Andrew Bayley

Voo Doo mathematic... That what it all comes down to!!! I know I'm sort of entering this discussion a little late, but I'm hoping I can still shed a little light (and no shadows ) on this subject. I've debated carb size over and over again with myself and others for years. One thing I've learned... it's all voo-doo witchcraft!!! Seriously though, one thing that I recently taught, is to make sure the carb is "listening" to the engine demand. I know this sounds stupid, but it made sense once I read up on it. The basic concept with a carb "listening" to the engine relates to engine speed and engine efficiency. As we all know, an equal amount of air passing through two different diameter tubes, will travel with a higher velocity through the smaller of the two tube... up to a certain amount. With a higher velocity venturi, a stronger "signal" is being pulled through the carb boosters. A strong signal equates to excellent drivability (assuming the jets are correct) at that specific RPM where the signal is strong. Most people use the typical formula of displacement vs. RPM to calculate carb CFM (see Lone's post above). I've always stuck pretty close to these calculations, as they make great base lines for street motors. However, this equation neglects air speed and density. ...enter the voo-doo magic. Basically, when the air flow starts to increase above a certain point, the linear correlation between RPM and CFM starts to go astray. I've still yet to find a good representation of where this "magical" point occurs. Most of it is due to the V.E. of the engine. This next part is what blew me away when I first heard of it. When playing around with large CFM carbs on high revving motors, "fore sight" is needed when calculating CFM. For example, when the motor is at 6500, the carb should really be supplying it with 6800 - 7000 RPM worth of air. The RPM increase is guess-timated by the V.E. of the engine. The higher the V.E. the further forward the carb needs to be listening. Sounds messed up, doesn't it? Took me a while to believe it as well. As for real word examples, I ran three different carbs on my 355 small block. Estimated output is around 350hp. At the track, I recorded the following results: Test 1: Holley 600 CFM vacuum secondaries Shifting at 6100 RPM 1.86 sixty foot 12.61 @ 107.7 mph Test 2: Holley 670 CFM mechanical secondaries (modified 650) Shifting at 6300 RPM 1.87 sixty foot 12.53 @ 110.2 mph Test 3: Holley 780 CFM vacuum secondaries (modified 750) Shifting at 6300 RPM 1.94 sixty foot 12.77 @ 111.1 mph As the results show, I lost a lot of off-idle response with the larger 780 while the upper end seemed to fall off with the 600. All three tests were run back to back to back on an 80 degree summer afternoon (N20 solenoids seized, I had nothing else to do except play with carbs the rest of the day). Well, I hope I haven't bored everyone to death. I've got a great article laying around somewhere that described the "listening" process in much better detail. I'll try to dig it up tonight. -Andy

Awww Damnit!!! Now you guys got me thinking about a twin turbo small block again. ...thanks a lot! (Desiring best of both worlds) -Andy

Thanks for the vote of confidence. The flares I got are the identical 3 inch MSA's. I'm not that concerned about those wheels I told you to look at. Looks like I will scrapping the 4-lugs and going to a 5 lug some time soon here (just decided this morning). -Andy

Hmmm... I don't believe the American 70 - early 71 Z's had the hand throttle. I could be wrong (most likely) but I though the hand throttle was not an option in the American versions. Oh yeah, I forgot that the early 240Z C-pillar emblems were different, thanks for the refresher. -Andy

Mike, I have a few questions about your flares. What size (width) & offset wheel were you running in the pictures posted in the Featured Rides? I've got a set of semi-chessy Eagle's that stick out of the OEM fender wells quite a bit. Don't believe me? Go ahead, check out my last picture in the members rides. Go on now, I'll wait... ...pretty nasty, isn't it. Don't worry I only drive those wheels and tires at the track. Anyway, I just want to be 100% sure that the flares are going to cover up the tires. The rims I got are 15 x 8 with a 3.25" back spacing. I really wanted to go with at least 3.5" or even 3.75" (I got coil overs) but the price difference in wheels was over a $100 just for the offset. Any information on what you've got would be appreciated. Thanks -Andy

These are by no means all of them, but it's what I go by to determine specific years: 70 - early 71: 240Z Rectangular vents in bottom of hatch, turn signals underneath front bumper, reverse lights and tail lights in one common piece. late 71 - 73: 240Z Same as above, except the hatch vents were intigrated into the C-pillar Z emblems. early 74: 260Z Smaller 240Z bumper with 2.5 mph shock mounts, turn signals still underneath front bumper, reverse lights seprate from all other tail lights. late 74: 260Z Larger "rounded style" 5 mph bumpers, turn signals now located above front bumper in the grill. 75-76: 280Z Exterior identical (I think) to the late 260Z, only noticable difference was the fuel injection in the 280 models. 77 - 78: 280Z Large switched to the "squared style" 5 mph bumpers, louvered hood vents. -Hope this makes things a little easier. -Andy

I recall seeing something like that in Zcar mag a while back as well. The only thing I remembered was that the custom water-to-air intercooler split apart somewhere around 180 mph. I don't believe they ever got it much faster than that. -Andy

The amount of "safe" N2O is more a factor of the extra fuel available. With carburated systems, things couldn't be any simpler. Make certain that the fuel line in the carb plate has at least 5 psi of CONSTANT fuel pressure. Personally, I run my setup at 7.5 psi. This allows me to run normal sized jets in the carb for street driving, and is also an added security. As for "how much", jeesh the only suggestion I can say is to start small and work your way up. A good start would be a 125hp shot. Most healthy small blocks will accept this much "juice" fairly nicely, even with stock components (as long as the proper fuel PSI is supplied). One key thing to consider is multi-stage systems. This is where a small(er) shot is sprayed intially, then a larger shot is sprayed at upper rpm's. The main reason a lot of people use multi stage systems is becuase N2O can be potentially deadly at low(er) rpm's. Once the cylinder velocity increase's, more N2O can be added. But at the low end, keep it easy. I am currently running a "modest" 125hp shot off the line and I am still breaking driveline components with drag radials. As for fuel injection systems, I personally stay away from "dry" manifold setups. I was able to safely run a 150hp shot in an LT1, but it was a lot of work and EXTREMELY tempremental. The slightest change in temperature would send the system either way lean or way rich. Also, the NOS supplied in-line fuel pump crapped out after about 5000 miles. I'll agree that NOS sells some real "shady" equipment. However, I can't say that anything else I've seen is much better. Good Luck -Andy [This message has been edited by Andrew Bayley (edited November 13, 2000).]

...stupid T1 connection [This message has been edited by Andrew Bayley (edited November 09, 2000).]

Also, If the the timing chain jumped a tooth this might cause the "glowing manifold" problem. Something very similar happened to me on a 2.3L Furd. Timing BELT jumped about 15 degrees advance. Yeah, it would run... but not very well, and the header was glowing BRIGHT orange. Good Luck -Andy

Oh my god, Someone is actually using what I said as an information guidline... Seriously though, Chris, I'm not surprised to hear that you've only got ~1 inch above the seat belt pockets. There are a lot more subtle differences between the 240/260 and the 280 than most people think. My ledge is about 3 inches wide. I did the same thing you mentioned where I welded the tubing to the flat plate then welded the hoop w/ attached plate to the car. The way that the main hoop was sized from S&W it appears that they intended the main hoop to sit in the vacinity of the retractor pockets. However in my 260, the loop would have been at a slight angle to the B-pillar (due to the 3 inch ledge above pockets) if I decided to go this route. Also, I was interested in retaining the passenger seat belt. Very interesting thread we got going here. I'm wondering if we could at least put together a FAQ and put it up in the technical documents section of this page. -Andy P.S. I'm going to try like hell and get some digital pictures of the cage this weekend (in storage at Dad's place).

Dry Ice, hmmm... I'll have to try that next time. I received eight 4" x 6" plates of 1/8" thick mild steel with my cage. Your right, they are nothing fancy. I think even Home Depot carries this stuff if you didn't get it.

S&W supplies all the plates needed to weld the cage to the body. These pieces made my installation MUCH easier. Do yourself a favor, invest in a really nice gasket scraper. This will be needed to remove the insulation material off the floors. I started off with a large screwdriver and that just didn't cut it. It was tempting to use an air chisle, but I kept reminding myself that I was working on Japanesse sheet metal from the 70's. As for Gusset's, I believe S&W will sell a bag of twenty or so for cheap. Try them first. Again, good luck -Andy

...WOW, that's a little too close for me. I'm suddenly remembering why I have two fire extinguishers on board. Glad to hear that nobody (or nothing) was hurt. -Andy

I agree... That S&W 8-point is quite the heavy weight. -Andy P.S. Mike, I think I would have a difficult time sneaking my car through the main lobby here to work on it [This message has been edited by Andrew Bayley (edited November 07, 2000).]

Not sure about the Z efi, but most domestic cars prime the fuel line for about 1 sec when the key is switched from OFF to IGN (ignition on). You might want to try turning the ignition on for two seconds, then turning it off. Repeat this process... oh, about a hundred or so times. Next, find the schrader valve on the fuel rail (it looks like a valve stem on a tire). Press the center of the valve and see if gas shoots out. I realize this is not the safest technique , but you will definetely know if there is pressurized gas or not. Good Luck -Andy

Hmmm... If it can't be described in ohm's law, I probably wont understand. My tubing DID have an apparent seam in it. I can't confirm that it was welded or not, but I did see a seam. void ROLLCAGE(void) { if unsigned char SEAM == WELDED { Quality = garbage } else { Deal = Good } } (some one has spent a few too many hours coding today... sorry) -Andy

Thanks for the reference Pete: To clear up any confusion, The S&W cage kit is NOT a bolt in unit. Basically, S&W provides all the material needed to do it yourself. The big thing I was concerned about was the main hoop. This was something I could not bend up myself. As for the back supports, door supports, etc... I had to get creative. S&W provides tubes that are cut to "generic" lengths. From what I saw, most of these "generic" tubes were cut for use in a tubbed out Z car. For example, the "generic" rear supports landed right smack dab in the middle of the spare tire well. I had to shorten the bars a bit and increase the verical angle on them. It's pretty steep, but still within NHRA guidelines. Getting the main hoop to fit did require some finnessing One thing that S&W didn't account for was a decent seat brace. Basically, if you're taller than 5 feet, the seat brace needs to be set back. I stole this idea from Mike Kz's pictures in the readers rides. I only set the bar back two inches. I would recommend at least three inches for anyone close to the 6 foot mark (I'm 6'3"). All in all, I am very happy with the cage. A friend and myself installed it in about 6 hours. My friend is a very experienced welder, so that helped speed up the process a bit. The most important thing I learned about doing this was preparation. We had everything ready to go, and that made all the difference in the world. The following is a list of the tools I used: Wire Feed Mig welder Drill Press 2 1/16 metal hole saw Circular metal cut off saw Chisle (to get rid of all the insulation) ...and a whole lot of beer If you desire good welds, I recommend preium beer. If anybody looks at some of my welds, they can tell I cheaped out and went with Milwaukee's Best. As far as seemless tubing is concerned, that factor didn't play to heavily in my mind. If a bar is going to be loaded to the point where the weld is going to split... the crash would probably not be survivable regardless of what material was used. Just my $0.02 Good Luck in you search -Andy

Ross, Waaaay back in 1995 a friend and I built up a draw-through L28T engine for my friends 240Z. For the amount of money we had into that project, (or for that matter, DIDN'T have) the car ran amazingly well. The first thing we decided was which method of fuel induction we would use... EFI, suck-thru, or blow-thru. The EFI route was just too expensive at that time and we were having a difficult time figuring out how to properly "boost" reference the carburetor in a blow-thru application. The logical, and final, solution was to use a suck-thru design. In building the setup, we were procured a L28T head, exhaust manifold and turbo for $40 (all in great shape). The turbo head was bolted to the 280ZX na block. This gave us a slightly high compression ratio of 8.5:1 Next, we welded a common plenum joining the two separate SU intake manifolds. This wasn't the prettiest thing on the engine, but it worked. Next, we welded a pipe to the bottom of the intake plenum directly below the compressor outlet. Now, this is where things got tricky. We took a two inch mandrel bent exhaust piece and welded a square funnel-like deal where a Holley four barrel sat. It was a very awkward looking setup. Most people's first comment were, "Your carb's in the wrong spot!" Anyway, we capped the project off by going with a full 3 inch exhaust. As for how it drove... well that could be debated for a long time. Once the car warmed up, it ran "good". However, it was a royal b-i-t-c-h to keep running when cold. Warmup usually consisted of at least a good 15 minutes. Under warmed conditions, the car would pull very hard. We only had 10 psi of boost, we were afraid to go much higher. Regardless, it was MUCH quicker than before. Throttle response leaved a lot to be desired though. It took a good bit of finessing to drive that setup to it's full potential. It would often bog, or sometimes even backfire thru the carb when getting on it below 3000 rpm's. Also, we wanted to run the larger T3-T4 hybrid turbo but could not. I guess the T3 uses a compression type seal between the compressor and main cartridge. This allows the compressor to hold vacuum without sucking in a bunch of oil from the main cartridge. The T4 compressor did not have this seal, so we could not use it in a suck-thru design. A few years we both agree to convert the setup to a blow thru design using a 4 barrel manifold for the L-series motor. However, my co-part was losing interest in the project quickly and I started playing with the V8Z a lot more. This setup is still sitting in my friends back yard rotting away. It hurts me to see it there, but I can't imagine too many other people understanding much about what we did. Heck, most days it amazed myself that it even worked! Again, the car ran strong. The motor was in a 71 240Z with the weaker 280ZX na 5-speed and a 3.7 open R200. On a warm summer evening, he ran a 13.6 @ 100.1 down the 1/4. Also, I know of two autocrosses in Michigan (and one in Minnesota) where this car set fastest time of day. So, it wasn't slow by any means, it just wasn't the easiest car to drive. However, we did manage to take this car all the way from norther Michigan to the Gulf of Mexico in one weekend and we also made it to the 1997 Z car convention in York, PA. I think the final nail in the coffin for the old draw thru design was when my friend and I swapped cars while coming home from the convention. He immediately fell in love with the throttle response and the on-demand torque. I could tell by the way he was driving it Sorry for the long winded response, I've got a few too many stories to tell. I hope I didn't deviate from the main topic too much -Andy

MSA Long Tube headers work just fine with the JTR kit. I've got a VERY LARGE oem starter and it fit's fine with the long tubes. Getting the starter in and out, however, is an entirely different story. I really don't think header selection is going to limit engine setback. Even the long tube headers allow me to set the engine all the way back to the firewall. In fact, it is very difficult (to the untrained eye) to notice any differences between a set of long tubes and block huggers. They can 'sort of' be seen from up top while looking down on the drivers side. But unless your looking for them specifically, you're not going to notice. I tried to get MSA to cough up supplier names and part numbers, but they were reluctant. Do you blame them? A '23 Ford T-bucket with a SBC sounds right to me. At that time I decided to go with long tubes, my father really wanted some birthday present idea's. I made it a little easier for him and just gave out the MSA #'s. I think I'm going to hit him up for the 383 conversion this year Not sure if my wife will agree though... -Andy

I just wanted everyone to know that I "feel their pain." When I bought my 260Z, all electronics worked just fine. Within a month of driving it, EVERYTHING shorted out. The only stock switch I managed to save was the turn signal stalk (I really had to work for that one too). Every inch of wire except the harness going to the rear lights had to be REPLACED. What a headache!!! If a small problem arises, take care of it immedately... more are sure to follow. Pete, it would not surprise me the least if Lucas "Prince of Darkness" Electronics designed the wriring for these cars. After all, they made Jaguar of the 80's the reliable car company that it was. I knew it was time to leave TRW when they announced they bought Lucas Varity. They were working on electric steering. Now "that's" scary! -Andy [This message has been edited by Andrew Bayley (edited October 13, 2000).]

Randy, I totally agree that a turbo 302 would kick butt. Check out the following site: http://users.erols.com/cosby/stang/ Nice article on an "INCON" twin turbo 302 Mustang setup. I saw a vendor selling one of these kits at a Detroit area auto show and it looked very nice. Well put together, no cheap looking parts. I believe the price was somewhere around the three grand mark. Not cheap, but there's a lot of good stuff included. Now only if someone made an inexpensive twin turbo kit for an LT1. Hmmm... Turbos kick ass, no matter how you look at it. -Andy

Bruce, There are quite a few people on this list alone that are pushing well over 400hp through a stock R200 Datsun Differential. The weak link seems to be the U-jointed half shafts. Some people claim success, while others complain of catastrophic failure using the stock units. Personally, I've run a handful of 1.6xx 60 footers through a stock half shaft. Yes, it held up... for a while, then it finally broke loose taking out a brake line in the process. I'm glad I was still in the staging area and not running through the big end Hopefully all these problems will be solved with the 280ZX turbo CV half shafts. Look into the "Driveline" section of this list and there should be a few threads about CV axel conversions. It sounds a little tricky, but seems worth while. As for the brake and suspension, I am still running bone-stock-OEM brakes all the way around. I've never had any fade problems at the track, even from +120mph. Also, for a long time I was running stock suspension (springs are struts). Two years ago I went to a coil over setup specifically so I could fit more tire under the fender and get a little rake out of the car at the track. I figured if I was doing the back... might as well do the front. I guess it really didn't need to be done in the front, it was more the back that needed to stiffened up a bit. Well, good luck in your pursuit. If you need any "less than perfect" Z parts, I might have a contact for you up in Duluth. A friend of mine up there took two of my old Z cars and I'm not sure if he still has them anymore or not. -Andy

Wow, I thought every last Z car in Minnesota had rusted into a fine dust. I've had many wonderful (and slightly reckless) experiences with Z cars and Minnesota. Something about trying to beat a Grand National on I-35 in downtown Duluth that brings a tear to my eye. Needless to say, the 45 mph speed limit was WAAAY exceeded. Welcome aboard. As for the tube front end, ask Ron Jones what he did. I "believe" he is running something similar to what you previously described. Good Luck -Andy

Pete (and others): I hate to say this infront of everyone, but I've never done anything to prevent heat soak in the starter. I guess I always expeted to have starter problems on a hot summer afternoon... but alas they never arose. At first I commended it to having header wrap on my block hugger headers. However, the main downpipe that passed directly under the starter was totally bare with no insulation at all. Still, no starter problems. I use just a basic generic GM starter. I'm not sure what vehicle it came off of, it's been used on EVERY V8Z I've ever built (a course of 5 years). It's very big and extremely heavy. I've often thought of swapping in a smaller mini-torque, but the one I've got works so well. Anyway, I next swapped out the block huggers for a set of long tubes while adding a bit more compression to the engine as well. Still, no starter problems. I'm actually starting to get worried. For all intensive purposes I "should" be having starter heat soak. Don't get me wrong, I'm not complaining... I'm just wondering why I'm not having the same problems a few others are having. I guess one area to be suspecious would be the starter wrap. I could see how it would help keep heat out... but once heat found a way in there... wouldn't it also help contain the heat? Also, is the exhaust the only source of heat for the starter? I suspect the a good deal of heat is also being transferred through the engine block. Once the heat works it's way from the block into the starter, the heat shield/wrap might actually hold the heat inside the starter. I may be crazy, but has anyone else thought about this? My underhood temps get nice and warm while sitting in traffic. I've seen 220 - 230 on the temp gauge a few more times than I would like to admit. I blame most of this due to the uncoated long tube headers. I'm starting to think it would be nice to have them coated while the engine is out. I am NEVER going to install those long tube headers while the motor is in the car. PERIOD!!! But that's a whole 'nother story. Anyway, I just thought I would add my $4.95 (fed tax, state tax, tip and destination charge included). -Andy P.S. Check it out, triple digit posts for me. Yeah!