6-speed with KA-T?

[AZhitman]

Guys, I am LOVING boost on my droptop (1 bar, built motor, lots of engine mods, 4.36 VLSD).

However, I'm still spinning pretty high in 5th on the freeway.

Don't want to lose the low end grunt, so I'm thinking another gear will be perfect.

Is there a suitable 6-speed (S15, Z33?) and how can I mate it to the KA?

[s13rb25det]

I have wanted to do this same thing for so long! but I think it would be pretty hard to do, I would use the s15 trany because it bolts up to the ka engine block. but if you wanted your speedo to work you would need to fabricate a new one or use the s15 diff housing. also the ratios of the s15 are pretty close together so out on the highway it would be just a few hundred rpms lower than the 5 speed, it would still be very cool!!

[EstoMax]

keep in mind though that the s15 transmission is the same size as the s13-s14 trannies... That means the gears are weaker and i read somewhere that they dont hold a lot of power.

There are z32 transmission mount adapters in the works i know, but that would be a 5 speed.

sorry no good info on the 6 spd from meMarko

[Sil40_Mayhem]

Not an expert gearhead by any stretch of the imagination, but wouldn't a taller final drive accomplish the task? I know that there is a desire not to lose any low end pull, but I figured that more powerful (read: larger displacement or boosted) vehicles would have the balls to rock out on longer gear ratios anyway (look at stock Z32TT, S/C Mustang Cobra, Vette, etc. final drive ratios).

Having no personal experience, myself, I can't speak on the strength (or lack thereof) of the S15 transmission, but I would guess that it would be the easiest (in terms of size, dimensions, etc.) to mate to the KA (after swapping/modding the bellhousing).

Simply put: I dunno.

[AZhitman]

I can't imagine the S15 trans being any weaker than the current trans, which was designed for 140 crank hp...

I really, really don't want to give up my 4.36's...

[Sil40_Mayhem]

Well, then it might be the S15 6spd FTW. However, if you ran a taller FD ratio, you could donate that 4.36 to a very worthy, slow, 155hp (crank) cause.

[GEO]

Greg, hes right, the S15 transmission is weaker, I was talking to a few guys and they said in the next month or so a supra ( 2jz ) transmission adapter for the KA will be out, which will allow you to use the turbo 6-speed transmission. PAINTENCE my young one.

[crzycav86]

the s15 transmission is notorious for sucking ***.

hitman, swapping to the 4.08 or even the j30 3.9 will make your power more useful.. and insanely easier and cost effective.

[KATwo40]

^^^ He's correct. If you're spinning the tires in 5th, you certainly need a taller final drive.

[AZhitman]

Not spinning the tires in 5th (that would PWN ), spinning too many RPM's in 5th at freeway speeds...

[fiznat]

Greg, is this about *gasp* fuel economy?!?! Dont try and hide it saying you want your low end power on the highway! I dont believe you!! hahahaha

*ahem*

Anyways, yeah, not sure about what 6 speeds could be used. The supra one would be sweet. Might require a custom job. Why not give Ivan a ring?

[Rex]

Find a transmission shop to swap your 5th "gear", you may have to run a little farther in 4th for normal driving, and then drop way down in 5th??

Worth asking a transmission shop??

[AZhitman]

Both good ideas.

Hell, I can WATCH the gas needle drop in this thing... Those 780's must be pissing like racehorses.

[TheOne]

you could try a T-56, custom bellhousing and driveshaft, and you may need to do some fabbin to the body to make it fit(not 100% sure on this, seemed fine for ls1 in 240 i think, but thats totally custom position), 1 out of a 03-04 mustang cobra will do nice for low end and high speed.

the S15 trans is supposely weak due to it bein a ka/sr trans with another gear added, making the other gears smaller/weaker, it should do 300-400hp or so, maybe less.

[Jookmasta]

well this has already been done as 2 ka-t's down here run z33 transmissions supposedly. the guys at backyard productions supposedly made some sort of custom bell adapter and have mated the z33 transmission to it. im sure the z33 transmission would fit your needs lol.

as for the high rpms in fifth gear, i would've expected high rpms in fifth gear due to ur gear ratio................great acceleration but no top end right? the z33 transmission would solve ur issues but u will still run out of room with the gear ratio ur running. out of curiosity, what is ur max speed throughout first gear, second gear, and third gear? i was contemplating on getting a 4.4 gear ratio so perhaps u could help make up my mind.

[j-z]

i think swapping to the stock 4.08 final would be the most practical thing to do. but if you must insist on 6 gears, the t56 is one of the most well known and used trannys. any transmission swap from another chassis is going to require about the same amount of work. best thing to do is make a list of the trannys youre thinking about using, compare gear ratios, compare physical dimensions, weight, and cost. that should narrow your choice down rather quickly.

[gaehrings13]

One of my friends aquired that setup from byp and he is selling it I think he said something like 700 but I can't remember, if you want me to call him hitman just shoot me a email at [email protected]....

He has everything so he says but just email me and I will look into it.

[sultan]

the z33 6th gear is shorter than his current 5th, so he'd still have to change the rear end gear.

[BOOMSHAKALAKA]

Can you put a 350z transmission into a 240sx? Keep the flames low it's just a question.

[SeVa-S13]

Can you put a 350z transmission into a 240sx? Keep the flames low it's just a question.

You can match any transmission to any block; you just need a properly machined adapter and mounts, both custom normally.

[BOOMSHAKALAKA]

You can match any transmission to any block; you just need a properly machined adapter and mounts, both custom normally.

Well in that case...Greg would you use a 350z transmission on your vert? It's a 6 speed...

I just might do that later in the future.

[USsil80]

i have seen a new fifth gear that you could get ... belive it was from nismo.... that was lower than the current inthe trannie now...

[PapaSmurf2k3]

just put giant *** wheels on the back

i think the best choice would be to pick up a spare KA transmission and do the different 5th gear thing the other people have been talking about. you could get all new synchros and everything els while your at it

[hek1620]

i read somewhere here on nico that u could use the fifth gear out of an exterra. they said it gives u lower highway rpm's. i was planning to do this aswell, i hate cruising at close to 4k.

[AZhitman]

just put giant *** wheels on the back

Like the 275/40/17's that are on there?

I like this idea of building a spare trans with a higher 5th gear.... Anyone familiar with the exact part?

[Chezedik]

I like the idea of the Z33, myself. I bet enough punk kids have wrecked them, that I could get ahold of one. And if the adaptor is already made, that would be way easier than a MKIV.

[USsil80]

here you go hitman.... http://www.nismoparts.com/catalog/?section=241

[Chezedik]

.838 is going to be less of an overdrive.

[s13rb25det]

I am pretty dumb when it comes to transmissions, so keep the flames low but would you have to do any clutch/flywheel mods when you change to a z33 trany? also what about the input shaft that goes into the engine block are all of them the same size? and do they have the same amount of splines?

[hannibal]

^ not sure at all, but thats easy compared to fitting the Z33 bellhousing to a new KA blcok