Tony D

Good point, yeah, WOT. I don't think it's a viable way to test it anyway. Like you mentioned, getting onto a hill, with a VOM and piercing probes in the correct wires, and going WOT in fourth gear will creep you up to the point where you can read the correct voltage. Nobody said tweaking the stock system was easy, right? LOL

He he he.... his first dyno run down at Jim Wolf was showing 381 Ft-Lbs at 8.39psi at 4500rpm....and that was when he sunk rings on five pistons because it started running lean at 5525rpm when the ECU went from single fire to twice a cycle firing of the injectors! He has since surpassed that mark with the correct tuning of the fuel curve. And to answer that question, yes, he is into pain. Matter of fact, I spent two hours last Friday running a Mustang dyno for him while he ran the map on the ECU again. We got RIIIIIIIGHT up to the section where he formerly was having problems and an alternator diode toasted, and melted the lo-temp solder out of the rectifier block stopping our dyno running for the day. And to be honest, the first 30-45 minutes of that was me learning how to run the thing the most efficient way to get the car up to load quick enough to do what we needed to do. Once we got a routine down, we were mapping four blocks on his ECU at a time. The interface he has for the fuel table is very much like a standalone setup, it allows reburning of the stock ECU in a similar fashion. The problem Jeff is up against now is that there is a point two places on the stock Z31 box where the ECU rescales the map. The first one is relatively low load and low rpm---they use a lot of the OEM for off-idle drivability which is understandable from an emissions and customer satisfaction standpoint. The SECOND switching point is where it will make or break wether the stock Z31 ECU will be able to support the system to the full 600+ HP Jeff wants. I recently dug up an old photo I had taken of Steve Mitchell's Z31, and was shocked to find that Steve's dyno chart had the SAME DIP at 6300rpms that Jeff was experiencing in his setup. Since JeffP formerly made his 415 RWHP number at 5800rpm and 23psi, this ECU anomaly was not an issue. And we had never really discussed with Steve where he was making his 600+ from (730+ ft-lbs of torque!!!) From the dyno shot I had taken, it became clear that Steve's unit was well past horsepower peak, so the dip was not an issue. On JEFFP'S runs, though, he is peaking now at 7000-7300rpm, so that calculation comes right in an area where you don't want an ECU farting and deciding to rescale the map and think about what pulsewidth it should be sending out to the injectors! Formerly this was evidenced by a quick spike in AFR to VERY lean (under boost---BAAAAD!), and then to a PIG RICH situation which took a few to recover from. On our final pulls we were jumping to 12.8 and 13.0 AFR under boost. We were not detonating like before, but the jump was still there. Jeff had JUST put in some parameters to alter the fuel block there to see if it would compensate, and on that run the car started misfiring, though we didn't see the dip before we shut it down. When we shut it down to cool, Jeff added even MORE fuel into the block in an effort to turn the lean spike into a rich spike which would tell us if we could get through that portion of the map without the former problem...and when we started up again, all the AFR's were 1 point leaner than they were before....and Jeff Discovered he was no longer putting out 14.1VDC from his alternator. DENIED! So hopefully we can get contact with someone at the dyno place and show up there tomorrow and FIND OUT ONCE AND FOR ALL if the stock Z31 ECU will handle a 600+ HP L28. He ALREADY has the standalone purchased if the blocks won't work, and he then will know the limitations of the Z31 Box which is the theory he is testing. It's a great bunch of information for people to know if they are planning on using the Z31 ECU. It can handle and make a GOB of horsepower, but to do it you will have to BOOST the hell out of it because at this point it doesn't look like it will handle it over 6200rpms due to that recalculation routine. The software he is using should become available soon, and it will make for a viable option for people who want to use junkyard parts to tune their vehicles similarly to a standalone. It will easily support 450HP... Jeff considered the M30 Box, but I deviled him to the standalone route. ;^P But yeah, he was making 381 Ft-Lbs at 8.39psi of boost at 4500rpm, so 350HP at 7psi should be easily doable. The dyno is irreplaceable BTW. Wheel speed preceeding his 'problem area blocks' are requiring a 13% grade and making passes from 80 to 110mph...kind of difficult to do on the street!

Yes.

On an N/A car it should come to 3500 and that flap should be wide open regardless of load. On a TURBO car, then, YES---then the car must be under load for the turbo to load up fully and suck the proper amount of air to "pin the flap". Like I said, the systems all interact. If you are trying to avoid work DITCH the stock system. To tweak it closely and properly is FAR MORE effort than the couple of hours needed to hack the harness and install the MS-n-S, AND TUNE IT FOR BETTER THAN STOCK DRIVABILITY!

Yerpo! Quite a great effect actually. In this regard, it should actually be said the Blowthrough is the one that is limited, to about 10psi in regards to boost without intercooling. A bolt-on Drawthrough can easily manage 17psi simply due to the fact that the carburettors fuel is impinging on the turbine blades and flashing to vapor during the compression process. The latest trend in smaller Oil Free Industrial Compressors is to use "isothermal compression" using a water-injected screw element. The temperature of the compressed air leaving the element is nearly identical to the temperature of the air ENTERING the element. Revolutionary process in smal packages. Instead of air entering at 85 F and Exiting the typical Oil-Flooded Screw Compressor at 165-175 F, it exits more closer to 90 F, and the water is recovered and separated using conventional means. Imagine that compressor on the front-end of your Z: 125Psi Manifold Pressure at 100% R/H! Turbine Discharge Pressure and Temperature is quite different between the draw-through and blow-through. At say 150Kpa, or 6.5 Psi thereabouts the stock 280ZXT has a discharge temperature of around 60C given a 28C ambient. On the same application in drawthrough, your discharge temperature would be hard pressed to break 40C. Quite a difference! Of course as you up the pressure, so do you up the temperature produced. The manifold temperature will remain constant as more and more of the gasoline is vaporized (at 6psi there are still liquid fuel droplets to puddle in your manifold....muhahahaha!) to the point where you start to see a rise in manifold temperature. It is at that point, using thermometers and thermocouples that you use your old trusty and reliable Two-Stage Spearco Water Injection system to spray methanol, windshield washer fluid, or water into the manifold to act as a supplemental anti-detonant. With this system operating, your boost then went to 20+ easily, depending on your carburettion. A Single Z SU on a Turbo Corvair would not supply enough fuel through a .125" mainjet to keep from detonating at 17psi, a drawthrough Z SU on a similarly-sized 240Z with the same Corvair Turbo driving the Crown Turbo kit was almost identical in terms of detonation. You had to supply anti-detonant to make 17psi reliably. BUT, put a Holley 650 on either of them, and MAN! 17psi? No problem. Being we are talking stone-age NON-WASTEGATED systems here, once you got to the 17psi you were effectively choked on the Corvair Turbo in either setup. Derestrict the front end some more, and then you saw that old Vair Turbo (or the Rajay Equivalent) would make upwards of 20 psi! And knock knock knock 'Mr Holey Piston' started sniffing aroudn again... So back to Spearco to stop the Knocks, and then you keep your foot into it till about 22-23psi where you surged the damn thing. Boost was totally dependent on your right foot in those old systems. I actually long pondered reinstalling my Crown Kit on the 240 as a period resto, but instead using the stock wastegated turbo and a manual boost control valve. The problem with the early kits was they really relied on inlet and exhaust restrictions to keep the boost under control...gawd help you if your Turbo Vair shook it's muffler off or got a sizeable exhaust leak: you would detonate the thing to DEATH in an overboost condition due to tunaway turbine speed! I was thinking restricting the boost would allow me to conquer the woes of the old SU setup.... Of course I was also thinking of driving the thing with twin 550CC fuel injectors and a Megasquirt so it LOOKED vintage, but DROVE MODERN! Looks are a big thing, and something that looks old, and vintage-period correct is really neat IMO...especially if you can hide the technology and actually enjoy the ride. I know tuning the MS and twin 550's would be FAR easier than what I had to do in 79...... That took literally WEEKS after work with the hood off, watching the station pole in the top of the SU and listening for detonation sitting unbelted BACKWARDS looking out the back window while a friend drove the car... Ugh... you made me remember...YOU BASTARD! LOL

The 'baffle pipe' is actually the return line on a 280Z tank. On the ZX, the return line swirls in the pot. That 'through the baffle' line likes to get obstructed right at the first 90 degree turn inside the tank and remind you why you can't be cheap and use normal carburetted fuel line on the 'return line because it's just a return line there's no pressure in it anyway'.... When it blows up and you hear this "SSSSSSSSSSSS" and smell a STRONG gas odor from the back of the car you get out to look and wonder "what's all that on the driveway?" about the same time you drop down to see the fuel spraying like crazy all over your exhaust pipe and onto the ground from the ruptured line... Not that this has EVER happend to me. Not that I try to be cheap and skip replacing stuff...

Oh GAWD! I SHUDDER to see those photos. I originally knocked off the HKS Type 1 Plenum on my 73, and it worked great save for me being an idiot and not tapering the front of the thing to clear my hood. At idle: knock knock knock knock..... Till my hood 'autoclearanced'---then the knock was intermittent. So to get something that 'looked better' I figured to make a simple box like the Cartech Plenum, and like everybody else was running here in the USA. WHAT AN ABYSMAL MISTAKE! First, my mileage with 44 Mikuinis and the HKS Type 1 Knockoff was averaging 17mpg in daily commuting to and from Corona and Brea through Carbon Canyon. Put the Plain Box on, and my car started lean surging at light cruise. Had to up the jet sizes. Mileage went...er...down. Still had an annoying pop at light cruise that would NOT go away. Boost response was MUCH quicker and harder with the smaller volume plenum of the 2X4 Box, but going to 3psi on every light throttle application is not the best for mileage either. In short, the SK and the HKS both incorporate different methods of "Modulator Rings" which are present in the Maserati BiTurbo, a car that was OEM with a blowthrough turbo and Dual Dellorto DHLAs (think Mikuini or Weber). These modulator rings in the Maserati, and the two-plenum or internal baffled design of the SK and HKS boxes allow for a slight pressure differential between what is pushing down on the float bowl, and what is actually present in the main venturi of the carb. This raises the fuel level, richening the mixture ON BOOST ONLY while keeping the SAME smaller N/A size jetting. At higher flows, the pressure differential is more acute, and the richening is greater. The HKS and SK boxes take two different methods for approaching the pressure differential that is better than the Maserati approach of the modulator rings. HKS uses a two-plenum approach whereby the boost enters the top of the plenum box first, pressurizing the floatbowls slightly before the lower plenum is pressurized for the main bores---there are two cast in holes in the dividing wall between upper and lower plenum to regulate the differenital at higher flows. Some racers really hogged out those holes on high-horsepower setups. SK used a baffle to direct the air to the float bowl vent holes in a dynamic way, and then divert it to the main bores past a static diffuser that let the air enter at lower velocity and lower pressure. Maserati used smaller than open bore rings in front of each main throttle bore. You can screw with the rings for a while to line it all out. Generally the modulator rings are of the same diameter as the main venturi/choke, on a Mikuini 44 say somwhere between 34-36mm for a choke size of 34mm. They don't cause a flow impediment at lower airflows, but under boost they start righening the mix. That, from what I have discerned is the MAJOR difference that made the car run SO MUCH BETTER on HKS-Style boxes, than on the simple Cartech Style Box... I NEVER DID get the thing to stop lean popping after the switchover. If it wasn't for that damnable Cartech-Style box, I'd still be driving my blowthrough HKS Knockoff now! I really didn't have many drivability issues with that setup---and I'm thinking since Cartech was the predominant setup here in the USA I can understand why some have such a distaste for them. The drivability and fuel mileage on the HKS was worlds better than the other plenum. Though I could get as low as 5mpg when driving spunkily...LOL Heat soak during stop and go driving on a non-intercooled setup was another issue but it was probably equal in both setups HKS and Cartech. I was running 17psi+ without an intercooler (there were anti-detonant measures) but no matter what, when I was running long and hard at 10psi (before the coolant would kick in) those carb bodies would heatsoak like a big dawg... And THAT is where EFI comes in! LOL

I've hoisted my L28 Complete from the rafter of my Tuff-Shed to put it on the engine stand. Obviously now I have 'the Container' and can simply clevis some Gr 80 Chain across the top tie hooks and hoist them with the chainfall that way. In and out of the car....oh man, concrete is SUCH a luxury! You guys don't know how good you got it!

No, I'm a a$$, really! just ask the folks at ZC.C in the "Tony D Voodoo Doll Collector's Club" LOL Some of the sharks are circling now on one post in particular. How entertaining... One of my best Torque Specifications came from the Cooper-Bessemer Manual, Head Bolt Torque for a GMVHS V16 Natural Gas Integral Compressor: 9 Foot Bar, Six Men, Strong Pull. Matter of fact, almost ALL the torque specs for that engine were quoted that way---something designed in the early 1930's. I could just see those guys doing that! Eventually they succumbed due to pressure from NASA/JPL and in the early-mid 90's converted them to actual REAL foot-pounds. Those head bolts were torqued to 1600 ft-lbs. 8 per head, 16 heads. Plus the compressor section... I can imagine that the last bolt torqued by the 1930's methodology might just maybe might have a tad less torque on it than the first one done on the other side if they kept the same crew torquing all the them! Heck I would do em all using a torque multiplier and 600 ft-lb Snap On torque wrench and then take a break! Manually? "The days when men were men!" LOL Yeah, I felt REALLY priviledged to grow up in the age of Pneumatic and Hydraulic Wrenches!

Like I said, if you tighten the spring too tightly, and the ECU gets funky signals and doesn't process them right. Tightening the srping RAISES the RPM whereby the ecu reverts to "preprogrammed" WOT injector pulsewidths. You experience confirms this....eventually your AFR's should have gone back to the same 11.8-12.0 when the Flap reached the 'full open' position. But if it doesn't reach that by the time the ECU reaches 3500rpm, where it's SUPPOSED to go back into open loop regardless.... See what I mean about confused ECU? There is a fine line between this tweak and that tweak, and in many cases, simply because of the way the system is designed, you can't adjust just ONE variable at a time---you end up affecting more than one because of the way the program interacts. What you need to realize is that while the flap is in play, and the O2 sensor is active (if you don't have a heated O2 sensor on the ECCS this may never happen) the O2 sensor wil ltrim another 10% out of your fuel. As long as the injectors you added did not exceed the 10% range this should occur. You can NOT adjust to 14.7 by the AFM, it has to be slightly RICH and the O2 sensor has to do the final trim or it will never work. With the size injectors you have you are supplying 15% more fuel than stock, juuuuust outside the O2 sensor's range. Did you try only two or three clicks, and make sure your O2 sensor feedback loop was being enabled? (The flashing lights under the ECU?) If the O2 sensor is not working, the ECU will default to the 'safe' program, and that only compounds the issue. If it sees rich for (I forget the number) X cycles or seconds, it reverts to the failsafe map---which isn't the greatest under boost. If you are cruising at 13's the O2 sensor is dead, try replacing it with the heated type from an 87 Z31 T and try tweaking a bit more. Those mods aren't so bad they would disable the O2 circuit, you are right on the edge of plug-n-play actually.

Yeah, I see that now. Ceramic Nozzles wear better than the metal ones. You just have to keep replacing them if you use excessive pressure and agressive media. You can get nice deadman's handles at the places where they sell the name brand stuff, and in some cases at rental yards where they rent the stuff. It's really clamped down here in SoCal as you need an AQMD Permit for portable sandblasting rigs... So parts aren't as readily available as they once were. But once you get a source, use it!

Haven't read the reviews, but many times people try to run these units with a compressor that simply is too small. We drove ours from an Atlas Copco GA11 Oil Flooded Screw Compressor, and had plenty of dry air. If you are running a recip on a small tank, you will get hot air, and moisture which can lead to problems. Many of these vessels are generic, the real difference is the ends. It wouldn't be the first time someone used up the HF components and then replaced them with name-brand guns and nozzles on the end. I use ALC Ceramic Nozzles in my HF siphon unit, they fit just fine, and last way longer than the metal ones form HF. In my ALC Sandy Jet, nothing has really worn but I keep close watch on those nozzles, especially when running higher pressures and agressive media. They wear out the nozzles, and then can cut the gun right to nothing. I haven't done it yet, but I've seen the results on people who have! Using a smaller nozzle, with lower pressure really is the way to go with any abrasive media. It may take longer, but you will reduce dusting, panel warpage, and nozzle wear. I will have to go read those reviews and get back to see what the complaints are about.

I've got the "Marginally Better" HF unit (freebie from a chop shop bust via the impound yard owner giving it to me) and the downfall I see with any of them is they are bolted together. Like Grumpy states, they CAN be tippy, especially on uneven surfaces and when up high. For lifting, it's great, but I am continually going back to tighten the bolts as I find they work loose over time working on the dirt in my back yard (no concrete). This one was outside for a loooooong time, and looks to be at least 15 if not more years old. The ram is rusted, and it leaks. But it functions O.K. other than the bolts loosening. I have replaced the casters with something of higher quality, and because one of them was ground almost flat when I got it. As for the engine stands, I have 'a few' of them, and use the 750 and 1000# units for STORAGE ONLY. I have one larger one of much greater capacity that I got in a similar fashion to the hoist, and feel a LOT more comfortable wrenching on the engine on it than I do on the 750 or 1000# models---they ARE tippy with the full weight of the L28 on them. I also noticed the deals on them as a closeout at Kragen one day, and loaded up a couple for 'future usage'---they seem fine for static storage. For moving them and working on them, get something more substantial. In Japan they almost always work on the block when it's on the floor on two 4X4 Blocks of Dunnage and they make great power. My gut will not allow me to splay leggedly squat like that any more, so I'm relegated to standing and working form the bigger engine stand. "A Few" LOL

"we normally only found that when the customer was overcompensationg for poor FLOW with higher PRESSURE, using dirty air, or not using enough oil." AB-SO-LUTELY! Running the guns at 120psi inlet through a 3/8" ID hose on utility air and no oil to break 1 7/16" bolt loose on flanges daily. Like I said, once I got the tool into the MECHANIC'S control, and gave the OPERATORS their own guns, the IR started lasting longer, over a year between overhauls. But the operators still burned up their guns on a regular basis. Funny thing, using the Snap-On 1" impact in 600 ft-Lb service on head bolts, the thing was well over 5 years old and still was going strong. Simply because THAT service was hot, heavy, and a total Beyotch, and the OPERATORS steered clear of the HOT HUMID Engine Room! Work outside breaking flanges, suuure! Actually WORK? Not on your life! Curiously, the MECHANICS oild that big 1" daily, and ran it on the INSTRUMENT AIR HEADER.... CDA is CDA! "Clean Dry Air" No argument here from me at all. I'm just telling the facts from the real working world. Without calling the Operators a bunch of slack-jawed idiots that didn't know one end of a wrench from another who THOUGHT they were mechanics, because after all "Grease Monkey" is a generic term for Mechanic, right???? Oh, I'll also add that the former 'mechanic' at the site continually cried that the I-R air starters only lasted a few months before needing a vane package and overhaul. My diagnosis of the big smoky acrid cloud from the starter on startup made me think "gee, shouldn't there be an oiler on there?" Shure enough, Einstein had REMOVED the oilers LONG AGO (like 8 years!) because 'they were just runnning through oil like crazy, and don't do anything anyway'.... I'd tear down those starters, and they were scored, had blue heat marks on the vane barrels, CRACKS from spot heating, and vanes cooked to within an inch of their life. His instruction to me on removing the reduction gear was "You take a punch and beat the hell out of the gear till it pops out off the snap ring, and usually you have to replace the shaft"---I asked why he didn't rotate the gear till the snap ring was visible in the HOLES of the Reduction gear, and stick a snap ring pliers in there to release the snap ring... Hey, in the industrial world of the USA, there is no appreticeship program, no competence testing---this guy got his job because mommy was diddling the safetey manager, and she wanted him out of the house. I got my job there (I'd like to think anyways) because I was qualified technically.... Yeah, after I rebuilt the first starter, and installed it along with the original oiler amazingly you only had to fill the oiler after each third start of the engine, and the starters ran for almost 4 years till I-R offered us a direct upgrade to their newere generation Turbine Air Starters which used less air and made more torque than the old vanepacked units. Oh, please don't get me started on that place, it was literally 'the little shop of horrors'---the stories I can tell! And being that I'm a Factory Field Engineer for IR Direct now....those stories really help me illustrate those EXACT points of CLEAN, DRY, AIR to customers! LOL

I would not 'call it a day' with simply a larger tube on a carbbed application. The stock SU's will starve on hard, banked, longer lefthanders below 1/4 tank! Even Nissan in their competition prep manual for the Mikuinis recommended a surge tank/swirl pot for carbs when using a 240Z! Make the swirlpot and fuel return line dump into said swirlpot to keep it flooded. As mentioned gated trapdoors and etc all can be added. The parts from a 280ZX tank could probably be adapted fairly easy. My photo is no better than the one already posted of what it should look like, sorry. While they have the top off, why not have them add a 1/4" flange with captive nuts on the TOP of the tank, and make a removable cover so you can access it later at your convienience? You already hacked it up, make it easy to access in the future NOW while it's apart, and if you need to make changes again later, at least you will be able to access it without paying more $$$. Though for a radiator shop, that may be asking for a lot...

SHO-Z, for your application, I would recommend drawing through the supercharger simply for the fact that the fuel will give the 'inherent intercooling' advantage, and though packaging will be a nightmare, the need for a blowoff valve and supplemental air cleaner would be eliminated. For only 10psi on a blower, given it's characteristics, drawing through it is very easy compared to blowing through and having to blowoff pressure, and setting up a proper compressor bypass valve (that can fail and dump boost while accelerating). Frank 280ZX is working on a blowthrough compound-charged engine (turbo blowing into a supercharger) similar to the old Stratos Rally Cars... But he's EFI, using BMW ITB's... Maybe he can reveal some of his super-secret plumbing ideas to you! The SK is a good Blow-Through Carb, they were really popular in the late 80's in Japan for that application. I have seen engines with 2Bar+ Blowthrough pressure on them, and over 450HP at the rear wheels using a turbo setup and blowthrough SK's. The issues of daily drivability on a PROPERLY SETUP BLOWTHROUGH are not that bad, but most are cobbledtogether Cartech Log-Plenum setups that don't run for sh*t in comparison to an HKS or SK Plenum. Now, speaking of SK BLowthroghs, 'can I interest you in an OEM SK Blowthrough Plenum Box perhaps'? I think I have a spare.... Interested? PM me if you are, I can send photos as long as I don't get sent to BFE again for a month...

You realize the AFM has absolutely nothing at all to do with fuel delivery above 3500rpms, right? To tune fuel delivery above 3500rpms, the only practical method is fuel pressure. Normally the methodology is to stick incrementally larger injectors in the car, and tweak the AFM spring tighter so your idle and light cruise is 'leaner' in the stock ECU, but once the cam kicks in at 3500 and starts flowing air (and the AFM is wide open by then) you go solely on the pulsewidth generated by the preprogrammed curve in the ECU combined with the larger injectors to give more fuel on the top end... Wind the spring too tightly, and indeed you set up a condition whereby the ECU gets confused signals, throw in the 35% open "Full Throttle" TPS switch and you get even more ECU confusion. For $400 and two hours of hacking, the MS will cure this Bodge-Job of Bosch Nightmare-Tronic! The idle air bypass screw will skew the AFM trace through the off-idle to 3500 rpm range. Close it further, and your 3500rpm point will change incrementally. while you richen the idle by not allowing more air to bypass, you thn move the AFM flapper to an incrementally different position at the same time... "54KPA, 700RPM, Shift-ARROW UP, ARROW UP, ARROW UP, ARROW UP Check O2 Feedback, .7V, next load block...."

Damn, no I don't! I thought I had one on the Cardomain page... "We shall have to remedy that now..."

http://www.cardomain.com/ride/735451/4 Hopefully this is the correct link to show the BYPASS LEG I am talking about, it's off my Cardomain Page, and I forgot it was there all this time---DUH! This came up before, so I went out and shot it, then posted it there---these at the supply line and return line I am talking about---this should make it all clear for everyone. Tony D

I'm going to add, reading closer through these posts: WEAR A GOOD RESPIRATOR!!! I got silicosis being young and stupid doing my 73's engine bay in 88 with the Sandy-Jet. After that little experience of LUNG PAIN like you wouldn't believe, I started wearing a GOOD catrtidge respirator with dust prefilters. The dust you will raise WILL knock you down. If you are dusting, you are using TOO MUCH PRESSURE as well. You're not supposed to do it, but I recycled my media several times through a fine seive so the finish got progressively finer as the job went along. Not supposed to do it, but it works well for me! Jut get a GOOD RESPIRATOR before you start ANY blasting, and use it EVERY TIME. You don't want silicosis. Trust me on that regard.

I would vote for a #2 as well. I recently had a portable diesel driven IR compressor given to me (185cfm) so my blasting equipment is going to take a BIG jump in size! LOL So what if it labors to go over 90 psi...for stripping what I want tostrip with a pressure pot, I will need less than 60 psi anyway! FYI we stripped the underneath of a Sport Fury Hemi that sold at Barrett-Jackson in 2003 using the larger HF Pressure Pot like #2. Boss was going to spend some big $$$ for the 'name brand equivalent' and buying the HF saved almost $1000. He was so happy with the way it worked, he wouldn't let us finish the stripping! Talk about a kid with a new toy!!! He was under that thing blasting away grinning through the hood like it was christmas morning. The pressure pots work SO MUCH better than the siphon guns. I also have an ALC Sandy-Jet siphon gun (100# hopper) and comparing the pressure pot to it is like night and day: #2 HANDS DOWN!

I like that counterweight idea, what I was thinking of in particular is repositioniing without getting up and going to the end of the stand to move the car. This is assuming you guys are safety-pinning the car in place---only so many pin positions you can get, but with a gear rotator you can infinetly position the vehicle and only need to pin it in position if you are done for the day. Basically punch a pendant and it rotates---or better yet a foot switch---and it STAYS where you rotated it to, not so much the ease of rotation, but an infinetely adjustable positioner. The Z-Resto rotators were a clamp on a pipe so you could do it like that without a pin (like on the HF Stands), but loosening to rotate and then retightening is not the same as the geared rotator. The best example I can think of is those pipe rotators you use to rotate piping whlie you are making passes on it. I like to weld in some positions more than others (take that any way you like: can't weld vertical, can't weld overhead, only wants horizontal buttwleds...lol) so getting the car to move while I'm welding so I keep the correct-for-me-position would be nice. I really like the counterweight idea, though. That in combination with some sort of lighter electric rotator would probably be what I end up doing. Come to think of it, with a rotator, I could invert a car, then hoist it to the roof of the storage container, and roll antother one in below it. Hmmmm, this means I can fit four in the container in the back yard. That would free up some space. Yessss, ex-cellent! Thx guys!

Funny thought, I was buying I-R Impact "Tune Up Kits" for our nice IR gun, at $58 a piece. Till I realized the HF gun could be bought for $58 COMPLETE and lasted the same 6 months as the tune up kits in heavy industrial use. For the $58, I started buying a NEW HF gun every six months, and giving the old guns to operators for 'personal' use---that kept them hammerring away on flanges and stuff with their OWN gun, and not using the 'shop impact' which meant the $58 tune up kit in the IR-Gun started lasting a year or more. So I kept my "Good Gun" longer, and they had something just as good for everyday use. Everybody won! At that time, the internals of their $9.99 Die Grinder were EXACTLY the same as the Snap-On AT-100A...SHOCKED ME! Especially when they broke the same way. Incidentally, the older HF Castings were close enough that I could transplant IR Internals to them, rotors, hammers and anvils, vane cylinders, etc... HF on the outside, all IR inside! I did the same transfer on the AT-100 Die Grinder to an old HF Die Grinder case when an operator dropped it and broke the air inlet off the damn thing. That was the LAST time I spend $100 for a Pneumatic Die Grinder. After that, it was HF every day, all day! But as for 'pro use'---I don't travel with my 'good tools' any more. Almost everything is HF bought, if it walks I'm not out $500 for an impact gun! And travelling it DOES eventually walk. Even the TSA has a need for the occasional shiny tool (bastards!) Doing some coolers in Tempe AZ last month on an I-R 4C Centac Compressor, we went to HF and bought 4 of their 4" anglegrinders to put cup brushes on them. For $18 each, you couldn't beat it, and I have so many laying around now I have them with sander attachments, grinding wheels of different grits, cutoff wheels...etc. For the cost to the customer, buying 'disposable tools' for a one-time big job is actually CHEAPER than shipping a job box with 'good tools' to the site. Which is a terrible commentary on shipping costs, but like the impact gun example, once the job is over, there are a BUNCH of electric hand tools that are dirty, grimy, and maybe 50% used up---and off they go to customer mechanics, helpers, kids walking by the open doorway: EVERYBODY is happy. As for wrenches they are nice donors for those wrenches that eventually you need to cut and weld for this particular bolt, or to take the torch to and bend offset to acces this fitting waaay up inside somewhere. For general purpose work, and where you are going to knowingly abuse the tools, buying the cheapest thing that holds together makes me feel much less guilty about what I'm doing to them! And if it survives, it can look forward to a long life of home usage by someone I know. Gawd knows I don't need any more! LOL

Ohh, that guy works in Lomita. I say 'STICKY' so it's easy to find and reference when the pressure vs velocity arguments get going next....

Nope, you have it backwards! When the thermostat is closed, the motive force comes from the water pump. When the thermostat is open, the motive force comes from a function of the water pump's pressure, and the differential from the lower radiator hose. This is the ONLY practical way to do it, and si how the circuit is designed in the OEM application. The car needs a bypass line anyway, why not use it for cooling the turbo as well. If you take the source from the upper thermostat housing, you get NO FLOW. The only way to do it without a supplemental pump is to take it from a place where the water pressure is raised by action of the water pump. The only practical places on the engine to do this is the lower thermostat housing (llike OEM), the lower plug on the block between #5&6 cylinder bores (if you have it---and probably the best place considering the temperature there), or the heater connection on the head below #6 (probably the worst place to take it because it's the hottest place on the engine). Yes, you are bypassing the radiator, there is no way to do it elsewise without serious modifications and reengineering of the coolant flow system. The engine is designed for a bypass hose from the lower thermostat housing circulating uncooled hot fluid back to the inlet in the basic design of the engine, the easiest and most trouble proof way to accomplish the objective is to use THAT circuit to do the cooling. Like I said, check out the later models Z31's, and how they route the coolant lines for the turbo on the bypass loop. They are not taking it off the pump before the engine, they take it off the engine, towards the end of the cooling loop, and simply recirculate it. Easiest way to do it, and provides the POST COOLING requirement nicely through a thermal siphon action from the lower radiator hose through the turbo and to the HIGH POINT on the engine when the engine is not running---and THAT is when you want coolant flowing. During engine operation flow is flow, but after shutdown having a circuit that functions from a cool place to a high point where steam bubbles formed in the turbo after shutdown can rise and be dissipated---and my discribed circuit functions in that way. As does the OEM setup. It does nothing for electric fan operation nor temperature readings...not any more than the OEM stock Bypass Line does anynway. That is a moot point. This does not impact the thermostat in any way. The bypass line is there from the factory, all you are doing is letting it perform another function. JeffP reports that his engine seems to warm up quicker after installing the line as it allows more internal recirculation before the thermostat opens...quicker warm-ups, that's a good thing, no?