tube80z

Do you have a real pic in a corner? This looks like you're about to lose it and have lifted off the gas. Often when the suspension is compressed and you do this it makes the roll look worse because the suspension has overshot on rebound. When you start looking at putting on sticker tires, etc. you will need to increase spring rate. They should be used to support the chassis. So if you increase the amount of traction the they will need to increase. I guess the trick is figuring out how to do this in the best way. Probably swaybars first. You can also try to raise the RC and that will help cut down the roll angle. The problem will be the lowering the car causes this to go down too. So on one hand lowering both helps and hurts you. If part of your roll is caused by the suspension jacking up you can try and use the droop limiting crutch. It's worked for me and is cheap to implement. Many people don't understand how it works very well and like to claim it's BS. It can really help with turn-in. Cary

If you tune to a specific suspension frequency it takes this into account. C

The posts above have some good info but it will be hard to find an ITS or GT-2 car in Australia since those are specific US classes. If you don't have money to add a cage and still want the suspension to work best I would suggest working out your spring rates so that the car has equal front and rear roll angles in a corner. This will help with a car that's not as torsionally stiff. If you don't know how to do this you might consider contacting the folks at http://www.racing-car-technology.com.au, they are located in NSW. Cary

My sentra was rear steer so the rack would move the opposite direction you need. Take a look at the rack pinion. If it's the same as the Z (on top) then it will probably work if it's the correct width. If it's on the bottom, like I expect it to be then the rack won't work in a front steer location. Cary

Can you vent into the fenders? GT rules and prepared autocross rules allowed this but I couldn't add the vents into the hood that have been talked about. Cary

Nice work Phil! For the oil cooler why could you move it the left side of your box and let it vent out the core support? Sort of a bookmarked type arrangement. I've seen this one on a number of racing cars over the years where they have a central duct. Cary

When I have no clue I first calculate the magic number for the suspension and use a few rules of thumb. What this gives me is a baseline to test from. The magic number is the concept taught in Rouelle's (also in Milliken) seminars and is nothing more than the percentage of total weight transfer seen at the front of the car. The idea being that this percentage should generally be in the 3 to 5 percent higher than the percent of static weight on the car. 5 being for sporty street car and the 3 to 4 range for racing cars. This is driver and course dependent but will almost always be in a .1% range. You can use this number to play with track, spring, bar, RC changes to your hearts content and keep the balance the same. I made simple spreadsheet to do this that makes many assumptions but works reasonably well (no tire stiffness or chassis stiffness is used). My rules of thumb are to try and not go more than 60% of the front stiffness with bar and no more than 30% in the rear. For track cars I prefer to use half that, YMMV. My guess, without knowing too much about your car, is that you have too much front percentage and it will end up understeering more than you want. I'm not seeing an option to attach a doc to this post. If you want I can send you my spreadsheet but be forewarned it was quick and dirty and I didn't try and make it user friendly. Just PM your email. Cary

Here are a few of my favorites: Dave Kipperman warming up his brakes. Check out the guy on the left (Peter Brock) One quick Z car The pit crew in action. I did this shot by panning the car as they jumped the wall. Father and son on a Sunday drive (Morgan and Gavin Smith) One of my all time favorite shots. Taken at dusk on a practice day. We'd been telling Dave that sideways was fast Here's Dave lapping more slow cars at PIR And sometimes I even get my picture taken.

Years ago I weighed a VG30DE (complete) with custom lightweight headers and a really light clutch and flywheel. It was 424 pounds. This was done using a bathroom scale and lever system. I've told Paul I'll weight this engine again as I still have it but with real scales this time (race car scales). I'm going to weigh a shell with a cage because I've never seen a weight posted for one that seemed realistic. What about something that looks like scissors. You put a spring on one side and the crane mounts to the other end. When you lift something it compresses the spring and you measure the compression. You pick a few known weights, measure deflection, and put that in excel and create a normalized curve. Seems a lot cheaper and close enough. I'd guess it would be 5 pounds accurate. Cary

I don't have a picture of it but I saw a sentra with a cow in the backseat. I about crashed from laughing so hard. It's head was sticking out one window and the backside out the other. Some old lady was driving. Cary

I had a airbox like that on my car. It also helps with cooling by slowing the air going into the radiator. Another option if the rules don't allow hood vents is to open the inner fenders and vent there. Ideally you should not have the tires sticking out in the aristream and a proper flare covering this. This is how most GT cars are done. Cary

You do realize the main hoop diagonal isn't straight in your model don't you? Are you trying to create a half cage for a street car? Cary

Staniforth's competition car suspension is a really good book to start with. There are a number of calculations given on the back of the book you can put into a spreadsheet and use to help make decisions. Bare in mind it's a little data but highly recommended. Adam's book has some useful info more on the chassis building side and is in general a disappointment. You might take a look at the following website, http://www.racing-car-technology.com.au/index.htm. They have some good information but don't bother with paying for their weight transfer worksheet. They give you all the info you need on the site and you can finish the rest with what you get in staniforth's book. Another idea is to see if you have any local shock or data experts. Many of these people put on weekend seminars to help out beginning racers. Being able to ask questions is a huge help. And once you have a good basic understanding you can go to the mother of all seminars by optimumG (http://www.optimug.com). Hope this helps, Cary

In that size I'm not sure if they even make 0.065. It may depend on your steel supplier but I think the thinnest I could get was 0.095. That may dictate what size tube you end up with. My personal feeling is 0.065 would be about the same as the stock rails. I'd start by measuring how thick they are and keeping close to that thickness. Cary