johnc

Look closely at my second pic above and notice the line of spot welds at bottom left of the mount. The mount is tall enough to span the whole cowl box and stiff enough to not flex (.100" 4130). That area spanned is the base of the cowl box triangle and its plenty strong for loads involved. I was able to up the front spring rate by 50 lb. in.

The key is in the tuning. With OBD2 and later engine controls its very difficult to get addtional power from just "bolt-ons." What the legit exhaust system people don't talk about is the 100s of hours of tuning they do to get the dyno numbers they use in their marketing. Stillen is a prime example of that. What the illegit exhaust system prople do it just make up numbers that are just a bit better then the legit guys claim. Pre-OBD2 cars can respond better to a well designed and well built exhaust sysxtem. The L6 engine in stock condition responds well to a 2.5" exhaust system without any changes to the stock exhaust manifold. In general the real gains to an engine that is modified beyond stock is in the header and merge collector (if one is used). The exhaust after that should be deisgned to stay out the way as much as packaging requirements allow. One does not follow from the other. Its absolutely in the automotive exhaust aftermarket's best interest to have people believe that aftermerket exhausts are a good idea in general. SEMA doesn't even pretend to police the complete frauds out there selling "Vortex Generating Muffelrs" and crap like that. Go to the next SEMA show and see the lies.

No.

I don't think anyone needs a time-out or shown the door for posts in this thread. And right now the site is an easy runner.

Excellent marketing.

You can get an OS Giken Super Lock for less then that Cusco and its a far better diff.

Had the exact problem Saturday on a customer's car at a race - all 4 tires on brand new Keizer wheels. Took them back to the Hoosier tire busters and they swaped the tires around on the rims as mentioned above. That got them all to seat. Should not be a problem in the future according to Hoosier.

Whether and how an arch or bend flexes depends on the material used. Any arch or bend will move more more then a straight tube given compression loads that are in line with the tube. That movement can be reduced with material selection and positioning of the arm on the strut tower. Remember, the strut towers actually twist slightly and move back more then they move inward. That's why a triangulated strut tower bar setup is significantly stiffer then just a lateral bar.

I can't take credit for that welding - although I can probably do as well after 10 years of TIG welding. That fab work was done by Bill Savage of T-Mag and NPTI fame.

Disassemble and inspect. Make sure the gland nut is not bottoming on the strut tube threads. Throw a 1.5" OD washer on the bottom of the strut tube and reassemble to see if that solvers the problem.

What Jon said...

Uuuhhhh, the driveshaft MOI is insignificant compared to the MOI of the wheels and tires and the tire's grip on the pavement. They are diecrtly connencted to the output shaft in the transmisison - via the halfshaft, diff, and driveshaft. The synchros slow down the inout shaft, not the output shaft. In the context of synchro life its input shaft speed, not output shaft speed.

For the long nose R200 your CLSD choices are: OSG Super Lock Kazz or Cusco 1.5 and 2 way (if they are available) Used Nissan or PowerBrute CLSD. Search on this site, escially in the Driveline FAQ.

What I suggest is running the O2 sensor for tuning and then remove it once you have the maps and everything is set right or you can add a second port downstream and put the O2 sensor there. That minor throat after the merge is designed to increase velocity and creat a low pressure area in the cone section. Creating turbulence in that area will reduce its effectiveness - by how much I don't know. It may not make any difference at all. Its just not something I've ever seen tested.

Oh... not the best place for the O2 sensor. It would be better in the 3" section. Did I suggest putting it in the merge itself (I hope not...)?

No.

I cut mild steel on my DoAll band saw at high speed. For stainless slower is better.

Jet Hot 1300 is next to useless. Go with Jet Hot 2000 at a minimum if you want a functional coating. Better yet, go with Swain White Lighting which offers excellent thermal insulation - but its not a pretty as the others.

Yes, without the washer the nut might bottom on the stub axle threads.

This is a much better option then any of the HF or Home Depot products - and not that much more expensive. http://www.amazon.com/Grizzly-G0555-Ultimate-14-22-Bandsaw/dp/B0000DD0AC

You would better off using 309L filler for welding mild steel to stainless. It will reduce (but not eliminate) the potential for cracking and will reduce future corrosion in the weld itself. Being in Alabama, the exhaust will most likely rust from the inside out (due to condensation) so an external coating won't help a lot with that.

DOW Deckmate Polystyrene foam. You can get it in blocks up to 4" thick. Because its polystyrene you have to put some bondo over it and a coat of gel coat or release before laying on the fiberglass.

For mild steel the cheap blades work fine. For stainless the expensive ones are needed along with a low speed and some beeswax on the blade.

I have a Milwaukee portable band saw that has worked well for me. The issue with these kinds of saws is the quality of the blade.

Unfortunately what you're biuilding will not be legal in any SCCA road racing class except your local region's "run what ya brung" Improved Touring class. Here in CalClub that class is called ITE. Your car sounds more like a HPDE or Open Track day build. In that case, you have no rules to comply with unless you want to do some type of sanctioned time trials with SCCA, NASA, Redline, or Speedventures. A fuel cell without a bladder is not a fuel cell. Its just a fuel tank and is no better then the stock fuel tank as far as safety is concerned. At least the stock tank has been designed and tested by professional engineers and meets a set of standards. If you do put a fuel cell in your car and are using it on the track I recommend a FIA/SFI approved cell with a bladder.