pparaska

I don't think Jason will mind me telling, but months ago we emailed on the subject of springs. He found that stiffer springs in the rear caused horrible wheel spin, and he ended up with 175 lb/in to be able to hook up. Incredible - 109mph in the 1/8th! With a stockish suspension no less!

Michael, was your Richmond new when you got it? I was just wondering if someone had worn out the synchros before you got it. Also, did your mechanic check for input shaft alignment (offset and angle) into the pilot bushing? I can't remember if you have an aftermarket bellhousing, but this can be a problem with the aftermarket bellhousings. The tolerances on offset of the register hole for the bearing retainer in the bellhousing is like 0.005" and there is a parallelism and flatness tolerance as well. These measurements being out can cause big problems with shift quality, since the input shaft will be side loaded on the pilot bushing and it will tend to keep it turning even with the clutch depressed.

My first engine rebuild, when I was 17, was a Chevy 327. I put a Holley chrome mechanical fuel pump on it. Shortly after driving it the first several hundred miles, it started to knock. I was young so I thought it was a lifter. I pulled the valve covers and started it to try to determine which lifter. It was hard to pin down, but I pulled the intake and put new lifters in a few suspect positions. No difference. I took it to a local machine/hot rod shop, and they thought it was a lifter or rocker arm, but said it did sound like it was a deeper noise than these make. I just kept driving it since most people that listened to it thought it wasn't loud enough to be a rod bearing. Plus I didn't have the money to pull it apart just to look. Years later, the Holley pump failed. I put on a Carter mechanical unit (much nicer piece) and the sound STOPPED! Just a thought, but the fact that it's oil pressure dependent on your motor makes it sound unfortunately like a rod bearing or piston pin. Hard to tell over the Internet . Time for a 502/502 crate motor maybe?

bubafett, Thanks for posting that. We now have some good info on what the motorsport kit does for engine placement (sounds very similar to the JTR. How far is your HEI cap from the firewall? I think it's pretty exciting that the motorsport headers are full length and 1-3/4". I guess I'm now wondering if they are equal length tubes, and how thick the head flange is.

Scottie, I hope my post didn't come across as a criticism, it wasn't. But the driveline u-joint angle issue is overlooked and missunderstood by the beginning swapper many times, unless they are aware of the problem from a book on the subject (JTR covered it a bit in the later revisions, the first one didn't cover it) or some other source like this site. Since I know it's a particular issue with what seems like a good engine/trans placement/attitude in the Z, I never let a swap thread go by here if it isn't mentioned. I'd hate to see someone make custom engine and trans mounts up for some kind of undocumented swap and then have to do them over once they found out that it gave them driveline vibration. Driveline vibration can cause people to start looking at other things ("bad" u-joints, bent driveshafts, "bad" differentials, "bad" halfshafts, etc.) before they come to the driveshaft u-joint angles. Cheers, ------------------ Pete Paraska - 73 540Z - Marathon Z Project - pparaska@home.com">pparaska@home.com -

Scottie, that's the first time I've heard anyone give details on how to do an undocumented swap. Thanks, I'm in the V8Z crowd, but love seeing all kinds of swaps. One thing that you probably do but didn't list is to make sure the driveshaft u-joint angles are proper (less than ~3 degrees each, and equal). The exact placement of the engine and trans has a large effect on this. When I was doing the JTR swap, I was amazed at what a small movement of the trans rear or engine mounts would do to those angles. It's very important to get them equal and small, for if you don't you'll have from just mild to horrendous vibration issues under load. And most people are doing these swaps to put lots of power to the wheels, so this is very important. There's info on how I handled this part of the swap on my site under "Driveline Modifications", along with a link to a driveline shops very good web page on this topic. HTH somebody, ------------------ Pete Paraska - 73 540Z - Marathon Z Project - pparaska@home.com">pparaska@home.com -

Wow, that's the most variety I've ever seen for the Z. Thanks for letting us know! It ought to be on our links page.

Scottie, time is really precious, so I'll decline on making one. It should be made with the car available anyway, as it's a tight fit. I was underneath the car probably two dozen times as I made it up. But with a template of mine it should be easy to fit to any Z. The layout of the trans, etc. is critical for getting it right. I'd suggest making the loop part first and measuring for the mountinf arms after that. I can scan in a dimensioned template and put it on my web site. I'll post to this forum when it's up.

Clint78z wrote: quote Actually, cutting noise has two approaches, absorbing the sound once it's in the air (the foam, or other acoustic absorbing materials or techniques - including active anti-noise) and controling the "source" (the sheet metal in this case). Mass loading (weighting the panel to lower the resonant frequency) or damping (not wetting ) the the vibration of the panel through energy absorption. There are two ways to do the vibration damping, passive (coatings) and active (drive the panel with an actuator to cancel the vibration). Tar, bedliner, non-foil covered Dynamat, etc. are passive coatings that have some energy absorption (as well as mass loading) due to the hysteretic properties of the material - called viscoelasticity. These are called free layer damping materials, since they have no "constraining layer" on the top of them. They absorb the vibration energy as well as mass load the panel to lower it's resonance frequency. So if you still hit the resonance frequency with the noise, the vibration is still cut down by the damping properties. Mass loading alone (inefficent damping material like tar) doesn't have that benefit. The foil covered Dynamat is called a constrained layer damping material. It does a better job of damping (higher damping coefficient) for the same thickness of viscoelatic material. The foil cover acts to amplify the strain in the viscoelastic material (the gooey stuff) and get more damping out of it. Both the free layer (e.g., bedliner) and constrained layer (foiled Dynamat) have frequency dependent damping properties - they act in a range of frequencies dependent on the viscoelastic properties of the gooey stuff, the thickness of the goo, and the thickness and material type of the "foil". More than you wanted to know, but the upshot is mass loading works, but if you use a lighter foiled dynamat, it can be more effective and lighter. Also, adding it to just where the panels vibrate is weight efficient as well. (I used to work in the field of submarine quieting Believe me they want those things quiet!)

I have pics of my driveshaft loop, out of the car at: http://members.home.net/pparaska/drivelinemods.htm Simple to make and install. I have it about 4 inches from the U-joint in front. One for the rear would be similar and a good idea!

Pics - you have to have them on a web site to be able to reference them. Then, when putting your post together, click on the "*UBB Code is ON" link next to the Reply box to see how to put in links to pics (also urls, email, etc.)

BLKMGK, the tap test is cute, and effective . All of these liners and sprays add some weight if applied liberally, and may trap water, as you pointed out. Not all the surfaces in the car are going to vibrate. But finding the vibration anti-nodes (that parts tha really move around and make noise) is tough, as your tap test may miss a resonance with teh exhaust - but it's a tried and true method of vibration damping /noise control. Where is that accelerometer instrumented hammer anyway . The point is if you just treat the areas that really vibrate, it's alot less coverage than doing the entire car. Dynamat ain't cheap!

My machinist buddy at work was showing me that site the other day. Hmm. almost $10K US for a 1/4 scale Viper V10. Dontcha wish you were absolutely filthy rich and could buy these babies!

Darius, Thanks for the info on the R230 install. It sounds like you have Z32 CV joints at the diff and Ujoints at the stub axle? Any chance Cahant and you can get that puppy on a lift and take some pics of the details of the diff install and halfshafts? Thanks, ------------------ Pete Paraska - 73 540Z - Marathon Z Project - pparaska@home.com">pparaska@home.com -

Mike, I agree. I went with the Hybrid late/early 280ZX setup that's documented on this site initially mostly for looks and easier maintenance. The used AZ Z car stuff became available for half price (in great condition), so I went for it. Big calipers look good. The AL Wilwood pieces are very light as well as large.

Yeah, I think the POR-15 is not UV resistant. The stuff that Hirsch Automotive has is also the same kind of paint (they call it Miracle Paint), that is a moisture cured urethane. All but the clear that they have is not rated for UV. The black is ok. with UV (they say) and the Silver very good.

No, it doesn't cut down the steady state pressure. Their theory is that rear wheel lockup is due to the sharp spike in braking on rear tires that have just been unloaded do to weight transfer. I wonder if there is any info from the stock car set (that isn't classified) on this topic.

Yes, please tell us how you swapped the R230 into the Z. That'd be a good topic to put in the Driveline Forum. Sweet RIDE!

Now, 1/8" steel is not thick, but there is a TON of metal in that design that doesn't need to be there. Specifically, all that metal around the bolts that hold it to the strut. Alot of that sees absolutely no stress. Plus a few big lightening holes toward the caliper side make a difference in weight, and not stiffness or strength. BTW, emergency brakes have saved me from wrecking when I had a hydraulic failure.

Yeah, the NASCAR guys use that setup. I agree it would be overkill unless you do 10/10 driving on a road course. Another product they had is the LBS - Lock resistant brake system. It's a dampener you put in line to the rear brakes. What it does is delay the full brake hydraulic pressure to the rear brakes to get away from shocking the rear tires into a slide when you stand on them. Their theory is that you don't need a brake proportioning valve, just an LBS (I think the LC/SB has this function as well). I put one on, after I had already put a proportioning valve in line (on the tunnel, underneath the driver's knee). Like everything else, I'll have to wait to test it out. ------------------ Pete Paraska - 73 540Z - Marathon Z Project - pparaska@home.com">pparaska@home.com -

The 280Z stub axles are larger in the splined area. This area is one of the weak areas of the stub axle. The other area that breaks is the friction weld of the wheel mounting flange to the axle. Since the shaft is larger in the splined area, note that the companion flange for the 280Z must be used with the 280Z stub axles as well. The short tubes that hold the torque strap needed to be turned around on my 240 to shift the strap back (?) so the bolts would clear the torque strap. I added a polyurethane bumper to it (it has a stud on the back). The strap and bumper no push the diff down enough to compress the mount about 1/4". ------------------ Pete Paraska - 73 540Z - Marathon Z Project - pparaska@home.com">pparaska@home.com -

I have no drag experience, but I got to the track no and then. That looks like an incredible launch!

I'm going to foam brush POR-15 on mine. POR-15 levels out very well. It sounds like spraying it was no fun!

Go and read "Seperating Rear Lower control Arms and stub axle" in this forum at: http:// http://24.4.88.29/ubb/Forum6/HTML/000163.html[/url] I posted a response to this there. I know, it's no fun pulling that pin! ------------------ Pete Paraska - 73 540Z - Marathon Z Project - pparaska@home.com">pparaska@home.com -

Ross, that's O.K., I enjoy the ribbing . I went with a Group 26 regular battery. It's pretty small, not very heavy, and cheap. $40 US. If it isn't enough, I'll probably upgrade to an Optima. Those things are bucks though. Battery technology is changing rapidly, and I've heard that in a few years, they will have much high power/weight ratio, so I'm kind of biding my time. I have the sealed Summit box that BLKMGK has, and the battery has little vent tubes on the covers that I ran tygon tubing from, to a T, and then to a fitting I put into the boxes vent fitting. So no gases will exist even in the box. I ran the vent from the box to the right rear inner fender. The box is very close to the center (left to right) of the car. Hey, I'm like 220 lbs, so I needed some ballast on that side of the car. Hmm. I might need to put a few more batteries in!