Mike

, Wayne Burstein wrote (alot, but I'm addressing just one point): >I am wondering why you are going to coilovers in a street car. Racers >use them to be able to raise and lower the car, and particularly to set >corner weights. Setting corner weights lets each wheel do the maximum >work keeping the car hooked up in corners. The only reason I would see >for using coilovers in a street car is for someone who wants to change >ride heights -- possibly lowering the car for autocross or track >events. Well, there are a few more I can think of: 1) You want to put wider wheels and tires one, but not flare the fenders. By using coilovers, you can use more backspacing in the rear and put wider wheels on. In fact, you can put a 17x9 wheel on with 255/45-17 tires if you use just the right backspacing, 8 inch coilovers, etc. 2) You want to try different spring rates with a wide selection. Once the coilovers are one, you can swap in springs in rates that vary by 25 lb/in over a wide range. 3) One unforeseen benefit is that you no longer need a spring compressor to change springs, etc. Just lower the spring perch to unload the spring and disassembly can begin. 4) The prices for coilovers have come down. I paid a pretty penny to Carerra for mine, but you can get them cheaper at places like http://fonebooth.com . I see more and more people going to coilovers for reasons 1, 2, and 4 above. BTW, use the search function on HybridZ.org on this topic. There is alot of good info posted there on coilovers. Regards, - Pete Paraska <pparaska@home.com> <http://members.home.net/pparaska/> IZCC#15 73 240Z under marathon body restoration, V8 swap, suspension & brake mods Check out HybridZ.org for Datsun Z cars modifications, no holds barred! ------------------------------------ Internet 240z Club - http://240z.org

This message was posted to the list by Wayne Burstein. I thought it needed to be captured and put into our database permanently. Mitch asked about coilovers on a street car (including shortening the struts and how to get a compliant suspension): Let me address that in two parts. First, getting a suspension that performs well in a street car, but is not too stiff is not particularly easy. In a Z that is driven daily, I would recommend lowering the car less than an inch to avoid problems with speed bumps, etc. Also, I would recommend keeping the springs/struts fairly soft and running stiff sway bars. That keeps the ride acceptable but minimizes body roll in corners. If you want a race car type of suspension, expect to feel every pebble on the road (that is what I want on my street car, but it is not a daily driver). It is very important to get the right springs and dampers (strut cartridges in the case of a Z). Basically, you want to match the springs and struts. The springs do the work of holding the car up and allowing the wheels to react to bumps in the road. The dampers are there to keep the springs from bouncing the car up and down for a long time after hitting a bump. If the dampers are too weak, it is like the old commercials for worn out shocks -- the car does not quickly settle after hitting a bump. Too stiff dampers keep the springs from doing their job and the car reacts to the bumps instead of the wheel moving up and down in relation to the car. I am wondering why you are going to coilovers in a street car. Racers use them to be able to raise and lower the car, and particularly to set corner weights. Setting corner weights lets each wheel do the maximum work keeping the car hooked up in corners. The only reason I would see for using coilovers in a street car is for someone who wants to change ride heights -- possibly lowering the car for autocross or track events. And even this use brings into question how you would re-align the car every time you changed the ride height. Maybe you could come up with some kind of compromise alignment that would work for both ride heights? I am a little concerned about your comment that your current suspension is too stiff, but bottoms frequently. Suspension dampers are not designed to handle frequent bottoming and you should fix this problem. A couple of years ago I posted a fairly long explanation to the IZCC list about shortening struts and the trade-offs that need to be made. Here it is: Let's start by defining the task at hand. We want to lower the car in order to lower the center of gravity. I'll skip all the analysis on why we want to do this because there are lots of good books on the subject, and confine my comments to what you might run into in performing this on a Z. First I need to define a couple of terms: Bump -- suspension travel in the compression direction (i.e. the result of hitting a high spot in the road). Rebound -- suspension travel in the opposite direction (i.e. the result of going over a hill and the wheels leaving the ground). The first problem we run into is that when we shorten the springs, we are reducing the available bump travel in the strut cartridges by the same amount we lowered the car. With all the travel available in a stock Z, this is not too much of an issue when we lower the car only an inch or so. For those of us who are racing our cars, we often lower them much more; for instance, in the SCCA's IT class, we are allowed to lower the car until the rockers are no lower than 5" above the ground. This causes a problem because the suspension is almost fully compressed when the car is sitting at rest. When you hit a bump, the suspension quickly bottoms out (hopefully on a bump stop of resilient material). This is a real problem because in effect, the spring rate increases very dramatically and negates all of our efforts to drive the car smoothly. When driving at or near the limit, this often is the beginning of a very impressive crash. Well, we now have the car at the desired ride height, but need to increase the travel in bump. The way to do that is to shorten the struts. Now things get pretty messy. Don was correct in stating that this is dependent on the length of the struts; however, this is only partly true. The struts need to be long enough to insert the cartridges of choice. For racing, the ones that I would recommend are Carerra, Koni, or Tokico, in that order ( this should cause a bit of discussion on its own). If we automatically shorten the strut to exactly fit the cartridge, we might actually shorten it too much. This leaves us without adequate rebound travel. Just in case this does not scare you, it should. I learned my lesson the hard way when I had the rear wheels pick off the ground while cresting a hill that had a slight turn to it. That made for a looooong full lock slide at 100 MPH! Ok, now we need to decide just how much we want to shorten the strut housing. The desired end result is to have about equal bump and rebound travel. In other words, when the car is sitting at rest, we want the struts half way compressed. On a street car, this is fairly easy to do, because we generally set the car up once and never play with it. Race cars are another situation entirely. First of all, different tires require different ride heights -- for instance, switching from 60 series to 50 series tires lowered my car by .75", causing me to have to raise the car by the same amount. We also play with spring rates, and assuming that we are using coil overs, need to keep the spring collar low enough on the strut housing to avoid it interfering with suspension travel. The bottom line is that before cutting anything off your struts, you should carefully think about what you anticipate doing to the car over the next few years as far as tire/wheel, strut, spring or ride height changes, and then come up with a compromise that works for you. FWIW, most people shorten struts 1-2". If you figure out that you want to go more than this, recheck everything before cutting. Yes, you can add a section, but speaking from experience, it is much easier to remove than to add. I almost forgot to mention this, but if your strut housing is longer than the cartridge, you need to put a spacer below the cartridge inside the housing -- typically, these are just pieces of tubing that is slightly smaller in diameter than the inside dimension of the housing. Just a couple of tips to consider: 1) The best way I have figured out to cut the struts is to use a large pipe cutter. This gives a fairly straight cut with minimal cleanup -- you need to grind the burr off the inside of the housing and bevel the outside edge before welding them together. Be careful not to make the cut so high on the strut that you hit the threads for the gland nut! 2) To remove the original spring perch, the quickest way I have found is to cut through it just above the housing with a grinder or cut-off tool, and then grind the remaining metal off. I found it much easier to do this before cutting the strut because even though I was not cutting the section with the perch off, it did interfere with the cutter. 3) After lowering the car, you need to align the suspension because you have added negative camber at both the front and rear wheels. Of course, you should probably do this any time you remove suspension components anyway. Finally, Carerra was of invaluable help to me in figuring out what to do and how to accomplish these modifications, as well as supplying many of the parts I used. You can reach them at: 770-451-8811 Sorry to be so long winded, but this is a fairly complicated task to plan and implement without too much trial and error. Wayne Burstein WDCR SCCA ITS #10 IZCC #214, NVZCC wburstein@mountainmotorsports.net www.mountainmotorsports.net

Thanks for the compliments on the Z. And, thanks for the links! If you give us a TON of links, I'll give you a Zcar Microfiche CD. Can you find at least 40-50 links? If you are having a hard time, try to visit other Z sites and look at their link areas. [m]

So, you wanna post a pic of your ride? Go for it. We wanna see it. Just a few rules. 1) Max image size = 640x480 2) Picture Resolution = Any (but please resize to 640x480) 2) Color Depth = Any 3) Compression/format = JPEG or JPG preferred You can either supply a link to your picts from other sites within the message. Or, you can also attach a file to the end of separate messages. To post more than one pic of your car, submit one message and then post the rest as REPLIES to your original message. 3) Give us good descriptions! We need to know what we're looking at. 4) JPG images will show up in the messages. Other formats will only show up as "click to see" links.

Pic

Well, here's a pict of my Z as it still sits. I'm working on getting to the restoration progress again. I just had to buy a house. Damn.

That is a NICE rig, Aux! You've got quite a job on her. Do you have picts of the project underway? Post 'em if you've got 'em. I'd love to see what you're doing to it right now. [m] PS: Can you make the picts a wee smaller to fit in the window?

Jesse, Thanks for posting the stuff you've found! We all appreciate the work you've done on this! Great job. [m]

Dan, Can you post that even to our calendar events area?

Do we have weight specs on this vehicle yet? I guess I'm trying to determine how people think this car is an overgrown beast. Some people say it looks like a heavy toad. Well, unless we have some weight comparisons, I'm still of the opinion that Nissan knew how to build it. In fact, I wonder if it's lighter than the original (all steel) Zcar with even more horsepower. Of course, I am speaking w/out the detailed specs. But, from what I can imagine, they wouldn't build another overpriced 300zx. This thing is supposed to be around $25k. That's the same price as a Camry or Honda family wagon. Next up on my list would be the Volvo turbo sedan. But, for a two seater vehicle, it can't be beat. I hear that the designer used to work for Audi. Is this true? That explains why the design features are so close to the TT. Isn't the Audi TT around $40k? This looks like an affordable option in that case. [m]

I like it. But, yes, a picture can be deceptive. Especially when it's a high-quality advertising photo like this. I'd like to see one up close and actually drive it. Hopefully they plan to do a turbo-ized model. We'll see.

Ya some of those links aren't right. I've been trying to get some time to take those old links and put them on our new site. This is a good reminder for me to do it. Thanks. [m]

Now that you know the coil works, I'd at LEAST replace your points, condensor, and distributor cap. This is all under $20. [m]

You weren't able to order the parts cd? Here, try this link: http://scarab.240z.org/zcd/zcdorder.htm Mike PS: Tell me what troubles you were having. I'm trying to upgrade the CD purchase system. Thanks!

If she's been sitting for a long time, there are many things you should do. I'm pretty notorious for buying new parts all the time. But, this is a good case where you will probably need new points, condensor, rotary cap, and spark plugs. Other ideas I can come up with is a new coil and spark plugs. You never know if something is shorting out on you. Most of this is under $150-$200 if you are doing the work yourself (for everything). But, you can do it cheaper if you skip the coil and spark plugs. [m]

The new 350z is making headliners across the counrty. Tell us if you like it or hate it. Or, if you just aren't sure, tell us what you think!

Let me tell ya. This car is sweet. I was looking at the forums tonight and came across your little "project".... very nice. Love that black in the fall season. Webbers, eh? I went with the Mikunis... [m]

Kick arse man... love the hat!! Nice color. I'm doing the same thing on my restoration.

Nice rides man!

Timberwolf, We just got done making changes to the 240z Club website. This change is bringing a lot more traffic to our forums. Good things come with hard work...

Yep, heads are pretty common on a Z. This is primarily due to the different metals used. For instance, the engine block is iron. The head is aluminum. Due to the different expansion/contractraction characteristics, your head can warp. Heads can also get warped because they weren't installed correctly. There is a certain pattern to tighten the head bolts. If this pattern isn't followed correctly, the head can be tweaked out of shape. A head can also only be milled so many times before it's no good.

Yes, it's a problem with the move to our new site. Sorry abou that... I'm still working on moving everything over. This is one of the stragglers... Anyway, you can download the demo from THIS LINK Let me know what you think. Better yet, buy a CD!

Exactly what bearings are you talking about?

Chandall, you can also post pics in this forum.

Welcome to the club! Feel free to post messages with any questions you might have.... -- Moderator Mike