johnc

It sounds like the shoes are still extended enough to either contact the drum or interfere with the wear ridge when you're trying to remove the drum. Turn the drum so the adjuster hole is straight down and look through it with a flashlight. You'll see the wheel cylinder (spray some Brake Kleen in there if it all looks dusty) and just below it is a sheet metal stamping that's part of the brake adjuster. Use a screwdriver to pry that stamping down, away from the wheel cylinder until you hear it release (a little pop). Then rotate the drum and forward until the adjuster hole lines up with the serrated adjuster teeth. Use the screwdriver to spin the adjuster backwards. You'll probably have to put about 3 to 5 turns into it. The drum should slide off once you've backed the shoes off enough. The rear drum brakes on an early Z actually work very well and they are very light. On a racing 240Z, the braking issues are mostly with the front brakes, not the rear drums. Like any drum brake, you have to constantly fiddle with them to make sure they are adjusted properly and everything works perfectly. [ August 24, 2001: Message edited by: johnc ]

Who am I to argue with Larry McReynolds... I searched the NASA Technical Reports Server using the terms: "extraction", "extract", "exhaust", and "vent" in conjunction with "submerged duct" (the proper term for a NACA duct) and didn't find any documents. It appears that no one at NASA, NACA, Langley, Ames, Dryden, etc. felt a need to research how a submerged duct works as an extractor. That doesn't mean it doesn't work and I'm not saying that Larry didn't get air out using a reversed duct, but maybe the air came out because it was pressurized in the confined space vented by the duct? Here are probably the most relevant research papers on the design of submerged ducts: An Experimental Investigation of NACA Submerged-Duct Entrances Charles W. Frick Wallace F. Davis Lauros M. Randall Emmet A. Mossman NACA ACR-5I20 November, 1945 http://naca.larc.nasa.gov/reports/1945/naca-acr-5i20/ An experimental investigation of the design variables for NACA Emmet A. Mossman Lauros M. Randall NACA RM-A7I30 January, 1948 http://naca.larc.nasa.gov/reports/1948/naca-rm-a7i30/ An experimental investigation at large scale of an NACA submerged intake and deflector installation on the rearward portion of a fuselage Holzhauser, Curt A NACA RM-A50F13 August 30, 1950 http://naca.larc.nasa.gov/reports/1950/naca-rm-a50f13/

The hood isn't the expensive part. The mold is where the money goes for this stuff. I would expect a correct and perfect mold for this hood to cost about $5,000. Who's covering that cost? FYI... Hiten Patel already has a good mold and a couple complete carbon fiber hoods done for his EP 240Z. They weigh about 7 pounds without hinges or latch. Because of the mold cost, he sure can't sell them for $600 each.

Personally I don't know of any racer using progressive rate 2.5 or 2.25" coil over springs, at least by choice. One of the big reasons to run coil overs is how much easier it is to swap springs to setup a car for a specific track. Normally, shock tuning is used to adjust what the street oriented progressive rate springs are supposed to do. Progressive rate springs make shock tuning much more difficult, if not impossible. That being said, they do work well on street cars.

Rear stud pulling tip (sounds like a line from a porn movie): A strategically drilled hole in the brake backing plate makes rear stud removal incredibly easy.

If you can't scrounge the correct parts from a junkyard, then order the parts from Nissan Comp or MSA. 1. $600 for a new ring and pinion in whatever ratio Nissan offered (from 3.36 to 4.38). 2. $800 for a new Nissan Comp LSD. 3. $50 for an R200 case out of junkyard. 4. $200 for a good driveline shop to set it up. 5. Search the archives on this site for the "how tos" on swapping the R200 into your 240z.

I'm confused...? You can run any ring and pinion combination avaialbe in an R200 with pretty much any LSD. If you want to run a 3.36 or a 4.38 R&P with a Quaiffe, Nissan Comp, or a welded up set of spiders then you can. You just have to get the correct parts and assemble them.

I do agree that the GM (Buick) 3800 is a great engine, its still a pushrod tractor motor (ducking... Spekaing of tractor motors, I was looking at this as a "daily driver": http://www.vipclassics.com/stk1540525.phtml I think I'd look cool driving this with a crew cut, white oxford shirt, narrow black tie, and some Ray Bans. [ July 16, 2001: Message edited by: johnc ]

> I'll be interested in feedback from John > Coffee! You think (after paying stupid amounts of money for my engine) that I'll say anything bad about it?

I talked with 3 engine builders (Javier at JG Engine Dynamics, Don Potter at DL Potter, and Jim Thompson at Sunbelt) and they all suggested I stay away from the Electromotive Tec2. Inital setup, stability, and maintenance of the fuel and ignition maps were their biggest complaint. I've seen, first hand, sections of the maps "disappear" from a Tec2 configuration while a car was running - talk about a "flat spot"! Hopefully Electromotive has corrected that with the Tec3.

I'm having Jim build an engine for my exBSP 240Z to run in the new Street Modified 2 SCCA Solo2 class. For more rules information, go here: http://streetmodified.org. My engine requirements are: 1. 3.0L max displacement. 2. Normally aspirated. 3. As much and as flat a torque curve as possible from 3,500 to 7,000 rpm. 4. 275hp minimum (at the crank as measured on their Clayton dyno). 5. Runs on 100+ octane fuel. 6. Less than 5% leakdown over 200 hours of use. According to the SM2 rules, the minimum weight of my car with that engine configuration is 1,900 lbs. Right now, my car weighs 2,260 lbs. I should be able to easily take another 200 lbs out of it and still meet the rules. I think the car will be pretty quick... When Jim dynos the engine I'm flying out there and video taping the event. Probably sometime near the end of August. Why did I go with Sunbelt? 1. Conversations with Keith Thomas and Don Potter. 2. Donn Vickrey's Sunbelt ITS engine pulled 10 car lengths Bryan Lampe's JG Engine Dynamics ITS engine on the dragstrip at Firebird Raceway. 3. A long conversation with Jim Thompson about heads.

The problem I saw could easily be tuner/driver error. Another admittedly anecdotal story: Vic Sias lost all of his fuel/ignition map above 5,000 rpm on the first day of the 1999 San Diego Solo2 National Tour and he had to fix it in his hotel room. He lost a great chance to win the two day event. Why did he lose the map? I don't know. Again, it could be his mistake. I've never personally used any Electromotive product and am really only relaying what the engine builders above told me and what I've seen. Vic Sias has won bunches of Solo2 championships with his TWM/Tec2 setup so it does work well. Also, the engine builders I list above are distributers for competing engine management systems (Sunbelt - DTA, JG - Motec, DL Potter - ?) As with any advice/opinion - YMMV...

Mike, I'm having Jim Thompson at Sunbelt build me a 3.0L L6 and he STRONGLY recommended DTA: http://www.dtafast.co.uk/. I later talked with Javier at JG Engine Dynamics, who is a Motec distributor, and he said DTA was about the best. That's what's going on my engine. If you can wait until the end of August, I'll tell you all about it.

How about a Quaiffe? For about $1,000 for the diff and $180 installation it bolts right in to an R200 or an R180.

This is a racing battery and probably not up to the demands of a street car. I do keep it on a trickle charger when the car's in my garage. It works fine to start my 9.5 - 1 compression L6 after hot soaks and on cold (20 degree) central California mornings. I've also used it to jump start a friend's Dodge Cummins Turbo Diesel! Shoulda seen the harassment that guy got when the other competitors saw my little Datsun jump starting his Dodge. FWI... the battery costs about $125 last time I checked.

You can save more weight with a racing battery. I run one from the Race Shop in Garden Grove, CA. 4" x 3", 660CA, and it weighs 12 lbs.

Along with the Marsch, any of the Bogart based wheels (Monocoque, Taylor, Litespeed, etc.) are very light. I have some 3 peice 15 x 8's on my 240Z and they weight 9.2 lbs. each. As Mike said, they are NOT for driving on the street. Very lightweight wheels also require maintenance. At least once per year I have to scrape the Permatex Gray sealant out, re-torque the rims, and reapply the sealant. If I don't the rims start leaking air.

Ya know, if you can cover the carbon fiber dash with some very stock looking vinyl, then a lot of cheatin' racers might be interested...

I think what we need is a row of spoons taped to our rear spoilers!

T56s are huge! You can get a brand new Quaife 5 speed transmission with your choice of gears, input shaft, and tailshaft for about $1,800.00. For an additional $350.00 you can get it with an aluminum case and cover that lops off an additional 20 lbs. Sequential 5 speeds start at $4,500.00 if you want to really get fancy.

Funny... I did a search of NACA, NASA, Dryden, Edwards AFB, Langley, and Marshall technical report servers and only found 6 references to Coanda in all of the published flight research from 1920 through today. These mostly had to do with vectored jet thrust research. I'm not disputing the article, it just seems that little basic research has been done on this effect.

Frank, I don't want to sound like an *******, but as I've posted before in this thread: > And the recent discussion about the > Advantage CFD software in the June issue > of Racecar Engineering confirms that, > without a rolling ground plane, wind > tunnels are inaccurate by some significant > numbers when testing underbody aero. Your wind tunnel idea would be great for overbody testing but when you start working under the car, the road, spinning tires, suspension movement, ride height changes, et. al. are very significant contributor's to your ultimate results. Everyone, At 200 mph you are taking a big risk relying on bent up street signs and yarn tuft testing. Aerodynamics are the big issue, but there are a lot of other things you have to check: 1. What happens to the rear hatch, door, hood, rear 1/4 windows, cowl finisher, fuel door, and inspection panels at speed? 2. Can a stock windshield and gasket handle that air pressure without blowing out? 3. Can the wheel bearings, spindles, stub axles, differential, halfshafts, brake drums, rotors, wheel studs, etc. handle the rpms they will be experiencing at 200 mph? 4. What happens to the car if a side window blows out at speed? If you are going to do this, work up to that speed slowly over a period of a few weeks. Kinda like what the Thrust SSC team did on their quest to break the sound barrier. Going 200 mph in a Z is a similar accomplishment.

For racing purposes, Porsche engines generally work out cheaper over the course of a season than most others. A friend who raced a GTS Dodge Viper in the ALMS series last year did some figuring for the GT class this year (where Vipers based on the production car chassis run). He calculated that it would be about $150,000 cheaper over the season to run a Porsche GT3R even though the initial costs were higher. Almost all of those savings were in the cost of engine rebuilds/refreshes. [ June 22, 2001: Message edited by: johnc ]

Also, current L6 cranks have problems when you run 14:1 or higher compression and run consistently over 8,000 rpms. Bearings need to be replaced frequently and the crank needs to be checked often. But, we're talking about full race GT2 NA engines making 350+ horsepower.

> Increasing rear sway bar will decrease > roll in favor of skid, right? IE, more > rear bar equals more oversteer? As a VERY general rule of thumb that's true, but sometimes reducing overall vehicle roll (thus reducing positive camber gain) can improve the tire's grip, thus increasing traction. > I'm getting really comfortable with my > current setup (although no track time > yet), except for it's tendency to > oversteer. All of the discussions in this thread are about running a 240Z on the track which is remarkably different that any street driving. You might be surprised how differently you car's balance is at speed. > I don't have a rear sway bar, was planning > on installing one, but now I'm having > second thoughts. At your first track event, run the car the way you have it setup now. Then decide what you might want to do to change the car's balance. > The front bar is stock (71 240). I have > 150lb springs front, 175 rear. It's stiff. > You guys talk about 250 or 300lbs per > corner?! Yikes. My car is like a > skateboard. Expansion joints on the > highway are torture. But, on a track, its pure joy! The feeling you get when you're foot to the floor (or almost there) as you hit the apex of a corner and pass a Porsche 996 just after corner exit is a real ego booster! Those Porsche guys just give up trying to drag race you down to the next corner 'cuz you have such a nice head start.