jgkurz

Austin, Thanks for the great post. I did the same as you and extensively modified the factory wastegate. My wastegate hole is also roughly at 1.25 inches. My problem is that I can't get more than about 15psi of boost. I've tried everything from adjusting my Blitz boost controller to changing out my wastegate actuator. All with no success. After reading your post I think I probably have the same problem as you with the wastegate door blowing open. I'm going to try and preload the actuator then try it again. Maybe I'll get better boost response. Does anyone know if a large diaphram has any advantage over a small diaphram wastegate actuator? The reason I ask is I have the choice of either one.

Hello everyone, I have an update on my brake situation. I went ahead and adjusted the rod out several turns. There was no improvemnt. It simply bottomed out the piston in the master cylinder. Funny how a pedal gets real hard when you hit the end of the M/C. For whatever reason the M/C just won't build pressure. For the life of me I can't figure out why the 7/8 M/C works fine and 15/16 won't get a solid pedal. At this point I think I'm going to try the Power Bleeder. I'd like one I could use on any car. Motive Products offers several types including a universal model and an import model. Does anyone know if the universal will fit a Nissan/Datsun? http://www.motiveproducts.com/02bleeders.html Thanks

Ed, I'm encouraged by the fact that you were successful with your upgrade. I'm starting to think I need the matching booster assembly. Did you use a booster and rod from a 280ZX? My brakes with the 7/8th MC worked fine prior to performing the upgrade. The pedal was firm and the booster did not leak. The vacuum bottle had all the vacuum lines intact and none were leaking.

Tim, the Toyota 4x4 vented calipers only have one bleed point. I believe it covers both sides of the caliper. As I understand it, with a larger master cylinder it requires more effort to get the same amount of clamp to the pads. The 7/8 MC will have a more sensitive feel, but is more difficult modulate or between slight and hard braking. I think it boils down to personal preference. The only idea I can come up with is that maybe I need the vacuum booster and rod assembly from a 1980 280zx. That's the car my 15/16th MC is for. My pedal is bad with the car on or off so it might be a problem with the rod not the vacuum booster. I don't know how it could the rod, but that all I can guess.

Hi Doug, I have installed a Wilwood proportioning valve, but I ruled it out as part of the problem because I had a similar bad 15/16th experience with my 78z that had the OEM prop valve. What year is your Z? Maybe my 280z uses a different length rod than the 240z or 260z. I do remember playing around with the rod length on my prior 280z. At the time it didn't make any difference. I'll give it a try again if someone thinks that is what the fix is.

Hi all, I finally got my car (77 280z coupe) back on the road today after being on jack stands for eight months. One of the upgrades I installed was a new 15/16th master cylinder to compliment my Toyota 4x4 front and 240sx rear caliper upgrade. For some reason I cannot get a firm pedal with a 15/16th master cylinder. I had the same problem on a 78 280z I owned about twelve years ago. The car was stolen before I could figure out the problem. I chalked it up to a bad master cylinder. Seems like I was wrong because my current Z is exhibiting the same phenomenom. I HAVE searched all forums without finding a clue on how to solve this. The general concensus seems to be that bleeding the system properly will solve the problem. I have bled the brakes in this order MC, LR, RR, RF, LF then over again. I honestly believe the system is absent of any air. Evidence of this is the fact that the pedal does NOT build pressure no matter how many times I pump it. The pedal creates some pressure to stop the car but goes to the floor everytime. It will slow the car but will NOT lock the brakes. Has anyone installed a 15/16th master cylinder successfully? I know the advantages of staying with a 7/8th MC, but I'd rather have the larger MC so I can modulate the pedal better. I'm pretty bummed right now. I have spent a fair amount of $$$ on my new brakes and can't use them yet.. Thank you.

Hi everyone, For two reasons I've changed my mind about leaving the hardline mounts on the car. One, Ross C emailed me and recommended removing them for my installation. He has seen many installations so I think I'll take his advice. Second, there is no way around the fact that the mounts will hit my calipers if hit a large bump or bottom out the suspension. To get around this and still have safe brakes I will use steel braided lines up to custom length hardlines. Each line will connect at the T block then come out to the wheelwell. I have already installed a 20" hardline. I need to buy a 10" hardline tomorrow to complete the upgrade. As for the ebrake, you will need to swap the left cable to the right and right to the left. To do this you need to unhook the ends and cross them above the differential. They line up perfectly after that.

Thanks everyone for your responses. The installation took me several hours, but I'm a very slow mechanic. I broke it up into several sessions. I'd guess it would take someone more competant than myself the better part of a Satuday afternoon to do the whole conversion. The hardline mount in the picture is the one I'm talking about. I definatley DO NOT want to remove the mount if I don't have to. My only conncern is impacting the mount with the caliper when the suspension compresses. My test was to jackup the control arm as high as it would go. When I did this it hit the mount about 3/4 way up. : ( My test may have not been real world so I think I'll do the same as Drax240z and leave it as is for now.

The mount currently is used with the 240sx conversion. It holds the hardline in place where the steel braided line connects. If I remove the mount I believe it would still work, it just won't be as secure. I'm just curious if anyone has removed the mount for this conversion.

Hi all, I am in the final stages of getting the rear disk brake converson done on my 77z. I have purchased the Modern Motorsports 240sx rear disk brake conversion. I have been impressed with how well the kit has been designed which has made the install soooo much easier. The question I have is whether or not I should remove the mount for the hardline that is next to the rear calipers. The mount is the one that is on the front lower side of the rear wheel-wells. I looks like the 240sx calipers might contact the mount if the suspension is fully compressed. Have any of you that used the 240sx kit had to grind this mount off? Thanks,

Well I found the problem... Looks like I have two driver side CV shafts. I got the correct one for the passenger side and it locks right in. Thats the good news. Now for the bad news. As I was working on this problem I noticed that the "used" CV shafts have a tiny amount of play in the bearings. Although this is probably not a big deal it seems to me that any play is bad in a Z. My halfshafts had zero play in the u-joints. Is a little play with CV shafts normal or should I have them rebuilt?

The problem CV shaft DOES seat all the way in, it just won't lock into place. I am comparing it to the side that does seat correctly. Does anyone know if the C clip's can be replaced while the diff is in the car?

Thanks for the advice Terry. I have verified the clip is still in place it just doesn't seem to want to slip into the groove properly. I'm thinking the groove may be somehow burred or something not allowing the clip to seat. I have also wondered if running the car would seat the clip. I just don't want to risk a catastrophe.

Hi All, I finally went ahead and started the CV shaft upgrade on my 77z. I used the MML adapters with 280ZXT CV shafts. My problem is that the passenger CV shaft won't lock into place. The old halfshafts were both locked into the C clips perfectly. I know because it was a pain to get them out. The driver CV has locked in nicely, but the passenger side can be pulled out easily. There is a slight resistance or detent when the splines move past the C clip, but it just won't lock. My worst fear is that I will have to pull out my differential. Any suggestions? Thanks,

I believe a leak in the intake plumbing could also cause the boost to spike then leak down.

Thanks for the thorough response Dave. I'm saving my pennies! Just curious, for a street car do the chromoly arms add significant road noise and ride harshness? I know they are meant for the serious competition car, but most of us drive our car on the street part of the time. Thanks again.

Dave, Can you explain what track adjustment is as it relates to your control arms? Also, other than many years of road experience, have your arms undergone any type stress testing? In your experience how have they held up on track cars? There has been some previous discussion on this board about how chromoly arms hold up to repeated track time. Thanks much for your input.

Here's the site that one of our HybridZ members had when he was building the mounts for the finned diff cover. He no longer makes the mounts so we have to fabricate our own now. Personally I'd like to buy something I could bolt on rather than fabricate. I'd like an R200 mount, but I'm sure there would be plenty of interest in an R230 mount as well. http://www.linfoot.net/ Regards,

Dave, That looks like a high quality piece. From a functionality standpoint does the new bar shave a few pounds or add some rigidity as opposed to the OEM bar? Also, have you ever considered building similar bar that supports the rear A arm aft mounting points, but allows the use of a factory LSD finned cover? The factory bar forces us non-fabricators to use the early Z diff covers on our LSD's. I'd buy a custom LSD bar if you made it...

Congrats Savage42! That's my Z club. Unfortunately I couldn't attend.

Those are nice motor mounts! Just curious... What do the RB26 folks do for manual transmission mounts? Some day I might do the swap.

So did they just take the car for a spin a pull it into the grass to take the picture...? Strange for sure. For those tires to be original they would have had to put the car up on it's frame and deflate the tires for 34 years. It looks real enough, but I don't buy it. Literally! I almost bought a 1970 white SS Chevelle LS5 a while back, but didn't want to spend the money. Definitely nice cars any way you look at it.

Yes, there are members in the Portland metro area. I haven't been able to participate in many functions yet, but it seems to be a great group of folks who love their Z's. They are based out of Salem, but often have functions in the Portland area. For $50.00 a year I thought I'd give it a try. http://www.northwestz.org