2eighTZ4me Posted March 15, 2011 Share Posted March 15, 2011 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!! Quote Link to comment Share on other sites More sharing options...
CamH Posted March 15, 2011 Share Posted March 15, 2011 My understanding was that it had a lot to do with how you drive it. I'm running a ZX 5 speed in my car, and I shift it smoothly and slowly, with no launching, and it still feels perfectly healthy. I believe I am somewhere in the high 200whp zone based on what others have gotten with the same setup and how it fares against other cars. I can show actual results in a month or two Quote Link to comment Share on other sites More sharing options...
TimZ Posted March 15, 2011 Share Posted March 15, 2011 (edited) 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!! Third gear seems to give up the ghost at ~450 rwhp, at least that's where mine gave up... The gear on the right looks pretty bad until you realize that all of the teeth have sheared off on the one on the left. That made for a pretty interesting ride home... Edited March 15, 2011 by TimZ Quote Link to comment Share on other sites More sharing options...
BluDestiny Posted March 15, 2011 Share Posted March 15, 2011 wow learn something new everyday. Quote Link to comment Share on other sites More sharing options...
2eighTZ4me Posted March 15, 2011 Author Share Posted March 15, 2011 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) Quote Link to comment Share on other sites More sharing options...
CamH Posted March 15, 2011 Share Posted March 15, 2011 Have you considered the 240SX transmission? Quote Link to comment Share on other sites More sharing options...
Tony D Posted March 15, 2011 Share Posted March 15, 2011 Yep, that is the progression. I have run 350 in mine since 1988, and never had an issue. For a while I attributed it to the fact the tranny only had 24K km on it when I got it...but generally people say below 400 they are good for quite a while. The shear pins tend to go more than gearing.Gearing damage like TimZ saw can be either horsepower, or poor lubrication on the gear so people may think they are encounterin horspower induce lubrication shear at a much lower level if they aren't using a good film-strength synthetic lubricant (and in some cases of endurance applications, a COOLER.) AFter that, consensus in Japan is the 240SX tranny is good for 'more power, 450 no problem', if you physically measure the gears they are wider, or have hardened spacers to widen the gear engagement widths which means more load carrying capability. The same thing goes for lubrication in this tranny. Upgrading the internals to the OS Gikken straight cut gears, or alternate gearset raises the power capability a bit, but at quite some cost. A sequential shifter is available. In this same class is the BW T5 Tranny. JeffP had his survive at 450 real rear wheel HP for a while but as he said "it was really screaming"... The G-Force internal modifications will make it survive to 600 for a reasonable cost if you need to keep a specific case in the car. The G-Force modification is less than an OS Upgrade on the T5. A sequential shifter is available. Then ultimately in the Nissan Built Tranny selection is the 300ZX tranny which stock is supposedly good to 750 and that kind of upsets JeffP since he spent around $3400 for his Tremec because neither of the two prior options were available when he was making his 450+ to the rear wheels. A sequential shifter is available for this tranny as well as an array of alternate gearsets from various manuifacturers. Stock, it's probably the cheapest reliable tranny but it's a bit more work to get it in compared to either of the two prior cases. If you are below 500HP, the 240SX box is a good option which fits in the tunnel of earlier cars far easier than the Z32 Tranny. Quote Link to comment Share on other sites More sharing options...
sticky280zx Posted March 15, 2011 Share Posted March 15, 2011 ....and WIKI-D strikes again...i love the fact that people dont just blurt out an answer, but yet they make you read AND show pics/proof of all of this. Good times, thanks for the info Quote Link to comment Share on other sites More sharing options...
Tony D Posted March 15, 2011 Share Posted March 15, 2011 I'll add the bearing condition is CRITICAL in the earlier trannies. I have snapped teeth off them when a bearing was "noisy"---that means the countershaft can get misaligned---not paralell with the main and this misalignment of the gears causes massive loads that can shear the oil film leading to fretting and wear on the gears if you aren't shock loading it...up to teeth fracture if you do a 3500 clutch dump with 175's on the back to do a donut under the 'if it's making noise I better wring it out better for it to break here than break 3000 miles from home!' Man, I was lucky to get that one home the 3 miles from my favorite 'burnout box'! (Google Earth: 33° 48.957'N 117° 14.377'W) Quote Link to comment Share on other sites More sharing options...
2eighTZ4me Posted March 15, 2011 Author Share Posted March 15, 2011 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?? Quote Link to comment Share on other sites More sharing options...
ktm Posted March 16, 2011 Share Posted March 16, 2011 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) Maybe I was unlucky, but my 5-speed was spitting metal chunks (not just shavings) with 330 lb-ft at the wheels. I've since upgraded to the Z32 tranny. The Z32 actually fits better in a 240z than a 280z. You need to extensively modify the transmission mounting points on a 280z, while for a 240z you simply build a different transmission mount that bolts to the stock location. Attached is a rather grainy picture of my mount, but you get the idea. Quote Link to comment Share on other sites More sharing options...
rossman Posted March 16, 2011 Share Posted March 16, 2011 Here is another pictures showing a Z32 gearbox in a 240Z tunnel. The custom brackets are made by McKinney Motorsports. Quote Link to comment Share on other sites More sharing options...
2eighTZ4me Posted March 16, 2011 Author Share Posted March 16, 2011 (edited) 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! Edited March 16, 2011 by 2eighTZ4me Quote Link to comment Share on other sites More sharing options...
ktm Posted March 16, 2011 Share Posted March 16, 2011 The bell housing needs to be machined and an adapter installed. There are two stickies in the L6 forum that discusses this swap. Quote Link to comment Share on other sites More sharing options...
rossman Posted March 17, 2011 Share Posted March 17, 2011 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! I don't see it either. IIRC it wasn't on the a year ago when i purchased it. Try giving them a call. Ditto what KTM said. Also going to need a custom drive shaft. It's covered in the stickies. Quote Link to comment Share on other sites More sharing options...
rossman Posted March 17, 2011 Share Posted March 17, 2011 ...my favorite 'burnout box'! (Google Earth: 33° 48.957'N 117° 14.377'W) ROTFLMAO 1 Quote Link to comment Share on other sites More sharing options...
Ricky Posted March 17, 2011 Share Posted March 17, 2011 Here's a short video of my stock gearbox letting go in fifth in the warm up lap. The force inside the case was enough to split the tail shaft housing, the gearbox was rebuilt the season before. The engine makes 330hp and is NA. Quote Link to comment Share on other sites More sharing options...
johnc Posted March 17, 2011 Share Posted March 17, 2011 It really depends on usage. The ITS road race guys will lose the synchros after a couple years (at best) with only 180hp. Quote Link to comment Share on other sites More sharing options...
2eighTZ4me Posted March 18, 2011 Author Share Posted March 18, 2011 (edited) Damn Ricky - that's a stout car at 330 in NA trim......what the heck is in that thing? Back to topic - I got the stock 5 speed in and everything seems to feel OK. Went through the gears up on jackstands - Works fine there. Haven't test driven yet - that's tomorrow. Going to put +/-350rwhp and 380 rw torque to it on Sunday at the SCCA PDX event at Road Atlanta - IF everything checks out on the street drive. Driving the car to the event, but my buddy's bringing the trailer .... just in case.....we'll see if she can withstand 2 - 20 minute sessions of somewhat sustainable abuse..... will report in Monday. Anyone want to take any wagers? Edited March 18, 2011 by 2eighTZ4me Quote Link to comment Share on other sites More sharing options...
Tony D Posted March 19, 2011 Share Posted March 19, 2011 My 73 240Z doesn't have mounts like that...my 71 does. My 72 does not. Hmmmmmmm... McKinney makes some nice stuff. I should stop by there one day. I think they are like 20 minutes from my house. The aforementioned box is much closer.... like less than 3 miles. (Start looking for the containers with Z's parked around them... ) The neighbor up the street from me told me about that place. If you look you realize entrance and exit are visible, no on or off roads, it's between Aarmco Barrier of the main road (behind a privacy wall) on the left, and a railroad grade on the right. You are effectively 'below the grade' when viewed from the nearest road. Length is good and great for launch testing. Best part is now in the big open lot to the southwest is a big boat manufacturing facility so that blocks the sound to the nearest road (which is patrolled...) When I say burnout place, I mean "Burnout Place"! This is where Jeff P blew one of his engines... I call it "The Hidden Cove" Quote Link to comment Share on other sites More sharing options...
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