Guest Anonymous Posted March 31, 2003 Share Posted March 31, 2003 ive been reading stuff here for a while, but i was wondering if a 6 speed tranny from the new Z would work for an rb26? and if anyone knew what kind of power they can take. thanx, eric Quote Link to comment Share on other sites More sharing options...
Mikelly Posted March 31, 2003 Share Posted March 31, 2003 1st Question I would have is availability... That thing, or anything from the new 350Z is gonna cost a fortune from a salvage yard. Just my $.02 worth... Mike Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted March 31, 2003 Share Posted March 31, 2003 i understand that...and i dont have the money now, nor the Z...im still looking for a solid shell. the reason im asking is because i want a 6 speed...and the r33 tranny is only 5, and i dont know of any other 6 speeds that would be even close to fitting the rb26 block. basically, i have no budget cuz im still window shopping, and i can spend all the imaginary money i want eric Quote Link to comment Share on other sites More sharing options...
Mudge Posted March 31, 2003 Share Posted March 31, 2003 There is always the T56, it may be one of the cheaper 6 speed options. There are other import 6 speeds out there also, but it may be cheaper to adapt an LT1 T56 to one of the RBs. It has been done on an L6 by a Turbo L6 510 guy on the board. Quote Link to comment Share on other sites More sharing options...
Mikelly Posted April 1, 2003 Share Posted April 1, 2003 Well now let me pose this question... Why a six speed? What makes you think you want one??? MInd you, I had a T56 behind my 383 stroker, so I'm well aware of the W-O-W/ C-O-O-L factor. But beyond that, is there a REAL need? Mike Quote Link to comment Share on other sites More sharing options...
Mudge Posted April 1, 2003 Share Posted April 1, 2003 With the power I could easily appreciate a 6 speed, heck I own one. Big rear end gears and still maintain very low RPM on the freeway, one part of the 60s that I am glad is gone is cruising at 4000 on the freeway. For now a 6 speed suits me fine, but I'm driving an L6 which doesn't have all that much power, and with the turbo setup I am not going to be running 4.11s or even 3.90s (although I am now), with the late model NA 5 speed and some decent tires it will do just fine on the commute, only thing is high speed stuff will still put me at a pretty high RPM (interstates). I love em, but without a V8 in the car it isn't going to happen for me personally. Quote Link to comment Share on other sites More sharing options...
Mikelly Posted April 1, 2003 Share Posted April 1, 2003 The main reason one should look at a six speed would be torque and horsepower concerns over breaking the transmission. My biggest concern was my 383 stroker... However, With my setup I never was able to USE sixth gear unless I was doing 90mph or 2000 RPMs, whichever came first. The added weight and cost of the unit just simply wasn't worth it. Mike Quote Link to comment Share on other sites More sharing options...
j260z Posted April 1, 2003 Share Posted April 1, 2003 firstly, let me say, i have no idea what is involved but couldn't you get a front clip from an awd skyline with the 6 speed, remove the transfer case and front diff and then fab a cover for the transmission. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted April 1, 2003 Share Posted April 1, 2003 well, i want close ratio's for the gears, yet i dont want to be limited by a too tall 1st or too short 5th... i figured out today that for a 26.5" tall tire (what id choose if i had the money), and 390 gears, a t56 will do just over 2000 rpm at 65 mph...so it appears the choice would be easier than i thought--assuming it could be fabbed to fit the rbXX's eric Quote Link to comment Share on other sites More sharing options...
Mudge Posted April 1, 2003 Share Posted April 1, 2003 The 1993 Fbody LT1 is a close ratio trans. With most of us running smaller tires, gearing should not be a problem with the .5 OD. Even with 411RWHP heads/cam car I could lug 55 MPH in 6th (would not advize it), that puts me around 1450 RPM IIRC. http://www.f-body.org/gears Quote Link to comment Share on other sites More sharing options...
Mikelly Posted April 1, 2003 Share Posted April 1, 2003 Mudge, In that configuration you would be correct. However, If you take THAT trans and put it behind a fairly high lift cam'ed car running a carb and less than optimal vacuum, then you run into issues... I was running 3.7 gears and 26.5 inch tall tires, and the car (260 Z) would do the herky jerky at anything less than 2000RPMS. It REALY is important to know all your variables before you do the buildup... Now, if I was gonna put a warmed over LT1 into the car, with the same trans, I'd run trhe T56. But I'm thinking I personally don't need .50 OR two overdriven gears... Jim Biondo Warned me about this when I was building my 1st V8Z, and I always wondered why he was using a modified T5... He told me that the weight, as well as the parasitic drag on the internals of the T56 actually ROB horsepower. He did dyno tests with both the T56, and his custom modified trans, as he had both transmissions at the time... He kept the T5 and sold the T56. Now I don't want to dump a ton of cash into doing a custom bomb-proof T5 for my 500+hp buildup, so I'll probably go with a TKO or Richmond... Also, weight difference alone in the two transmissions is more than you might think... Mike Quote Link to comment Share on other sites More sharing options...
Scottie-GNZ Posted April 1, 2003 Share Posted April 1, 2003 Regarding Mike questioning the need for a 6-spd, I have asked the very same question before. I see lots of mention about big gears, etc, etc and no one seems to make mention that this is going behind a turbo engine, where the typical NA mindset does not apply. Cruising down the hwy off boost, the RB26 will be like any small turbo engine, a no-torque, weak engine making the .50 6th gear totally useless. As Mike said, except for the torque capacity, WOW factor or thinking a 6-spd makes your setup more exotic, it is not needed nor worth it. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted April 1, 2003 Share Posted April 1, 2003 I've got a t-56 behind a warmed over lt-1. I typically use 2 3 and 4 around town. 1st for impressive wheel spin. I will get into 5th on the freeway, 70+ and occaionally 6th at speeds over 80 on the freeway. I basically use 3 of the 6 speeds I have. Quote Link to comment Share on other sites More sharing options...
Mudge Posted April 1, 2003 Share Posted April 1, 2003 I usually only use 3 of my 5 gears as well, thanks to the worthless 3.90 rear 195/60 15" wheels. I am into 4th around 28-30 MPH, anything over 35-40 MPH and I'm in 5th. Quote Link to comment Share on other sites More sharing options...
Mudge Posted April 1, 2003 Share Posted April 1, 2003 However, If you take THAT trans and put it behind a fairly high lift cam'ed car running a carb and less than optimal vacuum, then you run into issues... I was running 3.7 gears and 26.5 inch tall tires, and the car (260 Z) would do the herky jerky at anything less than 2000RPMS. Thats the beauty of fuel injection and "complete" control over fuel and timing I ran a good sized cam with stock rear gears, and a 26.1" tire and it ran great. With 91 MTBE I was limited on how much timing I could run down low, which is quite unfortunate - only because I felt like I lost about 30# off-idle TQ (felt like it...) when I had to remove timing from a couple hot spots in the MAP range, it was a freaking beast but I'd run into ping and could not get rid of it without losing the power, I played with alot of cells 1 by 1 and could not make the power without the ping. Dyno started at 2500 RPM and I made 325TQ, peaked at 385 TQ at the wheels with 411 RWHP. Yes it had less power from 1000-1400, but I didn't have to burn up the clutch or get new gears, I really feel that the fuel is piss easy to tune, the magic is all in the timing. 2 pulls on the dyno and I had 50# TQ versus when I pulled in there, so fixing the fuel is pretty easy. I ran a 234/246 on a 110 LSA, and it was a daily driver at the time 3.42 rear gears and 60MPH at the top of first, I ran open loop (bit of a story to why) and got about 17 MPG average running no leaner than 14.9:1, although I know a guy with similar numbers who was able to get near 20 giving up some timing here and running around 15.2:1 (at the leanest MAP range). I am very preferential towards FI based on my limited experiences, you can really and truly tune a "big" powered car and still pull good street numbers with FI. There was a stock LT1 Camaro doing nearly 40 MPG on an open loop DFI tune just as proof of what COULD be done with tuning. It can be dangerous on these cast LT1 pistons and our crappy Californian gas, but anyway. Sorry for the ramble, back to transmissions! Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted April 2, 2003 Share Posted April 2, 2003 Regarding Mike questioning the need for a 6-spd' date=' I have asked the very same question before. I see lots of mention about big gears, etc, etc and no one seems to make mention that this is going behind a turbo engine, where the typical NA mindset does not apply. Cruising down the hwy off boost, the RB26 will be like any small turbo engine, a no-torque, weak engine making the .50 6th gear totally useless. As Mike said, except for the torque capacity, WOW factor or thinking a 6-spd makes your setup more exotic, it is not needed nor worth it.[/quote'] at 2000 rpm's, the motor might be off boost, BUT if youre just cruising, its no big deal. my 82 audi weighed in at much more than a Z, only had 1.7 liters to work with--absolutely NO power--and only sat at about 2200 rpm at 65. i had no problem with it. why would running 2000 rpms at 65 be bad if its just for maintaining a certain speed? you keep out of boost, and you get good mpg please correct me if im wrong here. eric Quote Link to comment Share on other sites More sharing options...
Mikelly Posted April 2, 2003 Share Posted April 2, 2003 Eric, The problem for me was that my power plant, when Running 65MPH in 6th WOULDN'T run. It wasn't happy at all... The Audi was a bad example to use. Making 2000RPMs and 65MPH is PERFECT, but not likely in a Z, unless you are going to use programable fuel Injection to tailor your fuel and spark. Mudge, I'm changing everything over to porgramable fuel Injection, but I still don't plan to use the T56. I sold it. I'll use soemthing that allows me to HAND PICK my gearing so all 5 or 6 gears are fully usable, the reason for having gears in the first place. Mike Quote Link to comment Share on other sites More sharing options...
Scottie-GNZ Posted April 2, 2003 Share Posted April 2, 2003 If he retained the 3.90, he would be cruising 65mph @ 1750RPMs! My engine is 3.8L with gobs more low-low-end torque than the RB. Even though we would be running radically different gearing and tire sizes, the MPH/1000RPMs are almost identical. I cruise 70mph @ 1900+ and anything less and I am lugging the engine. For me that is no problem because the slightest pedal pressure at that speed kicks it out of 4th-gear lockup. I personally agrre with Mike and think the RB, with its smaller displacement and hotter cams, would not like cruising at 1750. That means lots of shifting while cruising or leaving it in 5th Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted April 2, 2003 Share Posted April 2, 2003 If he retained the 3.90, he would be cruising 65mph @ 1750RPMs! My engine is 3.8L with gobs more low-low-end torque than the RB. Even though we would be running radically different gearing and tire sizes, the MPH/1000RPMs are almost identical. I cruise 70mph @ 1900+ and anything less and I am lugging the engine. For me that is no problem because the slightest pedal pressure at that speed kicks it out of 4th-gear lockup. I personally agrre with Mike and think the RB, with its smaller displacement and hotter cams, would not like cruising at 1750. That means lots of shifting while cruising or leaving it in 5th i took the time to figure it up, and with a t56 and a 390 rear...and a 26.5" tire is 65 at 1992 rpm in 6th gear. a 410 rear would put it at 2100 rpm at 65, and in first gear it would still do about 45 or 50 before having to shift...so maybe the 410's would be better. by the time i can afford any of this, ill be running all of it with a tec 3so it should make work pretty well. eric Quote Link to comment Share on other sites More sharing options...
Mudge Posted April 3, 2003 Share Posted April 3, 2003 You could always consider the 93 also, its a close ratio trans but I think 6th is "only" .78? Anywho its listed at http://www.f-body.org/gears You can also calculate gears http://www.geocities.com/z_design_studio/transmission.html if you didn't know of it. Quote Link to comment Share on other sites More sharing options...
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