Tony D

There is source code available and directions for several on-board MAP sensors that can be used in the MS that allow maps for higher boost levels. Rick Yaoccuci uses one in his Bonneville Streamliner---I think he is running 30+ or 45 psi on his Busa Motor to make over 619HP at 10,500rpm....

Oftentimes the thread pitch and diameter of the outer portion of the helicoil is different than the inner pitch and diameter, leading to that statement. KeenSerts arguably are stronger, but those aren't Helicoils. Also, Helicoils are normally used in non-ferrous metals, so because of the outer diameter and pitch, it would be harder for Godzilla The Torquemonster to pull the helicoiled threads out as the former raw alloy threads....

Pendantic is my middle name. Fact being "getting it balanced" after your field fix will cost just as much as a cartridge assembly completely done. Custom turbo balancing isn't readily available, but mass-produced cartridges are readily available CHEAPLY, considering a core value. Sometimes below $200! For that price, it doesn't make sense to do the replacement and hunt up the balancing. But then again, anything I say won't sway the movement of the sun either way...

I'll let you know when we get ours on the dyno. In Japan, many back in the day would use the service liners for the L24, overbore the L24, and install the crank and other internals into the block---that way they got the advantage of the larger displacement, but didn't have to pay the taxes required for something over 2000cc's. Other than running in a displacement limited class, or doing a Fairlady Z restoration, the engine is about useless. Better is to take the crank and put it in the L28 block. That gives you 2.5L, which was the formula for the GTU cars campaigned by some back in the late 70's and early 80's... Both the 240Z and the 510 could compete in GTU at the time if I recall.... I know if you use an E88, you gotta relieve the bore SERIOUSLY with the stock diameter pistons in it!

All I'm going to add to this thread regarding L28's in the 9's is "Old News". For a "Link" I will refer you to the Carboy "L-Motor Issue" containing the "L-Motor Shootout" at Fuji Raceway from 1989. 11's and 12's were all over. There were L's in S130's doing 9's and 10's... It's old news in Japan. Real old news.

My link isn't working but I am questioning if the cap BLOWS OFF, or if you simply HEAR the sound. Most common is that you hear a sound like escaping pressure. In fact, what you have is vacuum in the tank. If you have hoses that are marginal, it is possible that the car, on long high speed drives, starts bucking and surging, and running lean because of a vacuum buildup in the tank from the fuel being sucked out. On short trips, you have no problems. But on those longe trips it may completely stop the car. I have seen the filler neck COLLAPSED from this phenomenon. On earlier cars, people usually plug the crankcase accumulation line from the vapor cannister. This is the only way for makeup air to get into the tank. On the later 260 and 280Z, removal of the carbon cannister and plugging the line is the culprit. Opening up the line is all that is needed to resstore proper fuel feeding. Pressure in the tank, that is a different story. And can be caused tby the same things.... Good Luck. WIsh this damn computer was working so I could get to the symptoms. I have seen this problem three times this summer (and that's saying something since I have only spent 19 Z-Related Days since May!) BTW, the cap is designed to be SEALED. The venting is controlled completely through the line to the crankcase, or through the vacuum valve on the top of the carbon cannister. The fuel pump does NOT add pressure to the system, it only imparts FLOW. The restriction by components in the system downstraam build pressure, as soon as the fuel is allowed to flow unimpeded, the thing will revert to flow, and not cause pressure. To build pressure, you must increase the VOLUME of a given fluid within a space---this is decidedly not the case with fuel in a running car, it DECREASES in volume! now heating of the fuel will cause an increase in pressure, but the aforementioned valves will vent this pressure (some 3 to 11mm of pressure water column I believe) to either the crankcase or carbon cannister when the car is sitting idle and not running, or to the engine for combustion through the air cleaner or other port if it's running. Hpe this helps, you can e-mail me directly if youwant. This keyboard is being a beyotch right now! LOL

For Real Dude? http://www.bandmzcars.com There Bryan Blake MADE a set of ITB's, then fired them with a MS... I could post another photo of ITB's... Mine.....

5.5 hours is about correct for the kit. Don't feel bad. I went to the NASA high reliability soldering class, and my first MS kit took 5 hours flat start to finish, and it fired up and ran on the first try---I was driving it around the block within 15 minutes thereafter. Then all hell broke loose. See Archives....LOL

I'll agree with JM, our L24 with Triple Mikuini 40PHH's routinely got 28mpg, which was FAR better than it EVER got with the SU's! The Mikuini was designed for OEM duty: DAILY Drivability. Most High Performance cars in the JDM had them straight from the factory. The myths and legends about multiple carburettors ard dispelled pretty quickly once you drive, say, a 1973 Toyota 2-TG Powered Corolla. Toyota drivability and reliability on a twin PHH carbed DOHC four. Same for the Fairlady 432.The linkage was rigid, and you spent more time attending to the cam chain tensioner than you did on the carbs! The Mikuinis are very simple compared to what you have to go through with Webers or Dellortos. I know, I own all three! If you are getting bad gas mileage, I'm with the gent above who says it's fuel pressure. Many a time I have bought carbs that "didn't work" or that had "bad sets of floats" and in the box was an EFI pump. You use that pump on these carbs without a regulator? "Yup!" Uh....O.K.... Uh, I'll give ya $150 for the set, being they got 'bad floats'! LOL Anything over 3.5psi and you can sink the floats. I have never had to screw with my float bowl level---though a bad air cleaner causing a differential between the float bowl and the inlet horn will cause really rich running also. Good Luck, they are a good carb, and will drive really reliably once you figure out what happened to make them go rich!

Every Freakin' DAY! But I think you are referring to Automotive Turbocharger Compressor Wheels, and not Turbocompressor Wheels... Automotive stuff really isn't user servicable, a new center section is CHEAP compared to if the thing is imbalanced and rubs and trashed your inlet housing! I should post some crash photos. I got big stuff that went "boom"...

The common problem I have been seeing is not hoses that are off or knocked free, but ROTTED. They LOOK good, but when you start testingthem, they are all porous, or have cracks down the side. This is a major problem when you have the auto-climate control system. Like others have said, is you heater working correctly? If so, then it may be an actuator leaking. If not, chances are it's hoses. They are of the age where they start causing problems (at least in Ozone-Ridden SoCal!) so when I go under there, it's with a roll of tubing and a razor knife----and I just start replacingthe hoses wholesale. Some people got offended when I refused to help on their car---I mean, it's got to be WORTH the effort, right? LOL Good Luck. Let us all know what you find!

What's this "We"? YOU GUYS! I was involved in the discovery of the thing, if at all! LOL

Wow, suprised nobody said it yet: You have an EFI car, why not simply stick a Megasquirt on it? Doable for low cost (probably under $500 for a DIY kit), and will give your car superior drivability and power over any of the other alternatives, including a functioning stock EFI system!

never argue with results! I watched in horror as my colleague smeared JB Weld over channels in a head surface where the fire ring of the head gasket sits, then slap it on the engine for running. This was on a stationary engine running 23psi boost, 24/7. Not my idea of "what should be done" but it held till next maintenance interval. As great as my horror was, I could not argue with the results. If it gets you to where you can fix it in a correct manner later, all's fair! I would rather drive to the hotel at the end of the day with an "improper fix" than WALK in the rain ANY DAY! What is this "repair purisim" I'm seeing? LOL

I drove from SoCal to Albuquerque NM to pay $100 for an L20A engine, and then drove south to ElPaso Texas to salvage the engine out of a ZXT that was free. That ride home was 14 hours alone. So Free/ZXT=28hours should be the same equation as $250/ZXT=10 Hours Making the cost $13.88 and hour in my case--yeah, that's reasonable in my mind... I am diseased.

I'm running (and have run) up to 21# on my 77 L28. It is a JDM engine using an N42 head, that was 8.5:1 CR from the factory (Cedric Company Car). The engine has not missed a beat, and I got it with 42,000Km on it. Normally I am running 17psi, but for a short time broke several turbos quickly running 21psi using a JDM .43AR turbine housing... I did stupid things when I was younger. Anyway, at 17psi, there has been no problem since 1987. I am pulling the engine whenever I return home to put in a higher boosted Megasquirted EFI system fueld engine. Right now it's old school blow-through Mikuinis... Ehay! I know it's not F54 flattops, but they are JDM FLat Tops, and the CR you are concerned about. From what I understand the N42 is a little more knock prone than the later heads, too, so that should relieve your stress a bit, too! Good Luck with the build.

hey, I was nowhere near the brake calipers...LOL

my welded knockoff of an HKS cast surge tank held up just fine at 21psi. The stresses to break welds need to be higher than 1800# to break them, or even fatigue crack them. There was some issues on some squared tanks at Bonneville blowing the boxes apart, but that was a problem with the welds themselves (usually is in the case of failures), and not because of the design of the tank. Many times people use an extrusion now, but IMO the extrusions used currently usually don't have enough volume for the engine size... Ideally the tank would have rounded edges, but the craftsmanship required to roll "O" Aluminum to that shape and then properly weld it isn't usually in the realm of the home builder. BTW, I have decided to go with the KA tranny in my 73 for similar reasons, I will simply limit the output to below 450HP, and since I'm road racing, and high speed touring, that should make the tranny happy for a while. I'm not a big dragger anyway.

if you have access to a robotics supply house, or even a very good bearing supply house, you will be able to order a small seal that will replace it from the NTN catalog. I almost warrant they will have to order it, but the seal you get is nice, and will last a long time. The red silicone ruber ones you can buy work well for sealing leaky shafts on N/A carburettors, too! Old School, you slipped an O-Ring over the shaft, and then a washer that was machined to slip fit over the shaft, and a spring to preload against the throttle arm, to preload the o-ring against the body and seal it up... For the effort of removing the junk to get to the seal, you may as well just find another throttle body and install it, then fix this one, as you might have to machine some of the surfaces to make the replacement NTN seal fit perfectly. But when you are done, yo uhave a damn nice repair, and an easily sourced standard seal for service in the future. Good Luck. Wait 20 years when the bolt on stuff frrom the junkyards is no longer readily available---then the above procedure will not sound so daunting! LOL

so, your contention from these verified testings... is.... that.... you get about "3 HP per pound of boost"... (Ducks into the shadows, runs for cover) LOL Neat Graphs BTW... I'd run my stock T3 to 21 psi on a few occasions, but usually limited it to 17. This is an interesting graphset.

Ahhh, we have digressed into the 'dynamic' compressor feeding a 'positive displacement' compressor discussion... There is actually a lot of information on that system, as in industrial compression systmes it is very common. Two different typse of compressor feeding a single system for a higher pressure with greater efficiency that could be achieved with one system or the other... (hmmmm, does this sound familiar?) I get into nasty arguments over the "vacuum" versus "pressure" arguement regarding cylinder filling. All I can say at this point is that if an intake system was TRULY working on "vacuum" they would be designed VERY differently! Even on N/A engines, the intakes are UNIVERSALLY designed using pressure-flow dynamics. It is indeed atmospheric pressure PUSHING air into the cylinder. If you follow with the Turbocharger, you see that the VE increase on NON-BOOST areas where the turbo is only aiding ABSOLUTE PRESSURE flow, you see the torque get pumped up, and realize the pumping losses are affected even when the turbo is not pumping enough air to go to positive boost. It is STILL boosting even while still in a "Vacuum" state by the compound gauge in the cockpit... I digress. I go to sleep now.

Chatter comes from run-out and those damnable springs in the hub center. I ran a solid Centered disc four-puck clutch for years in my VW, with never any chatter. Went to a spring centered disc, and it started grabbing. I was told some time ago if you can't get a car to launch smoothly with a solid centered clutch disc, you don't know how to use a clutch right. I tend to agree, with the solid center, modulation and actually slipping the clutch (even a puck style) is possible. Not particularly easy since it becomes grabbier the more you slip it... But it CAN be done! (I'll remind you this is with a 1934 era designed CABLE clutch linkage, too, not the antiseptic Hydraulic Actuators we have in the Z!) Come to think of it, the Corvair had a launch problem with the six puck disc until we had it changed to a solid center style.

Yep! My experience with Water Wetter is similar to above. I noticed a 15 degree drop in temperatures under extreme conditions. What the biggest difference was "pukeover"... What I had when I took my 260 cross country was a littly bit of "pukeover" every time I shut the car off after a long highway run. In 6,000 miles I used baout half a gallon of 50/50 radiator mix to top the radiator from this little "puking"... On my next cross-country trip, I used waterwetter, and since it was 18K miles more or less, I provisioned 2 gallons of backup fluid to put in the "support trailer"... Well, having absolutely NO pukeover really impressed me. With the Water Wetter in the radiator coolant, I had NO puking after shutdown. Matter of fact, I did not hear the normal "plunking" noise from steam bubbles forming in the head after a long highway run and a shutdown. That amazed me, and SOLD me on the Water Wetter! When I rearended that truck in Houston, my fan went into the radiator, and it sat there idling for about 5 minutes before the thing started puking coolant from boil over! Amazing, simply amazing. Since that experience, I am wholeheartedly recomending that Water Wetter be sued in all the early cars. If for nothing else, the guys who are not running a catch can will simply not have to add fluid between oil changes---if at all! That is worth the price of admission alone! LOL Oh, and the numbers you are seeing are pretty good. Especially for a turbo and a three-row. Mine has a four core radiator, and 160 thermostat, and unless I actually run the car I will not get above 160 degrees. And under boost I might see 190 to 200 on the CHT sensor, which I find reads about 10 degrees higher than the same sensor in the thermostat housing.

My vote is "both"! My father-in-law has a Camaro with some hellacious GM engine in it... LT1 or whatever. Crankdistributor, blah blah blah. Local shop there in Michigan was doing his exhaust and told him he "didn't need those second O2 sensors in there, just tape up the harness" BWAHAAAT?????? Told him to go back, make them ADD the bungs for FREE, and beat the hell out of the idiot who said that. Amazingly when he went back with my explanation of how OBDII works, checking before and after cat 2 signals, they said something like "no sh*t?" and then added "maybe that is why our check engine light comes on all the time".... Uh, DUUUUUH! Muffler Men are not on the top of the Engineering Food Chain apparently. Those fools back there didn't even know about the little Dongle you can plug in that gives the ECU a dummy signal so the OBD system does not record and error. And the bad thing, the REALLY REALLY REALLY bad thing is that I (forgive me guys) really can't stand V-8's, and have never owned one! I am not even UP on the technology on them, yet even I knew about those things! That really is pathetic when you think about it... I mean hell, I only peruse the Summitt Catalog probably once a year to "see what's out there"... I suggested my F-I-L not return to that shop, and when I am there in August, I am going down to the shop to "talk" with them about the work they did on his Camaro. Idiots. Moron, Lazy Idiots. I guess I would use three adjectives to discribe them, not just two! LOL

From that first response to me about the CF2 or CFDF clutch, and having a DROP in the power delivery, then YEP! You got clutch going out. I was at JeffP's when it started slipping (CFDF Clutch) they seem to hold fine to around 300 hp and around that much torque. ufortunately the WAY the turbo makes tortque overwhelms the CF's ability to clamp at lower rpms (like 4000) and the things slip. In lower gears you pass through peak torque so fast, the little centrifugal weights can clamp and ther is no problem. Let me guess, you started to loose power transmission right around 4000rpms, right? That is where JeffP's took a dump. And the CFDF WILL smoke, and WILL smell like slipping clutch if you slip it consistently and badly enough! Curiously it was around 20 to 23psi that it was slipping, also.... So I wouild say you have hit the limits of the CF clutch assembly. Jeff had dual driver rings and extra weights, blah blah blah.... Still slipped. Mine is still holding, and and has since I installed it in 1991. But then again, I only dynoed it once after I installed it, flashed to 325hp, and then turned the boost back down to 275hp, and was happy with that since my wife was driving the car.... If you don't want a jerkey clutch, consider a dual or triple plate organic clutch. HKS and OS Giken make them. But they are around $1500. They are smooth as glass on engagement, and if you swap from organic to ceramic friction material the torque holding capabilities go to unreal numbers.