johnc

When ever someone brags to me how much horsepower their engine makes, I always ask, "Is it running?"

Talking with a few engine builders over the years, the basic header design for a normally aspirated L6 is as follows (at least in my mind): 28 to 32" primary length from the back of the exhaust valve to the central point in the collector where all the primaries finally merge. That will be the final merge collector/Y pipe in a 6 into 2 into 1 design or the collector in a 6 into 1 design. All lengths should be identical and longer is better. Primary OD should be 1 5/8" to 1 7/8" depending on horsepower and rpm goals. Most common is 1 5/8" and you need to be making over 300 hp to go to 1 3/4". Over 340hp and you'll need the 1 7/8" primaries but only if you're spinning over 8,500 rpm. Run good, fabricated 12 to 15 degree merge collectors with a cone on the exit to the final single exhaust. The minor throat should be 80% of the cone exit. No muffler shop "Y" pipes. Run a big an OD single exhaust pipe as you can fit. Typically 3" for the power levels we're talking about. All mandrel bends, welded square, and with a few or as shallow bends as possbile. Use a 6" CLR bend over a 4" CLR bend if you can fit it.

Nope. This is car site (Zs specifically). We don't want to see folks selling their sex dolls and old Starland Vocal Band album collections.

Bad Tony! Go back to your room! FYI... Its most likely not a Nissan rod.

You've answered your own quesiton.

You scared the car so bad it shit a parachute!

Not bad. Spray with a high zinc primer, POR15, or some other rust treatment.

They are not Nismo headers. They are made by Nissan Motorsports (USA). You order them through a dealer or directly fro Nissan Motorsports if you're a racer registered with them.

I have said repeatedly that caster increase the load on the inside rear wheel. I've said that based on testing I've done on a set of scales. I was wrong. Here's an article from mark Ortiz that explains Caster and SAI. I called and talked with him about it for about an hour last week and I agree with what he states in the article. I don't know how I ended up seeing an increase of load on the inside rear wheel in the test I did, but it looks like the test was wrong.

This rust is worrisome. Pull the front fender and check to be sure the upper frame horns are not rusted through.

That's about 350+ more then the R180 can take in a 2WD application.

The dash bar needs to be welded to the front legs of the door hoops (or the down legs from the halo bar). It does not get welded to the chassis in any place, its a front lateral reinforcement for the cage. If the Redline cage rules allow attachment points 7 and 8 then you can run legs from the dash bar to the firewall as you state. If the rules don't allow 8 attachment points for your cage, don't try to outsmart Redline Tech staff them with your little plan. They are a lot smarter then you and have doubtless seen this before. Also, the additional plating on the engine side of the firewall won't be allowed at all, regardless of the number of attachments allowed. And why are you using .160" wall thickness tubing? The thickest I've ever seen specified is .120" wall in 1.5" OD tubing for the weights your 280ZX will likely come in at. More common is 1.75" .095" wall. EDIT: I just checked the Redline cage rules. .160" wall tubing isn't listed. I think you should download the rule book.

They don't have to be snug. Sometimes its better if they move around a little bit to help reduce spring bind, although they can be noisy. If its a concern you can wrap the strut tube with some aluminum tape to snug things up.

The diff was moved but the transverse link braces and control arms are still in the same place. Probl still exists on the 280z.

You need a fixture to weld headers otherwise you have no idea where the primary outlets end up. Collectors can be purchased from SPD, Burns, or others.

And then there's the braking loads on the tires. The front tires do a lot of work even on a RWD car. On a FWD car they do even more work. As long as the total amount of work they are asked to do is with the capability of the tire, there's really no disadvantage to FWD. When you exceed the tire's capability then you have problems - which is also true for high horsepower RWD cars. F1 on the new Pirellis is a perfect example of how rear tires go away on a high horsepower RWD cars. Watch how quickly the rear tires grain in a race, especially the super softs. Its really hard on a high horsepower RWD chassis to get the fronts to do enough of the work. On my old race car the biggest focus was on getting the fronts to do as much work as possible because the rears would go away towards the end of the session. Its the same problem the FWD racers face, just on a different end of the car.

Its a chicken, not a hamster. Not enough blood in a hamster. My method is: 1. WTF? 2. Why did I do that? 3. Hope no one finds out. 4. Better fix it. 5. That worked. 6. Better just leave it alone from now on.

Preparation wins races. To be even more nit-picky, nothing we do is science. Its just application of technology. Science is that whole Theory, Experiment/Observation, Document, and Publish thing.

Science doesn't win races. I can do lots of science to prove that the odds of Jack winning his class in that race were slim to none. That's my point. You and I can do lots of science here on the Internet to show that a FWD can't win against a RWD car "all else being equal" and none of that means crap when the green flag falls. Its Internet Engineering Masturbation.

Remember the thread about the TEP poly upper insulators? You've made something far worse. You'll snap a shock shaft in a few hours of driving.

I would put the main hoop as far outboard as possible between the speaker and the front of the wheel well. Use the mounting plate allowance to build a little platform/box that ties in the beam, front of the wheel well, and the vertical side panel. Tieing in those three body panels will make that mount very strong.

"All else being equal" is a BS Internet Engineering argument. Nothing is ever equal. The race I posted above was in an unlimited race category (Super Unlimited) with NASA. Again, a H1 class Honda Civic, driven very well, beat a lot of big dollar RWD cars on the track. FYI... Jack's Honda had to weight 2,400 lbs with driver. That was 200 lbs. heavier then the GT2 RX7s he was running against.

FWD cars have won the Indy 500 a number of times. You guys can argue Internet Engineering all you want but when the green flag drops, I've seen FWD cars humble many RWD cars. Again, driveline configuration isn't the big issue on a race track that it seems to be on the Internet.

I don't think its a good idea to use that roll bar in your car so I'm not going to offer any advice.

I've always been a counter point to those that claim RWD is better the FWD. Here's an example of how FWD can win in an Unlimited race class. Its even a class limited Honda (NASA H1) beating unlimited Vipers, Corvettes, RX7s, etc. On race day it really doesn't matter what your driveline configuration is.