2eighTZ4me

I can only assume Tim and TonyD, that you were using a stock driveshaft and driveshaft bolts with those power levels? I'm doing the swap today (hopefully). I know I'll have to swap out a few parts, but I think I have them lying around...... Rossman - I searched McKinney's site this morning and can't find the tranny mount you pictured. Do you happen to have a link to it? Also - what needs to be done to the bellhousing to get it to bolt to an L motor?(I will search later - but thought you would know off the top of your head) - Thanks!

This will strictly be a road racing application. Not in to the burnout or drifting thing. The box I have is completely rebuilt - new bearings and synchros, so it should hold up for a little while. I'll have to do some research on the 240SX tranny swap....but for the time being..... I have spoken with a knowledgeable Z guy from years past (the guy that built my racecar originally) - he said that I need to get that T5 out of my car ASAP - due to the fact that first gear is on the mainshaft and constantly spinning, and has no roller bearings and is subject to poor lubrication. Several of his buddies have experienced the same thing when downshifting from 140+ down the back straight, first gear literally "welds" itself to the mainshaft due to poor lubrication, and the box puts itself in first gear and then all hell breaks loose. He's lost 2 T5's this way (and sheared of several 1/2" ARP lug studs when the box locked up) - and several of his buddies have lost T5's in a very similar fashion. I've got a pair of T5's I'll be selling soon. One is completely rebuilt, and the other is in the racecar now. Shifts and works fine - but I'm not willing to take that chance on track. Perhaps someone with more "detailed" experience on this phenomena can comment, but this is what I was able to glean from a 10min. conversation with him. Anyone?? Bueller??

Holy Shnikees Tim! Yeah - that had to have been a "crunchy" ride home. I'm putting 366rwhp down at the present moment - but the forged motor is done and sitting in a plastic bag in the corner of my garage. Guess I'll have that tuned below 400 and be reliable. Only other option would be the 300 ZX 5 sp. - but then again - would that even fit in the tunnel of a 240? 280 is a bit larger and more forgiving from what I've read - but 240 - that might be a fab job on the tunnel...OR - other options??? (I'm asking you guys)

Basically - what the title says. What's the most hp that has been "reliably" put to a stock 77-78 (or even ZX for that matter) transmission (FS5W71..) and held together? I searched for 20min. and couldn't find much, so I thought I'd ask the question directly. If someone finds a thread on this elsewhere, just tell me what keywords to search for and I'll go from there and butt out. But, since it's a fresh question (at least in my mind) - maybe you all could reply with your personal experiences? --Thx!!

I was "told" that it was raw data - but now it makes sense what you say about the circuit output. All I know is they said they took one sample before the VR conditioning board, and one sample after it. I've got a bunch of questions for those boys!! Hopefully, I'll get the car back tonight. Yesterday - without timing completely dialed in, at 15psi, it was making 300rwhp and 320 torque on a bone stock 80 ZX motor with 150K mi. on it. Curious to see what they were able to squeeze out of it at 20psi and with all the timing dialed in.... I gots me some learnin' to do.....

They had to install a VR conditioning board to even get it to function. Car wouldn't run at all without it. They were showing me both raw data right off the sensor, AND the converted/conditioned data. Raw data was in blue and the conditioned data was in red. The conditioned data was a perfect +5v all the way across - amplitudes dead even. The raw signal looked like a seesaw..

It's rather interesting that this is the way it was explained to me (perhaps I'm ignorant and didn't pick up the "whole" gist) by the guys at DIY AutoTune. They're the ones tuning my car - and explaining this to me and showing me the scope output. Jesus - I just don't know who to believe anymore. I'll read over the manual again and try to digest - and then question them again when I go to pick up the car. It's probably a "detail" I missed in passing. Moby - the car is running MS II now. Most recent firmware as well. Regardless - if you look at a peak of the wave on the teeth in question - there's a huge downward spike, then back up again - and the curve continues. It's far from smooth, and extremely erratic.

Sine wave is analog and a smooth curve. It would stand to reason that in the "digital" domain - which is what this information is being broken down in to (1's and 0's) - that you have an on or an off state. There are no "in betweens" which is what a sine wave represents in the audio world. A digital sine wave is merely a representation of bit depth coupled with a sampling rate. You never get a smooth curve, but rather a stepped curve at each sample location. I'm just letting you know what I saw on the scope output. It was clearly an on or an off state. There were no smooth transitions between peaks and valleys. Just 90 degree transitions. I'm an audio engineer on the side, so I know what you're talking about WRT a sine wave. If this were a sawtooth trigger wheel - I could understand that logic, but this is a square toothed wheel, and by all logic, it should mimic on the scope what each tooth physically looks like. OK - I know you know more about this stuff than I do - but I need to ask you to explain the differences in amplitude that I'm seeing on a recurrent basis as the wheel goes around. On an electric guitar pickup (which is exactly what the VR sensor is) - the closer the strings are to the pickup, the hotter the output signal. In a perfect world, every tooth the sensor reads "should" output a consistent +5v. I'm getting lows down in the 3's and then up to 5's and then back down again. If logic follows here with the guitar example - the closer the sensor is to the teeth, the hotter the signal it gets. Conversely, the further away from the pickup/sensor, the less voltage is going to be generated. I'm all ears though - I love to learn - but have been an audio engineer for over 25 years and know what a digital sinewave looks like compared to an analog one - and am just applying that logic to what I'm seeing on the scope. Could you please elaborate? I'm not challenging your response - I know what I saw on the scope (and maybe the whole shebang is wrong) - and I'd like to learn more.

I don't have the BHJ on there - yet. The balancer that's on the mule motor is a euro balancer of some sort that has had the toothed wheel welded on.....and not very good to boot. Based on the scope output that we picked up yesterday, its both out of round, AND a few of the teeth are screwed up. Kind of hard to explain, but the out of round is obvious - the scope output gets higher and lower in amplitude based on how close the wheel is to the sensor. Also - some of the teeth are showing "spikes". When the signal is running over a tooth, it should be a perfect square wave. We're seeing LARGE dips in about 8-10 teeth, that really gets exacerbated at higher RPM's. The bad teeth are so bad that - when the sensor is reading the tooth, it will make a large enough spike to cause the VR conditioner board to breach the threshold and drop ignition (it thinks there is no tooth there, when in reality, it's a valley within the tooth that it's picking up). I'm fairly confident that with the new BHJ damper and the new trigger wheel - it will be able to hit 8K. Problem is - I've got a bunch of $$ tied up in the current setup with the mule motor, such that I'm just having them finish the tune, and I'll drive it as-is with the rev limiter set to 6200 and thrash the holy hell out of it until it a) breaks or I feel like tearing the motor out of there. The mule only cost me $150, the forged motor, about $6000. The other major difference is the TEC3 that you're using. That thing is a hoss. I went MS due to cost, and it looks like it will be sufficient for what I want to do with it. FWIW - I spoke to Uwe at Electromotive at length yesterday, and he stated that there is no difference between ANY of their sensors. They just used the smaller 3/8" sensors for "tighter" applications where room was at a premium. It's nothing more than a magnet. I was asking for the very same reason - is it stronger? Will it give better resolution? Has the inductive "technology" come a long way since my original sensor was produced? No, no, and no. He has got me drooling over their XDI ignition setup though.... I may eventually go that route - if I can scrape together $900 for the box.... Just damn.

I mean - 60 tooth (-2) wheel mounted to the crank with a sensor right down there on it. No dizzy at all. I want to avoid a distributor for several reasons altogether. Just spoke with Brian at Rebello racing and he suggested with the MS to drop down to a 36 tooth wheel. He stated they have had good luck with them up to 9K with MS. I'm awaiting a call back from Electromotive to find out if any of their new sensors would provide a better signal. All signs are pointing to dropping (and modifying) to a 36 tooth wheel though.

The folks at DIY just called me to let me know that they get a crap VR signal over 6100rpm's. (They're tuning the car now) Either the wheel is out of round, or is warped slightly. OK - no problem. The forged motor I have ready to drop in has a brand new Rebello BHJ damper with a(nother) 60 tooth wheel mounted on the inside of the damper. I mentioned this and they stated that the 60 tooth wheel is pretty much "too much" for MS. Said the wheel was too small to boot. Too many sensor events per revolution. I really wonder how Rebello is getting 7500+ rpm's out of their cars on a 60 tooth wheel - based on this observed limitation.....I'm gonna have to give Dave a call.... Nonetheless, to comply, I need to come up with another triggering solution. They recommended a 36 tooth wheel. The problem I have with that is mounting it on the outside of the damper. This will cause me to have to fab up aonther bracket to hold the sensor, not to mention probably re-engineering my (already tight with IC piping) engine bay. I like the idea of doing the marks on the back of the flywheel, but they stated that 6 holes is not nearly enough to be accurate. So - I'm curious what you MS'ers are using for distributorless ignition - i.e. wheel size/resolution etc. and what kind of performance pitfalls (if any) are you seeing?

I beg to differ with you DrSideways. This trailer has been done RIGHT. Double axle, and even has a tire rack. All welding done by a professional architect welder. I am intimately familiar with the trailer before purchasing it, and it has seen well over 25000 miles with a car on its' back with nary so much as a problem. It's been to Cali. and back to the East Coast at least 4x (with a car), so before you go bashing a trailer you've never seen, I thought I'd share a little history with you. It is a proper road-faring vessel. This topic is about a tow vehicle - not about the trailer. Randy - I had thought about the van thing, as my buddy who's an ITS racer has one that he picked up used from a transportation company. He's been all over the place with it and he sleeps in it too - I like the idea of no hotel fee!

Just looking to see what 'extremes" you racers go to to tow your vehicles to the track. Looking to get a used pickup or van - don't want to break the bank - but want to see what you guys are using to see if there is anything reasonably priced out on the market that would be suitable for towing. I have an open trailer (a converted boat trailer) and my car weighs 2380 - so I'm figuring maybe a 4500-5000lb load? Maybe less? I have a 97 Jeep Wrangler - but it's a short wheelbase, and I've been told that I don't want to do that. I haul our band trailer with it, and it does just fine. The band trailer loaded must weigh a good 3500-4000 lbs. Thoughts?

No - it actually states in the data sheet (in bold) that you need to coat the inside of the balancer with anti-seize to prevent the balancer from "welding" itself to the snout of the crank due to the heat. To quote them "the stock cast iron balancer will be far more forgiving than steel". I'm just doing what they tell me to!

" The chambers on the 47 and 79/90's are very similar" Not quite..... the 79/90 has a 53.6cc combustion chamber - the MN47 has around 39.5. They're worlds apart. Smallest piston to head clearance?? Last I checked, that bumps compression ratio and compounds detonation. You're talking about quench. When you start getting in to using a MN47 on a flat-top motor, you've almost batted yourself out of the pump gas field - unless you have a monster cam. I'd have to run the numbers through OzDat's engine calculator - but I bet compression ratio would be at least 10+:1. There is scant little room for larger valves in the MN47 as well. I don't have the specs on the valves on each head in front of me, but the MN47 was a bit smaller - I believe 42 and 34mm. The 79/90 valves "may" fit though. Nonetheless - I agree with rejracer, that a P90 head on flattops would be plenty good for what you're trying to do - and the head would flow better in general. Throw a decent cam in there and you're even mo' better off. I've got a MN47 on my stroker motor (dished pistons) and am seriously considering swapping over to a P90. Even with dished pistons, I can only get max 33 degrees total advance without pinging. A P90 would drop compression ratio a bit, and allow me to bump more timing and probably build more power over a broader curve. Even though the head is race ported, I think I'd gain more through the added timing and flow of the head than a couple points of compression ratio would give me. Here's a good link to find all the differences in the L series heads (as well as a boatload of other useful Z-car information) http://xenons30.com/Heads.html

Welp.....I thought I'd end up taking more pics than I did. It was probably due to the fact that this is the 18th L-Series I've built, and I got on a roll and zoned out and forgot to pick up the camera. Painted the assembled bottom end....whoopee - ain't that purdy.... Copper coated and installed the ($150) head gasket...... Head is ready to drop on...... Aaaaaannnnndddd - there it is. Done deal. Still going to remove the balancer and wipe the inside with some anti-seize compound - but other than that - it's ready to drop in the car......the car......where's the damn car!!!???? Oh yeah.....it's up at DIY Autotune being tuned on the 150K mi. mule motor to produce 400rwhp or 20psi of boost....whichever comes first. So, if it goes on the dyno, I've got backup!!

So - in summation, THE best place for a cat..........(wait for it.........................) is to leave it in the bag!!

OK - been a while. Had to order an overbore sized head gasket, timing kit, and started on my cam wipe patterns - ONLY to find that I was 4 rocker arms short of having the Full Monty. Sent some core rockers off to Delta Cams (Thanks Ken!!) and received the rest of the allotment (along with 2 other sets) just the other day. Based on my wipe patterns across 8 lobes, I was at an "average" of .180 lash pads with a 190 and a 170 here and there. Interpolating that info, I bought a bunch of .180's - as well as a few .170's and .190's. They showed up just yesterday. Will finish the cam wipe patterns tonight and start assembling the timing components. I have also ground out the front timing cover to accommodate the diesel Maxima water pump. Everything's just about ready to go together - so stay tuned for upcoming pics.

Zeiss - with a post like your last one - you've likely pigeonholed the number of people that can and will actually answer a question the next time you have one. This thread is chock full of GOOD and (somewhat) relevant information for people that want to learn. Just because you don't like the "attitude" by which this information was presented, doesn't discount the validity of the information. "I always want to learn new things about my Z car but I want to learn it from people that aren't trying to prove how much smarter they are that the rest of the morons on the web site. " What did you do when you had a teacher in school you didn't like? Did you just fail the class?? Or suck up your ego and do what you had to do to LEARN? FWIW - I didn't "ask" you if you'd replaced your hatch seal - I told you that it could be a major factor in the problem you're seeing (ref. post #12). I guess because I didn't "ask" you if you'd replaced it - then the information is not relevant? Jeez man - you've just screwed yourself out of two or three people that actually KNOW their stuff and would be willing to help you in the future.......not so much anymore. Shame that people let their feelings get in the way and discount what is right in front of their nose. You'll learn.......

Nor is your cockpit sealed off. The majority of the fumes sneak in through a bad hatch or taillight seal. I'd be checking those "lower cost" items first before stuffing a cat under there. You can also get a 90 degree exhaust turndown to point your exhaust at the ground. It makes a WORLD of difference.

I had suspected the same being that diesel burns at a completely different rate than regular gas. Guess while I'm building the race motor, I may as well stick the cam in there and try to get some specs.

I yanked apart the diesel head I had lying around in a quest for some core rocker arms, only to find that the rockers are about 1cm shorter than the standard L series rockers. Also come to find that since diesels don't rev that high, they only use one valve spring instead of the inner/outer standard arrangement. So now I have all these useless parts (I "was" able to scarf the valve keepers/retainers though) and wondering what to do with them. The cam was of particular interest. I was unable to get a "letter" off the butt of the cam. In feeling the lobes, it feels like there's a plateau on the nose that would keep the valve open a little longer. I didn't try to fit the cam in a standard L series head, but it looks like it would work. Has anybody messed around with this? Is the cam usable? Anyone have specs?

Junglist - the MSA gasket and the Nismo gasket are indeed the same. I just plunked down the $150 for one from the dealer.

Yeah - I've seen those - and that was what I was trying to avoid!! I've seen a couple folks on EBay that claim they'll make you a copper head gasket for $x.xx - is that what you'll be going with? I always tend to question the integrity of "low cost" items on Ebay. Good things aren't cheap and cheap things aren't good! Tell me more about who's making your gasket.....

Hey Pete - the pistons are custom JE pistons with a reduced pin height - designed to work perfectly with a stroker crank and provide a zero deck height. Pistons are dished even moreso than stockers. They were designed especially for a turbo stroker by a guy that is FAR more "advanced" than I. Head has only been cut just slightly to make it flat. Nothing major at all. What I lack in compression ratio, I can make up for with boost (I figure). My "measured" bore is 89.5mm at the top of the piston walls - and the stocker gasket came out to 90.5 - but I still didn't feel comfortable with that little clearance. I'm going to measure the 91mm unit when I get it in and go from there. Not terribly fond of the copper gaskets either, as I've had several racer friends develop leaks. I'm comfortable with a Nissan factory part. Worst case - I'll go the copper unit if this doesn't work. The fact that I'll have a low(er) comp. ratio regardless of which gasket I use - gives me a little leeway to experiment with the thinner gasket. Just rambling - what do you think?