4 or 5 speed faster?
08-18-2002, 06:47 AM
#3
Guest
Posts: n/a
Re: 4 or 5 speed faster?
You need to know the rear end gear ratio you have. If you dont want a 5-speed a 260 4-speed and a 3.90 or a 4.11 would give you the fastest acceleration. I run a 77 280z 5-Speed and a 3.90 rear and my car moves and I still have a 5th gear for the freeway (important to me maybe not to you). The 77 5-Speed has the best ratios for a 5. I dont know about the T-5 tranny found on the 83 turbo maybe some knows the ratios I have heard its the best all around. ( http://www.geocities.com/zgarage2001/ratios.gif ) go to this page and ck out the gear ratios. lol
Rick
Old School Imports 4lyfe
Rick
Old School Imports 4lyfe
08-18-2002, 03:57 PM
#4
The Evil Twin
Join Date: Mar 2001
Location: Seattle, WA
Posts: 9,294
Re: 4 or 5 speed faster?
Here's the deal, in simular years, the 4-speed and 5-speed manual transmissions have the same acceleration! 4th gear in BOTH is always 1:1 ratio. 5th gear is just an overdrive. The L28 doesn't have much power in 5th gear, but you do gain a little bit of top speed with one. You can go about 100-115 in 4th gear depending on what rear gear you have. My 280zx with an R200 at 3.9:1 and in 4th gear (1:1) hits 99mph at 5200 rpm. That is where I shift because that is peak horsepower with my fuel injection. You can still revv higher. If you have a higher gear ratio like a 3.54 found in most 240Z and 280Z's, then you can go a little faster. When I shift into 5th, I can accelerate some more, but I can't reach 5200 rpm again because I don't have enough power to get up there... a turbo engine would move farther.
Off the line, you'll be the same. As in, if you compare a 1977 280Z with a 4-speed to a 280Z with a 5-speed. Thing is, they changed the gear ratios of 1st through 3rd a little bit through the years. As the rear end ratios went lower, the lower transmission gears seemed to go a bit higher.
280Z 5-speeds have a 3.3 1st gear. same up to 1980. 1981-83 280zx n/a have a 3.0 1st gear but also have a higher 5th gear so they do better with a lower rear gear. (which they have) The T-5 has a 3.5 1st gear and a high 5th gear so it gets you off the line fastest.
But, since 4th gear is the same in the T-5, you have larger jumps between gears. Its also something to think about. The best transmission is to use the 1981-83 280zx n/a. It has the highest 1st gear and since 4th gear is 1:1 like always, it is the "closest ratio" transmission. Put in the lowest rear gear you can find so you can still launch off the line. with that transmission, 4.11 rear minimum or try to find a 4.375 or 4.625 R180. You can also buy a new R200 in those ratios from NISMO, but they cost about $700 or so. (they even come in LSD)
:-D
did you understand all that?
Off the line, you'll be the same. As in, if you compare a 1977 280Z with a 4-speed to a 280Z with a 5-speed. Thing is, they changed the gear ratios of 1st through 3rd a little bit through the years. As the rear end ratios went lower, the lower transmission gears seemed to go a bit higher.
280Z 5-speeds have a 3.3 1st gear. same up to 1980. 1981-83 280zx n/a have a 3.0 1st gear but also have a higher 5th gear so they do better with a lower rear gear. (which they have) The T-5 has a 3.5 1st gear and a high 5th gear so it gets you off the line fastest.
But, since 4th gear is the same in the T-5, you have larger jumps between gears. Its also something to think about. The best transmission is to use the 1981-83 280zx n/a. It has the highest 1st gear and since 4th gear is 1:1 like always, it is the "closest ratio" transmission. Put in the lowest rear gear you can find so you can still launch off the line. with that transmission, 4.11 rear minimum or try to find a 4.375 or 4.625 R180. You can also buy a new R200 in those ratios from NISMO, but they cost about $700 or so. (they even come in LSD)
:-D
did you understand all that?
08-18-2002, 09:16 PM
#5
Guest
Posts: n/a
Re: 4 or 5 speed faster?
I have a regular 240 with the stock 3.36.
We put a 77 5speed and 4.11 R180 into my nephew's car. He is young and loves it because he can spin his bigger mags in first and second an loves to do burnouts at the school parking lot in front of the hondas. hmmm.
I am building a 260 with r200 3.70 and the 83 T5 borg warner that handles the big hp. 280T with Saab Intercooler, sds computerized fule inj system, msd ignition, 60mm Throttle body (plan for 12- 15 pounds of boost and 3 inch exhaust.)
The car you have does not come stock with an R 200. They are quite a bit heavier and handle about 500hp. where the stock r180 is good for about 250hp. - anyway that is what I have heard.
If you have the stock tranny (3.36) replaced with a 3.54 R200 which is common then it is a bit faster off the line.
You can get a 4.11 r180 out of the front of a pathfinder 4 by 4 and if you want some advice just email me. but you will have to go back to some of the original mounting stuff - older mustache bar.
my stock 240 raced my nephew and I was a bit faster but he was not experienced and spun his wheels a lot and shifts slow. He has the overdrive with the five speed and should
get better mileage too.
Greg from Vides club knows lots about gear ratios. znut2@shaw.ca
good luck
We put a 77 5speed and 4.11 R180 into my nephew's car. He is young and loves it because he can spin his bigger mags in first and second an loves to do burnouts at the school parking lot in front of the hondas. hmmm.
I am building a 260 with r200 3.70 and the 83 T5 borg warner that handles the big hp. 280T with Saab Intercooler, sds computerized fule inj system, msd ignition, 60mm Throttle body (plan for 12- 15 pounds of boost and 3 inch exhaust.)
The car you have does not come stock with an R 200. They are quite a bit heavier and handle about 500hp. where the stock r180 is good for about 250hp. - anyway that is what I have heard.
If you have the stock tranny (3.36) replaced with a 3.54 R200 which is common then it is a bit faster off the line.
You can get a 4.11 r180 out of the front of a pathfinder 4 by 4 and if you want some advice just email me. but you will have to go back to some of the original mounting stuff - older mustache bar.
my stock 240 raced my nephew and I was a bit faster but he was not experienced and spun his wheels a lot and shifts slow. He has the overdrive with the five speed and should
get better mileage too.
Greg from Vides club knows lots about gear ratios. znut2@shaw.ca
good luck
08-19-2002, 09:18 AM
#7
The Evil Twin
Join Date: Mar 2001
Location: Seattle, WA
Posts: 9,294
Re: 4 or 5 speed faster?
I would advise against using a 4-speed in there. Besides, I hear that the 280ZX has a longer transmission, so you probably already have a custom driveshaft? (unless you bought the car as it is now)
Keep your current transmisison and lower your rear gear to a 4.11
Can you max out your rpms in 5th gear? You must have a pretty powerful engine with good torque around 4500rpm! If you can't quite max it out in 5th now, then lowering your rear gear will give you higher top speed. You'll basically have a little more power at the rpm that you usualy can't go past and then you'll climb higher.
As far as 1/4 mile time, I'm not sure how much it will improve, but I would say probalby 2 tenths in just the gearing alone. You'll like the new launch too.
Changing to a 4-speed to get a lower 1st and 2nd won't really do all that much for you. Going too low of a 1st gear is hard because you have too much torque. It will require careful launches to not just spin the tires. What you need is the best combo of low gears and close gears. Like I said before, you have (in my opinion) the best transmission, so go with a 4.11 rear end or 4.375 if you can find one. 4.11 is probably best since it will still allow you some crazy top speeds. 4.375 might not go as fast as you like.
Keep your current transmisison and lower your rear gear to a 4.11
Can you max out your rpms in 5th gear? You must have a pretty powerful engine with good torque around 4500rpm! If you can't quite max it out in 5th now, then lowering your rear gear will give you higher top speed. You'll basically have a little more power at the rpm that you usualy can't go past and then you'll climb higher.
As far as 1/4 mile time, I'm not sure how much it will improve, but I would say probalby 2 tenths in just the gearing alone. You'll like the new launch too.
Changing to a 4-speed to get a lower 1st and 2nd won't really do all that much for you. Going too low of a 1st gear is hard because you have too much torque. It will require careful launches to not just spin the tires. What you need is the best combo of low gears and close gears. Like I said before, you have (in my opinion) the best transmission, so go with a 4.11 rear end or 4.375 if you can find one. 4.11 is probably best since it will still allow you some crazy top speeds. 4.375 might not go as fast as you like.
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