JMortensen

I thought John had already ground off the end of the control arm for clearance. Am I mistaken? I'd seriously consider the 280 hubs. They are slightly heavier, but if I'm right and they do have the offset needed, then that would be a preferable solution IMO. I just hesitate when you're talking about removing structure from the control arm. I don't honestly know how extraneous that material is, but it just seems like a bad idea to this non-engineer.

I think that is why Juan says to switch to 280 hubs. More offset. Jon

Can't wait to bolt them up and try not to flat spot my tires!!!

So what's the plan Amir? You gonna take up John's spot in the OTC? Looks like a screamer...

I bought a set of Matco taps and dies. Then I went to my machinist to do my last rebuild, and he said they were crap. Then again, he pays about $40 per tap. I paid $110 for the whole set on sale, and I'm not a machinist... Jon

Lemme just say what I've been able to glean so far, and say that I have no firsthand experience, because I've always dealt with the 240 suspension. The 280 sat higher than the 240 stock, but I couldn't say how much. The 240 rear struts that you get from Tokico are the same as the 240 front struts with a 2" spacer on them. So if Juan had the rears with a 3" spacer, then the difference in the tube is 1". If you take a regular 240 and drop it more than 2" then common practice is to section the strut tube. Likewise if you were to put that same tube in a 240 with a 240 hat (also shorter) then you'd be equally well off sectioning the strut if you went lower than 1" below stock 240 height. So IF the 240 hat is an inch shorter, and the tube is an inch shorter, you could drop the rear 2" by swapping in 240 stuff. But then you'd lose your stronger stub axles, and if you're going to section them, the process is the same so you'd be better off sectioning the 280 stuff and not having to swap stubs. Take that FWIW, Jon

Agreed. I have no doubt that my Z with triples is faster in the 1/4 than my old SU's were. And I'm sure that you are correct that you could choke off the trips to perform better than the SU's at low rpms. That's just not what they're good for. They're good for screaming at high rpms and scaring children with the giant sucking sound, I think you'd agree. I'd still love to see what Norm's car would do with properly set up triples. I bet he'd be a convert too. The real decision maker is racing or street driving IMO. EDIT--Norm, I'm not a 1/4 mile guy, but I did a Gtech test once with a badly slipping clutch and it said 108 trap speed with my buddy in the car (still not sure I believe that thing, that seems pretty high, but that's what it said). Did I mention I get 20 mpg on the highway...

The 280 tubes are longer.

If you're talking about slow corners where you come out of the corner at 2000 rpm, you would be the FIRST person who I've ever heard talk about getting a triple carb to do that better than an SU. This would include Rebello, Malvern Racing, Nissan Comp, and others I've talked to about making that situation better. ALL of them said that is the give and take with triples. You pay on the low end to get the top end. Maybe you're just that good, or maybe you haven't driven a Z with a properly setup set of SU's. Not sure. If you can tune them to be stronger there, that should be your business. SU's have an infinite number of jettings if you make your own needles and nozzles (every slightest bit of the taper change is a "jetting change" on an SU. Even the factory ones have 8 or more stages on the needles IIRC, so they still have more variation than the trips. WOT is WOT. Both the Mikunis and the SU's have a setting for it, and I don't think ANYONE would doubt that triples are going to kill SU's at WOT. Jon

Here's another potentially controversial statement about why SU's make better low end power. The oil dampened action of the pistons means that the holes that then engine sucks air through get larger slower. On triples, you've got 6 of the equivalent size holes to the SU's instead of 2, and when you slap the hammer down, all 6 butterflies open almost instantly. Intake velocity goes to 0 (or close) until the rpms come up enough to suck enough air for them to start working again. So at low end port velocity is bad and fuel atomization is bad, even if you have relatively small chokes in them. On the high end, no problems. This is why the SU's work better on the low end IMO. On the SU's the velocity is much higher at any engine speed but especially at low rpms, so the atomization of the fuel is much better at low rpms. The triples are more adjustable unless you grind needles and nozzles for your SU's, and IME once you get them set up they don't need a lot of tuning once they are on and set correctly unless you change altitude drastically or move from Florida to Wisonsin or something like that. I've heard differently about Webers, but this is in reference to Mikunis. Ed says that most people don't know how to tune their triples. This is exactly correct. That's why I said previously that if you know how to tune them great, but if not, then you'll either have to learn or pay someone who tells you that they know big bucks to do it, then hope that they have as much expertise as they said they did. I LOVE my triples, and I'd can't forsee any change in the SU's that would make me want to go back. It was a HUGE top end power increase on my car. But the SU's would be a better street carb IMO. Jon

So what's the solution? Getting ready to stitch weld the rear subframe and living in Seattle makes me interested... Jon

Gotta love silver

John, do you think the Blacks are too aggresive for autox? I'm looking for a pad that I can use for both. I know the Blacks need to heat up a little, but according to Hawk they only require 100* to start working. Sorry for the thread jack...

He's got net toe in on the back. So the car would crab very very slightly, and he won't get wear on the left rear from the toe IME. The rears are going to want to drive to the left, and the fronts are going to want to drive straight. I think he's got the tire wear problem down correctly. When he punches the gas, the rear squats and he's got more neg camber, then he's trying to put down 300+ hp to the inside edge of the tire.

Well you could use camber bushings to get more positive camber, but that's gonna suck around turns. How about leaving the camber alone and taking corners harder...

If you don't want to mess with the strut tops, then Tim is right. Camber bushings would be the cheapest way to do it. Adjustable control arms would also work, but I get a little nervous adjusting a lot of negative camber in with a threaded rod bearing the load. You probably wouldn't have to worry too much since you'd only adjust .3 degrees. You're actually within spec on the rear toe (total), but it is pointed off to the left a little. You can move it back to the center by slotting the holes in the uprights and sliding the transverse link to the left like Rick Johnson did, but that won't fix your camber. Camber is pretty damn close, I don't know that I would worry about it if this is a street car. .3* is not really very far off. HTH Jon

Man I HATE those adjustable bushings, in fact I'm going to great lengths to get rid of them. Have you considered trying to loosen the front and rear crossmembers in the back and retighten? I know John Coffey has also talked about putting shims in the bushing cups to move toe. The camber would be easily adjustable by slotting the holes in the strut towers. Just another option.

Poor man's camber plate (slot the holes). Jon

This I'm sure is the correct answer! So the spacers are there to PREVENT preload, and I'm sure the drag test is a measure of how much preload is present and if it is low enough to be within acceptable limits. This is also evident in John's FSM excerpt: 3.9 in lbs preload is basically like taking your pinky and pushing on the inner race on both sides. It's just enough to take out the slop in the ball bearing, but not enough to make the ball bearings wear too quickly. Jon

WELL I DO NOW!!! Yeah the piston basically worked like a big hole puncher. I never did get the center of the pad out of the piston. R4's worked ok at the big track for me, but I still had problems boiling the fluid every time. But at least the pad didn't evaporate!

New development. I just pulled the stubs out of my '71 spare struts tonight. I had a copper washer on the left side with a B spacer. On the right B spacer with no copper washer. So I guess the question is do I procure a washer, or do I use what comes out of the 280 struts, or do I leave it alone and reassemble. Any ideas? Jon

Just wanted to let everyone know I think I came up with a very good solution to this one tonight. I used a dremel with a cutoff wheel and cut at a 45* angle to the flat of the stub shaft BEHIND the peened area on the nut. I was able to cut a groove all the way across the flat on the nut without cutting the axle. Then I pulled the dremel over the area that was left back and forth until it was almost gone. I also ground over the corner a little to make sure that I had gotten everything that would affect the threads. Zipped the nut off with the impact. Worked really well. Much better than my previous method. I don't know why the old system wasn't working for me today, but I'll use the new method if I have to do this again anytime soon. Jon

So how did this all work out John? Just curious to see how good those pads are...

One last comment Juan, because it sounds like you're getting fed up with too much advice. If you are going to take the car down 3.6" by moving the spring perches, you are going to lose 3.6" of available travel. I think that equates to about 2.5" of actual strut travel. IIRC the Z has 7 inches of travel at the wheel, and figure about 5 or 5.5" at the strut with a bumpstop in place. That means that IF you have 4 inches of travel available at the strut right now with the weight of the vehicle on the suspension, that you would be left with only 1.5" at the strut or 2" at the wheel after moving the perch down. This is all THEORETICAL, but maybe it will help to explain why Ross was trying to pin down where the strut is in its travel at rest. I'd love to help you more but it sounds like you've had enough... Jon

I have what is probably a very stupid question. I know about pinning or dzus fastening the hatch, but how do you seal it so that you aren't high from carbon monoxide poisoning while you are trying to hit that next apex? If you don't use the inner part bonded to the outer, there would not be a place for the stock weatherstripping to seal to... Jon