Jump to content
HybridZ

johnc

Members
  • Posts

    9842
  • Joined

  • Last visited

  • Days Won

    56

Everything posted by johnc

  1. In the SCCA ITS racing world it was somewhat common to hold full throttle between 7,000 and 7,300 rpm for 5 or 6 seconds at a time on each lap due to the transmission limitations in the SCCA rule book. That's with cast pistons and a stock damper. Cranks do break from that use especially if the damper is old - I've seen it and I've seen a damper pop off the front of the crank, go through the hood of a car, and into the windshield of the third car in the line racing for turn 1. That's where a lot of these crank harmonic rumors came from. There are also the fools who used to remove the damper completely and replace it with an aluminum under drive pulley set. Still very common in the BMW world and you see posts weekly on Bimmer Forums from people wondering why their crank snapped between 3 and 4.
  2. johnc

    R230

    Pick it up. That will show you the difference.
  3. For street and autocross use an R160 LSD is fine until your power levels get about 200.
  4. The flange to axle joint is a common failure point for Zs run on a race track. I've lost two on the track. The lateral loads cause flexing at that fusion weld and any kind of surface imperfection becomes a stress riser. The 280Z stub axles have a larger OD shaft, a thicker flange, and generally a better fusion weld at the flange/shaft junction. But stub axles used on a track S30 are an inspection item and should be replaced if there are any small pits or cracks seen in the fusion weld. You should inspect that weld every time you have the wheels off the car.
  5. You're not mounting it any higher up by building a false floor. Your diffuser should have an angle of 7 to 10 degrees and in most cases (with a 8" deep cell) the cell top is close to flush with the trunk floor. Also, the issue with a fuel cell out back is yaw inertia not cg height. Moving the cell as far forward as possible while still allowing room for a ratchet to get the rear diff nuts off is more important that a 2" install height difference.
  6. Have a great bike ride. A good way to clear the cobwebs.
  7. Or build a wedge shaped box for the rectangular cell. Just need a false floor so the rectangular cell sits level.
  8. You were the engineer? Wow! Glad you're OK.
  9. The Quartermaster 5.5" DD clutch I ran could not be used on a street car. I suggest using the stock VK56 setup to start. You might also look at what OS Giken might sell for your combo.
  10. Looks like it was for another application and someone re-drilled it to fit the R180 ring gear. Its not a clutch pack LSD so it might be a Detroit Locker. The Torsen's I've seen have openings in the case to allow fluid inside so I don't think its one of those.
  11. Diesel truck engines are large displacement low operating rpm engines. They operate in a narrow rpm range and the turbo system is designed to product a high volume at low psi (5 to 8psi) within that narrow rpm range. Typically the operating range is only 500 rpm - from 1,200 t0 1,700 for example. There's no need for waste gates, blow off valves, etc. for an engine that's essentially designed to work at a fixed rpm for hours on end.
  12. FYI... I'm a huge fan of cryo treating rotors. I've seen at least double the life of the solid front S30 rotors when used on the track and that was with some pretty nasty pads.
  13. My engine was about 91 ft.lbs./L which is nothing for a race engine. Hell, my 2000 F350 with the 6.8L V10 gets 73 ft.lbs./L. I have a more fundamental question about where this thread went. Who cares about ft. lbs. per liter? What ever happened to the more common measure of horsepower per liter? Why are off on this obtuse measure of performance? Are we building diesel engines?
  14. All brake rotors will develop cracking when used on a race track. Brake rotors are a consumable item the same as brake pads when used for racing. Get used to it. This cross drilled vs. non-cross drilled rotor argument is silly. There is also another big reason that people run the SW12 or SW13 iron calipers on their race car - rules. Very few vintage racing organizations allow modern aluminum monoblock calipers. You're stuck with cast iron and some groups are even more anal and require the FIA Group 4 approved Nissan cast iron calipers which are over $1,000 if you can find a pair.
  15. Put some miles on the brakes before doing anything else. Check it again after a couple hundred miles. Also try a hard panic stop to see which tire/end locks up first. And expect to adjust the rears a few times during that 200 mile bed in.
  16. Terminology problem. Halfshafts are not axles.
  17. IT, SS, T, and ST, allow an 8 point cage with two mounting points from the door hoops or knee bar to the firewall. No firewall penetration allowed. All other categories have complete freedom on cage design once the basic SCCA cage design rules are met.
  18. But those "complicated systems" are what make the GTR such a great car. The computer control of every aspect of the engine, transmission, and 4wd system is what gives the car such supercar killing levels of performance. Remove that stuff and you've got a generic twin turbo 3.8L V6. What's so special about that? Might as well build a turbo VH37 for half the cost.
  19. By Ty Rap zip ties (the originals and still the best) and use a flush cut nipper like this (http://www.amazon.com/dp/B0002BBZIS/ref=nosim/kkorg-20) to remove the ends.
  20. For your car the lightest is the CF hatch at 5 lbs. The sale price is $708.13 plus $98.00 for the box and packing and shipping to you is around $160.00.

    1. dat 280zx

      dat 280zx

      Hello I was looking around the internet for a true cf his fir my 280zx and I came across your feed in 2006 I was wondering if you were still making them or if you ever did because I would be very interested in buying a full cf hood fir the 675 that you talked about. Thank you so much

  21. John, price on your lightest hatch for S30? I have lexan window already...

×
×
  • Create New...