69sroadster

My ZX JDM gauges are in metric, but they were showing 125ish Celcius on oil and water at Hallet over last Memorial day weekend. The outside temps were in the 90's Fahrenheit I think, off track. My SR ZX normally runs around 100-110 C on normal driving with the A/C on. I was interested in this response too given the higher temps I thought I was seeing. I'm not 100% certain that they are calibrated to the SR water temp sensor nor that the oil temp sensor is spot on too.

I was running wilwood 570 BF and porterfield r4s pads all around. I have read through the brake faq and saw consistent negative feedback with rebuilt BMC's to replace the ZX unit. I will flush the system, again with 570, once the 1" wilwood comes in. If that ends up being overkill like you mention, then I'll figure out the best place to get a rebuilt ZX unit and swap it back on instead of the wilwood 1". That just seemed like a cheap alternative that should provide more juice if/when I ever do swap to the big brake kit. When this happened I thought at first it was just a hard pedal but then realized it was all the way down. I pumped and it came back up along with the braking response. It's still like this now, but like I said I have not been able to find any source of brake fluid leak and still haven't seen the fluid level drop in either bowl. I need to get another pedal pusher to confirm the fronts aren't doing what they should while I try to rotate a tire up front. I was also running soft hankook ventus DOT slicks at the time...245/40/17's. Boy did I love those around the turns versus the old nitto nt05's.

Where do those holes near the BMC and batter go to? Do they exit out to the side of the car's fender somehow? I've read about that as an option to exit air from under the hood but it seems like you'd need to create a lower pressure differential to get air in that area to actually exit out the sides. I've seen someone use Trans Am side vents which have a front speed bump on them possibly to help this out but don't know if it actually worked or not. Does yours exit the "trapped" air some other way? I've got a ZX that althought theoretically more aerodynamic than the S30 still makes the hood wobble from this high pressure under the back of the hood. It seems that the louvers near the front of the hood aft of the radiator make the most function but I don't like the way they look too much. I'm also wondering what is too hot for the SR. At my last track day it seemed my oil temps maintained a steady 120ish celcius with the water about in the same ball park, but I didn't have any overheating indications. I didn't get a look at the EGT values, but they might indicate higher than most others since my probe is right by the exhaust port and not aft of the turbo. The highest I've seen there is during lean cruise at 1400ish Fahrenheit. This is a damn near stock SR. Good luck and your car looks nice.

I agree about the MAF differences. First fire up on the SR proved that out for me as it kept dying after a couple of seconds. Swapped to an actual SR MAF and it's been running fine since then. The other MAF I am 99% sure came from a KA my brother accidentally confused for me when he gave it to me. I love the passion everyone has here in the discussion. It seems we can all do great things with some patience, advice, time and money to whatever motors we want. I opted for the SR because it was lighter and gets better gas mileage and I was familiar with it. I guess I could have gone KA too saving cash, but at the time I wasn't as familiar with it. It was a fun learning experience doing the SR and I still think the torque in it is just fine as it is. I've had it in for 4.5 years now, been to 14+ autox events and a recent Hallet HST event. The A/C works and it gets over 30 mpg on the highway in my 2+2 ZX (3.7 rear gears & 255/40/17's). It makes me smile, and that's all I need. To each their own. Whatever you choose, I hope it can make you smile too.

Just had my 1st HST event at Hallet in my ZX and I LOVE the non-PC flag definitions here. Unfortunately for me I was the A-hole who lost his oil line going to the cooler on the track but at least I did get off the line and the track ASAP. Also thankfully I did not lose the motor in the process. I will also say that I only had to let 1 corvette pass on a straight before the drama hit and I'm proud of that for my 4 banger ZX...but it was a new ZR-1.

So over memorial day weekend I took my zx for the first time to a "real race track" at Hallet with my family camping there over night. After about 5 minutes into the second HST session my brakes seemed to disappear going into the near 180 degree turn. After a brief panicky feeling and pumping the brakes, they came back enough to slow down in time for a deeper than normal apex (not in the grass). I've bled them and found no air, but a little chunk of blackish hard crud came out of the left rear bleeder. I thought that was wierd. I also bled the master cylinder first, again no air. I also found no fluid leaks anywhere. The pedal initially seems low but pumps up quickly and holds. It also seemed that the rear brakes appeared to be abnormally worn than previous to the racing....excuse me high speed touring...and more than the fronts. After reading a good lexus master cylinder 101 write up I think that the front circuit of the master cylinder is failing or has failed. I've ordered a wilwood 1" for now as I'll be upgrading the brakes eventually to a larger set. I've also looked into the front resevior again after a few days of local limping to/from work at slow speeds to confirm that the fluid is still not leaking out. No leaks noticed, level was the same but I did notice how much more dirty the fluid there looked than the crystal clear it was after I flushed just prior to the racing. My bet is that the original seals in that original master cylinder broke down under the high temp fluid and hard braking from 100+ mph speeds. Has anyone else seen something similar to this? Also, for those who have done the AZC big brake kits to the ZX and track their car...has it held up to your expectations over time? I've seen writeups with initial great reviews but haven't seen a long term feedback on them for a ZX yet. Sam Kraemer

Beermanpete, Great ideas about using the metric and SAE line like that. I also thought about just getting rid of the stock proportioning valve and running the front brake lines together like you mentioned. Either way the rear will be directly from the master cylinder and through the Wilwood to the back. Also thanks for the info that the WW adj PV comes with metric adapters. Would leaving the front brakes through the stock proportioning valve help with kneeling etc based on a non-constant or linear effect it might still have on those only?

For those brake experts, I've researched on here and am looking for confirmation of the following: 1979 280zx has 3/16" brake lines with 10mm x1 tube nuts To use a Wilwood proportioning valve I would need an adapter for the lines like this from BrakeQuip BQ50 3/8" x 24NF M10 x 1 I would also need to plug the stock zx prop valve rear output or at least route it back on to itself so the right front still works normally.

Does anyone know of a good shop to take my 2+2 to for a custom roll bar install in Arkansas? Also, I'm looking to install a pair of Corbeau FX1 seats when I get back too. Anyone have some feedback on those? My stock seats need a lot of work and I don't really like them anymore. Not to mention those things are freakin' heavy. I had one out before to get at the relays under it. Wow, I'd guess they weigh close to 50 lb a piece.

If I were to do another Z swap I'd go with a Toyota 1J or 2J as much as I like the SR in there now. Despite the sometimes insane prices on Supra parts, you can still find good deals and put together a potent package. The best part is parts are more available here in the US and you still get that awesome inline 6 sound. Power levels can be rediculous still if you wanted. My brother has one in his Cressida with a single turbo and some cheap add-ons...finally had it tuned and now his clutch is slipping when he turns the boost up. Can't wait to get a ride in it someday and see this infamous power out of a sleeper.

Calico, if you're willing to pay some $ and do some swap work why stop at the motor and tranny? Ditch the R-200 concept altogether and swap in a solid axle differential and tub whatever you need to. I know you'll lose some of the handling beauty, but you said you want to hit 10's and will be drag racing it. You can find a Ford 8.8" solid diff from an explorer with traction lock for cheap at many junk yards. They can take a decent amoung of abuse (with minor work) and there are tons of options for those that aren't expensive or hard to find either. Also since this is going to be basically a street/strip vehicle, look at what you can drop weight wise with ditching the glass windows. I don't know what rules you're going to have in your class, but if you're stripping it down that glass can weigh a lot. I also agree with ditching the dash and entire HVAC system. I had mine out to repair some stuff and was amazed how heavy some of those components were. Front seats are pretty hefty too. Look up the thread on here on how to do a coil over swap with S13/silvia/180sx/240sx parts. There are plenty of options with those suspensions to get stuff as well and still do it on the cheap. I don't know enough about those tranny's you mentioned to comment on them, or how much you'd have to do to get 450 hp from a 3.8 motor. I would think it wouldn't be hard to get the power on a good motor. Out of curiosity, what does the 3.8 weigh compared to some of the small block V-8's and why are you shying away from those? Do they just suck gas all the time more than you'd like or do you like having boost?

Cool thanks. I'm out of town for a while, but when I get back I'll have to test this out. I don't think the rears are doing as much as they should from what I remember. I don't recall them locking up but maybe I didn't give it enough pedal pressure either. It seems to me like they haven't worn down much at all over the last year after the brake system rebuild. If this is the case and based on the tips you gave, I guess that would mean taking out the prop valve and putting in an adjustable one with less pressure restriction dialed in.

Wow, there is some great teaching material on here from everyone sharing their experience and feedback (good or bad). I've learned that the reason my hood wobbles back and forth at the trailing edges is more than likely due to high pressure air trapped underneath. I'll fix that in time. I've also replaced my brake lines, rotors, calipers, and pads (porterfield? or hawk I can't remember). Also stepped up to the 17" Rota's with Nitto NT-05 235/40/17 up front and 275/40/17 in the back. I realize now that I could probably fit 255's up front with no problems. Well, I haven't messed at all with the proportioning valve and was wondering if this could help out some more after reading through a few articles about changing setups. It seems like my ZX is now a bit off balance into braking and I may need to swap out the prop valve for an adjustable unit. Without having some fancy tools, can I find my new sweet spot just doing some brake tests in a clear area or track? What would be the objective and subjective measurements to look at besides stopping distance? I guess a better way to ask that is what would I want the brakes to behave like at their optimum? Slight front bias? What would that look like? Thanks again. Maybe I'll just go to the AZC upgrade kit for the track work I want to get into.

How did this ever work out? I also had to make a decision a few years ago in the same way, chose SR20 and have never looked back. Just wondering if Echo had the same results. I'll be honest that it was a lot easier in most ways than I thought. Fabrication was not difficult either, but I guess I took it a little easier without mounting the whole motor aft of the crossmember or switching crossmembers. I'm definitely not an expert, so if I can do it, then any experienced gearhead can. Wiring was very simple. All it took was a good wiring harness from the SR and patching into the ZX ECU relays and fuel pump relay. I can't wait to get home and take part in some aftermarket goodness for the SR finally as she's still pretty stock. Oh yeah just for some quick stats (not really something to brag about but interesting) S13 redtop w/underdrive pulley and lightweight flywheel and stock turbine in my 2+2 gets 29-30 mpg highway consistently, 240 rwhp 265 ft lb. I've had it in there going on 4 years now and haven't had any issues with regular floggings every month at the SCCA club and occasional highway merges.

After reading all of this data and other test results, this is what I get: Install headlight covers (tested), block off a majority of the MSA air dam opening (tested), ensure air is shaped through the radiator (tested), hood vents need to be closer to the back side of the radiator and possibly directed up from underneath (tested). A closed cowl hood, higher center bulge, may help reduce some of the high pressure at the base of the windshield (untested). Fender vents may also help pull air out from the engine bay/firewall zone (tested already?). Whale tail or SDI spoiler will add rear downforce (tested). How much would running a ZX with the fan on high and rear 1/4 windows open help (relatively)?

I apologize if I missed this in another thread somewhere...but the numbers listed under the lift/downforce on the thread for the windtunnel test results, does a negative number = downforce? The legend at the top said otherwise, but then the numbers didn't make sense that way. I saw something like -.2xx for the whale tail spoiler and then +.1xx for the test mule. Also, how can you take those numbers and extrapolate into an equivalent weight in lbs? I could really use some downforce over the back of my ZX and want to decide which type to go with. Also, with the blue Z did those fender vents go through to the engine bay?

Also when you say jump start, do you mean a push start with the car in gear to turn the motor over, or with a set of jumper cables?

It could be completely off the wall, but I've had a similar issue with the ignition switch in my ZX sometimes if its turned too far and gives a similar response (ie bad switch). I don't think this is likely for your case, but just one of those things that could have developed with curious timing.

So the car is back up on the road again and driving smoother than it was a few years ago. I must have had a problem for a long time without realizing it. Thankgs Greg for the ZXT CV's and stubs. I didn't know how much I missed driving my Z until I took it to work again yesterday. I should be getting some better video this next SCCA meet in a few weeks to post/share. Anyone who wants to talk about SR swaps can feel free to PM me about what all is entailed. So far I'm still loving it.

It was the stub axle that was bad after all on the right side causing the wheel wobbling. I had to take out the left side stub axle which was fine in order to replace the bearings starting to go and I temporarily tried it out on the right side...no problems. I think the inner seal on the left side started failing a while ago since there was some slight surface rust and it was a pain in the butt to slide out. I should be able to put it all back together later tonight and hopefully get the car back on the road again, yeah!