johnc

Euro springs are NLA. Someone did a custom run of these springs a couple years ago and sold out almost immediately. The Tokico HP and Illumina spring and shock kits for the 280 come with 185 lb. in. front and 200 lb. in. rear linear springs. While they will lower your car about an inch (depending on how much your car weighs) dynamic ride height will probably be higher then what you have now or with the euro springs. Your suspension won't compress as much given the higher rates and better damping. You can also machine a small spacer for the upper spring perch or run a spring rubber to get some of that 1" drop back. I sell the kit and have shipped them to Denmark and Norway.

You should be OK with a 2.25" exhaust and a turbo muffler. But just in case, buy a 90 degree 2.25" bend, flare one end to fit over your tailpipe, and clamp it in place with the open end pointing away from the sound meter and angled towards the ground. It will look like crap but will knock at least 2db off your reading.

Sticky.

The bolt is an M10 x 30mm x 1.25p if I remember correctly. You should be able to source it from most any metric fastener supply in class 8.8.

The old school way was to prevent air from going under the car. New school is to allow air under the car but control what its doing. Changing from one to the other will take more testing and head scratching. IMHO, FWIW.... Reducing the size of the front air dam reduces frontal area and should increase top speed. You might have some stability issues to work through and working with under tray shape can resolve some of those. If you look at this web site: http://www.mulsannescorner.com/ you can see a lot of examples of undertray work for maximum down force. Less extreme forms under your car can generate smaller levels of down force helping stability at either end of the car while minimally affecting drag. EDIT: What you're trying to achieve is this kind of a down force profile: http://www.mulsannescorner.com/diffuser.htm

Got the rough machined prototype and I've welded the shaft to the flange. Next step is more machining, heat treating, final machining, broaching, and case-carburizing. Material is 9310 which is typical for carburized gears.

25.2" tall tire. 4.64 ratio

3 x 2 x .083 is overkill. You're looking at what... 600 ft. lbs / 2 (300 ft. lbs.) spread over a beam that's 18 to 24" long? According to Machinery's Handbook 26 a 3" x 2" .083" ERW tube can support 4,500 lbs at the mid point of a 24" span supported at each end. You can also look it up here: http://www.steeltubeinstitute.org/pdf/brochures/beam_load_table_bro.pdf

The length measurement is fron the back of the exhuast valve and includes the exhaust port length, header primaries, secondary y pipes, etc. When you hit 3" all merged together you should be 28 to 32" from the back of the exhaust valve.

28 to 32" is typical from the back of the exhaust valve to the last merge for the cylinder displacements we're working with. If you have to miss the length for packaging reasons, longer is better but try keep it with 10% of the range above.

Testing your garage flow at low speed is useless because you're not getting any weigh transfer. You need to run the car up to a real road speed and test. Don't do anything to your brake system until you go out and do some real testing at 40 and 60 mph.

Ron, You missed the vertical surface on the hat.

What a fascinating story. Sorry to hear about her passing but she had a great childhood.

It matters but I doubt anyone has taken the time to weigh the parts.

Go for it.

Exactly! John Benton's shop (http://www.bentonperformance.com) is across the alley from mine and over beers after work we've talked many times about the things needed to make power from the Porsche flat 4. Twin plugs are a band-aid - although a very necessary one in some cases. Absolutely not needed for the L6.

I don't know. I use merge collectors built to spec by SPD. http://www.spdexhaust.com/pdfs/02-11_Merge_Collectors.pdf

Keep reading. It should take you a week or two to digest the information here before you make a decision. We're not a quick answer kind of forum.

FYI... fluid boiling problems are caused by the front solid rotor, not the rear drums. I've seen 1,000+ degree rotor and 650+ degree caliper temps on the front of an ITS 240Z.

That might be true of a worn or damaged OEM 240Z shocks but I think they are designed to seal the oil inside the unit. I've disassembled probably a dozen 240Z struts with the stock OEM shocks that have been lying prone on a pallet in my shop for 5 years. Its hit or miss whether the units have any oil left inside when I go to tear them down. Some are completely full and make a mess despite my most careful efforts and others have just a tiny bit of oil left inside. The factory gland nut has a double seal and a wiper.

If the single exhaust is designed properly with a good merge collector and either 3" or 3.5" tube then you'll probably gain power over the dual exhaust. Why don't you do some dyno tests with before and after comparisons and let us know?

That app just might make me actually buy an iPhone.

Alignment, alignment, alignment.

Generally (check with your local sanctioning body)... 1. Fuel cell bottom needs to be at least 6" off the ground or make sure that if one rear wheel comes off the car is not dragging on the fuel cell. 2. The cell needs to be isolated from the passenger compartment by a metal sheet. Normally its a sheet metal box that covers the top of the cell. 3. A plastic cell needs to be set in a metal box/can to protect it from road debris. 4. All fuel lines running through the passenger compartment need to be hard line or braided stainless. 5. All lines running though bulkheads need to be sealed and grommetted or bulkhead fittings installed. 6. All lines need to be secured.