JMortensen

Laminar? Laminar flow is smooth and has no vortices, right? I think that the VG trades a bit of drag to reduce the boundary separation layer, but is not laminar AFAIK. OK, so what this means is that it makes the spoiler effective, and in the plane example that means more lift WHEN THE FLAPS ARE USED. On a car it does not mean more lift, it mean less boundary separation layer, and then beyond that it would make a spoiler or wing more efficient by giving it a larger amount of airflow. We at least agree that it makes whatever is at the end of the hatch more important. I don't think this is right (again not sure). If I'm correct than the boundary separation layer creates vacuum right above the hatch. The question then is what has a lower pressure? The boundary layer coming over the hatch which is turbulating without the VGs or the higher velocity low pressure air more closely following the hatch contour with the VGs. I think that the VG's themselves increase drag, although when everything else is taken into consideration there may be a net reduction in drag. I don't see how you can argue that there is no net gain in downforce though. We'd need a test to figure that out. Fences definitely work. I've been tempted to try that myself (hood fences too, just like NASCAR, just because they only turn left doesn't mean they're idiots). I have done more searching and read more articles, and I have yet to find one article that says that the VGs increase lift. Quite a few that say that it will keep the wing from stalling even with a more aggressive angle of attack, and they ALL say that they make the flaps more effective and the FLAPS can provide more lift, especially at low speeds. Our top speed is extremely low speed for a plane, so I am still thinking that the benefit to us is that we keep the airflow attached to the hatch and use the wing/spoiler/whatever to it's best advantage. Without the spoiler I see the VGs reducing net drag and increasing downforce by eliminating the vacuum from on top of the hatch. I haven't done any testing, and I may be wrong... Agreed, but you still may find a net reduction in drag by installing parts that reduce the turbulence behind the car, along with a wing/spoiler/etc. That's what the C&D article John quoted shows.

Looks like they have a lot of info that you can ORDER John. Do they have any that you don't have to pay for?

I'm not sure that I'm right John, but I did find this: http://www.aerospaceweb.org/question/aerodynamics/q0228.shtml And the last paragraph says this: And that seems to say to me that trying to use the flaps in separated airflow doesn't do much, so the vortex generators are used to keep the airflow stuck to the wing so that the flaps work more effectively. Since moving the flaps provides a lot of the lift you're talking about, I think that is where the VGs provide and advantage. I'm not totally sold on my own argument though.

You can download the entire SCCA rulebook online at http://www.scca.com. It is somewhat vague though. It will tell you what tubing to use and has some vague guidelines for the structure of the cage, but that's it. I guess the idea is that if it isn't in the rulebook it isn't legal, so if you have something you want to do with the cage check and see if it is listed first.

When I read it the paper it says that separated air is essentially creating a vacuum which lifts the back of the car. As I understand it this is also why we put lips in front of vents on cars, because the resulting turbulence behind the lip will create a vacuum and suck the air out of the vent. By using the VGs the air sticks to the rear of the car which provides at least low pressure air over the surface of the car, so it does increase downforce. Again, I would think that in our case the benefit would be maximized because we're talking about putting a spoiler right in that airflow. So instead of catching just bits and pieces of the airflow, we would have a nicely directed stream of low pressure air headed straight at the spoiler. This could be compared to the hood maybe... the hood has high velocity low pressure air going over it, then that air hits the windshield and that obstruction like a spoiler causes the redirection of the air which creates a lot of pressure. The pressure is what gives us downforce.

There are 3 pinion bearings. The inner is pressed onto the pinion bearing. The middle one is not a press fit and there is a long spacer tube between it and the outer which is a ball bearing pressed into the case just inside the pinion seal. The ball bearing is the one which I think tends to go out most frequently. In the two R diffs that I've driven that had a bad bearing there, they had a high pitched whining noise, almost a squeal, and the faster you went the higher pitched it got. The ball bearing is NLA, but the others are still available IIRC.

89 was the last year of the longnose R200, they went to the shortnose in 90. It wouldn't surprise me if the 90+ parts didn't fit.

All the longnose R200's are use the same seals. Pinion bearings are different in different years, but the seals are the same.

Small lathe job required, should take literally an hour or two. I was complaining about trying to find a shop that would do small projects a while back and someone said that they knew somebody, might have been in Bremerton (?). I need 4 threaded tube ends like the one in the picture turned down from 1" to 3/4". Just the shank part needs turning, the head can stay the same size, and that's the whole job. I have the parts in hand, just need to find a shop to do the work. Can someone point me in the right direction?

I would think a Quaife would be good in a straight line too. I've heard (and seen with my own eyes) them slip in tight turns at an autox and also long sweepers on the road course, but straight line is the easiest slip to limit. Might slip out of the bleach box at a drag strip if there was really no traction on one or the other wheel.

Sounds to me like the rings just haven't seated yet. Take it out and don't hit the freeway. Accelerate and decelerate is the key. Find a windy road or drive in trafficky areas. You need that accel and decel to seat the rings. You don't have to take it all the way to redline, but I wouldn't stop short of 5000 rpm.

Take a look at the "What diff should I choose" sticky, and check the section on front diff mounts. Couple ideas to get rid of that crappy strap setup.

OK, well if it's rings put a little bit of oil in #6 and redo the compression test and the numbers should jump right up.

White smoke usually indicates headgasket. If you don't have a vacuum source hooked up to that hose barb on the valve cover, then it (and the block breather) will vent any pressure in the crankcase. So it wouldn't suck air in normally. If you have a shop in the area that does A/C services, you can usually get them to stick a sniffer (leak detector) in the top of the radiator. The sniffer will sense hydrocarbons, so if it goes off, then that would indicate a leaky headgasket. If the gasket is blown from the headgasket to a coolant passage, that would make the compression test low and cause the white smoke.

The little dust cover on the pinion flange didn't get bent or anything, did it? Just unusual that the noise wouldn't change with load or turning. This might help with a diagnosis: http://www.ringpinion.com/content/technicalhelp/default.asp?pid=109 http://www.ringpinion.com/content/technicalhelp/default.asp?pid=110

I'm not sure what you're trying to eliminate or make shorter. Apparently you're trying to make the upper spring seat shorter to lower the car without losing travel. That's a great idea and camber plates do the same thing. The one thing that concerns me is that I don't see the original rubber part of the hat there. The rubber is the obvious thing to eliminate, but it is also the part that lets the strut move. If you eliminate the rubber, you MUST MUST MUST put in a monoball or some other pivoting joint in there so that the strut can change its angle as the suspension goes through its travel. Otherwise you'll be buying new struts a lot because you'll introduce a hellacious bind in the suspension. Maybe you already know that, but I didn't see it in the pictures.

Don't use blue stuff. Use a sharpie or any permanent marker, and just cover the whole rocker pad with ink. It doesn't smear like the blue stuff, so it's easier to read.

Or you could do it the right way...

If the steering wheel points right turn the wheels to the right, if it points left turn the wheels left. If it's just a gnat's ass off, go 1/4 turn or 1/8 turn on the tie rods. Doesn't take much.

It's been discussed before. The basic jist is that if your camber isn't the same on one side and the other that you might have to really lengthen the control arm on one side, which then leaves the wheel on that side sticking way out. The best solution IMO is to adjust the track equally with the control arms, and then adjust the camber with plates on top. Search and you'll find more info.

Although I've never heard of a Quaife breaking, I used to sell replacements for Torsens out of Camaros all the time when I sold diff parts and TimZ broke a Torsen in his R200. The Torsens in the Camaros which are very similar to the Quaife in design were considered particularly weak. I'd go with the VLSD for pure strength and LSD, or as JNJ said, a welded diff for ultimate strength with no regard for street driving.

I've seen drawings, but never an actual illustration or test result with pressures in different colors. Can you find one and provide a link?

Yes, probably 4.11 or 4.37s, depends on the rest of the car.

Read BRAAP's post: http://forums.hybridz.org/showthread.php?t=113533

Somehow I knew it was going to be that one before I even opened it. Talk about minimal body roll...