JMortensen

I bought some MM stub axles and they have a nice anodizing on most of the surfaces, but the hub face is just exposed steel. I'm wondering what I could do to protect it a little bit. I haven't been able to come up with anything except rifle bluing. I have some cold bluing that I could use on it. I guess I'm just wanting to prevent the brake hat from corroding itself to the axle face, like the drum brakes so commonly do. Anyone have a suggestion or a recommendation for or against the bluing. I know bluing won't eliminate rust or corrosion, but I think it would slow it down a bit.

I just became aware of caster's affect on bumpsteer, sounds like Richard already had a handle on this issue. As the caster increases the angle of the bottom of the strut and also the steer knuckle increases. This means that as the caster changes the outer tie rod moves up or down in relation to the ball joint, changing bumpsteer. I know I've related my bumpsteer adjusting experience here quite a few times, where I moved the LCA pivot up while measuring with dial indicators on the front and back of the rotor and jacked the car up and down 3 or 4 inches and had no measurable bumpsteer. I realize now that's basically impossible. I guess I did my testing wrong, could have been that the jack was putting weird loads on the chassis which was messing things up, I can't really say. I was able to minimize the bumpsteer and got it to the point where I couldn't feel it at all and was doing a lot less sawing on the wheel on bumpy sweepers, but a more accurate gauge or better tester I think would have shown that I didn't eliminate it completely because that isn't possible. Johnc has also noted on previous occasions that shorter, adjustable aftermarket TC rods like AZC or TTT or Mike Kelly's old units mess with the caster curve. That's true, and that also messes with the bumpsteer, potentially making it a lot worse at the extreme ends of the travel (I can only imagine how bad this might be on some of these stupid low Zs). I think it is likely that my short TC rods were exacerbating the bumpsteer issue that I was having where my car was doing an emergency lane change maneuver without any input on the steering wheel on one particular bump at the track. So for minimal bumpsteer you want the angle of the TC rod level or slightly down at rest, and preferably on a race car you want to go with the old "make the suspension work by not letting it move" thing. Richard, first thing that jumps out about the camber adjusting bolts is that you could use that to affect scrub radius.

Be aware that some of the cheapo spacers don't quite fit (Mr. Gasket for one). It's SO CLOSE that you might think that they fit like I did and chase a "tire balance problem" for a couple years until one of the spacers starts to crack. FWIW, I like lugcentric spacers for Z cars, these are hubcentric, but if they fit the hub correctly maybe it's a moot point.

Just keep adding friction modifier until the noise goes away. You can do figure 8's too to get the FM distributed throughout the diff.

He used to be a member here but couldn't control himself and was banned. You might find some old posts if you search, or try zcar.com, I think he was over there for a while might still be. I know he did things like resurfacing his rocker arms by hand and ran 2 headgaskets. Some people don't like that, but it's tough to argue with his results.

The TC rod prevents the control arm from moving backwards and forwards. It locates the lower control arm. Making them shorter in a 280ZX also increases caster, making it longer decreases caster.

Seen it before, think I actually posted it here, but it still sucked me in and I had to watch it again.

There is another "What's up with Modern Motorsports" thread, you should have just added to that one. FWIW I just got a set of axles from Ross about a month ago.

The speed of the engine after the shift is determined by the road speed, not the engine speed. The aluminum or light flywheel allows for a faster shift due to the speed of the input shaft of the transmission slowing more quickly and the synchro having to brake the mainshaft gears less, so given the faster shift the road speed should be higher after, and hence you'll be at a HIGHER rpm after the shift with a lighter flywheel than you will with a heavy one. These all sound like poor machining issues or people overtightening bolts. I remember the spec on the pressure plate bolts on an older 911, because I was pretty shocked when I looked it up the first time. 13 ft/lbs. People tend to want to crank these things down, and I think that is the source of the problems. Poor machining of a part doesn't mean the idea behind the part is bad. I've got friends who have used the same Tilton aluminum flywheel on L series engines for 15 years. The fact that you saw one that wasn't machined well doesn't prove that they don't work. I can see where launching a turbo car with a lot of lag would be easier with a heavy flywheel, or maybe similarly a very heavy car with an underpowered engine. Barring the "not enough power to get off the line" scenario, I can't see the heavy flywheel being a benefit to overall speed. I'd have to guess that they wouldn't have a spring resting directly on the aluminum. I would hope that is the case anyway. I was more concerned with the flex in the pp as the spring is compressed and whether that slight amount of "oil canning" would eventually lead to a brittle area in the pp.

Way too small for 300 hp. I had trouble putting down the power at autox with 205/55/14's when I was making probably 170whp.

Dave have you driven a Z with an aluminum or otherwise lightweight flywheel? They're pretty easy to drive and get off the line. I had a bunch of people tell me "Don't go that big with the cam, you won't be able to drive it on the street" and "Don't go with a light flywheel, you won't be able to drive it on the street" and "Don't get triples, you won't be able to drive it on the street" and "Don't get a stronger pressure plate, you won't be able to drive it on the street" etc. I ignored them all and drove my Z daily for years in stop and go traffic, never had a problem. I think I had the idle set at 900. I probably stalled it once a year when I completely brain farted or my foot slipped off the clutch pedal. I will say that on a small 4 cylinder or an engine with no torque like a Rotary it can be hard(er) to drive around town with an aluminum flywheel, but when you get into L6's they already have a pretty good amount of rotating mass with that long crankshaft and a lot of low end torque, so I think it's a non-issue. As to the OP's aluminum pressure plate, I think my main concern would be how the aluminum deals with the stress from the springs over years of use. I'm not a metallurgist or anything, but that could be a long term concern as I think aluminum work hardens easier than steel.

I saw that too. I thought it was just stickers that he put on the wheel to locate center and where his thumbs should be or something. EDIT- looks like they do go all the way around, so I'm guessing Paul is right.

Yep. Looks like a Mustang with springs and shocks should be a giant killer.

I had a friend who successfully twisted a shaft that was bent like yours. It's been years, and his were Mikunis, but I want to say that there is a flat spot on both sides of the shaft and he put wrenches on both sides and torqued it back.

Flat tops and N42 is pushing it. Really pushing it. IMO, I'd try for 9.5:1 or less, and I wouldn't get it by putting a 2mm headgasket on. I'd go with a different head, preferably one with better quench. I like the P90 head but it gives about 8.3:1 if I recall. Shave it a bit if you feel the point in compression is worth it, or run it at the lower compression with 87 octane if you don't. Like I said though, this has all been gone over even very recently, so a bit of searching will prevent having the same ol argument again and again.

I wouldn't use allthread. First off it's usually not the hardest grade of thread, and I think it's safe to say that the spindle pin is under a good deal of stress, not to mention you'd have the threads in bending. I think the thing to do is use a long 5/8" grade 8 bolt that has the shank engaged on the rod ends or bushings so that you don't have threads in bending. That said, the spindle pins are well suited to the task they were designed for, really no reason not to use regular spindle pins, especially if you're going to continue using bushings.

Consider the effect of the compression on total hp and the cost to a 17 year old to bump it up by changing heads, not to mention the cost of 91 octane (or mixing with race gas if you go too high and find that it won't run on 91). This topic has been discussed quite a bit, even just a few weeks ago. I think it's a bit foolish to try and get that last hp with compression when you can get so much more via headwork and cam and not have to worry about being on the ragged edge all the time, wondering if you're going to put a hole in a piston via detonation. I warn you of this as a guy who put an E31 on an L28 flat top block, did a few mods like changing valves and going with valves that didn't have a dish in the face, and then found out that I needed 95 octane to keep it from pinging.

202, 195. My guess is 10% more power, estimated based on the 10% increase in displacement.

If I were to venture a guess, I'd say cam or cam timing is the most likely culprit. Also remember that you shouldn't compare numbers with another dyno, they're all different and as Drax has pointed out you can get a dyno to read vastly different numbers with a little tweaking. You could do a 1/4 mile test and check your trap speed to get hp that way, it's at least independent of the dynamometer's inherent inaccuracy.

Cary has been saying that for years. That was one of the original arguments that made me want stiffer springs; I could never get enough heat in my tires, even on track days in 100+ heat with 30 minute sessions I never saw tire temps over 200 degrees. If it is shimmed tight or if you enter the corner on the throttle, then yes. If not, then no.

Is the motor you're planning to use underpowered for what you want to do? If so, is running long tube headers the best way to get more power from the motor? Seems to me that there are many ways to get more power out of the engine, and I'd rather have the handling benefits that come with moving the engine back, but my priorities might well be different than yours.

If I ever own a convertible, it will have a roll bar.

I ran mine with an early set of SU needles for a 70 (not as rich as SM needles, but I think they were supposed to be richer than the 72 needles) at sea level and never had a problem. You should have less trouble at altitude, as you don't need as much fuel with your thinner air. Carbs deliver fuel based on the amount of air going through them, so you'll get more fuel out of them with a 2.8. I think the problem with SU's on an L28 is that they don't allow enough air through. When I switched to Mikunis I gained a LOT of top end power. Mikunis will work a lot better with a later 5 speed and 3.90 or 4.11 rear end, so if you can't do all of it you're probably better off with the SU's and better part throttle response IMO. Only use the race gas if you need it. You'll make more power without it if you can run without it. Dan Baldwin did back to back dyno runs with regular gas and with race gas and lost power with the race gas.

If you're going to do vintage racing you'll need to conform to the rules, which probably means Toyota vented setup and 79-81 280ZX rear disc in back. If you're not racing, do whatever you want. Try searching for options. The subject has been beat to death.