has anybody ever heard of a 6 speed 300zx here in the states? i know HKS makes a 6 Speed manual transmission for the 300zx tt which goes for $7,926, but i have never seen a 6 spd 300

 

id like to put a 6 speed on my 1986...that would be hot...But i do plan to swap in a z32TT sometime in the next few years, ill have to look into that tranny

 

6 spd is pointless. its more weight and ull never hit it unless you do alot of clear higway drving...if u do alot of higway driving then i guess i could understand its a cruising gear, and nothin else for most cars.

 

6spd isn't pointless. it gives u piece of mind knowing that your car has the ability to go just a bit faster

 

Hopefully we're all remembering to take into consideration speed limiters, different gear ratios, major mod's to make the bell housing match up, matching the tranny splines w/ the flywheel splines, mounting of the tranny, driveline flanges, etc. Ya know... the minor details.

 

HKS makes the tranny specifically for the z32 TT but it can only be used with an HKS clutch.

 

Is there any particular reason you want/need a 6 speed? Because, I hate having my gears run up on me to begin with. But, with a sixer, they come really fast, which would really get on my nerves. My take is this: Unless you are going over 200, there is absolutely no need for a six speed. And, the Z doesn't go over 200. That equateds to time lost due to shifting. So, why do you want a sixer, anyway?

 

shorter gear ratios would equate to quicker acceleration no mater what your power levels. Kinda like putting a lower gear in the rear end. most 6 speeds do not equate to a higher top end just closer ratios. when you try to control overall top speed with the tranny instead of the rearend you are getting into major headaches. If you have big spools that don't light up unitl way up in the tach then the 6 speed would help you stay revving easier.

 

HKS 6 spd. transmission for VG30DETT gear ratios:

1st Gear Ratio: 2.971

2nd Gear Ratio: 2.094

3rd Gear Ratio: 1.548

4th Gear Ratio: 1.246

5th Gear Ratio: 1.000

6th Gear Ratio: 0.807

 

6 speeds Zs never sold as far as i know. But i remember a guy that converted his 5 spd to a 350z 6spd. There used to be pictures, but you can try to contact him..

http://www.twinturbo.net/net/viewmsg...0z%3a%3atranny

 

i know they were never sold here in the U.S. or in Japan, but HKS makes a 6 spd tranny for the Z32TT. I just wanted to know if anyone had ever seen one.

 

I love when someone asks a dumb question...

follows it up with dumb justification...

and then posts information that proves himself wrong...



Yes, there are 6-speed 300ZX's in existence. One method is to use the 6-speed from the 350Z and fabricate a bracket to bolt it to the VG30DE.

No, there is no real justification for this. ESPECIALLY on a turbocharged car, where every time you shift, you take your foot off the gas pedal, thus losing boost pressure and requiring your turbos to spool up one more time than usual. More shifting = more times you have to build boost. And as I'm about to point out, there is NO TOP SPEED GAIN.

The HKS trans is a close ratio trans. The sixth gear of that trans is .807 compared to the stock 5th gear of .752. This means that with the stock 300ZX transmission and a JWT or Ash chip (on a TT with the stock rear end), which is limited at 7,450 rpms, the 300ZX would reach 197mph. With that HKS trans, the top end would DROP to 184mph. The purpose of a close ratio trans is not to gain top end, it's to allow better gear selection when coming out of the corner of an autocross track. Even then, ... every time you shift a Twin Turbo, no matter where you land in your rpm's, by letting off the gas pedal to shift, you just lost boost and your turbos need to spool up again.

 

so basically the swap over to a 6spd trans is actually more "cosmetic" than performance. I would say the only reason to do it is to be different. As no obvious performance gain is realized. Unless you build your own 6spd trans where you set your own gear ratios but this is real life, not Gran Turismo the video game.

 

I wouldn't go as far as to say it's cosmetic, but it's not beneficial to someone who drives their 300ZX daily or even relatively often on the streets. Since I have nothing better to do right now, I'll explain my logic a little further.

The closer ratios means that, when you're exiting a corner at speed, you'll have a better selection of what gear to go into. On cars that make horsepower on a very short powerband (large turbo cars), it'd be beneficial because, coming out of a corner, when you're too high to shift into (as an example) 2nd gear, but shifting into 3rd would choke the car on power (too early in the rpms to hit real power), an extra gear of a close-ratio trans would give you a sweet spot that the stock 5 speed couldn't do. On a car with a very broad powerband (like a wel built, small to medium sized turbo Z32), having that extra gear means that you're going to have to shift once more than you would with a five speed, and like I previously stated, that's one more time you're letting your foot off the gas and forcing the turbos to lose pressure again. If you have a nice wide powerband, you can select the higher gear and you won't have to worry about hitting your head off the steering wheel because the power isn't there.

On cars that are driven daily, as I also pointed out, the stock trans is better geared for economy. Fifth gear on the stock trans is going to get much better fuel economy than the sixth gear of the HKS trans.

Now in terms of acceleration... on an NA, the 6 speed may help (one of the reasons the 350Z accelerates good for its horsepower level). This is because every time you shift, you're going to be higher up in the RPM's. On a Twin Turbo, the shifting is just going to cause a loss of boost. Not to mention, the 1st gear on that trans is incredibly short compared to the stock trans (3.214 stock vs. 2.971 HKS). To take it to an extreme, I'd like to point out that luxury cars (Mercedes and BMW) are using 7speed transmissions now, while top fuel dragsters only have 1 forward gear... which one accelerates better?

That's even leaving out the top speed part that I already covered in my last post.

So in the end... is there really any reason to put a 6-speed in a 300ZX? If you're excessively autocrossing a TD05-18G powered Twin Turbo, then perhaps. But for the majority of people, there's no reason for it. And $7k for bragging rights is hardly worth it... you own a Z, you already have bragging rights that you're driving the best that Japan has ever had to offer.

 

My statement to the top speed thing is related to the fact that you can achieve a higher top speed with a 6 rather than a 5 given the same hp while still maintaning comparible accelleration. Yes, most 6 speeds are close geared, but there are many 6 speed trannies that have their gears spaced out a little more. Lambo's and Farrari's come to mind. I will admit that I am not familiar with the 6er for the Z, But I still don't see the point of having it. My point of lost time due to shifting is still true. It was better explained in the post above relating to boost.

 

guess some people have never shifted without lifting off of the gas (speed shifting), or used the heal toe method to keep the rpms within the powerband (or keep boost up) while shifting.

Some people would prefer to have more gears. Slightly better 1-4 gears. Maybe a better freeway cruise for the mileage. It could be an alternative to getting the 4.11 leader gears too.

All in all, there are always advantages and disadvantages to all mods. I don't know much bout the 350z tranny swap. I haven't heard much of it since, whether it can handle the the power of upgraded turbos and etc. The guy that did that adapter did mention that the gearing was perfect for the setup he was running, perfect shiftpoints and no turbo lag. Other than that, i don't know what's new with it.

I wouldn't mind a 6spd if the research and proper gearing where used (forget the HKS), but the 5spd is fine with me. Maybe i'll just go with the leader gears.

I didn't buy this car for good gas mileage!

 

and who is the guy that made the braket / kit. I have abudyd thta is very intrested in doing it. and he dosent really care about Cost / Benefit. He wants it. he dosent care. his money. Any clue on the guy?

 

I hope he didn't really say that... because if he did, he's either an idiot or he's dreaming, because if you have a turbo, you have lag and that's the end of it. I agree with you otherwise though. A 6 speed with similar gearing to the stock trans would be cool, if the price were right. I honestly wouldn't complain if the stock trans was a 6 speed to begin with, but it's a 5 and it works fine with the 5. I'm happy with my 5 speed.

 

With proper shifting w/gas control and gearing. You can achieve a laggless shift. must you read everything so literally? Should i break everything down? there's no need to offend anyone now. Simmer down tex

 

What do you mean this is real life Riz? We are mostly grown men (and women) debating how to spend our money on something that hasn't been sold new in the U.S. for 10 years. Got to live the dream!!

as for turbo lag... lag makes baby jesus cry. <-- slightly modifed line from "THE SIMPSONS" don't mean to offend anyone

 

What did i mean? obviously you've never played a racing video game then.
To make it a bit more clear. What i meant in my statement is that unlike a video game, you cannot change your gear ratios in your car "on the fly" so to speak. Setting your most optimal gear ratios for your particular car and powerband would be extensive and extremely time consuming in real life. Unlike a video game where one would just play with some numbers for a little while to get the desired results.
understood now i hope?
and having to explain yourself 7 posts and damn near a month later makes baby jesus cry also.

 

Hello, I am new to be a 300zx driver; it is really nice to have one because they look really nice and you get lots of people to look at your car. =)

However, I am not happy with this car performance; my Nissan Maxima 1995-186k miles is faster that my 2+2 none turbo 300zx-105k miles and it has better turning radius; plus it does not swing it's tail on a curve like the zx does.

So I would like to have a 6 speed with my none turbo car, because obviously I would be able to gain speed faster; also get out of a compromise situation as fast as I do with my Maxima (automatic transmission).

--don't even try to tell me that I don't know how to drive standard shift-- I learn how to drive with one in a very busy city and I was a pro in traffic, getting in a out of it; sig-sagin, etc. cut curves, lower gears, brake with engine and drive like a maniac ,lol - I drove standard shift for more than 20 years before switching to and auto transmission-
I don't know why a 190hp car bits a 200hp? maybe it is because the max has only one air intake in the maniful as supposed to synchronizing 2? -maybe when new, was a lot better-

Ps. I don't know much about mechanics just what a learn in forums like this one; I am just a regular car owner.

 

Maybe because the maxima weighs about 700 pounds less and has shorter gears and is a car built for driving in a crowded city where you accelerate more then you cruise?


How many gears you have won't make a difference unless the gear ratio's are different. Also with the 5 speed that's in there you would be limited to gear at about 176mph, or with the 4 speed automatic in the z's which would limit you to gearing at over 180mph.

It's best when you buy your first z to just spend the first 5 or so years reading and getting to know it inside and out.