JMortensen

So if I did my calculations right, that's .0632 psi lift for that part of the hood. Did you test the other side of the core support and hood? It shouldn't be the same everywhere, especially with your hood vents. Wonder where the pressure is coming from. Interesting stuff...

No, I was talking about going to SLA instead of strut. If you're going to pour thousands of dollars into custom struts, why not go the extra mile and get better geometry and a huge selection of high quality shocks while you're at it? As to your best next step, I can't do any better than the thread you're already in. Maybe someone else has an opinion.

http://forums.hybridz.org/topic/54124-step-by-step-installing-an-lsd-into-your-open-diff/?p=488661 Warning! The OBX apparently isn't machined to the same tolerances as the Nissan stuff so most people ARE having to adjust the backlash. Not a big deal to do that, but the writeup says that you probably won't.

The reason the clevis works better for larger amounts of caster is that you run out of room on the TC rod mounting holes. If you disconnected the TC rod from the control arm and then adjusted the caster to 7 degrees, you would no longer be able to get the bolts back in, because the forward angle of the control arm would mean that the TC rod holes would be in the wrong position. There is no simple way to fix this without a joint between the arm and the TC rod. You could oval out one of the mounting holes, but that's a crappy fix. Bending the rod is also less than ideal. If you decide to make a major change to caster later, you have the same problem again. That little clevis piece that Dan made (and I copied) fixes that problem. It bolts in the stock location and it also allows the pivot bolt to be loosened when adjusting caster so that you're not springing the arm by making the adjustment. As to the relative weakness of the tab with the TC rod bolted to it, that's something that I have pointed out as well. As of yet, haven't seen one break though.

There was a long, nasty thread about the Kameari part probably 5 years ago that's probably worth searching for. For my part, suffice it to say that I think it's a great idea because you can mill the head and not worry about shimming the towers up.

Someone will need to point out to him that it isn't a Ferrari.

I think it's possible to do a rad exhaust duct with the rad in the standard orientation and still hit the letter of the rules. I've got a couple things all converging though. I have tow hook mounts, the rad duct, splitter mounts, splitter, air dam and front end all coming together and I think since I essentially have to redo it all, I'd like to try and improve it if I can. I think laying the rad down allows more vacuum to get to the top side of the rad duct underside of the hood area as discussed here: http://www.circletrack.com/techarticles/0304_aerodynamics_tech_definitions/ and it makes the rad duct easier to make. My rad has a 1/8" NPT fitting, so I was thinking of getting the AN-4 adapter and then putting a really heavy rad cap on it. Welding it shut works too, but I'd have to have that done.

The real idea here is to lay it flatter for aero reasons. More room on top for low pressure to act on the hood and the tunnel for the rad exhaust would be easier I think.

The tapped holes are in the ring gear, so you'd not only need to drill them but also blind tap them. Just run the 10mm bolts with the mcmaster.com spacer. The ring gear bolt strength isn't likely to be an issue.

http://www.youtube.com/watch?v=kgv7U3GYlDY

Sorry for the repetition, but I think there might be an advantage to machining spacers to fit in there and getting rid of some/all of the spring washers. Several people have had their side shafts grinding on the housing because the washers wore away. Comparable helical diffs like the Truetrac don't have springs at all.

Sell it. There are a bunch of people who think that it is the hot cam for a class that requires stock cams, like ITS. Regrinds are relatively cheap. You could probably get more for the cam than you'll pay for a regrind.

Why not have a cam ground for your application? It's not expensive and you can do a lot better than the C cam.

Tyson is right. There's a combination of factors, how low you want the car to be, camber plates, which take a couple inches out of the top but don't stop the suspension from compressing so the wheel will come up further in the well, tire diameter, etc. I would venture a guess to say that most if not all of the cars out there with ZG flares are going to bottom the suspension at one point or another, and most of them are not likely to top out the suspension. Put another way, you don't see ZG flares very often with a stock height suspension under them. That being the case, the best test is the one that I mentioned before, which was also mentioned in Austin's thread. Take the spring off. Put the wheel and tire on. Jack the suspension up to the bump stop and make sure you have clearance. If the tire hits the body, the options are to install a longer bump stop (a really hard one that will prevent the suspension compressing further, not a Koni or similar foam stop) or to cut the body higher. I end up saying "cut higher" a lot and I'm sure a lot of people think I'm an idiot for it, but you really can't safely rely on what other people do. Your particular combo may require less or more clearance than mine. My car uses camber plates (bad for clearance) and I'm going for a very low ride height (bad for clearance) with very stiff springs (good for clearance) with a short 23.5" tire (good for clearance). When the car is at ride height there is probably 2 or 2.5" from the top of the tire to the body. I have a pretty good idea from looking at other cars that were built similarly that I will be using all of my bump travel despite the stiff springs.

Here's how much I had to cut to get clearance for the tire with 23.5" tires and sectioned rear struts and camber plates.

The right way to do it is to take the spring off and bottom the suspension with the wheel and tire installed to make sure there is clearance. Most people have them mounted too low.

Take a close look at 74_5.0L_Z's album. He has a tube front end, but you could do something pretty similar in the back and then either do a knee bar up front for the door bars to connect to or a dash bar, and then mod the dash to go back in over it. I think Dan's setup is the best I've seen for a street car. It's almost a full cage, but no halo to smack your head on.

Be careful on the rears. I'd say 90% of people with these flares have them mounted too low in the back. Read the linked threads, particularly Austin's thread here on hybrid z. He had to redo the rears because he mounted the flares where they "look right", which is too low..

Yeah, pull the trim off; reminiscent of Mike Kelly's fender vents. He has a relatively large hole in the fender, but then he put a cowl style vent on there and it covers over the huge hole leaving only much smaller, maybe 1x6 inch hole at the end of the vent. It will work, and so will yours, but if you think you still have pressure under the hood, utilizing more of the hole in the hood should help that pressure escape. Your comment sounded like you couldn't find the test data: http://forums.hybridz.org/topic/55944-windtunnel-test-data/ You can see by the lift in the front end on the aero testing that there was a lot of pressure under the hood, but they didn't use any rad ducts on any of the cars, which should have a huge influence. I think a few cars had a plate from the valence to the core support, but nothing to prevent air from going around or over the core support. In terms of where to exit rad air, there are problems with any solution. If you go out the sides, then your downforce gets disrupted by cars driving next to you. This is a key to NASCAR racing. If you have it come out the top of the hood, then you're feeding hot air to the wing if you have one. No perfect solution here. You really don't want it exiting out the bottom. Yes, low pressure under the hood, or even lower than the pressure in the rad duct will draw air through the rad. Still needs to go somewhere though, and a dedicated exhaust that takes all the air coming through and sends it out the top or the sides will help to pull air through the rad but also keeps that air from filling up the area under the hood. Add in some louvered vents to pull more air out and you should really be able to get some low pressure under there.

Yes I suck the old fluid out of the master first, then bleed. The first wheel in front or back will evacuate the hard line up to the T, so you're right, the second one shouldn't need as much fluid to clear it out. I'm sure 10 pumps is enough. If you have blue in the master now, you can verify that for your particular brake setup. Glad you're enjoying those axles.

You might try just removing the vent trim off of the hood and letting the large hole do its thing and see if you can tell a difference. I think the gurney would work better at the front of the trim, BTW. If you had a whole lot of pressure under the hood you wouldn't need to hit a bump in order to get it to lift up. Stock hood only weighs 45 lbs or so IIRC. Maybe just relatively stagnant air is the issue, although you would think that stagnant air = pressure and that would push the hood against the stop. Regardless, a rad exhaust duct would probably help a lot. Is that possible for you with your rule restrictions?

Waste a bit of fluid with a few more pumps on the pedal. I usually do 10 pumps per corner. Might be overkill, but brake fluid really isn't that expensive in the long run.

What have you done to get the air out from under the hood? I see the turbo hood scoop which typically lets air in, not out. Any other venting? That DIY VW undertray is right up my alley. Pinch the center of the side fences in a bit, and you essentially have my underbody venturi idea realized.

You've got a point there.

Yeah, I think that old argument about checking AFRs was based on an advertisement that claimed no restriction. FWIW, I didn't find them that easy to tune, and I messed with a lot more than main jets.