JMortensen

If you do the limiters right you can pull a much higher g without leaning nearly as far in total.

I got a little confused there. Higher brake pressures, not higher speeds. I don't hit the brake with the same amount of force in every situation, even on the track.

What load again? They pull OUT under cornering loads.

Not similar. As you slow down the rear wheels can handle more braking effort. If you use a balance bar only, then when you're going fast you'll set it so that it is biased correctly, but that will be a lot less braking than the rear tires can handle when you're going slow. By running a prop valve you get a steeper increase in the braking pressure that then tapers off at higher speeds. This in combination with the bias bar, should get you a lot closer than either one alone. The next logical question is "which prop valve gets you the closest?" I don't know the answer to that and I don't have the money/time/patience it would take to get it dialed in absolutely perfectly, but I will run the adjustable prop valve I already have in an attempt to get as close as possible with the least amount of work... More info: http://www.stoptech.com/tech_info/wp_brakebiasandperformance.shtml http://www.stoptech.com/tech_info/wp_proportioning_valves.shtml

The rear bias valve, if you mean an adjustable prop valve, doesn't change the bias in the same way. It has a knee in its pressure curve, so it is useful to have one so that you can get the max amount of pressure at low speeds and have it taper off at high speeds, this all being in addition to the bias bar.

If you email Tilton with the specs they'll give you a suggestion for master sizes. I'm pretty sure AZC runs 1.75 in front and 1.38 in the rear, but that doesn't mean much of anything to you because the rotor sizes are different, etc.

Right. Those floating brakes would do no good on the rear of a Z. ZX is a different story, but the Z doesn't suffer from brake jacking.

I think he might just be misunderstanding a phenomenon that is actually happening. With some rear suspension designs, hitting the brakes does indeed compress the rear suspension, and it IS actually the brake torque that does it. But what it does not do is lift the rear tires off the ground. There is still plenty of gravity to hold that back end of the car down when the brakes are applied, until the center of gravity is high enough, the wheelbase is short enough, or the deceleration g's are high enough. To me this idea is analogous to people thinking that Cary's limiters will cause the inside tire to lift off the ground. They don't. They cause the suspension to stop moving. The two are entirely different things. If the rear suspension stops moving, that is very likely to make that end of the car (or mountain bike) loose, because it can no longer follow the road surface. That is exactly why those floating brakes exist. They allow braking without jacking the suspension around or binding it up. They allow braking AND suspending to happen simultaneously. The reason that Cary's droop limiters are helpful is because they prevent an even more negative effect on traction (excessive roll), and the suspension stops moving on the least loaded tire.

Not always. Semi-trailing arm for instance usually has pro squat when accelerating and braking. And it's not necessarily a bad thing (especially on a car that tends to nosedive a lot under braking). If the rear squats when braking that levels the car and prevents it from nosediving as much. That is often preferable to the rear jacking UP when braking. Ask anyone who races a car with leaf springs about that. I know when I traded out my shackles for sliders when I was autoxing a pickup truck it made a big difference in stability under braking. Again, case by case is the way to judge what is "good" and "bad". I haven't seen what you're talking about on cars, but I have seen it on mountain bikes. It's purpose is not to get "pro lift" but it is to free up the suspension while under braking. If a car is set up with "pro squat" under braking, that means that the braking torque's effect on the control arm is to make the suspension lengthen as far as possible, and then to keep it there while that braking torque is applied. For semi-trailing arm suspension with the control arms pointing down from front to back for instance, that means that when you hit the brakes the rear control arm wants to level out, dropping the rear of the car down under braking. Until you release the brake it wants to stay in that level position, reducing suspension movement and essentially creating a bind. This is very similar to a single pivot rear mountain bike suspension, and the elimination of this effect is what the floating caliper is trying to achieve. http://www.therapycomponents.com/floaterfaq.htm From here: http://www.stockcarproducts.com/techtips.htm I don't know for sure, but my SWAG is "brake influence on handling" means that you would set one side different than the other to get the rear axle to steer around the track. Why? If you use upper and lower control arms, or even single control arms and struts like the Z, it is easy to set the suspension up to have NO toe changes. You might have a slight change in track on one side or the other as the suspension compresses, but those effects are present on a Z anyway due to the TC rods in front, and you don't hear too many people complaining about it. Certainly not like the solid axle guys complaining about rear steer. Which is why people so eagerly remove HICAS from 300ZX's and Skylines when they are raced, I guess.

A couple things anti-squat can do for you: Keep the chassis level. Might be less likely to pull a front tire. Keep toe from changing. If the suspension has a lot of toe change, anti-squat would help minimize that negative aspect. Keep the ass end suspended. If the car were really softly sprung or really powerful, neutral or pro-squat might leave you with the suspension bottomed on acceleration.

Eh, I think you need to take that one on a case by case basis. I know the Z32 300ZX has a lot of anti-squat built in. Apparently this was done with an eye towards road racing and has the side effect of making it a poor drag racer. You could argue that not having very much anti and running stiffer springs would accomplish the same goal and might work better, but again, case by case...

The problem is that the early R180's have a different ID to the ring gear than a later one. So you have to make sure that the LSD you buy is for the early style and they're harder to find. Later if you add the LSD to the 3.36 stock diff and then decide to install a 5 speed or anything else, that 3.36 is not going to be a desirable ratio, but any other ratio you get will likely not fit the LSD that you purchased. For a stockish 240, I'd suggest upgrading to a ZX 5 speed and a 4.11 diff from later 240SX (K housing) with the LSD added to that.

Heavy85 ran into that same problem with his APR wing and he modded the mount to put the wing at the proper angle. The problem is that all of those ricer wings are set up to install on the flat trunklid of your typical sedan, not the sloped decklid of a 240Z.

I would suggest deleting this post. If it does go to court and she finds this, it could be used against you in a "he's obviously poisoning the boy against me" sort of way. Maybe I'm a bit hypersensitive about posting things online, but that's my take. Having seen my cousin fight a psychotic bitch for several years for custody of his son, I wish you the best.

Yes. That one.

If your 280Z currently has an R200, then yes. Check the bushings out in the OBX thread. You might pick those up too.

What's so horrible? It's got an MSA Type II ground effects kit on it and a wing that needs a new mount. I've seen a lot worse than that. Anyone remember the 280ZX with the lion airbrushed on the hood???

Bump steer spacers change roll center and also change what part of the bump steer curve the suspension operates in.

You could run dished pistons. I did that for a while with my E31. The compression ratio ends up being pretty low, but it will still work. The other option is maybe sell the head to put something else together... My low comp L28/E31, cam, Mikunis, exhaust, etc.: http://videos.streetfire.net/video/2000-autox-indisde-and-outside-I-think-my_8051.htm

Agreed, I think we're saying basically the same thing. The most efficient way to get these effects is to step on the brakes or gas or to turn the steering wheel, so it is a response to those inputs, but it is not the direct effect of those inputs. Anti-X is the effect of load transfer on the suspension geometry.

I think what you're missing here is pistons. You'd need custom pistons with the pin height higher so that the longer rods didn't put the pistons 3mm out of the deck. What you're talking about is a good idea, the bigger displacement with the better rod/stroke ratio, but it's not quite as cheap and easy that. I'd just go with a standard L28 bottom end. As to the compression ratio being too high, I agree that it is. If you bought an engine with flat top pistons it would have a P79, which could be shaved .080 (relatively cheap machining) and then you could shim the cam towers, run N series valves in it and you have a nice little engine. http://datsunzgarage.com/

I think it's a bit of both. Anti-dive uses brake torque to affect suspension, anti-squat uses engine torque to affect suspension, high RC anti-roll uses centripedal torque to affect suspension. Or to say another way, the suspension compresses on the front of a car with anti-dive just fine when you aren't on the brakes.

Why are they not compatible? I didn't have to change the yoke when I went from a ZX to my 240Z. Is it the bolt size on the driveshaft? If so it might be easier to find a driveshaft than a loose yoke.

Anti-dive works by using geometric leverage of the suspension to resist compression. This is bind for all intensive purposes. It may not be bind to the point of the suspension not moving at all, but anti-dive is the tendency is to resist compressing (aka jacking) which makes it "more bound" than it would be were the suspension set up neutrally. Or, to say another way, a suspension acting under any form of anti (squat, dive, roll) has reduced compliance. Carroll Smith: In other words, the upforce from the jacking of the anti-dive and the downforce from the load transfer work against each other and in doing so they bind the suspension.

There is a bit of discussion on this topic in the strut thread. Aside from strictly cornering loads, I think the rear control arm Dan and I came up with eliminates a lot of side loading on the 240Z too. That was particularly what I was after.