johnc

A 5.5" backspace rim will require coil overs to clear. You might be able to get away with a 1" wheel spacer and no coil overs (doubtful) but you'll have to installer much linger wheel studs.

It depends on what class you intent to race in. IMHO, its probably not worth the effort. I've done it in the past for a roll bar but really didn't notice a big difference. With a full cage it is probably just extra work.

Well, you're not doing a Halo bar, you're doing regular door hoops. Again, no 90 degree bend limit stated but its best to have the bar coming up off the floor as vertical as possible and the rules do require the part of the hoop going back to the main hoop be horizontal, so in practice you do have a 90 degree bend limit when door the bar is viewed from the side. If you're going to run the stock dash, steering column, and pedal box, start thinking about the dash bar and the two braces going forward to the fire wall. How are you going to fit those, what order to fit them, and how are you going to weld 360 around them? Leave room for welding access in your design.

Halo bars do not have a 180 degree bend limit but must have the arms extending back to the main hoop horizontal.

Get the factory service manual and the book, "How to Rebuild your Nissan/Datsun Engine."

Try replacing your engine and transmission mounts. You can also cut the corner of the floor pan and weld in a new section. Evenly bending that many pipes is difficult. You stand a good chance of kinking one. Another option is an engine limiting strap. Goes on the passenger side and pulls down from the engine mount bracket to the crossmember. If its a nylon strap it won't transmit any noise.

Could it be 1/4 x 28?

Hell, I saw a normally aspirated VG30DE at Sunbelt make 425 hp breathing through a 25 or 30mm restrictor. It was one of a half-dozen LMP2 engines for the Nissan sports prototypes running the American LeMans series. The VG30DET engines run in Nissan's GTP 300ZXT made "crazy" amounts of horsepower according to a friend who ran the engine dynos at Electramotive.

Since you are putting a 280Z suspension into a 240Z then you should use the 240Z strut tube measurements and the 240Z upper insulators.

Those horsepower numbers have been achieved a number of times with the L series engine going back as far as the late 1970s with Electramotive. You're looking at around $20K minimum for the total engine build with a single turbo the better option. Spend the next month reading up on this site before spending a dime. Read, read, read before asking any more questions.

You'll probably be better off cutting the whole roof off the car then cutting holes. Its really hard to get the roof shape correct after a hole has been cut in it. Weld your entire roll cage into the car including the bottoms of the top welded junctions. Temporarily weld a bar inside the car across the C pillar below the factory seam. Cut the C pillar at the seam and near the bottom of the A pillar Use as thin a cutoff wheel or sawzall blade as possible. Clean up the seam area at the C pillar. There's tin solder and lead in the joint, don't want to weld that and definitely don't want to breath it when cleaning up. Weld the tops of your roll cage joints and then reinstall the roof welding 360 around the seams you cut. There's inner reinforcements in the C and A pillars that you won't be able to weld, but that's not a big deal since you've installed a cage.

Make sure you weld 360 around every tube junction. We're now using bore scopes to inspect the welds in places that are hard to see. I generally have to drop the cage through the floor of the car to get a complete weld over the top at the main hoop, door hoops, and windshield bars.

I ran my Contour SVT on Proxes RA1s for two years and 20,000 miles.

No word yet on the Bilstiens. I just haven't had time to do the research.

I don't profess to have engine skills. I was just repeating what Jim at Sunbelt told me when I asked why the engine was so easy to turn over. When I posted IMHO, I should have post WJTM (What Jim Told Me).

Thanks Belshore, Inc. for that. They are the Tokico product distributor for Hitachi here in the USA. Frickin' morons...

The biggest friction generator, IMHO, is valve spring seat pressure. The cam design and valve spring package Sunbelt designed for my engine (and as a package for other L6 engines) has 25% less closed seat pressure then stock yet was good for 8,000 rpm. That and perfectly round cylinder bores, loose forged pistons, a crank that weighed 35 lbs, and lots of detailed work to reduce internal friction.

Don't compare spring rates from one car to another. Different suspension design and wheel rates.

The BZ3012, 3013, 3015, 3016 are all the same shock - same body length, same shock shaft, same total travel, and same damping. Tokico just ships different gland nuts and/or spacers to make different part numbers.

You're fine.

Well... my Sunbelt built 325hp L6 could almost be turned over by hand using the balancer (with the plugs out) so my guess is the power drain in negligible in a properly assembled engine.

The shocks can overhead (very rare nowa-a-days), but what most likely happens on washboard roads is oil foaming. It can occur even with gas pressurized shocks.

IMHO, you want rear rotation on lift throttle in a corner. Its not a problem, its a requirement for a good handling car.

OK, your guys have each had your say. Give it a rest regarding the chain vs. gear drive discussion.

I've installed all of these on customer cars and have never heard of or seen a problem: https://www.pegasusautoracing.com/productselection.asp?Product=3400 https://www.pegasusautoracing.com/productselection.asp?Product=3419-005 https://www.pegasusautoracing.com/productdetails.asp?RecID=1056