JMortensen

Someone else will have to answer those questions for you.

IMHO, going down that road is a BIG waste of time/money. Get a bigger combustion chamber and lower the compression, or run the race gas. On a recent thread I had found a calculator that will estimate compression vs hp. If you plug in what you hope to get out of this motor and then change the compression to what you would have with a bigger chamber, you'll find that the difference is not that huge. Given a compression of 11:1 and a hp of 250, a change down to 9:1 gives hp of 237. Not worth hassling with water or meth inj for me. YMMV. That calculator is nothing more than a general guideline, but it helps to prove the point. http://www.bgsoflex.com/crchange.html Another way to put it is: is there something else you could do (headwork, cam, ignition upgrade, exhaust, etc) that might give an equal or better amount of hp with the lower compression? I would guess that if the difference is 13 hp, the answer is yes.

With the bumpsteer spacers that MSA sells there is a 14" wheel version and a 15 inch wheel version. I think the 14" version is 3/4" thick and the 15 is 1" thick, but that's old memory, so may not be entirely accurate. If the tie rod hits, you're running low on options. Could go to 15's, add a wheel spacer (requires longer studs) or take them off and get a different spacer that fits under 14's.

Good job Whittie.What you have done won't affect bump steer at all (unless the position of the outer pivot is slightly lower or higher than the Z car tie rod). It will neither improve or worsen it. The reason that the control arm lines up nicer with your new tie rods is due to the J bend at the end of your new tie rod. It's not the arm that needs to line up, it is the imaginary line from the center of the tie rod pivots and the line from the control arm pivot to the ball joint which need to be parallel. From the pictures it looks like they are the same or very close to the same. As to benitoz question, in the US you can buy "tap tube" from any number of racing parts houses, but it isn't set up for 14mm, it's always sized for the more common 5/8" or 3/4" thread we use here. I would imagine that 14mm tap tube would be more common there, as would 14 mm rose joints or rod ends (or you could use the tie rod suggested by Whittie. In the US you might be able to find 14mm threaded tube ends which could be welded to a tube that serves as a turnbuckle, then find a similar tie rod to complete the job.

Those pistons aren't that unusual. I can't recall the name of them, whether it's the Euro piston or the Nissan Comp domed piston, but they're a factory item and if you look you shouldn't have trouble finding more info on them. They don't look like they have a super sharp edge on the raised part, which would be a detonation issue. If they did you could knock that edge down with some sandpaper and call it a day. I think you're going to be around where I was in terms of compression with that combo. My slightly shaved head and flat top combo with flat top valves was about 11:1 compression and required 95 octane gas to keep from pinging with a .490/280 camshaft. I would suggest a larger cam than I ran if you want to run pump gas. If you're going to run race gas you can run a smaller cam if that fits with the goals for the engine in terms of power and peakiness of the hp curve. It's better to lower the compression a bit and be able to run the optimum amount of advance than it is to retard the timing to prevent pinging. There are a lot of ponies in those last few degrees of timing.

I'm betting some practice can draw those groups tighter. If it didn't FTF or FTE, I'd call it a successful purchase.

Crank fire is EDIS. Still will require a trigger wheel and a sensor. I thought Ron was doing those, using a Ford system. I know he posted about it a while back because I was thinking about doing it before I decided to go V8 (LSx has crankfire built in).

Thanks for the correction. If that is the case I would get Ron's coil bracket and save for the crank fire ignition.

You need 4 clutches, unless the original two in the diff are broken.

So have you actually fired the damn thing yet?

I ran a 6AL on my L6 for years with triple carbs. Worked great, increased mileage and I felt that it increased power, although I never dynoed the car. A friend of mine ran one on his L4 with Mikunis, and he did back to back dyno pulls with MSD and without and had something like 11 hp gain if I recall, which was a pretty huge increase. You'll read about how failure prone they are. If you're worried about it, just run the module right in the MSD, and if it fails, plug in your original module again. I had a spare pigtail and an E12-80 module in my glovebox just in case, but mine never failed. You mention LS coils. If by that you're referring to Ron Tyler's setup, that is FOR SURE superior to MSD. MSD still relies on the distributor, and the distributor is inherently inaccurate. Ron's setup runs off of a crank sensor which is much better for high rpm accuracy and the dwell time for the coils is MUUUUUUUUCH better on Ron's.

This was itching the back of my brain. Seems to me in front that the outside tire gets leaned over farther making the corner to corner height taller which would load up the outside front and take weight OFF of the inside rear. The inside front stands up straighter and hence lowers, adding weight to the outside rear. So caster in and of itself should make inside tire spin worse. Searched "caster weight transfer diagonal racing" on Google and came up with these: From: http://fsae.com/eve/forums/a/tpc/f/125607348/m/551104293 Seems to prove my point. From: http://racingarticles.com/article_racing-24.html This one doesn't make sense. I had to read it about 4 times and then draw a diagram, but he basically says that the inside front and outside rear both gain weight and the inside rear and outside front lose weight. I think he meant to say "produce a diagonal mechanical weight transfer from the inside rear tyre TO the outside front tyre, to the outside rear tyre and FROM the inside front tyre". This makes more sense to me. I do remember once reading somewhere about a guy who had his car on scales and turned the wheel and documented the weight change, and it wasn't good for the inside rear tire as I recall. Anyway, adding caster was one of the best things I did to get grip out of the front end of my Z, but it isn't going to help that inside tire spin.

Caster jacks the front end up by changing camber. Just sayin...

Gary is the guy to get them from. Phyxius did one run of the clutches and then I think he published the dimensions here. By the time you pay someone to laser cut them, Gary can get it done cheaper and easier. There really isn't much to pulling the spacers out and putting the clutches in. If you can pull the diff out of the car yourself, then you should be able to follow Austin's thread about adding clutches and do it yourself if you have the time. Adding the clutches won't change backlash or any other dimension in the diff, and for the street I'd just put the clutches in and not shim it at all beyond that, so it's pretty easy. Just take it apart, pull the spacers, put the clutches in the stack as show in the thread, and reassemble.

Camber bushings work for toe adjustment in the back and aren't nearly as expensive as control arms.

If you're running an R180, then it is an expensive modification. With an R200, not so much. You can get the OBX diff for ~$400, and a used Nissan LSD for $300 to $500, depending on where you get it used. Depending on your cost for the other parts to actually get it in the car (R200 mustache bar, the diff itself, bushings for mustache bar, etc), it might be significantly cheaper than the R180. If you don't have a lot of parts resources it's going to be expensive. If I had an autox car that was right at the weight minimum and had the money for an R200 swap with LSD but not the R180 LSD, I'd do it despite the weight penalty of probably 50 lbs. The ability to put the power down out of a corner is pretty crucial in autox. Raising the front roll center will increase roll stiffness and that should mean that it's easier to put power down. If it causes too much understeer, dial in more toe out. The primary concern is the bumpsteer though. Bumpsteer is bad, and getting rid of it might make more of a difference in the handling than raising the roll center. If it were a road race car I would say definitely will make more of a difference. Bumpsteer is more important on rough surfaces and at higher speeds, but certainly it is going to change the handling of the car, just as changing the static toe will.

Yes, this is a CLSD. Plenty of pics in the sticky posts.

Don't rely on bumpsteer to keep the front end stable. Fix it (meaning get rid of it). Keeping the tire pointed where the wheel is pointed will do more to make the front end stable than toeing out on bump in my opinion. There are different ways to fix it, I think slotting the front crossmember is pretty easy to do and mine never slipped in the 6 or 7 years that I daily drove it and autoxed and did track days. As for traction, I think the easiest thing to do would be to get a wider tire. 205 is pretty small, especially for an autox Z. If you want small diameter for less rotating mass you might try to grind calipers for clearance and run some 13" rims so that you can find some wider tires. I think tire sizes are very limited for 14's, or were last time I checked. EDIT-- The other obvious solution is a limited slip.

You could also get an early R200 flange from a 280Z. I know the flange is in my diff sticky as part of the list of stuff needed to swap an R200 into an early Z.

I believe the shaft lengths are different. Even if they aren't, the part that plugs into the diff is different. Not worth the hassle to swap the inner CV joints on the shafts just to make the test.

They're different lengths.

You need both axles for an LSD to work. LSD only "limits" the slip. Doesn't lock the wheels together. A locker will work with one axle removed.

I grew up riding my brother's hand me down SuperGoose which was probably about the same vintage as your GT. It was a pretty good bike, I thrashed the hell out of it for YEARS until I finally hit a car (yes, I hit the car) and bent the fork and broke the front axle. Then I went and bought a Robinson that some guy was selling. He had no idea what it was and used it for his paper route. I got it for $150. Raced that a little bit and also had a Mongoose FS-1 but never really warmed up to freestyle, then a Montagna mountain bike for commuting to middle and high school. About 15 years ago a friend of mine built a PK Ripper. I guess he had always had a hard on for one and finally had some money so he built one. Peregrine 48 spoke wheels, really nice cranks, pedals with the gigantic spikes on them, the whole 9 yards. It was pretty badass, but I don't think he rode it more than maybe 10 times if that. I rode it down the street and back and just thought that the geometry was all F'd up, but that's probably because I had been riding mountain bikes for years. Another friend traded some work for a Robinson cruiser with 24" tires about 10 years ago. He and I took that down to the local jumps and quickly figured out that we didn't have the stomach for BMX anymore, although I will say that it was much more comfortable to ride than the PK. We're both pretty good riders on mountain bikes, but that lack of suspension doesn't really work out so well anymore and if you're like us the idea of falling isn't nearly as acceptable as it used to be. I don't know if he still has it, but if he does I'm sure it's hanging from some rafters like your GT.

Check for binding on the end links regardless of the bar you decide on.

By marking where the tire is next to the car I think you're missing a couple things. The hub won't be at the same height with the new wheels, because the tires are taller. When you mount the wheels, the hubs will move up, so the fenders will move up in relation to the top of the tire. Assuming that it was a good way to measure (and it isn't), once you put the wheels and tires on, the suspension still has travel, so you don't know that you'll have clearance for the wheels as the suspension moves. The proper way to do this job is to put the wheel and tire on the car, remove the suspension springs, and compress the suspension to the bump stops, and make sure that you cut enough metal out so that you can get it all the way compressed without the tire hitting the fender. Here is another thread that has pictures of doing it the right way, along with pictures of several people who did this wrong on their car and had to move the flares up. http://forums.hybridz.org/index.php?/topic/47525-how-to-mount-them-there-zg-flares/