JMortensen

If you want a performance engine, you'll have to lay down performance dollars. If you just want a stock rebuild, then $2400 seems high to me (although I haven't priced out a rebuilt engine lately). 75K warranty on an L series is no big deal. Assuming the engine is built right 75K should be about the break in period. Now if the one shop is going to warranty the engine even if you start cranking up the boost and all that, then that's a different story. Realistically they'd be stupid to do that. As to his attitude towards a potential customer, that sounds like bad business practice. However, as a small business owner, I can say that I hate chiselers. I can't tell you how many times customers have called and tried to whittle down my already small profit margin. It gets very annoying. This guy sounds like he jumped the gun and didn't even listen to what you were asking him, but I think I have a good idea of why he was so reluctant to hear you out. Probably thought you were going to offer him $1800 for his $2400 engine. It gets to a point where it's not even worth it to make a sale if the profit margin is low enough. I'm not excusing what he did, just offering a possible explanation.

You're looking at a pretty big repair bill if you're paying someone else to do the work. It'll be big enough to justify a trip to NM or AZ to buy a relatively rust free car and start with that instead. Check bjhines very recent thread on fixing a dented roof, along with some of the threads in the past about replacing floorpans. Both are time consuming jobs, and at $75/hr, it gets pretty incredibly expensive in short order.

I don't know jack about body work, but I do know that there are 500 threads saying don't use bondo, as it is porous and will allow moisture into it and the sheetmetal can rust underneath it. I'll get a good deal on this stuff, because a friend of mine works at West Marine, which I guess is a pretty big company with 400 something stores in the US. As to how thick it has to be, there are no spots that I think will be deeper than 1/4", and that one 1/4" deep spot is a small dent in the roof that I put there spinning the car on the rotisserie when there was something underneath it. D'oh! The rest of it should be 1/8" or less I think. I'm not so much going for perfectly flat as I am trying to make it reasonably presentable. It's a track car, not a show car.

Please be more descriptive with your titles in the future. I changed this one.

Based on some further reading, sounds like the low density is the way to go. Anyone care to back up that assertion?

Bringing this thread back from the dead as I am now ready to start filling dents all over the car. Based on numerous recommendations to use "marine epoxy filler" and Richard's mention of "West System" I've come up with the following potential bondo substitutes. Which is the right one for filling dents and finishing the edge of the drip rail? Microlight (seems easy to sand): http://www.marine.com/product_info.php/products_id/308 Low Density: http://www.marine.com/product_info.php/products_id/304 High Density (sounds like it's a bitch to sand): http://www.marine.com/product_info.php/products_id/297 Or is there another better product I should be looking at?

That's an awful lot of bodywork for a track car, bj. Looks like it's going to be pretty sweet when it's done though.

I guess if it is 1.625" then I stand corrected. Still the welded junctions are not ideal.

Run straight gear oil in the diff. If you want lighter in the trans, go 50/50 ATF and gear oil. I use SWEPCO 201, and that blend in the trans shifts like butter. I haven't seen a synthetic that compares as of yet.

boosted, I wanted to comment on your tube frame. I don't want to be too harsh, as I was just torn a new one and treated rather rudely on another forum myself and I really don't want this forum to be as nasty to people trying new things as that other one was to me. My comments are that it looks like your firewall tubes are pretty small in diameter. A larger diameter tube with a thinner wall thickness might be a better choice. Also this structure should be a single tube with bends rather than 3 separate tubes for strength.

I thought that it did. Now I'm starting to doubt myself. I'm thinking now that Cary might have told me that I could ream my steer knuckles to fit that size taper and then use that type of part... Cary you out there?

I think the Pinto stud would work. Wish I had known about that part before I drilled out my steer knuckles. You'll still need to fab up the tie rods. bjhines and I both have threads on how we did it. Not too hard if you have a welder, helps to have access to a lathe like bj did, but you can do it without.

The thing that I see as a problem with trying to get the wheels further underneath the car is that the frame rail is going to limit the turning radius. I think the goal should be to get the wheels out farther without having a huge scrub radius.

One of the things they found in the RCE issue with the Lotus is that it didn't work effectively until the end plates were 40mm or less from the ground. The middle strakes didn't matter, but the end ones had to be close to the ground. Just something that should be considered for another windtunnel test. Mayolives doesn't seem to be real shy about getting the car lower, but that diffuser looks by that picture to be higher than 40mm...

I would suggest that you don't use those, or at least that you check for bind after you install them. The problem is what recourse you'll have if they do bind up. Can you make brackets and weld them where they need to be to fix the bind? And if you can, why not just buy the rod ends and make the brackets instead of buying the kit that's been posted, since I'm sure they'd be cheaper if purchased separately. If you read this swaybar mod thread, you'll see I had to get everything lined up just right to prevent the swaybar from binding. If you just bolt that piece on I think it will be bound up really bad. I don't know that for sure, but that's my hunch. http://forums.hybridz.org/showthread.php?t=105596

Sounds like ball joints to me. If you haven't replaced them yet, do it. In my experience the inner tie rods don't go bad very often. I have yet to acquire a Z that didn't need ball joints. While you're replacing the ball joints you can get a good hold on the tie rod and test the inner, but I doubt that is it.

I'm going to try one more time, then I'm going to leave your friends to burn their clutches in stupidity and perpetuity. A properly balanced braking system will be set to lock the fronts just before the rears at max effort. That means the rears might be at 95% when the fronts are at 99%, and to then try to add more rear braking via the clutch at that point is a very bad idea. I would venture a guess to say that actually improving braking distances by doing this would be damn near impossible, while making them longer would be very easy. I can only think of two reasons to engine brake (the correct way, not the way your friends are doing it). The first is to be in the correct gear when you exit the corner. The second is to try to save the brakes. That's it. I think Danny Sullivan actually has a bit in the book Going Faster about not engine braking and how it improved his lap times. What your friends are doing is useless in improving braking. Challenge them to a test of braking with the car in neutral vs doing the clutch burn and measure it out and see for yourself.

Nissan Motorsports does the same thing, you just have to fill out the paperwork. They're not too interesting in giving sponsorship deals to old Z's though. They'd much rather sponsor a 350Z, or better yet a off road racing truck...

I'm going to have to see some windtunnel test results in order to prove that a diffuser won't work on a Z. The wind tunnel guy said some other things that I thought were wrong too. I know, he's a wind tunnel operator and I'm a pet door salesman, but that doesn't mean that he is right and I am wrong. As I said before, I think some of his statements may have been made based on the cars he was looking at, none of which were very close to the ground. Since we are talking about "ground effects" I think that may have colored a lot of his comments. Call me a hardheaded dumbass if you want, but I think that a lot of what we see in the racing world can be made to function on our cars. Air is air, and pressure is pressure.

I don't think you guys are reading what Mike's friends are doing. They are engine braking, but instead of letting the clutch all the way out they only let it halfway, and in doing so let the clutch slip the whole time. This is a really bad idea, and using really good equipment (triple plate clutch) to do it doesn't make it a good idea. Mike says it's a great way to slow down fast. BS. There is NO way to slow down faster than using the BRAKES on the car. Half assed "clutch braking" with only the rear wheels does not work better than braking with both the front and the rear. Try coming to a stop with your ebrake from 60 mph a couple times and you'll see what I mean. The front brakes do MOST of the braking, and choosing to burn your expensive triple plate clutch in order to get some braking force on only the rear wheels is NEVER a good way to slow your car down.

The Euro damper bolt is also an improvement on stock. The head is 36mm if I recall, and I think the shaft is the same length as what you've got there...

Define "fully benefit". I think a diffuser can make a difference if it's done right. I'll be interested to see some wind tunnel results one way or the other. The Z actually has a fairly flat floor, its the suspension area in the back that is the problem. In the last Race Car Engineering magazine they did some tests on a new Lotus and its factory diffuser. I haven't seen the bottom of the Lotus, but the diffuser itself didn't look that spectacular. With a couple of mods they were able to increase total downforce 20 something percent I think, and FRONT downforce went up 8% (these figures are coming from memory, I'm too lazy to go look it up). They were supposed to continue the story in the latest magazine, but didn't, so hopefully they'll pick it up next month...

Here in the US the common modification is to use 300ZX 5 lug hubs and for the rear you can either redrill or replace with an aftermarket stub axle. A search will net you more info than you can read in one sitting on 5 lug swaps. Alternate gear ratios are probably going to be hard to come by, but there was a Skyline (R31 maybe???) which came with a long nose R200 and 4.375 diff. I know there were lower gear sets available, but I think Nissan Comp sold them all off a few years back. You could check with Nissan to see if there is anything left...

I'd be shocked if you couldn't find one between here, classiczcars.com, zcar.com, and ebay. If not you might ASK after one in each of those places. When you do the turbo swap, just add a small surge tank (search, there are a couple good threads on how to make one) and you're good to go.

Unless you're building a track only car, I'd buy another gas tank. They're fairly easy to find, easy to install and don't require hours and hours of tedious work to get in the car. You won't have to build a new floor to cover over the cell to prevent it from spraying fuel inside the car in the event of a crash, and the stock tank is about 25 lbs lighter than the 12 gallon fuel cell I installed in my car. Even if you decide to go FI and are concerned about the fuel pump sucking air in corners, you can add a simple, inexpensive, easy to install and plumb surge tank and use it in conjunction with your stock tank. In my humble opinion there is no reason to go with a fuel cell other than a rules requirement.