pparaska

I got ill watching that. No thanks.

A good friend of mine mounted the Nalle kits on several of the last cars built. He was given the last kit as payment for doing the body installation work. Hopefully he'll join here and chime in. He is in the process of getting his Nalle-kitted Z back on the road and hopes to have it done quite soon. When he built his own Nalle bodied Z, he modified every panel of the kit to make it look more like the actual Dayton Cobras. If you ask me, his car would be the one to pull the molds off of!

I hope that helps! Gotta keep these old Scarabs on the road!!!

Contact Mikelly. Jim's Scarab may be moving to a different clutch system and the slave may be up for grabs...

Good point. I found another site that recommends at least 1 degree of running u-joint angle: http://www.drivelinesnw.com/troubleshooting_symptom.html

I love the YZ fenders - you took it to the next step - steel!!! Cool. I just prefer steel for a street car.

Actually, you want to have SOME angle in the u-joints, at least 1/2 degree: http://www.vibratesoftware.com/html_help/html/Diagnosis/Propshaft/Propshaft_Angles.htm "The working angles themselves should not equal zero. This is because with a zero working angle, the needle bearings within a U-joint will not rotate causing brinelling and premature wear of the U-joint." Using the solid driveshaft to set up the driveline angles may not be the best way to go.

(Opinion alert - I have no real experience with ITB, but some experience with tuning plenum type engines. Below is my understanding of some other ITB vs plenum issues. Of course, my understanding of this could be flawed. But I'm a pretty good student and look to get to the facts. Which is why much of what I believe in engine theory comes from what I read from David Vizard - someone with alot of theoretical technical insight, as well as someone who's been testing those theories on the dyno and race tracks for decades. Anyway, here goes : ) Interesting that no one has mentioned a few of the supposed advantages of ITB beyond throttle response: (1) improved midrange torque and (2) the ability to offset the uneven low end that at valve events with large overlap that a plenum design will exhibit. These are related, of course. Overlap of valve events are useful in the exhaust (scavenging helping pull intake air or air/fuel into the chamber) but overlap almost always has a detrimental effect on at least some portions of the rpm range due to "stealing" of air or air/fuel from one cylinder to another. In some cases, the plenum can be made large enough that this may not be a big factor. In fact one way to look at an ITB setup is that the Earth's atmosphere is actually you plenum volume. When you have no communication between cylinders in the intake tract, like with an ITB setup, there are much fewer problems with fuel standoff, lean versus rich cylinders, etc. This is due to each cylinder breathing off of the huge plenum of the atmosphere, each intake runner getting to start with the same initial conditions as any other when the intake valve or throttle plate opens more, etc. I'll quote Vizard on this ("How to Build Horspower, Volume 2," page 97): Vizard's writes later in the book (page 116): I realize that Vizard is talking about a V8 here, but that's because the book is about building SB Chevy V8's. There's no reason this is a V8-only phenomenon. I plan to test this theory in practice - I'll be going from a plenum single plane intake with TBI injection to an old Hilborn mechanical fuel injection manifold with port EFI. Here's the Hilborn injector before:

A friend of mine used the stock Datsun auto shifter when he converted his 240Z to a V8 with a 200-4R tranny. He may have used a shorter arm on the tranny or a longer arm on the shifter to get it to work. What he did was to get that part worked out so he could have access to all the gears, and then removed the detent plate in the Datsun shifter and make a new one that had the detents just where they needed to be. It was pretty simple to make and install, as I recall. The Lokar throttle cable is very nice and worth the few extra buck as it provied plenty of ways to make adjustments.

If you can deal with it fitment-wise (I don't think having the subframe connector extend down 1" below the floor and 1" above is a problem, personally) , I think that 2x3 is a better solution. That's assuming that the we're adding the subframe connectors to add vertical bending stiffness to the floor area, and probably some torsional stiffness too. The stiffness in vertical bending of the subframe connector (with the 3" side being the horizontal side in this application) is a good bit higher than a 1x3 or 1.5x3. It has to do with the mass moment of inertia (I) of a hollow rectangular cross section ( I = width1*height1*height1*height1/12 - width2*height2*height2*height2/12 - where width1 is outer width of tubing, height1 is outer height of tubing, width2 is inner width of tubing, and height2 is inner height of tubing). http://www.engineersedge.com/calculators/section_square_case_10.htm Here are the numbers for the moment of inertia of the 3 tubes, assuming the 3" portion is horizontal, and the wall thickness is 0.120": 1x3: I = 0.15 in^4 1.5x3: I = 0.38 in^4 2x3: I = 0.74 in^4 The 2x3 is 5 times as stiff in vertical bending as the 1x3, and twice as stiff as the 1.5x3. I'll take the 2x3, thank you!!! The tubing probably also gets twisted as well, since the chassis in general twists, mostly under suspension loading. Thge torsional stiffness of a structural member is proportional to it's polar mass moment of inertia of the cross section (J). This is a bit messier mathematically, see this interesting Cobra builder's web site for an interesting discussion and the equation for J: http://www.erareplicas.com/factory5.htm Again, assume the wall thickness is 0.120" 1x3: J = 1.1 in^4 1.5x3: J = 1.6 in^4 2x3: J = 2.2 in^4 The 2x3 is twice as stiff as the 1x3 in torsion, and 39% stiffer as the 1.5x3 in torsion. Now, about weight of the different tubes (all 0.120" in this case): 1x3: 3.1 lb/ft 1.5x3: 3.5 lb/ft 2x3: 3.9 lb/ft No big deal really. The subframes are about 6 ft long each IIRC, so that's a total weight addition of: 1x3: 37 lbs 1.5x3: 42 lbs 2x3: 47 lbs 2x3 sounds good to me!

Looks REALLY familiar! But I pussed out and had the body shop do the outer rockers and 1/4 panels. Did you find much rot in the inner rocker panels? Mine were just about gone at the front and rear for about 3-7" and I had to make the replacements by hand (did it out of 1/16" steel), with all the beads, bends, etc. That was a TON of work with meager hand tools. But the front and rear rocker boxes transfer a lot of load throughout the unibody, so I felt it was worth it - even with the subframe connectors.

Yeah, I was out at Mike Mileski's house the other day and saw a pair of these - SWEET! Nice big, smooth radii on everything, undercut between bearing race areas just enough, beautifully machined. I need a pair!

Yes, 0.095-ish in the engine frame rails. 0.083-ish in the subframe connectors. I'd not go below that and do the .120"

Dude, that sucks it got hailed like that! Glad the insurance co. is going to fix it. What company is that?

Well, one thing to consider is that Kevin at Tex Racing responded with a "no" when I asked if they used a bearing stabilizer plate. I'd think either The Gear Shop or Modern Driveline would be fine for doing the build. Heck, I'd think even G-force transmissions would be fine.

I'm really confused now - I talked Kevin at Tex Racing. He says they source their T-5 Gear Sets from G-Force! And they are $1500 now, but is checking prices and getting back to me. He says they don't do very many of these (they're mostly NASCAR suppliers, hence, the do their own trans designs, the T-10, and Jerico). Update: O.k. the $1500 price is for the straight cut gear set. The helicut gear set (input shaft, 1st thru 4th gear sets) is $950. The helicut 0.80 overdrive gear set is $360. New main shaft is $295 Labor is $240 other parts would be extra (bearings, synchros, etc.) not sure exactly how much. Again, we're back to the only option being G-Force gear sets.

[update: I guess that Kevin at The Gear Box is confused. I called his supplier (Kevin at Tex Racing - see a few posts below this) and he said they get their gear sets from G-Force.] Wow, I'm shifting gears again Just got off the phone with Kevin at "The Gear Box" (see TimZ's post): The Gear Box 26405 Northline Rd Taylor, MI 48180 (734) 946-6088 Kevin uses Tex Racing gear sets, that he says are superior in finish and tolerance to the G-Force gear sets. He had numerous problems with the G-Force boxes binding up after building transmissions and running them a bit. The surface finish and gear tooth geometry, along with 5th gear spline sizing caused him problems. That, as well as the G-Force game of price increases and supply issues brought him to find a better gearset, and that is the Tex Racing Gearset. I've decided that this is the way I want to go - Tex Gear set, and use The Gear Box to do the rebuild of my GM trans. The gearsets are presently $1350. This includes the Input shaft, as well as all the gears, (but not the main shaft, I think?) The GM box rebuild labor is about $195, and the additional parts (bearings, rear bearing retainer replacement, fork pads, keys, synchros, etc.) for a full rebuild usually go into another $400-450 or so. So us GM folks are probably going to be spending $2000 for a rebuilt T-5, if you have a GM WC T-5 case. Kevin said the older pre-93 GM WC T-5 cases are almost impossible to find anymore. Kevin said he bought the last 6 pre-94 GM bolt pattern cases from Tremec (not sure how many he has left), that go for $285. I didn't realize this but the 94+ GM T-5 used the same case bolt pattern and input shaft as the Ford versions. Those are easier to find used. The Datsun stuff he has done several for besides Tim and Rick. He needs the Tail housing and shift cover from the Datsun T-5 trans to do the build. He says that the usual out the door price on the Datsun T-5 build is about $2550. He uses the latest Tremec carbon synchros (1-4, 5th has always been brass), Timkin bearings, and an upgraded bearing support. The usual stuff you see used in a good T-5 build. Guys, I don't think that a group buy is really available here, but if you want to try to do that give him a call. I don't think we have the numbers to do it justice. I think what's more important is that Kevin and his guys have a superior gear set choice, do good work (from what I hear), is easy to work with and knows how to do the Datsun T-5 build with the strong gear sets. Kevin says he has these transmissions in 650+ hp drag, roadrace, and pull applications and they are holding up great. The way I am going to progress, and the way I suggest others go is to just send your stuff/order to Kevin at The Gear Shop and have a good trans.

Thanks! I just rated this thread 5 stars - it has a good bit of info on the 280ZXT CV shaft adapter length, and how to get a 240-280Z behind-the-diff mounted anti-sway bar to work with them. Thanks again!

O.k. Current Count: Chevy form factor: 4 serious (Mikelly, pparaska, jt1) -- ( no_damn_240 PM'd me he's not interested any longer ) Ford form factor: 1 serious (Z-Dreamer) Datsun form factor: 1 serious (ww), -- ( maybe 1 more, if Jersey is still interested? )

No movement, past these posts. I suppose a Post in the Group Buy Forum that points to this thread would be a good idea? Not sure how to handle this as it isn't a typical Group Buy, where one person pulls the money from people and then makes the order. Also, Bruce seemed to say that the number of 10 buyers wasn't hard and fast, he just seemed to want some of the minimum of 10 gear sets he has to order spoken for, if I caught his drift. But before we move on this, I think that Kevin at The Gear Box (see TimZ's post in this thread) should be contacted to see what the deal is with them. If they are sourcing gearsets from the actual manufacturer and not G-Force, then we'd not have to deal with the lag that G-Force is putting on filling orders. Mike, I'm not in real need of this trans, but would buy one. Since you have the most urgent need, how about contacting Kevin and see where to go from there? How's that for delegating responsibility?

So far, it looks like me, Mikelly, jt1, Z-Dreamer, are serious about a Chevy form factor version. ww seems interested in a Datsun input/output shaft version. no_damn_240 I think is interested in at Chevy version. That's 4 serious GM versions, one maybe, and 1 Datsun version. We may have enough to move forward. But I think we need to make some kind of an announcement in the Group Buy forum, although this isn't a typical group buy, as I think we want to get good faith commitments together, and with that Bruce at Modern Drivelines may be able to move forward and order gear sets.

Yes, while it's running. A typical gage shows positive pressure or negative pressure (vacuum) that is in relation to the ambient pressure around the gage. So just hooking the gage to the exhaust pipe shows the pressure difference to atmosphere. This is typically called gage pressure, versus absolute pressure which is gage pressure plus the atmospheric pressure.

Great thread! SHO-Z really hit it I think - don't worry about the bends too much. Make sure the size transitions are slow (like Johnc's cone), the pipes are of adequate size to not have too much pressure change from atmosphere to in the pipe, etc., but the big issue is the wave tuning and scavenging. David Vizard did a really nice article recently on exhaust system theory and testing in the May 2005 Popular Hotrodding Magazine. "Exhaust Science Demystified" (byline: "The fact is most cars are leaving horsepower on the table. We show you how to get it all back.") He talks about how the (then) Cyclone Sonic Turbo muffler design he and an acoustics expert friend designed made more horsepower in a dual 2.25" system than all the other dual 2.5" systems they tested using other mufflers. Also intersting is his discussion on building a no-loss exhaust system - that's right - an exhaust system that saps NO power compared to a correctly designed open header setup for racing. He talks about the 5 cycles of a racing engine - the added one being the exhaust-driven induction event - what you have heard called the scavenging effect that pulls intake mixture into the cylinder during overlap. He describes a comparison of induction pressures between the peak suction on the intake port due to the piston going down the bore (about 0.5 to 1 psi) and the partial vacuum that an exhaust scavenging event has on the intake port during overlap (about 4-5 psi). David goes on to talk about primary header pipe diameters, saying a bit too small is better than a bit too big, and that the only real way to find out what the engine needs is to do dyno testing. However, he provides a nomogram showing the relationship between the primary pipe diameters that have been proven to work well versus exhaust port flow at peak lift, for street, hot street, and race Normally Aspirated engines. He adds that the primary pipe AREA must be increased by 6 to 7% for every 50hp worth of N20 injected., but that for street use, it's better to not do the increase as the engine is mostly in non-N20 use. Primary length is also addressed. David always boohoos the "equal length" argument. In this article, he gives some good reasons - you may not know the optimal length, so if the pipes are all of equal, but incorrect length, that may be worse than having some variation in the lengths. He notes that an exhaust system can scavenge at or near maximum intensity over a 4000 rpm range. His reasoning is then that if one pipe is 1000 rpm different in its rpm range of scavenging from the rest, pipe length differences of as much as 9 inches different have little effect on performance. Then he gets into an issue that came up in my mind recently when reading "Headers-by-Ed"'s header information. He's a big proponent of very equal length headers. As I was reading his theory, it seemed based on the assumption that the pulses were evenly spaced in time between the pipes. (He mostly does regular V8 headers). But as Vizard points out, the timing of the pulses on one bank of a two plane crank V8 are unevenly spaced (90, 180, 270, 180 degrees, etc.). Vizard likens this to the the collector on one bank of a two-plane crank V8 acting like it were on a 3 cylinder engine with different sized cylinders. He notes that the varied spacing makes the system less sensitive to primary length. He goes on to say that dyno tests on two-plane crank V8s show little sensitivity with primary lengths between 24 and 36". Collectors (secondaries): Start with a ratio of collector to primary diameter of 1.75:1. As for collector length, performance is more sensitive to it than primary length, and collector diameter and length have more effect on performance than primary length. Basic rule: shorter, larger diameter collectors favor top end, longer, smaller diameter collectors favor bottom end. He also says that for an engine with peak hp from 6000-8500 rpm, the collector length of 10-20 inches is effective. Again, shorter for higher rpm band (4500-8500). Mufflers: Other than noise reduction, get a high enough flowing muffler to handle the HP. Don't use a muffler that flows less than the correctly sized secondary piping. For each peak HP, have the total muffler flow be 2.2cfm. He gives a graph of percentage of maximum power retained with a muffler on versus cfm per open pipe horse power to show that at 1.5cfm/hp, you lose about 17% of your peak hp, 5% loss at 1.75cfm/hp, and 2% loss at 2.00cfm/hp. At 2.25cfm/hp and beyond, the loss is less than 1%! On the same graph is a curve for backpressure versus cfm per open pipe horsepower: 1.50cfm/hp gives 2.0psi backpressure 1.75cfm/hp gives 1.1psi 2.00cfm/hp gives 0.3psi 2.25cfm/hp gives 0.1psi (sorry, Johnc, David Vizard uses the term backpressure - it's just the difference between the average pressure in the pipe versus atmospheric pressure). David goes on to talk about pressure waves and mufflers, the flowmaster, glasspacks, etc. I won't go into that part...buy the magazine! What is REALLY interesting is the "pressure wave termination box" (or resonator box). What this is is a large volume box (muffler, empty, etc.) that is at least 8 times the volume of one of the engines cylinders. In the V8 case, as large as the engine displacement! It's inlet pipe extends into the box, and the end of the pipe is the end of the collector that the open header would have for best performance. What this does is make the rest of the exhaust system virtually have no effect (pressure wave wise) on the headers. If you have little backpressure behind the resonator box (piping, muffflers, tailpipes, etc.) the engine will lose no power. Without this box, the rest of the exhaust just causes the collector to get REALLY long, as far as the engine/header combo is concerned. He covers X and H pipes. Less noise and increased power is the result. Read the article! This is a really great exhaust science article. I urge anyone interested in this stuff to get the mag! What I like about David's stuff is that he has the theoretical background to make most any hotrodder bow down, but then backs up all his theory with TEST data, from tests designed by someone who understands the scientific principle and knows how to keep from chasing your tail by not changing too many (seemingly unrelated) variables at once. His review in this article of magazine muffler tests is a great example of this insight. I don't know if even now in early April that you'll find the magazine on the rack, but to get the May 2005 as a back issue, you can do this: MAGAZINE BACK ISSUES To order back issues, call McMullen Argus' back issues department at: U.S. Customers (866) 601-5199 International Customers (714) 712-2130 For back-issue questions, including availability, please send your query, including the magazine name, month and issue, to: backissues-mailorder@primedia.com Sheesh! I think my post count should be triple incremented for this one