you have only 1 shift after the launch, so that really reduces impact cycles, vs. a 4 speed manual which over the same 1/4-mile will experience 4 (twice as many) driveline impacts over the same driving distance. I still haven't met the guy who has broken a CLSD R200. We break driveshafts, outer stubs and axles. Axles being the most common failure. Stock axles at the u-joint, Z31T CV axles at the splined portion that inserts into the diff, Wolf Creek CV axles have trouble with the adapter bolts getting loose. Chequered Flag Racing had a prototype 930 CV axle with heat treated chrome moly stubs, but I think the combination of production cost and low demand killed that promising venture. Welding the diff solid tends to be very hard on axles with big sticky tires being the exacerbating factor there. Good luck!

Thank you! Tons of good stuff in there. I'm gonna think thru all your suggestions and work-in what I can. Glad to have you riding along. Honestly, a Z-car is a horrible Landspeed candidate. But, if I got a 240sx or an Rx7FD, I couldn't hang out on this forum-and I love you guys! So I'm gonna keep beating on this old chassis til one of us gives up-the chassis, or me.

My buddy James helped me til midnight last night and my other buddy, Evan helped tonight 'til 2am. Building off data from the past 2 nights, we started by increasing caster to 7 degrees positive. Then we ran the car thru the travel, measuring toe every 1/2" within the anticipated bump and compression range. It was great using the new 4-post alignment lift and doing chin-ups off the sway bar to settle the suspension! Then we plotted the curve that resulted. It looked like we needed a mix of the 4.5 caster setting and the 7 caster setting, so we went out and set caster to 6 and went thru it again. Son-of-a-gun, that was the ticket! Going thru the travel range and re-measuring to yielded the following results: 6": 1/8 out 5.5": 1/32 in 5": 1/32 in 4.5": 1/16 in 4": 1/32 in. I set ride height at 4.75" measured at an airdam support bracket and called it done! Final Landspeed alignment setting is: Front: 1/16" toe in, -.3 camber, +6.0 caster, stock inner tie rods, stock crossmember LCA pivot hole location, first-generation TTT LCAs adjusted to shortest length, 450# coilovers. Initial Koni rebound setting will be full stiff. 24.5" MT Front Runner tires at 50psi. 1-1/8" sway bar. Rear: zero toe, -1.5 camber, 400# coilovers. Initial Koni rebound setting will be fill soft. 275/60/15 MT Drag Radial Pro at 44 psi. No rear sway bar. Tomorrow is test drive and centering the steering wheel. And hopefully that finishes suspension. Or, we might be starting over completely!

Still anxiously awaiting release of T56 shifter from S1 Sequential. I'm ordering one the day they start selling.

Do you not think that slip plates handle the binding well enough?

I think you can send your Magnum to somebody like RSG or Liberty and have an f-body shifter housing put on it. Thats my plan for next year.

You got it right on the MM LCAs. I got them back when I was running 9" drag slicks inside stock fenders and they are the only version around that can be made shorter than stock as I needed to narrow the rear to maximize fender space. One phenomenon that validated my bumpsteer reduction was that the slip plates used to torque when I lowered the car. Now they just slip laterally with no torquing. So I do think I'm getting somewhere. I just took a nap and feel so much better (I used to be able to work 'til 2am every night!). But my assistants are all napping so I'm gonna work on a mounting pad for the spoiler til I have someone to turn the steering wheel for caster. I'm betting all my bumpsteer work from yesterday goes in the toilet when I add caster. Then it is back to the drawing board! Oh, bye, 450 springs are stiff as hell-I'm afraid my windshield is gonna pop out when I pull into my driveway! Sorry about having to twist your screen, but here is a photo dump.