JMortensen

Those are pretty surprising test results. Please repeat after so we can see the change! It still looks to me like the weight of the engine is pulling the front frame rails (and everything else in the front) down. It will be interesting to see if the SFC's can reduce that flex.

Diff gets hot in these cars. Road racers see temps over 300 degrees. As long as you keep the fluid changed and at the correct level you should be fine. When the fluid level gets low it starves the forwardmost pinion bearing.

Still think its the master...

My feeling is that a race car doesn't need all the travel of a road car. Even a sporty road car doesn't need all the travel of a stock sprung Z with its 80 something lb front springs. So I'd tend to want to go with the shorter struts.

I think MSA has them. They're very expensive from what I recall.

This is exactly how you test a master cylinder. If slow pressure makes it go to the floor, it's bad. It probably had some crap way down in the cylinder where it normally didn't harm anything, but when you bled the system you pushed the seal through the muck and damaged it. I think you need a new master at this point. I have a genuine Nissan master (not a rebuild) for a 280ZX that I used on my car. It was in great shape when I removed it. If you're interested, PM me about it.

Go through and check all your connections too. I once had this problem when bleeding a friends newly rebuilt 510. We bled the master and all the wheels several times before we found that one of the SS brake lines was finger tight. It wasn't leaking fluid out, but apparently it was sucking air in. My guess is that it is probably the master though. Also, if you use a tube from the bleeder back into the reservoir push the pedal down SLOWLY! If you slam the pedal down you'll put lots of bubbles into the master, which in subsequent bleeds will put that air back into the lines again.

I have no experience other than buying the parts. Haven't gotten around to installing them yet. My plan was to run the tube off of the block breather, and either cap or restrict the valve cover orifice. There is a bit in the How to Modify book about running too much vacuum and having the rear main suck in and allow oil out the back of the engine. That is my major concern. I think I'll run the valve cover totally blocked and then if it smokes I'll drill a small hole to limit the vacuum and see if that does it.

I'm just a dude with a welder too. I just got the welder maybe 2 years ago, and had virtually no previous fabrication experience before that. John is a professional fabricator, and I think Doc has the qualifications to be one as well. Not sure on Grumpy to be honest. I'm not sure I should be lumped in that same category though. I have ideas and I'm implementing them, and I try to think them through, but no engineering degree or certifications or any of that to back my theories up.

The play in the strut housing is not a bad thing. Any slop is eliminated when you torque down the gland nut, and you're left with room for grease or oil to prevent the strut from seizing in the housing. I don't see a benefit to putting a thicker wall tube in there other than maybe a little more bend resistance and it will just make the suspension heavier. If you really wanted the stronger tube you could just get the 280z stuff and not have to machine as much.

Well if you put it that way I get it!!! I know that my front end used to sag down probably 1/4 to 1/2" when I put jackstands under the TC buckets. I don't know for sure, but I always figured that this sagging was happening between the firewall and the engine mounts, so I wasn't associating that sag with the SFCs, and I definitely woudn't associate it with the door gaps. I never noticed any sag in the rear, but I guess that doesn't mean that it wasn't happening... I installed braces from the rockers to the frame rails (upper and lower) and did the strut tower to dash bar braces and the strut tower to lower frame rail braces to stiffen this part of the chassis. I also stitch welded the whole car. I don't think the SFCs will really help this issue much. I would suspect that the only part of the SFCs playing a role here will be the short section from in front of the footwells to the back of the TC bucket.

Found my source: http://www.circletrack.com/techarticles/0304_aerodynamics_tech_definitions/

The Mr. Gasket part is about 1/2 the price of that Moroso part. Jeg's has them.

Bigger cam = lower compression on the tester. Sounds fine to me.

I think we can. Limiting the amount of air getting into the engine compartment is a huge part of getting this done. The gaping maw in the front of a Z is way too big and allow a ton of air to get under the car, hence Z's with fiberglass hoods look like they're going to pop right off of the car. I think once the airflow going in HAS to pass through the radiator, then it's just about utilizing some hood vents to get the air out. By the way, I got that idea from a circle track site, but you see the same type of airbox almost universally throughout the racing world. I was looking at several catalogs today as I was packing them and they had the same basic radiator duct in them. Starts off with a small rectangular hole, then angles up to where it attaches to the core support. I can't remember what one it was... coleman, tc cline, pegasus, one of those. Only thing better than that in my opinion is a radiator/hood/airdam combo that never lets the air into the engine compartment like 74_5.0L_Z and blueovalz have.

This doesn't have anything to do with the testing, but sealing the core support to the hood isn't the best way to go. If you make an air box that goes all the way to the grill opening, then the WHOLE hood can exert it's pressure difference, from the front all the way to the back. If you seal it at the core support then you lose (guessing) 20% of the surface area of the hood. If you can get just a little bit of a pressure differential going, and spread it across the ENTIRE surface of the hood the downforce #'s will be a lot better than if you cut off the front 20% of the hood from that pressure differential. That was poorly worded, but hopefully the idea makes it through...

I'm sure that would work, but I think it would be better to seal the intercooler to the radiator. Less air under the car is better. If you had hood vents and a rubber weatherstrip between the intercooler and the radiator it should improve the flow through the intercooler compared to having it just sitting there in front of the radiator, and it would still allow the air to escape out the top of the hood.

I just had another thought... I wouldn't do anything to correct the gaps before you work on the door hinges. I'd be willing to bet that 99% of any changes in the door gaps have to do with worn hinges or poor door alignment.

I'm guessing that maybe there was another panel that covered the area where the stock grill goes. That would force all the air through the radiator and eliminate most of the huge hole in the front of the car. Good work guys. I can't wait for the "official report".

Don't really know the answer to that one... sorry.

I saw that show you're talking about, I think it was Musclecar, and that was a Nova they were working on. My impression is that those cars sag a lot more than a Z. I don't know where you would want to put the jackstands to "reverse sag" the chassis on a Z. I had the chassis on a rotisserie upside down, so I doubt you could reverse sag it more than that, plus it makes the welding a lot more convenient. I wouldn't suggest you put jackstands under the SFCs, especially if the SFC's weren't already attached to the chassis. I wouldn't worry about sag since the rocker is the primary factor there. I'd worry more about getting the welding right.

If you can weld on sheetmetal you can put these on yourself. They're not hard to install. Those self tapping screws that I used worked out great, and I think that is preferable to trying to bend the SFC to meet the floor. Also just to clarify, that shot is showing the piece that John @ Bad Dog had made special for me. I guess roostmonkey was the one that did that special part (thanks!!!) but the normal rails have the same flat flange on both sides, not just one side like the one in the picture.

Looks pretty much the same as this old thread where we dealt with the exact same issue: http://forums.hybridz.org/showthread.php?t=94933 I'm going to sticky this one so that people will see it if they search before they buy Tokico springs and struts. You can use the springs, but in my opinion you really need to section the struts to gain enough travel, otherwise you're just going to be bouncing off of the bumpstops all the time. The next thing that you'd have to worry after sectioning the struts is coil bind. Wouldn't want to section the struts too much and then have them coil bind before they hit the bumpstop. If you add up all of the gaps you've got there that should be the possible travel with that spring. If the gaps add up to more than you would section out of the strut, then you should be good to go. If you use the 88 MR2 rear struts in front I think you end up removing about 1.625". Anyway, here's another thread about sectioning the struts if you decide to go that way: http://forums.hybridz.org/showthread.php?t=103860

I think katman was running toe out in the back of his ITS car. My opinion is that the ultimate goal is to get the car balanced. You can do that by tightening up the front or loosening up the rear. In my experience it's better to tighten the end that isn't gripping until you can't get any more out of it, and then adjust the other end to match. In terms of comparison, I think this means more caster in the front along with more toe out, and which point you could probably toe in the rear and still be able to rotate the car.

It's the 405 / 5 interchange. You should have seen the ropes the guy had tying this stuff down. There was ONE rope lengthwise and ONE widthwise for the big stack on the roof...