Tony D

Yeah, be sure which you have... the Fairlady Z was the L20A powered version, the Fairlady Z Turbo was L20ET powered, and the Fairlady 280 Z was the L28 powered "33 Plated" car in the JDM. Each will have different badging, for nothing other than to denote engine size. The Japan Market has always had a "Fairlady Z" and it has always been a 2Liter Tax-Class vehicle.

Yeah...class rules, er...rule...

The "Lag" ARGH! The higher boost threshold? The supercharger is a full time consideration to allow for more efficient compression. If you mechanically compress at a 1.5 CR, then your turbo which normally would need to flow efficiently in the 3.2 C.R map will not be needed, and you can optimize a turbo for 1.5 CR (which has a much wider application band) and still have the same terminal power, with far more lower end torque. What you are mixing up is a supercharger that acts as a supplementary device, meant to fill the powerband below boost threshold, and a turbo that is sized to provide power with a LOW boost threshold using a LOWER Compression Ratio. This engine will not be running to 9000 rpms. It is limited in that respect. The Supercharger makes for an engine that in effect is a 4.2 L, and the turbo is supplementing that for midrange and top end polishing of the power curve. They are being designed to work concurrently not sequentially! There is a BIG difference in the application. While the larger compressor section may be needed to support the Supercharger's goals, the ultimate design will probably use a very large wastegate to bypass flow the turbine wheel to keep speeds under control, as you are using hte turbo with a boost threshold in the low 2000 rpm range! That's off-idle with the right cam, especially on a serious track car.

On a 2.8L that is NORMALLY ASPIRATED! On a 2.8L that has a 1.5 Compression Ratio Blower on the front, it's exhaust flow will be more like a 4.2 Liter...

My 73 has a big flat spoiler like that on the front, as well as the whale tail on the rear. It's stable at speed. The radiator opening is in the standard spot, but you have to be careful of obstructions---the pictured license plate placement would affect my cooling. Hell, putting ifberglass teeth on the bottom of the rear bumper affected cooling, I had to Appalachianize it and remove every other tooth to restore cooling to proper levels. The opening is right at 2 sq ft, so a duct is critical to proper radiator function. If you duct it, and lay the radiaiator down ALA Z31, you can lower the front of the hood, and make is a bottom-breather, keeping that front end aero-clean.

Thanks for THAT Eric! My wife hasn't spoken to me for the past week when she realized the 'windshield' I brought back from Hollister last Friday was connected to the rest of a 1971 510 Wagon....and a Tow Dolly! Now there's a tasty-looking Fairlady Z, with 'spares' for the 75.... YOU BASTARD!

I would have to disagree! The aero testing showed the "MODERN G-NOSE" increased both lift and drag if memory serves. I know Alan, as well as I pointed out that the MODERN G-Noses were NOT 'identical' to the original parts! Indeed the very subtle differences between the modern knock-off and the OEM pieces were enough to cause some disparities in the testing. Noted later on the MSA Type 3, little things like not having a radiator tray that goes all the way to the radiator, and having an under apron that does not completely cover and streamline the air's entrance under the car (leaves the flat piece of the lower radiator core support showing) DO have a great effect. Without knowing the period peices, you would make the wrong assumption that the original G-Nose was really trash----based on testing done today with today's parts. As a outcropping of the testing, we know if you buy a G-Nose in the USA (as the test unit was) you need to do some work before it 'works'! And I think this is part of the point Alan is making. If you don't know what the original parts worked like, or looked like, then you run the risk of running a part that while "cosmetically similar" will NOT be "functionally similar"... Granted, we all want stuff that 'works' but a lot of people think if cosmetically its 'close enough'....where the testing has clearly shown this is not the case, especially with aero parts!

That African Safari Car photo is interesting! Gas Strut and obviously the Steel Hatch! It's interesting, but I suppose for the rugged conditions of the EASR a metal hatch would be more suited than the FRP units used in many of the European Rallys. Nice photo. As for period correct parts...I'm a guy who had to fight ignorance of sanctioning bodies due to obviously stock aero body parts being disallowed (or trying to be disallowed) simply because 'nobody else was using them'... Forgive me if my competition is ignorant, but don't penalize me for it! On a curious note pertaining to that whole mess (the G-Nose), seems three other cars appeared at Bonneville this past year WITH the G-Nose on them, and one well-known gent who has been in the Land Speed Runs for over 25 years started building a Z (also with a G-Nose) and in one year, "The G-Noses" outnumbered the cars without G-Noses! I think that little fact played into their 'non-decision' at years end! LOL Sorry to veer off-topic, but it's kinda related... As for 'looking back', take a gander at MonZster's CFD of the mid 80's Style HKS Turbo Surge Boxes. Lot of information gained, and knowledge applicable to TODAY'S design was learned. Not so much what the HKS box did, but when he looked at a 1940's era P40 Oil Radiator, it meshed with what was being seen in the CFD on the HKS box, and a new design permutation was devised. If you don't know history, you are doomed to expend a lot of effort and waste a lot of time to recreate a lot of failed mistakes...find what worked and use it, or at least study it to determine why it worked!

Just about any commercial pipe and supply house will be cheaper than McMaster. In L.A. McJunkin/Republic Supply is a good source, as is Bell Pipe in Anaheim. McMaster is a nice catalog house and they got one of everything, but they also know they have a reputation of having it, and everyone uses them in a pinch, so MRO stuff gets a little pricey sometimes. They (McMaster) also have smokes plexiglass in almost exactly the same thickness as the Stock Side, 1/4 and Rear Hatch Glass on a 240Z...just an example of McMaster Diversity...You can get the same stuff at S&W Plastics in Riverside for about the same discount you noted, OTM.

Er, yeah... the damned bubbles. It also depends a great deal on who makes your plastic as well. "Slow and steady" is a good rule of thumb. I would set the 'oven' to 140 and get it there, stick the sheet in, put the cover on, and then raise the temperature from there to 325 in varying steps. My first attempt at just blasting six heat guns into a box with the thermostat set at 300 degrees had...er...'less than desirable effects'... ahh the impetuous rush of youth. I learned that 140, 225, 250,275,300,325 and then getting all set makes for a nice 'droopy' sheet that you can pick and fling pretty nicely. If you have a cold breeze, or a cold garage, you may want to bring the heat up another 25 degrees to 350. Some of the stuff drapes nice right at 300, other stuff likes it hotter. There is a 'feel' you will get when you do a few. if it's complex forming, and not just dropping it over a relatively flat window buck, I'd err on the side of 'hot' to make sure it drapes and you can form it (like stated with cotton gloves) while it's still hot...it will harden right there before your eyes. Get it too hot, and your gloves stick into it, you scream as hot plastic sticks to your flesh as you realize the cheap gloves your buddy gave you were nylon and not cotton... I digress, but I'd encourage anybody to try it. The cost is pretty low, and the stuff you can do is pretty amazing. I would say I will do it again when I get some time. Burnt fingers and all, the stuff you can make is pretty cool!

Ohh, post five. LOL I'm repeating myself. Argh!

My box had the air coming in from the fenderwell side, with a diffuser plate that went lengthways, kind of like the SK Comp Turbo box you had pictured earlier. You would vent from the inlet side of the diffuser, while the carb throats would draw from behind the diffuser plate. Like I said, I drilled holes at the bottom of the diffuser plate to let the air flow underneath it, and diffuse through the little (er, 3/8" 10mm, but LOTS of em!) holes to the main chamber on the carburettor side. This box worked REALLY well compared to the straight 2X4 plenum bolted to the front of the carbs that I later (stupidly) changed to...and I thought it was some sort of 'upgrade'! LOL I wonder how atrocious the flow is in a 2X4 straight box...yeech! Anyway, my box the air entered the center of the plenum through a single hole (the HKS box shows that maybe 2, 2" holes are better) pointing at the diffuser plate that was angled around 60 degrees inside the plenum which was 2.5 to 3" deep (as I recall, it's 2200 miles away right now). On the bottom of the diffuser plate, about 1/4 of the way from the bottom of the box (which I believe was 5 or 6" tall, and roughly 24 or 28" long) the diffuser bent toward the front of the box---it was bolted with a 1/4" stiffener at the top and bottom to the removable front cover, and there was a flange about 3/8" wide on the box where I used like a million M6-1.0 stainless steel metric bolts to hold it together under the tremendous pressures I was planning to run (yeh...) I believe in this instance, a photo would be worth 1000 words. I think blowing air directly at the carb throats will cause problems, I'd place a segregated baffle in there at least. The whole idea of the box is to allow residence time and let diffuse pressure fill the cavity so the air going down the throats is evenly distributed and without much velocity other than what the engine is calling for at WOT. i might be wrong on that, but it doesn't seem like directly blowing the pressurized air down the carb throats will be too advantageous. The air in the vent section has slightly higher pressure due to the size holes, as you want higher pressure in the vent section to enrichen the mix through raising the fuel level in the jet well (pressure differential greater than what normally would be there from the venturi effect). This is why the HKS box enrichens under boost with much smaller jets, letting you run 350 HP to the rear wheels and still get 17mpg in daily beat the heck out of it driving down Carbon Canyon twice daily back and forth from Corona to Brea.... Remember MonZster is designing a plenum for EFI ITB's and his goals will NOT be the same as someone running Carburettors. The carb guys will want the difference in pressures to allow for the float bowl air pressure to be slightly higher, and therefore you MUST have SOME restriction to flow before the main plenum area the carb throats draw from. What may be possible is using the EFI plenum, and like your box is set up SHO, running that Carb Vent Line from the super-high pressure inlet piping red-zone just before the box (or at the elbow where pressure 'backs up') that would probably allow sufficient pressure differential that would allow you do 'dial in' the differenital using those variable orifices we talked about some time...(er, valves in the lines to the float bowl covers I think).

Something similar happens in my wife's 260Z, WOT and it will hit a wall hard, but feather the throttle back slightly and it will pull further till you get the normal 'fuel is running out of the float bowls faster than it can enter' surging. Unless you got a very capable e-pump capable of forcing 7+ psi through the float bowl needles on the SU's (like the stock mechanical pump does at higher speeds) the float level will change and you start to run lean on SU's on the top end. I haven't solved that...oh, waitaminit, yes I did, I went to EFI! BWAHAHAHAHAHA! I digress, forgive me for being off topic, 'back to your regularly scheduled programming'...besides it was Coffee's fault I'm in this thread, if I misbehave, blame him!

Here I am, 4 years later, late but with interesting numbers nonetheless: As verified by the SCTA at Bonneville: 167.158 F/PRO 172.121 F/GCC 173.325 F/GALT 173.059 F/FALT--fuel used was GASOLINE (yeah, you can do that!) We had F/FCC as well, at a comfortable margin above 170, but were protested and got the record pulled... Most of these same records are ours at El Mirage and Muroc Dry Lakes as well, though with only about a mile to get to speed, they are around 10-15mph less. These are two-way averages, and in some cases the one-way speed may be considerably higher due to a tailwind, or mechanical distress on the return run... El Mirage and Muroc are one-way dashes, like Maxton's Monster Mile. I have watched events there a couple of times (try to schedule my training at corporate to coincide with the events during the summer--training is in Davidson, north of Charlotte.) Interestingly enough after all the dustup, we now may be able to run the 2+2 in "GT" class now, and take that as well... As for photos of Z-Speedos, they are notoriously innaccurate. A Z with stock sized tires will run 4750 in fifth with a 3.7 rear gear and late ZX five speed (stock L26) which equates to 125 mph. The same car with a 3.9 and an early five speed will top out at 5300 (stock L28...er, towing a small trailer...) which equates to around 120 mph. The car photographed at "130" with a late ZX five speed, stock sized tires, and a 3.36 rear gear, in fifth gear (the best scenario possible) 4100 rpms equates to 124mph... Hmmmmm:iospalo:

I am thinking that putting a TK81 on there and measuring resonant frequencies of the head will reveal what benefit there is from balancing camshafts... Of course you would need a before and after spectral analysis.

This is frightening, my series of smaller holes on the bottom of my diffuser plate on the 'Home Made HKS Knockoff Plenum' took that same approach! Like I said, I never actually got to hold the thing in my hand, so I could only guess what HKS did inside the box to diffuse the air after it's hitting the baffle/diffuser plate...I figured best I could do was drill a series of holes equal to or greater than the cross sectional area of the feeding pipe from the compressor! That looks pretty good! I think the key is to diffuse it through that series of smaller holes. I think the HKS Plenum I have can be easily modified to work that way as well...

They have a good reputation in the Muscle Car resto market. They are based out of Corona. Very small ECU box as well! Intuitive learning like OEM "short term and long term fuel trim" as well. I liked their idea of the PWM control on the fuel pump using a fuel pressure transducer to allow a returnless fuel supply. Though for now, their PWM amperage capabilities only support their pump to a 500 HP range---over that you have to lag the Fuep Pul ground at the ECU and run a standalone fuel pressure regulator. The box is VERY small. They are catering to botique sellers, buys that want their own "House Brand" box they package and sell under their own label. This setup is sold be a couple of vendors all with custom application setups (Claude's Buggies is one). I know of a Dyno Shop that is selling these as 'their system' as well, and is very good at tuning and installing them. If you are in the L.A. area and want some names to visit, let me know and I can give them to you for a visit. Their main distribution place in Corona (address on their website) is pretty accessible as well. Cool bunch of guys there.

Yes Jeff, the higher horsepower cars seemed to gravitate towards the Type 1 Box---one of mine has holes that are enlarged. I would think the reason they used the earlier boxes was they were available cheaper once the Type 2 came out, they could easily fabricate the inlet plenum from the 'T Log' the Type 1 used for inlet air, and access to the three diffuser holes was a simple matter of taking the front cover off and having at it with a die grinder. As I mentioned, one of the things they had to do at higher pressures was open the holes up to keep the float bowl from overpressurizing, and basically pushing fuel through the jets---as you can see the kind of pressure differential from upper and lower plenum can indeed cause that kind of problem. But it's a 'good' problem insomuch as you simply run very rich as you over-boost. A broken wastegate would result in you dumping fuel into the engine instead of running lean. Clever, no? For an EFI ITB setup, I'm thinking you could play with the hole size, as you don't really need the big pressure differential, you just want the diffusion at as little pressure drop as possible. On carbs, you would want the pressure to be something more. This is the same issue with Modulator Rings...you have to play with their size to fine tune upper end boost enrichment till you get it right. But hey, 'Carburettors are Easy', right? LOL Oh, and on most High-Horsepower Cars back then, it was TWIN turbos for the flow, so off the intercoolers there likely would have been a pipe to each entry hole, instead of that single entry plenum casting. Times change and you can get that flow from a single now---so the inlet plenum may need some revision to better suit the entry to the box. No matter which way you turn it, a 90 degree bend is going to hurt flow. Especially in the tight confines we have in the engine bay in regards to the strut tower...especially if you want to compensate for engine mount rocking (which is not an issue on your car, granted...but for us mortals with pinned stock rubber mounts...the engine may move a bit!)

THANK YOU RON! I knew that damn switch did something else! For the life of me I couldn't remember. Old age (4X... what year is it again? 2008? Oh yeah, 44 this September!) is a bitch. I could remember a lot more useless trivia when I was younger. Ever watch Bill Murray in 'Groundhog Day' while he watched Jeopardy? That was me when I was 26...same hair, too! LOL

PYP Prices in So Cal have risen with the advent of some marketing guy realizing selling parts for their scrap value, while making for a brisk resale / salvage business, 'left money on the table' so now a transmission costs you $180, instead of the former $75, and the engine will run you around $250 with all accessories. Retail, probably double those numbers. Routinely I see L-Engines sell for $450, and the transmissions for almost as much if they are sought after (like an early a-box five speed)...normally a tranny will be in the $250 range. So in SoCal, I'd expect someone to reasonably expect $700 for the pair if bought separately, and probably $500 if bought together. Separates always seem to sell for more. Pieces parts, you know? That's why just about any Z-Car is easily worth $500, as long as it has engine, tranny and third member, you can recover costs and make it a 'freebie'. My wife, of course, does not understand this, and says to 'get rid of the junk in the yard'---hopefully it's all too heavy for her to move while I'm working on the road.

Yes, I second the ShopVac idea. It will work nicely to either blow low pressure onto the top, or evacuate the area under the form to make the hot drape fit fast and tightly. Especially that 16HP bugger Home Depot is selling (Emerson Electric Plant shut down, so I don't know where it's made now but it was in the town I grew up in: Menominee, Michigan...which also has Coleman Racing Products...hmmmm, maybe I should move back...)

That linked to bad videos that I have since sent around... Those guys mudding the 280ZX are a blast. From what I can tell, they ran it into a tree, mudded it, and generally bombed around in the boonies. The sharp video production skills are nice, but the ham-fisted hilarious attempts at documentation that are linked together on the youtube page make for entertaining viewing. The 280ZX they use sounds pretty bad as well. And they really beat it. I'm going to stop there, before I get in trouble...

And curiously here I sit, in the middle of the day, no parts, waiting. In wonderful Brenham Texas, and I realize "Hey, maybe there's a Z_Club Meeting in Houston this week I can attend!" And I see you're the 'other way'...LOL Off Topic, but the thought just struck me.

Gaads, shipping to Oz seems a sketchy shot at best. I receive stuff from there quickly enough, but I have had simple bulky items that can't go USPS Air take literally MONTHS to arrive in Melbourne! My mate there didn't know he had a birthday coming in September (replete with Motorsport Auto West Coast Nationals T-Shirt, etc..to give an idea of shipping time!) And nobody wants to pay UPS/DHL prices on international shipments. Trust me...I just spent $486 American to ship a 9.5Kg Box UPS Air to Davidson NC! Total for all three boxes was just shy of $1300. Yeech! Talk about "unrecoverable overhead" all that got to be covered in the job pricing!

The original 432 Exhaust is segregated front-to-back, though it 'appears' they share a common resonator, the piping is separated and baffled. Original BRE and other Nissan-Supplied racers used segregated pipes as well. Scavenging has as much to do with pipe size and velocity as anything else. A lot of this kind of discussion is titter and tatter over theoretical points that don't mean anything appreciably in the real world. Look at it this way: Will 2HP really make any difference on your car for the street? Will you be happy with the sound, and can you live knowing that in a theoretical sense, your exhaust system is not perfect (and which one really is?) Some years ago, texts decried mufflers. Today, engines designed around mufflers make more horsepower than those without... Things change. Beware! Sounds good to me, BTW! Then again, I have a 432 Replica Exhaust under mine! LOL Oh come ON! Guys, only FOUR views? Maaaaaaan!