pparaska

Owen, I am currently psyching out the entire wiring harnesses and circuits of my 73Z. Man, it is weird. This is how the 73 circuit is. The other 240z's are probably similar: +B on Alternator to AMP meter AMP Meter to Headlight on/off switch Headlight on/off switch to 2 headlight fuses Each headlight fuse to each headlight common High and Low beam terminal of each light to Hi/Lo switch (they become connected in parallel in the harness out by the lights) The "arm" of the Hi/Lo Switch is connected to Ground. If neither of the headlights and the park lights don't work, try shorting across the head light switch (the large Red to the White with red stripe for the headlights, the other two wires for the park lights.) Let me know if you need more detail on IDing the connectors, or whatever. Pete

5 inch tip! Owen, you sick puppy! You sure you don't have an exhaust leak into the car?

I'm in total agreement with JTR on the bumpsteer spacers. I've written numerous emails to the IZCC list about this over the past ten years. I've studied the causes and design practices for eliminating bumpsteer in several books to research the topic. I've lower my 240Z with Motorsports Springs back in my L6 days and the bumpsteer was bad. I tried the bumpsteer spacers, but it didn't help much. Here's the long and short of it: The Z has a bumpsteer problem from the factory. The rack is too high in the car relative to the inner control arm (CA) pickup points. Or looking at it the other way, the CA pickup points are too low. To have no bumpsteer, the line connecting the center of rotation of the ball joint and CA pickup point must be parallel to the line connecting the center of rotation of the inner and outer tie rod ends. The lines must also have the same length. The problem with the Z (240-280) is that it the lines are not parallel. To fix the problem, you need to do one of the following: 1) Raise the inner CA pickup point (3/4-7/8") 2) Lower the steering rack (3/4-7/8") 3) Raise the outer tierod end (3/4-7/8") 4) Lower the ball joint (3/4-7/8") The "bumpsteer spacers" lower BOTH the outer tie rod end AND the ball joint, so they do nothing to fix the non-parallelism of the two "imaginary" lines discussed above. What the "bumpsteer spacers" do on a lowered car is relocate the CA and tierod to near stock angles to the ground, restoring the static position of the suspension on the stock bumpsteer curve. This is a good thing, but you still have a bunch of bumpsteer, since the curve has not been changed for the better (made straight, or in other words, gotten rid of the suspension movement dependency on the toe.) To fix the bumpsteer, you have to straighten out that curve, by doing just one of the above 4 choices. The easy fix is the one JTR recommends - raising the CA pickup point 3/4-7/8". They say 7/8" totally eliminates the bumpsteer (making the curve of toe change versus suspension compression/extension be zero throughout). They say to raise it only 3/4" to leave a slight bit of bumpsteer to compensate for camber thrust. They also recommend moving the CA pickup point out by 1/4" to gain negative camber. Another fix is to bore out the steering knuckle and put a bolt and spherical rod end on instead of the outer tie rod end. ------------------ Pete Paraska - 73 540Z - Marathon Z Project - pparaska@tidalwave.net">pparaska@tidalwave.net -

Man, that is one lazy cam at low rpm (L79 327-350 cam) I had one in a 10:1 327 that was in my 70.5 Camaro when I was in high school (20 years ago, kids and it felt like a 6 cylinder until about 3000 rpm, then it came on like gang busters. Even ate up a GT500 Shelby Mustang to about 90 with that car (3.08 open rear, stock Turbo 400 and converter). This car was not optimized for the cam though. It needed a stall converter and some higher numerical gears. I don't think that cam is a good choice for a 9:1 motor. It has a bunch of overlap. Low BMEP and all that. Cams are cheap though, so you could change it out for less than $100 with lifters. That engine sounds like a good candidate for the iron or aluminum (64cc) Vortec heads. You could raise the compression and get some good flow and torque out of it with those. Regards, Pete

I got an already-notch 280Z front diff crossmember from somebody and added a piece (about 180 degree section) of schedule 40 3.5" black pipe and reinforced the cutout. It was available for $25 from someone who was going to do a V8Z but quit. So I went for it. It allowed the exhuast to be tucked very tight into the car. you can see pics of the crossmember and exhaust on my site (see my .sig below, got to the Exhaust page.). It seems that all this trouble was not needed, but I like the way it is all tucked up. The exhaust is above the subframe connectors over the entire length of the system. When I get the car on a lift I will take pictures of the exhaust installed. ------------------ Pete Paraska - 73 540Z - Marathon Z Project - pparaska@tidalwave.net">pparaska@tidalwave.net -

Mike kZ, I'm refering to the liquid you put in after you insert the strut cartridge. It's there to transfer the heat from the insert (which can be considerable if really going at it on a road course) to the strut housing. If you leave that void empty, you ar relying on convection in the air gap to transfer the heat, which isn't very efficient and is to slow/low. Seems most people put oil in the void which can be insulating depending on the oil or use antifreeze. I think anti-freeze is a good option. Comments? I'd like to here what others use in the space between the strut insert and the strut tube.

SpencZ, Not sure about what availability is for good HP struts for the VW Golf, but that's a good place to start. I'm running Golf KYBs up front and 240Z front inserts in the rear until I blow them out. Don't know what I'll run after that. Maybe some Carerras. Some of the race shock places like Carerra have different length bodies available to do this. As far as sectioning, I'd do the front and rear the same amount. I took out 1.5" since it's a street car. One of the more knowledgeable L6 guys (he's a road racer) is Wayne Burstein. He advised me to use a big pipe cutter to cut the tubes. Worked great. I just rented one and did it. Ground the chamfer on the pieces, laid them in a piece of angle steel to align them and used a 110V MIG to weld it back together. Worked great. But be sure you make the weld air tight, since it needs to hold cooling liquid around the insert. I had one small leak I had to repair after I had the parts powder coated. ------------------ Pete Paraska - 73 540Z - Marathon Z Project - pparaska@tidalwave.net">pparaska@tidalwave.net -

I agree on the coilover if staying stock. That way you can have your cake (many spring lengths and stiffnesses available, as well as progressive rates) and eat it (relatively easy corner weight and ride height adjustment) too. One thing I would add is that if lowering the car more than say and inch, it's a good idea to section the strut tubes by 1.5" to 2.5" inches and use shorter strut cartridges. This way, when you lower the car by a like amount, you retain the jounce travel in the suspension and the car doesn't beat you up as bad as when you just put shorter springs on. I've done the MSA lowering springs only, with the strut spacers (ill-named as bumpsteer spacers) with Bilsteins and then KYBs and the ride was very rough, since it would bottom out alot. I've yet to run the shortened strut tube/coilover setup yet, but a few knowledgeable roadracers talked me into it based on their experience doing it both ways. I'm looking for comments on these ideas. Thanks, Pete ------------------ Pete Paraska - 73 540Z - Marathon Z Project - pparaska@tidalwave.net">pparaska@tidalwave.net -

Lee, glad to hear the vibration wasn't that bad and the driveshaft was out of balance. Hopefully, that will fix it. I've never talked to Mike Knell about it, but I wonder if he took the u-joint angles into account when he designed the engine and transmission mounts. I have the 1st edition of the JTR manual and there is no mention of any problems of fixes or the angle issue at all. The 7th edition shows the fix that Mikelly describes. The mount dimensions are the same. What I'm getting at is that I wonder if he considered u-joint angles when he designed the mounts for the engine and trans. I have the feeling he may not have, because some people have noted the u-joint angularity problem and the fix when using the JTR mount method. I've witnessed it in two cars myself that were done with the JTR and others here (Mikelly, maybe others?) have noted they had to do the mustache bar bushing fix to get rid of the vibration. I realize that the Tremec 5spd mount pad and rubber mount I'm using is at a different height below the output shaft centerline that the standard GM trans pad and mount height, so my case of having to add 5/8" to the JTR mount height doesn't fit the usual case. Has anyone measured their u-joint angles before and after doing anything like removing those mustache bar bushings? I got real anal about this on my car because I was using a different trans than the the mount was designed for and I really didn't want the vibration that I had witnessed in other cars. Sorry if I came across as preachy, but one of the things that makes the V8Z conversion not feel "right" or "factory smooth" is the driveline vibration. Other than cooling and non-optimal engine placement (Scarab) I feel this is one area we should pay alot of attention too. Maybe a link to my page on driveline mods or just the section of u-joint angles ought to be in the Tech info page? Maybe I'm getting too rabid about this, I don't know. Anyway, Lee, I hope I didn't offend you or anyone else. Best Regards, Pete ------------------ Pete Paraska - 73 540Z - Marathon Z Project - pparaska@tidalwave.net">pparaska@tidalwave.net -

I had my car on a rotisserie once the subframe connectors were in and considered torsional testing it, but just didn't for some reason I can't remember. I think I was in a hurry to get it to the paint shop. Yeah, I'd love to know whatthe effects of the subframe connectors are. Great point. ------------------ Pete Paraska - 73 540Z - Marathon Z Project - pparaska@tidalwave.net">pparaska@tidalwave.net -

The floor pan and tunnel are one piece side to side, there is no seam. Cut where there is no rust and it would be easiest to fab/weld to. As far as adding more to the structure of the subframe connectors, I built beefy "tabs" off of the inboard side of the connectors that are used for attaching the JTR type crossmember. The bolts (4 each side) that go through the 1/4" thick tabs and the 3/8" crossmember ar 7/16" UNF with unthreaded grip that extend through both pieces for good shear transfer with a tight slip fit. This is a very solid connection and should aid in tieing the connectors together. Here's a pic: Cheers, Pete ------------------ Pete Paraska - 73 540Z - Marathon Z Project - pparaska@tidalwave.net">pparaska@tidalwave.net -

Hi guys, Owen. I'm catching up on being away for a while. Owen asked why I made my own. Well the material was easy to get (a friend works at the door warehouse) and cost nothing. You could do the same thing I did (put in subframe connectors) and use the aftermarket replacement floors after hacking out a slot down the length of them and have better looking results. I had to go borrow a metal brake to put in a few bends. Cheers, ------------------ Pete Paraska - 73 540Z - Marathon Z Project - pparaska@tidalwave.net">pparaska@tidalwave.net -

Lee (JuJu) and others, Spend the $24 at Summit and get the angle finder. Then get under the car and measure the angles. Getting them the same front and rear, and less than 4 degrees is critical for getting away from driveline vibrations. I've been it 3 V8Z cars, and 2 of them had the problem. I don't know if either of them bothered to fix it. All I know is that the noise/vibration is very nasty and unnerving. Someday a U-joint will let go or worse if you don't get this right. Plus driving a car with this nasty vibration is no fun, IMO. Have fun, Pete ------------------ Pete Paraska - 73 540Z - Marathon Z Project - pparaska@tidalwave.net">pparaska@tidalwave.net -

Ditto. Same as Mikelly. I got the 18 gage from a door warehouse. They cut holes in the doors for "lites" (actually windows) and throw the "holes" in the dumpster. The "hole" is two pieces of 20 gage or 18 gage sheet with a cardboard honeycomb holding them together. Rip it apart and clean off the glue. If I were to do it again, I might take the pieces that I formed up to a shop to have some stiffening beads rolled into them. Mostly to cut down on them vibrating at low frequency. Pete ------------------ Pete Paraska - 73 540Z - Marathon Z Project - pparaska@tidalwave.net">pparaska@tidalwave.net -

Resistor on low speed? Nope. It uses two windings to get the two speeds. At least that's what I've seen in the schematic. I've yet to put voltage to it. I'll try that this weekend. Pete

Mike kZ, I'm going to use both speeds. The Haynes manual for the Mustang says that the low speed is used when coolant temp gets above 221F and shuts off when it gets below 200F. Then it says that the high speed is used when the Max A/c is used. Not enough info for me, as what happens when A/C is on, but temp is not high enough to trigger the low speed? Also, I can't tell from the circuits (lot's of black boxes in the schematics) if the low speed winding gets de-energized when the high speed one is energized. I think it ought to be though. The logic circuit I came up with will turn on the fan as such: ________________Coolant temp LOW_____Coolant temp HIGH A/C Press LOW______FAN:OFF___________FAN:LOW A/C Press HIGH_____FAN:LOW___________FAN:HIGH This way the fan is only on if needed. If I'm running down the rad and it's cool out but I want the A/C on to get defrost action, the fan might not be needed (Coolant temp low, A/C pressure LOW), or the A/C pressure might go high, with the coolant temp low, and only the low speed comes on. Only two Logic gat chips are needed, an AND gate and an XOR gate. I'm going to use the high temp (up to 125 deg C) chips for this circuit. This fan on it's low speed is supposedly more powerful than the flexlite 150 fan, So my logic above may be fine. IF not, it's only a matter of some more Logic gates to change it. Designing stuff is fun for me, so I don't mind if I have to change it. What would be a good improvement is to have two coolant temp sensors, on like I have (on at 200F, off at 185) and a higher one (on at 220F, off at 200F). I may go there if needed. [This message has been edited by pparaska (edited March 23, 2000).]

Mikelly, Any info (part numbers, method of installing it in the Z, etc.) appreciated on the electric hatch release. Thanks, Pete

I just started the wiring phase of my project. Like most of the rest of anything that does anything on the car, I'm not leaving it stock. The stock Z wiring and switching philosophy appears to be Lucas inspired. The turnsignals, running and headlights, blower fan, and other circuits have no relays. All current gets put through the dash wiring harness and the switches. Stupid design. The switches are overloaded when some other part of the circuit gets corroded connections and the fuse box starts to suffer also. Years ago, after numerous problems with the turnsignals, I put relays in the circuit. See my web page for an article on that. The switches aren't cheap or plentiful, so why not retire them to just handling the tiny current needed to run a relay? Now I'm putting in relays for the headlight and running lights, and the blower fan (I upgraded to a 85 Ford LTD fan wich really kicks out the air so the A/C will work). Yes, that's three Relays for the blower fan alone. Overkill maybe, but no biggie to me. I'm also designing a logic circuit to turn on the two speed cooling fan for various states of the coolant temp sensor (GMish from JET) and the trinary switch for the A/C, so that the fan only comes on as needed. This beast takes a 60 amp fuse in the 98 4.6L Mustang. So I have some 70 amp Hella relays for that also. Ain't no way I'm going to have my wiring ruin my day. The Z has a bad history of that happening. Oh yeah, I'm going to replace the AMP meter with a 280Z volt meter also. That Amp meter is a source of dead electrics also. ------------------ Pete Paraska - 73 540Z - Marathon Z Project - pparaska@tidalwave.net">pparaska@tidalwave.net -

Traction? I had a stockish L6 in there, and the tires were plenty for the engine . The handling was great though. I had the 225/60-14s up front as well.

I had Western Cyclones on my Z. The version with the fins about 1" apart at the outer diameter. They are 14x7". I had only a little bit of rubbing in the rear with 225/60-14s on them. I ground out the lip (still had an 1/8" left - you couldn't tell without looking under the fender.) and sealed it up. ------------------ Pete Paraska - 73 540Z - Marathon Z Project - pparaska@tidalwave.net">pparaska@tidalwave.net -

The 2000 Cobra R mustang has a T56 in it. At least that's according to Road and Track magazine and Car and Driver TV.

Dan, it's great to hear the engine is so powerful and sorted out now. About the brakes. Did you change the master cylinder to a different design? The pushrod coming out of the front of the booster had to be shortened or lengthened (I can't remember) when I put a 280ZX M/C on my 73 with the big booster. If there is too much play there, it will act like you say it does. Since you say it isn't spongy, I'd guess that the M/C was bench bled. If you didn't know this is a critical step, as you have to push the piston assembly of the M/C all the way into the body to get all the air out. Bench bleeding is the only way to do this. Keep the shiny side up and don't bug the fuzz with that beast! Pete

Lee (JuJu), Got the part numbers or car info for the radiator hoses that you found to work with your 85 Camaro AL Rad, 327, etc.? BTW, is that the AL rad that JTR recommends? I'm using the one they recommend. Thanks, Pete

I talked to the owner of SMC products about going into the R200 before I took my LSD unit out. I can't remember his name, but he is the author of the Z car Magazine article on diffs and LSDs from about 1996. Anyway, he worked at Nissan Motorsports for 14 years and did alot of work on the diffs. He assured me that if you take the gear carrier out, take it apart to reshim the clutches, etc., and put it back together with the original ring gear AND the shims in the original locations it will be fine. The shims I'm referring to are the ones on either side of the carrier bearings that position it left/right in the case.

Mikelly, yeah, the no Ebrake thing would cause problems at the inspection station. SInce I live in a state that only requires safety inspection when a car is re-registered, I decided years ago when I took the car off the road (thinking it would only be a few years - hah) I left the cheap liability insurance on it and kept renewing the registration. It's cost me a few hundred a year to keep it insured, but at least I don't have to be worried about the inspection Nazi's. I do think I will put those e-brake mechanical calipers on though - shouldn't be a big deal to do.