johnc

Actually, shocks control the rate of load transfer. In this case its applicable because a high rate of load transfer can cause an abrupt failure. But, the total load will still be the same regardles of the shocks used and that fabrication job was desinted to fail. Luckily for the owner it failed sooner then later. Imagine a track day and a long, fast corner with a bump.

Poor fabrication work. All the strength was cut out of the strut tower. Post the name of the fabricator so we can all avoid the shop. They are going to kill someone some day.

Search. Lots of discussions on here about welding the diff.

http://www.subesports.com

You will most likely blow the open diff before the halfshafts especially if you do big one wheel burnouts. You are going to break something and sooner rather then later.

Have the alignment checked.

I took measurements. The 3.5L Ecoboost will take A LOT of fabrication work to fit it in an S30. Likely the same for the 2.7. Work on your measuring, metal cutting, and welding skills if this is a project you want to tackle.

Does the rear end actually break loose or does it just feel like its gonna happen? If its the latter, then you probably don't have an issue and are just not used to a more neutral handling car. Find a big empty parking lot and map out a 200' diamter skid pad. Run the car around the skid pad until you find out which end of the car breaks loose first. Under steady throttle its more likely the front.

A roll cage is primarily for safety. Door bars and the firewall brace can add some stiffening but design them first for protection and easy access. An "X" is the easist to build and does the best for stiffness but makes access more difficult.

It's normal. Changing it will take a lot more work then adjustable a-arms and will likely have a negative affect on handling.

The braces to the firewall are there to keep the footwell intact in a collision. They protect your feet. You will have to mock up your door bar options to see which best clears the door latch and window cranks. Buy some 3/4" conduit and a conduit bender and have at it.

No recertification required for SCCA or NASA. They do get inspected every year as does any DOM cage and after a big wreck they typically pull the logbook for the car and require a full inspection after the repairs are done. But nothing unique is required for 4130.

4130 and T45 are medium carbon steel. The only sanctioning body, or any other organization, that requires stress relieving after welding this steel in thicknesses under .125" is NHRA. FIA, SCCA, IMSA, the FAA for experimental aircraft, and more all are fine with properly welded medium carbon steel tubing. None that I know require a cage replacement after 3 years.

What racing sanctioning body has that rule? 4130 weld cracking has much more to do with welding technique then material choice.

Oh! You you welded all the seams with a (essentially) continuous bead. That's not the normal practice when stich welding a chassis. Normlayy the gaps are left between the short welds. I don't know how that would affect your results but it does mean that the entire seam has gone back to the original yield strength of base steel if there was any hardness added via alloying or after the initial rolling.

Approximately 2000 lbs for a 1 degree chassis deflection at the wheel hub compares reasonably with what I've experienced in suspension tuning on the 280z. Once you get to spring rates above 300 lb. in. On the front of a stock 280z you don't see improvements in lap times by increasing that spring rate. The chassis is now flexing and absorbing spring rate.

Thanks for the data. It's was a lot of work and I appreciate the effort.

I don't think a cage work hardens over time, but I could be mistaken. I do know, from the folks at the Lincoln Electric Welding School (took their basic and advanced Motorsports Welding classes back in 2002) that if you use .023 or .025 wire in your MIG welder on tubing with a greater wall thickness then .083 the weld itself will work harden as it cools. I forgot what the exact process is but they said .030 wire up to .118 wall and .035 wire up to .150 wall.

If you are building a track only car, the first to second shift is generally only used when exiting the pits onto the track - if you're gearing is correct. There may be one 2nd gear corner on the track but if you've got the car geared correctly and handling well, you shouldn't ever have to use first gear.

They will work in a high pressure area. Just make sure that the exit of the duct is a low pressure area.

It rarely works out that way. I sold my shop back in March and after selling a bunch of stuff I had Datsun parts leftover. Offered them for free, publicly and spent two Saturdays at the storage unit waiting for people to come by and pick up the stuff the desperately wanted. Not one showed up. Wasted my time both days. I learned my lesson and started contacting people i knew privately. Got rid of a lot of stuff that way. Also, molds don't store well. They need to be used and kept maintained. They are fully depreciated and are worth nothing on the books. They can make someone thousands of dollars a year (and I've got the sales records for the last five years to prove it) but you have to market and sell like a business. That makes these molds worth something to someone who is serious.

If you are serious, contact me at the email address above.

The AZC and Ground Control weld in camber plates have always been IT legal.

240z OEM hood 240z OEM hood inner frame 280zxt OEM hood 280zxt OEM hood inner frame 240z cowl induction hood - 4" rise 240z OEM hatch 240z OEM hatch inner frame 7 molds, not 8.

I prefer to do the wrong thing unless you're willing to put your money where your mouth is. I've had three people approach me to buy the molds and all have just vanished after saying ok. A fourth is now checking with my composites guy. And yes, 8 molds take up a lot of space and cost money to store.