Tony D

That is correct, the L20ET's only support 145 HP, what you can do is install an adjustable FPR and up your fuel pressure to make up for the difference in fuel delivery between the N/A L28 (L20ET) injectors, and the 270CC units on the L28ET. 4 bar? I forget. You are limited on boost then, though, since the stock fuel pump will internally bypass at boost pressures above .7 bar. Getting larger injectors in the 270 to 320CC range is advisable. It's always easier to 'trim fuel down' somewhat, than to increase it appreciably by increasing the pressure under boost.

Actually, the center cartridge of the L20ET is identical to the L28ET. The only real differences is the A/R on the exhaust housing, which is a .43. If applied to an L28, your boost threshold is around 1700 for a 17psi boost level. You will be able to get full boost by 2000. Running the smaller L20ET turbo on an L28, it acts more like a Supercharger than the traditional turbo where when you drive it wrong, you find soggy 'bottom end' performance. My setup was all in by around 5500 with the smaller turbo, but it was a hoot to drive. I lament selling the turbo to someone with a 2L Isuzu!

Too bad you're on the wrong coast... as Roosty said, there is kind of a glut of this stuff now. I wanted a lathe, and ended up in a deal where I had to take the Bridgeport, 17X36 Milacron Lathe, a Trinco 48 Bead Blaster with media reclaimer, and a 20X20 Mezzanine! A mezzanine!!! I figured I would scrap the mezz and sell off the Mill, till my wife saw the mezz was constructed from pallet racking. Then she wanted it for storing stuff around the yard in different places. Whoodathunkit? And the Mill sits at the shop I bought it from, and they call me every so often wanting me to come pick it up. I threaten to return the trailer to them to park in their shop...and they decide the Mill takes up less space than 'the damn trailer'... I even tried to palm it off on John C...even he doesn't have the room! To paraphrase a Queen Song as my (second) mill sings: "Need somebody to love me, Need somebody to love me!" All I wanted it for was the R8 collett holder. I got everything else! LOL Anybody need a Bridgeport Mill in SoCal?

That's not entirely true! The flywheel is a custom piece, with the drive dogs on it for the standard 7.5, 5.5 or now the smaller 4" clutches. All you do is specify an inertia ring be incorporated in the flywheel, and they can do it. JeffP had a three-disc quartermaster mated to just such a flywheel after inquiring on it. I told him to specify it, and they made it so! Normally if you are running a 4 or 5 " clutch, inertia is NOT what you want. Most people running clutches on the street will opt for the 7.5" diameter discs. Far less inertia than most standard (Tilton 11# comes to mind) flywheels made for 'performance/street usage' due to the weight of the slippers, cover, and MOI decrease. The flywheel doesn't need the heavy bolting mass the stock 225 or 240mm clutch cover would dictate, so it can all go away---with vestigial webbing for the flywheel. All you do is have the flywheel machined thicker out by the ring gear. A little goes a long way. But due to their action they DO wear more, ezpecially if you slip them. ANY clutch wears, and single disc units are simply massively thicker by a factor than three plates in similar flywheel to throwout collar distance. Now, if you want to make a custom T/O collar, and thereby allow yourself FAR thicker facings on each of the clutch discs rubbing on those slipper drive plates, then you will get more wear. Our multi-disc Tilton was running around $300 to rebuild with discs, drive plates, and a resurfacing of the cover. But we only did it once. We used the clutch more in staging lanes or moving onto/off the trailer than we did in a pass down the track. They like 'on or off' but slipping simply wears them. And with less material there to wear, they get the rap of 'wearing out fast'----they aren't wearing any faster than a single disc...they just have less wear material as a function of the construction constraints most pople put onto them!

Then that bumps out Goldenrod! Back to the LSR Z...

Those VW's are much more tortorous than some paltry Auto-X 240 Engine! And they only go when your wife is driving. Let me refer you to my WIFE and you defend a decision to buy a spring center disc for her car EVER again! (Now you know why I do the clutch changes after dark, and keep the boxes out of sight!) If you have ever heard "Does that clutch have those damn springs on it like the VW Clutch did?" You would understand my pain! Limping home along Magnolia Blvd from Riverside to Corona through Home Gardens 'garumpha-garupmha-garumpha' in a VW Microbus with no Air Conditioning in August down a nary wide enough emergency lane and then having to cross traffic with a left turn.... I do that to her again, and it's curtians for my 401K!

Cam Timing? Our Bville car has a similar dip but the dyno operator thought it was electrical as it was nowhere to be seen on the Weber chart we ran. When we swapped the head/cam to the 2l, the same dip moved higher in the rpm band, making me think some cam issue rather than an electrical one like first surmised. It's around 6K on what we have now. Interpolating that 'above the dip' you still have at least 3K of useable pull, that seems about right. Ultra-close ratios and shifting above 9300 keeps us from hitting the 'dip' and loosing acceleration time. We did the same: more fuel, less fuel, more timing, less timing. What seemed to make the biggest difference was a 2 degree change in the cam timing at the sprocket. We went in 2 degree steps advanced and retarded from 'straight up' as defined by the cam card and indication. I think it was 8 degrees either way. We settled on the position that gave us the least dip in power. (Though I don't recall the Webers doing anything near that pronounced! But that was 10 years ago when we were running them!)

With a couple of Small Ball Bearings in the center of the hub, a piece of steel rod with small lever arm connected to a truck bungee or light spring of known tension could replicate this setup under a normal shop workbench thereby negating the requirement to put it in the middle of the room and have a long suspension setup... Various springs of various known tensions could be used depending on the physical mass of the object being tested. This variable springrate (also possible by using multiple holes in the lever arm...) could allow for testing of quite heavy objects as even a single 1/4-20 all thread piece can suspend several hundred pounds! The only drawback is the friction inhernet in my suggested device, but this could be compensated through by doing several tests of know differential and cancelling out through the calculations. And then it's under the workbench (kitchen table...), where the wife doesn't complain about it... A flywheel dangling in the middle of the family room with inscribed arcs on the wall and a laser pointer might upset even my wife if I was called away on the phone and she arrived home unexpectedly. She already suspects the issues with the stove stem from curing HiTemp Paint and Exhaust Manifolds therein...

Wouldn't a cone suspended from a central point be self-centering and have less 'noise' for hte calculations---and as long as your cone was big enough, anything with a hollow center could be hung on it and spun. Like, maybe, eviscerating one of those Harbor Freight Bubble-Style tire balancing thingamabobs, and using it as the centered hub. http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=91939

Oh gawd, what have I started!

driveshafts and wheels/tires were discussed earlier...

In the center of the clutch hub there are (on an older VW) simply rivets and a solid center. Many 'racing' clutches incorporate this. On most Domestic stuff, as well as all the 240/60/80 and 510 stuff I've worked on they all have clutch hubs like the newer VW's used: they have a series of springs and a thicker center hub that allows the friction facing part to compress these springs somewhat before transmitting motive force to the center hub with the tranny input shaft spline. Solid Hub: Sprung Hub: I used a Sprung-Hub disc at the insistence of my engine builder, after having nothing but solid discs in my bus for 15+ years and I don't know how many miles. I can tell you those springs popped out of the hub and locked up the works at 65,430 miles though! And a trouble free solid disc went back in...and my wife didn't know the difference! The springs are supposed to soften engagement, and 'prevent chatter'...some of the higher end clutches use elastomeric dampers, or a combination of springs and elastomer. If you have a disciplined foot, a solid hub is just as easy to engage as a spring hub, and without a failure point. What JeffP found in his hub was the springs compressed to a point where the hub had inertia, and was knocking against the rivets as a stop---and then driving the car. Bad Mojo! His new clutch doesn't do that by design and the disc is somewhat different in the spring configuration (dampers inside the spring). You can see the piece in the second photo that will 'knock' against the rivets. Compare the rivets holding disc to splined hub in the solid, versus the sprung hub and see what you decide about which is likely to hold up long term? I'm thinking I suffered more clutch wear with a solid hub, but I NEVER had a solid hub fail like the Sprung-Hub did. More parts, more failures...that's what I see. Make sense now? Gracias Amigo! ;^P

First the revalation Justin is having sleepovers... Now photos involving Mopars, Passed out Men, and Ponies Mounting something... I now know him who they call Y0RGO at Z-Car.com! LOL

Obviously, Braap is not a student of the "Mach 5 School of Design" Spritle and Chim Chim can fit in that battery box on the left side, and Trixie looks so cool on your arm driving it around... And, just as a reminder, the Toyota 2000GT was a 60's vehicle. If anything, the Tibiroun looks like a T2-GT not the 'other way 'round!

It was kind of what I was getting at earlier in the thread as well.

"Just look at his head, how many people have welded chambers on a street driven Z?...." I guess I make that at least 2 people here in the USA... In Japan? Back in the 80's almost every hot performance engine making power had a welded N42 in it... I could pick them up in the scrap heap after a spark plug electrode let loose and scarred a chamber, etc, for 3000 yen (scrap value, about $15 at the time!) Got an idea where I got my welded head from???

S130 and S30 are... Z31...what's that? Is that even a Z? LOL The parts bin doesn't change that much, two generations went along...I would guess they carried it on.

My comment on the external oil modification was the relocation of the pickup to the side of the oil pan, then routing that externally via a -10 hose to a specially modified L-Series Pump Cover, through the pump, and then to the block via another -10 hose. This totally bypasses all the restrictive gun-drilled galleys in the block, which can be restrictive. Stock pickup and feed to the filter galleys are plugged in this modification. The B-Car doesn't have it, but Sho-'Nuff did, an under 3L Hydro in the midwest that ran 9K+ rpms under marine loading conditions...far more serious duty than our land cars will see! You mention oil pressure going away---is it possible there was a drainback issue causing the pump to pass aerated oil? high rpom engines use that larger sump as much for keeping the pickup submerged, as to give you a ready reservoir for higher rpm operation when you are pumping a lot of oil to the top end...and it takes the same time to drain back at 9000 as it does at 4500...problem is you have 2X the oil you're pumping. This was the largest recommendation for the external routing of the pickup, to increase the volume moved. I know I answered this in a PM earlier in the week, but for the rest of everybody who thought I was a butt for not responding...LOL

It is absolutely possible to measure MOI! Yeah, unless you are making mongo hp and torque, multiple discs are difficult to live with on the street. We have a triple disc clutch in our B-Car and it's 7.5" with a total flywheel, clutch, cover weight of 15#! Look at the pedal and it changes 2000rpms! LOL "Serviceable" is a relative term. Mr. P is not happy with F-Wheel at this point in time...but what can you do? Make your own?

i REALLY MISS BEING SINGLE AND ALONE! Take a Travel Job, that will do it.

This has been posted elsewhere. CARB is cracking down on certification on the el-cheapo aftermarket cats out there, and to do it they had to snag everyone. Someone just tried to get a Volvo Cat, FROM THE DEALER, and was put on hold while they had to order a new 'California Compliant Catalyst' which likely is the exact same catalyst with documentation (since they are an OEM)... Before it got some pass, it was insane to be able to make a cat, and have a two-tiered system for longevity. Stock Cats now have to last 100K miles or 10 years, formerly they were 5 years 50K miles. And there were 'universal catalysts' out there??????? The loophole was closed, and CA wants replacement aftermarket pieces to last for more than a year. It was not uncommon for a replacement cat to die before the next smog check. But for only $149 hey! What a deal! Right? Dealer's Catalysts were more along the line of $1200... One would net you $400 in the scrap yard, the other one the scrap man would laugh at you and give you 0.16 cents for the stainless steel shell! There was a difference. Sucks to be a catalyzed car and have to buy a catalyst that is no longer supplied by the OEM....but the upside is that what you will have available from this point going forward will at least last some time period more than the next smog test!

Guess what? Last year at the Euro AG Trade Show CAT showed off just such a device, where a small turbine in the exhaust downstream of the turbocharger was geared directly to the engine through a 'fluid coupling' for power recovery/increased crankshaft horsepower! Just like that old Constellation... "There is nothing new!" LOL

"It would be nice if someone had a real number in a catalog or something as opposed to either of our recollections..." Ask and you shall receive: CF Steel SFI Rated Flywheel is 25.4#-Part Number 700800 CF Aluminum SFI Rated Flywheel is 12.5#-Part Number 800800 From the 2009 Midway Industries Online Catalog, though it claims not to be for a "2+2" but I know people who have gotten both 240 and 225mm Flywheels from them, and since the only difference is bolt patterns for the cover and friction surface, I don't see that adding up to a 16# wheel under any circumstances. MSA has always advertized them as 13#, which follows to the 12.5# number in ther factory documentation. http://www.centerforce.com/clutches.tpl?cart=123974506814732304&subsection=clutchselector&searchStr=fsearchStr2&fstep1=step1&fstep2=step2&flymake=NISSAN-DATSUN&flyapp=2.4L%20240%2C%202.6L%20260%2C%202.8L%20280%20%26%20ZX&option=flywheels&avail=no

The Kameari is Chrome Moly, and has more holes on the outside for morewindage cooling of the clutch assembly...(tic)

Interesting pricing, must be a different Centerforce/Midway Industries unit. Mine was only $345 and was aluminum at #13. Maybe you are discussing their billet steel SFI rated model? That may be more. I have the Midway/Centerforce Flywheel on three Z's right now, the Tilton 11# on one, a "roughly" 15# JDM Lightened Stocker on one, and Two HKS and one Kameari flyhweel sitting in the wings for 'lightening exercises" in the future, but have driven several vehicles with the HKS. All within the last year or two at the outside. I'm thinking my recollection, since more recent, may be fresher? I could not explain how my JDM Stocker revved quicker than the Centerforce unit, other than the way it was lightened. They both have the exact same clutch cover assembly and are both 225mm sized as well. I'm open to other explanations if anybody is willing.