Jersey

Thanks guys. Not really "bad ass' yet, but geting there! Cody, i do go through the first 3 gears REAL fast, that's another reason i think the stock '82ZXT rear, which should be 3.54 i'm running, is not really 3.54. I really have to drop that rear and read the ring. Doing the "spin the tire and count DS revolutions" tells me it is a 3.54 but reaching the end of the strip at about 6200rpm in 4th, only doing about 106mph tells me different. We'll see. Thanks. Drax - that ACT clutch/PP really grabs! Thanks again.

Here ya go... http://members.bellatlantic.net/~vze29q5g/12.88.avi

4.375! ha. Yes, i've got to be doing something wrong, unless they are 3.54's and i'm reading the tach wrong or something at the end of the track...or something. At this point, i think i'm just confusing myself and the info i write even more! I said to spin the tire 2 revoltions in my previous post and i meant only one wheel turn and count the DS turns. I get a smidge over 3 1/2 turns on the DS, which would mean 3.54's. 13 wheel turns should be 46 (46.02) revs of the DS. Got it Drax. I just really need an hour to pull the damn thing and read the gear! Thanks guys. Appreciate it all.

ZRL - i've never heard it done that way. I've always used the "spin the wheel 2 full rotations , while holding the other stationary, and count the # of DS full revoltions and you will come up with your ratio" method. Your way, which i will try, is telling me that if i spin my wheel one full revoltion, the DS should spin 3.54 times for a 3.54 ratio, correct? Because, using your example to detemine 3.9 gears comes out like this - 39 divided by 10 = 3.9 1 wheel revoltion should spin the DS 3.9 turns If i spin my wheel one full relolution, the DS turns 1.75 turns. If I turn it 2 revolutions, i get 3.5 and a tiny bit more. Why i considered it 3.54. If i turn the wheel 10 times, the DS would spin 17.50 full revolutions - 1.75x10. Try it when you ever have one of your rear wheels off the ground i bet you'll be surprised. Drax - a 3.54 rear will spin just about exactly 3 1/2 turns. A 3.70 rear will spin the DS just about 3 3/4 turns and 4.11's will spin it just over 4 turns. You can tell the difference easily if you know where you started on both the wheel and DS. I don't think DRL's method works with an open rear like the R200 i have, or i have something very unusual. I wish it did so i wouldn't have to drop this rear! Thanks again guys for the replies. Havent had the time, or will, this weekend to drop the rear and read the ring. And it's been bothering me all weekend! I will drop it soon and figure it all out. Thanks again and appreciate it much.

Drax - the reason why you spin the tire only 2 times because when you count the DS turns, that should equal your ratio. Example - 1 turn of the tire would make the DS spin about 1.75 turns...2 rotations of the tire should equal your rear ratio - make the DS spin 3.5 (plus a little) turns equaling 3.54. If you spin it 10 times, then you would have to divide the # of turns the DS made by 5 and then you would get your ratio, if you wanted to spin it that many times, try keeping count of how many full revolutions the DS made and then do more math. If you only rotate the tire twice and count, there should no cause of great error. The difference of tire diameter could be a factor but wouldn't throw my ratio off by as far as i am. The tach was reading within a 100 rpm difference at about 5k rpm than my meter and i figured maybe a little more at 6krpm but again, it would have to be off by 800rpm to throw me off as far as i am. I'm not trying to knock all your suggestions and appreciate all the suggestions, i just think something else is screwy. It has got to be that rear and i'm calculating on how to read an open diff or something. Yo - That's what i was thinking..then again, i'll be happy if it's a 3.9 'cause i'd ditch it and go for like a 3.54 or 3.7 which i think would help me boost off the line. Right now i'm through the first 3 gears so fast, i don't think it has the time to spool up. I wish i could post the video somewhere so you guys could see it. I have nothing to compare it to because i've never seen a Z with a BW-T5 mated with a 3.54 or 3.70, 3.90 take off at the strip. Dropping the diff and reading the gear is really the way to be 100% sure but...i PROMISED the wife to due the wainscoting she bought over a week ago and it will haunt me all weekend not knowing!!! Does anyone know if i'm doing the "spin the tire, count the DS revolutions" correct? I swear this was the way i did it on open rears for the past amost 20 years! I have to be doing it wrong....

So, at work playing around with the Trans/Rear ratio calculator at http://www.geocities.com/z_design_studio yesterday and figured with my T5 and the 3.54 rear that came out of the same '82ZXT, that i shouldn't have been really topping off 4th gear at the end of the strip Wednesday night. I was crossing the line in 4th at about 6100rpm @ about 106mph. So on the site, i chose the BW-T5 and the 3.54 (i'm running 215/50/15) and it says i should be at about 120mph at 6100rpm in 4th! So, last night i take her out and do some runs with my GPS while wathing the tach in 4rth - 3k rpm..52mph 3.5k rpm...61mph 4k rpm...70mph Now, the tach could be off by a hundered or so but i did check it against my meter at different rpms and it was pretty much right there. I go home, jump back on the Z studio site and select the BW-T5, my size tire and the 3.9 R200 and it's A LOT closer #'s as to what i'm running. I also punched in a 4.11 which turns out to be close as well. Now this has me stumped because i know i checked the ratio by spinning and counting when i did the swap. No, i didn't take the cover off like an idiot and honestly, i'm being lazy and really don't want to this weekend. I really shouldn't have to pull it if i do the turning wheel/couting method correctly. So i get back in the garage, jack her up on one side, other wheel touching the ground and check it again..3.54. Now, i may have lost my brain somewhere along the line and might be checking it wrong but this is how i always did it...with an open diff, lift one wheel off the ground or have someone hold the other stationary, rotate the opposite wheel 2 revolutions while counting the amount of times the DS spins...which i got a little over 3.5 turns....figuring a 3.54 again. What the heck am i doing wrong here? Note to self - losing mind @ 35 yrs old! AHHHhh. Thanks in advance for anyone that clears this brain fart of mine!

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Nice slip Sleeper! I put the BW-T5, the R200 and the DS all out of the donor '82ZXT into my '73. I had to modify the trans mount to line up with the '73's mount and changed the outer hubs accept the CV halfshafts.

bastaad - Didn't need to take the stop out with the smaller diameter slave, just cranked down all the way which raised the pedal about an inch. I could have pulled my seat up one notch also but felt a little too close to the wheel that way. I only adjusted it without freeplay for the track and re-adjusted it before i went home. Sleeper - Thanks man. how are your 60' times? I have got to go home tonight and climb back under the Z and check the R200 ratio out. I was crossing the line at the top of 4rth gear..like at 6200rpm! i actually tried to shift into 5th a couple of runs around 5500 just to see how the pull was and of course..missd the shift and blew the run! Now with a T5 and the stock '82ZXT rear, which SHOULD BE 3.54, i should be a lot lower in the RPM range at 105 mph or a lot faster than 105 @ 6200 in 4rth. And i remember checking the ZXT rear alongside the '78 280Z R200 that i had installed in my '73 and remember the ratio's were exactly the same - 3.54. On the trans calculator site - http://www.geocities.com/z_design_studio - running 215/50/15's, i should be nearing 122mph at 6200rpm in forth! Something is wrong. I'm thinking the only explaination right now is that i somehow messed up when determining the gear ratio when i checked it and the donor '82 ZXT car that i used the complete drivetrain out of had it's rear swapped out at on time or another. That really doesn't make sense either because he was a 60 year old man (not old but unusual to start swapping rears i would think) that bought the car new, drove it 70k miles, parked it for 10 years then passed away. I also found nothing added on performance wise when i pulled the complete ZXT apart to put in my '73. I will check again tonight. The #'s would match up more if it were a 4.11 but i REALLY doubt that it is. 1rst gear would be non existant i would think We'll see tonight.

Bastaad - youre' right. once the taste is there, you just want just a liiiitttle more! I bought the small NPR I.C. off of a kid that i found he was selling on EBAY. He also lived in NJ and i contacted him and ended the action early. $150 and i picked it up. I THOUGHT that was going to get away cheap by putting in an I.C for $150 and maybe a few more bucks for the pipes, couplings, clamps....WRONG. Everthing that i needed to completly install the I.C. probably cost me as much as the I.C. and i did all the welding myself. So i figure about $300 total, which is really not bad but still a good amount for me to spend. My Z is starting to definetly get faster but i'll say this - there is nothing like the true tourqe pull of a V8. I love that off the bottom, sink you in the seat, type of pull right off the bat. Then again, i love the pin you back when the turbo gets good and spooled at higher R's also! ha. Thanks Bastaad. Bay - Thanks. I think i'm really starting to push the stock stuff to it's limits. Wish you could have made it. Maybe next time. The throw on the pedal was ok. I raised the pedal height up as far as i can go and took all the free play out of it and then it was fine. This was after the first two runs of the day when i missed 2 shifts on each run and ran 14's It was either adjust it the way i did or slow down on shifting. I chose to adjust it for "track shifting speed" I'm still not super happy with the way the long throw is, even with the pathfinder 11/16" slave, but one thing is for sure, it grabs like a mutha! Everytime i made the 3rd to 4rth shift, I got a prominant chirp and it never did that before! Need to post this video somewhere...

Thanks guys for all the praise. I was sweating it out last night right near the end. Ran a few 13.02's and it finally just all came together the last run. Had to shift a little quicker between 1-2 & 2-3. It seemed it was spooling a little faster and since i don't watch the tach between those shifts, i was sifting a couple hundreds late. One i got the shifting down, the grab of the new clutch, the traction...blahblah...she ran. I have video of it and am trying to find a site to post it for you guys to see. When i do, i'll post a new topic so you can check it out. Bastaad - Stopped on the way home for a beer to celebrate the breaking of 12's, that's why i didn't get a chance last night to post results. Sorry 'bout that. I will get a list of all my mods over stock as soon as i get a little time..work is crazy right now. The changes since the 13.33 was - ACT clutch setup, small NPR I.C., downpipe, Walbro 392 pump and boost raised to about 14psi. I guess there were more mods that i made than i thought, just by listing those. Guess i should have done better than 12.8 maybe? i don't know, i'm happy. haha. Bastaad, shoot for 11's. I think i was really stretching the T3 but, she held! Thanks. MobyVan - Thanks. NOW GET TO WORK!!! Pete - Thanks. GOOD LUCK with the birth!!!! Good decision on staying close to home - the right thing to do. I was the same way with our 2 children. There'll be many more times to go to the track, birth of your child only comes once in a lifetime..per kid anyway haha. I would love to go side by side with another 240. I ran a 300ZXTT last night and a 350Z last time, still not the same as the 240 side by side. Anytime, let me know.

Bastaad - you aren't too anxious about getting this car, are you? haha! Believe me, I am as bad or probably worse than you when something is just at my fingertips. Like the 12 second 1/4 which I WILL get tonight! hopefully Hey sleeper..watch the "crappy" T3 talk!!! (i really need to upgrade to a t04 make some REAL 1/4 mile #'s ) And this is my take on the time to shift with the turbo thing. I don't have loads of experience yet but, this is what i've found. Without the I.C. runing about 9psi boost, the Z would pull strong all the way to just about 6k rpm and then i could feel a bit of drop off. That's about where i shifted before. Now with the I.C. and running about 12-13psi (still stock T3) she seems to start losing power around 5.5k rpm. I will see tonight at the track what works best with this setup - running more boost. I'm thinking that pushing more boost through the T3, ever though it's cooler air cause of the I.C., it's efficiencly level is not as good causing the power range to lesson, even though it seems stronger when it is in the power range at this level of boost. Hard to explain and hope i didn't confuse you. I haven't dyno'd this even and have no hard evidence on what i'm saying is even remotely correct but this is just what i feel in my Z. When i ran the N/A L28 10:1 in this same Z, i'd pull it all the way to about 6500 and she would pull all the way through. I'm not technical enough with the #'s to answer your "which would be faster" question but, i'll give it a shot - I would think the turbo engine would be faster, the N/A would be quicker because of the better bottom end tourqe (higher compression)

Will do. Thanks Lock.

Got ya. Thanks anyway Joe.

I know this is the tech forum but, I hang here. I just wanted to let anyone know that if they're in the NJ area. i'll be running my '73ZT "we" built tonight (Wednesday) hoping to get a 12 second 1/4. 12.999 would work It would be great to see some other Z's there if anyone can make it. Island Drags - gates open at 6pm, racing usually starts around 6:30-7pm. Sorry about posting this here...i swear i'll never do it again. UPDATE. YEEHAA. Did it guys. Last run of the night, all alone. Talk about pressure! Fun as heck. Here's the slip...

ZR8ED - thanks. The 300zx slave is the same bore size as all the Z's - 3/4". What i looking to do is downsize it to match the MS - 5/8" - or, which i think would be a better solution, would be to increase the size of the MS to match the stock slave - 3/4" - or go a little lager, like Joe did with the 7/8" Tilton. Good call of the "shift fork" I matched the '82ZXT fork and the '78280Z up side by side and they are exactly the same BUT, the one that i was using had some stress marks where the slave pin made contact with it. I used the '78280Z's fork which looked new. Thanks. Joe - $60? Thats it? That's a lot cheaper than i thought it was going to be. Question - with the 7/8" MS and the 3/4" slave, i'm sure with the difference in ratio this way, the slave moves faster than the master but has the pedal pressure increased alot with this opposite ratio? I'm pretty sure that's why most cars/trucks have the master a little smaller than the slave - because it makes the pedal easier to push. This would be the opposite. Thanks.

Yes. you've got it. If you find out any info on it, would you please reply to this or send me an email? Thanks.

Not sure, you'll have to ask Joe about that one. I do have a '78 nissan 5sp laying on the groung in my garage, i'll try and take a look at it to see if it's got the space between the two bolt holes to accomodate for the pathfinder slave.

Sean, i'm going to have tp disagree with your theory. I could be 100% wrong but, this is how I think it works. One side of the Air Regulator (front) "can" pull air from before the throttle plates. I say "can" because, when the Air Reg is cold, it opens and allows this air from before the throttle plate to go through the Air reg and to the AAC. If vacuum is applied to the AAC from the VCM because the ECU senses a cold condition and triggers the relay, the AAC lifts it off it's seat and allows the air coming from before the throttle plate to enter the intake, which causes the idle to rise. Cold condition, throttle plate closed, higher idle. When the little element inside the Air Regulator gets to a certain temp (60deg?) it closes off this port and doesn't allow the air before the trottle plate to supply the AAC. That's how i understood it anyway. And like i said, i could be completely wrong and am always willing to learn so dont take what i'm saying in a bad way. I've eliminated the VCM and AAC and my Z idles without a problem. Cold starts may be a different story but i'll worry about that then So, if by any chance i am right, the air coming out of the stock J-pipe nipple does not supply the AAC valve with warm/hot air. It's the air coming through the Air Regulator. What i was asking was what does the VCV - Vacuum Control Valve do, how does it work and does the stock J-pipe nipple have any effect on this valve? Wish the darn FSM would say something about how this valve works! Len - the AIC is the little hat shaped thing on the manifold that creates a higher idle up when using the air conditioning. Easy to get those two confused - AAC/AIC! I need a picture of a '82-'83 ZXT stock motor so i can post and point to what i'm taling about...

The slave from the '88 pathfinder 4x4 is the one i used. bolts right up. ahhhh...are you using the T5? Cant remember your setup. I know it bolts right up to a T5, not sure about the nissan 5sp. Before you go out and blow $20, let me see if there's another solution, a better one for you to spend $ on like i did. I like the idea of the Tilton that rags suggested. 7/8" master to the stock 3/4" slave would probably make the pedal a little lighter to press and make the clutch action much faster. The pathfinder slave definetly helps, imop.

Sleeper - I know with my BOV, i shift and the boost gauge reads right back about where i left off from the last gear. It wasn't like that before the BOV. It keeps the T3 spinning at a good rate between shifts instead of back pressure/slowing the turbo down/compressor surge. I don't know...I wasn't looking for any big gain with this because i didn't spend much for it ($20) but i did find out it made a good difference for me and worth ever penny. My opinion.

Hey all. Thanks for the all the info. Joe, i think you're right on track with the 7/8" Tilton. He's what i did yesterday - I couldn't find a car that used a 3/4" MS and would come close to mounting into the Z but i did find out that the Pathfinder used a 11/16" slave so, i popped it in. It definitley helped. Now when i'm driving i can shift quick by only having to throw my leg about 3" instead of 6". I think the right way to go is to increase the MS size, as Joe did, because the way i did it by reducing the size of the slave, increased the pedal effory even more. Yes, i hope i NEVER get caught in traffic with this thing the way it is! But, it's tight, i can shift, it holds and i'm trackbound tomorrow night. I think someone asked about breaking the clutch in? I've never really "broken" a clutch in because all i've ever used was the organic kind. Kind of just let it seat itself. I do take it easy for the first day or so...somewhat...but after that, it gets abused. I never had a problem so why change now? haha. I would think it is important to break a puck clutch in though, but i don;t have any experience with those so cannot advise. Never ran synthetic so i cant comment on that either. Dot3 has always worked for me. Stony...great lookin Z. Sorry to hear about the clutch. Youch. Drax - yes on the flex line. I figured the same thing and will replace it soon but, i knew needed more than what the rubber was giving up that's why i was concentrating on a bigger gain like the MS/slave ratio. I will find braided and swap it for sure. Thanks much.

You can use the 240 tank but if you run under 1/4 tank and take a turn, she'll cut out on ya...which is tough to handle if you're taking a turn with some good speed. There is a way that some put the pickup out of the bottom of the tank, probably from the drain hole but i'm not sure of the process. There's a bunch of articles in the archives because i found them right about at the stage you were at You'll have to run a bigger feed line from back to front to supply the FI. I ran a 3/8" SS that i got from Summit (cheap) and used the stock feed on my '73 (5/16") as the return. I did change the tank out with one from a '75 - it has the baffles and still fits in the older Z because of the spare tire configuration. Turbo AFM = 3". Turbo does quiet the car down a bit. I would think if you get the fuel there, you should be able to pull 9-10psi with 91. I haven't adjusted the spring on the AFM yet but many have and there is information in the archives as well. Yes, do the BOV. It helps a lot and it's cheap, the way i went anyway. And you're correct...it puts you right back on top of the turbo when you hit the next gear. I felt a big difference when i added mine. Thats my opinion and experience anyway. I just got my Z back on the road last night (actually 3am this morning) and have the boost cranked up to 12-13psi and i think i'm at or a little over it's peak efficiency. Thanks for the replies on the other thread. I did some part swapping and will post over there if you're interested. Later.

Yes, Doug is right. The Dawes Boost controller is a better idea than cutting and adjusting the WG actuator arm. I have to get to grainger one of these days to build me one of these. 1 - I like making stuff and 2, i'm cheap BTW - I left out that i'm running a 2 1/2" mandral exhaust. You should definetly have this or 3" to let it breath. Cant wait until you get it and feel the power. Boost if fun and VERY addicting!

Bastaad - got your email, just been in the garage fighting this clutch issue. I will write you back soon with any info i can give. You'll get 13's, don't sweat it. I got that 13.3 and dont (didn't) have a lot of $ or add on parts to my '73. No manual boost controller, just wacked and threaded the wastegate actuator rod, removed the POV and plugged it with a 1" pipe plug, Boost gauge (autometer) - this is important - need to know exactly what boost you'r running...especially with a stock bottom end, top end and head gasket as i am, 1G DSM BOV - works great plumbed back in right after the AFM - $20, 9" "Green" air intake out in front of the radiator - not sure if this helped one ioda but, i know it didn't hurt. Electric fan, again, not sure if it really helped much but i know it didn't hurt. I was running about 9psi on 93 pump gas with no knock, with 3.54 and the BW-T5 and pulled the 13.3 - consistant 13.4-13.5's. I think you said you have a 3.90 and a 3.54 and i'm not sure which would make you faster down the 1/4. i would think the 3.90 but i don't have experience with it so i cant suggest. I do know i like the 5th gear with the 3.54 for cruising and that's mainly what my Z is for. I think 3.90's would be a little high in the R's for me down the highway. I'm running stock injectors, stock ZXT fuel pump and stock ECU. Like i said, you should have no problem getting into the 13's without blowing a ton a money. And before i get flamed, i'm not saying all the mods i did are the correct way of doing things but, it works for me until get the more inportant things done. Bastaad, i think i was running on the edge of REAL lean with the stock pump at the level i was at and would suggest one idea is to upgrade that when you get the $. I'll let you know how the Walbro 255lph does by itself without an aftermaket FPR in the leaness deptartment. I'll write more when i get a litttle time. Need to battle the clucth some more! ha. Later.