johnc

There's an alternative strut thread int he FAQ section. I'll lat Dan know about this.

OK... what we are really concerned with is wheel rate, not spring rate. Spring rate is a way to achieve wheel rate as related to suspension frequency. A 240Z street/autocross/track car a suspension frequency in the 2hz range is good which means front spring rates around 250F and 275R (assuming stock vehicle weight and balance) and gives a wheel rates of 235 and 258. For a street car that's occasionally run at an autocross or on the track a suspension frequency in the 1.9hz range gives a reasonable ride with some handling benefits. That would be spring rates like 200F and 225R with wheel rates of 188 and 210. If you look at the motion ratio of the S30 rear suspension you might find that the wheel rates are very similar to what I posted above so shock re-valving might not be needed.

Or maybe someone reads about your mods on an Internet message board. As a scrutineer for SCCA and NASA I suggest you disclose the mods on your car to the powers that be when you show up for the annual tech. They will find a place for you to race and have fun. If you show up as a newbie and then get caught cheating, you'll never live that down and it will follow you everywhere. Racing is a small community and word travels fast. BTW... Unfortunately, now that I've read this, if you show up at an SCCA event where I'm the Chief of Tech I will have a talk with you about car classing regardless of what car you're driving. Sorry, but that comes with my job. It will be a friendly talk and we will find a place in the event so you can race and have fun, but you won't take a trophy away from someone who complies with the rules.

Buy the cleanest, newest RV you can afford and have it professionally inspected before purchase.

How much longer then 1/2" is the crack in the picture above? Its probably 11 1/2" longer then the one in your car and is beyond the frame rail and making its way up to the upper front frame horns. And the crack is on the good side (non-rusted frame rail side) of the front clip. That means both side of the front clip are compromised. If the car from the firewall back is good then replacing the front clip is an option but, IMHO, if I owned that car I would scrap it and if a customer brought it in for me to repair I would clip the front after trying to talk the customer into buying a new, good shell for $1,000 or less.

It sounds like you had an oil starvation issue more then anything else. Did you see any oil pressure drop in right hand turns? I would also check the oil pump, oil pickup (for pinholes, leaks), and the pressure springs. I've seen oil pickup tubes with small rust pinholes near the flange which causes the pump to suck air.

The front clip of the car is tearing off. My guess is that the car was in a bad wreck and someone did a crappy job of welding on a replacement front clip. Junk the chassis and start over.

Lower the front of the diff until its 3 deg up. Also, make sure the diff and trans are parallel in the horizontal plane.

Class A is generally a heavier duty chassis and will get marginally better gas mileage then a class C. Class Cs are generally cheaper and give more sleeping space.

What oil pan? What oil pump? What oil cooler? What oil filter? Properly route all your oil lines so there are no kinks anywhere.

Ahhhhh... (the lightbulb comes on). Forgot about scrub radius. It would be needed (in a negative way) to make positive caster work as I described. I need to call someone smarter then me. EDIT: Scrub radius has an effect but not as much as I thought. The Go kart example is an extreme because it has no suspension and has to go on three wheels to turn.

Well... I just had my 350Z on the scales and it comes with +9 front caster. Turning the wheel to the right saw a increase in total load on the LF and RR of .5% of that cross weight (80.9 lbs). Turning the wheel to the left saw a increase in total load on the RF and LR of .5% of that cross weight (79.9 lbs.). Remember the fundamentals - if you raise any corner of the car the weight on that corner and its diagonal corner increase and the weight on the other two corners decrease. Think of a four leg chair.

Adding caster does help with rear traction in a turn. Due to the jacking effect on the front you transfer more load to the inside rear tire. A friend who autocrossed a car very similar to yours ran 8 degrees of positive caster in his 240Z and put 1/2" wheel spacers on the front. Both of those changes helped a bunch with rear traction, although his steering effort and scrub was huge. I wouldn't recommend those nubmers for a track car but often in the autocross world we need to do strange things to get quicker runs. I also agree with the rear toe comments above.

I see more and more 40-50 year old fat guys riding around on BMX bikes here in SoCal. I used to think it was because of the economy. This thread has got me thinking the old codgers are reliving their youth.

Jon just posted "Yes". If it helps, I'll post "Yes" too.

Solving traction problems by compromising handling, not so good. Solve traction problems by adding traction. Start searching for used LSD R180s. They are out there. I've also started another production run of the STi side axles if you are lucky enough to find a cheap R180 out of the back of a WRX STi. It takes some searching but they are out there too.

Oil starvation as the oil in the pan sloshes forward. Overfill by 1/2 quart and see if it goes away. if not, pull the pan and check the pickup. While the pan is off, add a lateral baffle and a lip off the shallow part covering the front part of the sump.

Won't fit.

Ding, ding, ding, ding! We have a winner!

The Konis are generally a better shock then the Tokicos, but if price is a concern the Tokicos are a better deal.

If the rims are zero offset and 7" wide they will fit under the fenders with 225/50-15s.

The 1 1/8" is the biggest front bar normally run on the front of a 240Z. The 7/16 rear bar sounds like stock OD rear bar. A more typical bar setup is 1" front and either a 3/4" rear or 5/8" rear bar. Suspension Tecniques sells the 1" - 3/4" bar combo and Design Products sells an adjustable 5/8" rear bar.

Piece a cake. Just pry open the seams, slather in the glue, pound the seams flat again, and wipe up the excess glue. Oh wait, there's that bending fatigue thing that steel is subject to, not to mention the new "rippled look" of your entire car. Probably not a good idea.

The stock springs work fine with the HP shocks.

You can install the ST 3/4" rear bar or get an adjustable 5/8" bar from Design Products: http://designproductsracing.com/Z_Suspension1.html