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s15 gearbox into s13

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Hey guys,

I am strongly contemplating a s15 gearbox conversion for the taller gears/ better economy in 6th..

 

and as I'm on my p's and will be until 2015 (sigh..) no turbo for me so I want to make this s13 a reasonable cruiser and try get a bit more economy out of it..

 

so my questions are as follows

what I understand is For the conversion I need the:

-gearbox

-clutch ( but not flywheel?)

-s15 diff

-custom tailshaft(?)

 

also, does the hole In the tunnel line up with shifter from s15 box?

does the gearbox mount line up with s13 one?

does the s15 diff fit into s13 cradle?

how would I go about connecting speed sensor? would I need a s15 dash cluster..?

 

thanks for any help guys, even if it clears up one or two things -

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Hard basket as the S15 diff is where the speed sensor is therefore there is nothing on the box to get it from.

 

I know there's a couple S13's gettin round with the boxes in but i dont know if they'v changed diffs.

 

6th gear is very close to 5th gear ratios between the 2 boxes btw, will be little gain in ecconomy

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The economy does not come from the 6th gears ratio, but more that you change sooner in the rev range.

It's been scientifically proven that you will save fuel in the 'long run' if you mash your accelerator peddle and whiz through the gears but chaining before 2k.

In contrast to going easy on your throttle and revving just a little more. As you are taught to drive to save fuel.

The more gears, the better the fuel economy.

So you do get better economy from the 6speed gearbox, but it depends on how you drive it.

 

Bit of an article here http://www.drivingfast.net/road/fuel-economy-techniques.htm#axzz1YpfTadXQ

Goggling the Dr's name and his research will provide a wide range of sources.

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Ahh thanks guys- yeah I've read that the speed sensors in the diff but surely theres a way around it...? I've read I can chuck a bike speed sensor on one wheel haha but ill do that if I'm desperate.

 

suspop- half of me wants the 6 speed for economy other half is for the taller gear ratio's and sheer extra gear haha.. great read that tho cheers mate

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use the s15 flywheel, s13 clutch, s13 clutch slave will fit too, box lines up to the shifter hole, i cbf walking out to check the 6 spd box i have here but think you may be able to bang a speed sensor into it and use the s13 tailshaft and diff.

 

 

i wouldnt bother though, if your worried about fuel econ buy a vw diesel...

 

 

 

-dan

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I thought reason for s15 clutch was because the input shaft has different spline count?

 

so boxes are same length and mounts in the same position? how would you bang In a new sensor is there a recess for it or a bung in a hole where its located on the s13?

 

cheers for the info- I realise its not going to provide many gains but its a thought in my mind and had been bugging me for weeks

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I have a 6 sp in my s15 now and you can feel that it won't stand up to the punishment that a 5 sp will take

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yeah but how much punishment can a Sr20de give? :P well its still a possability might keep my eye out for a box with a snapped selector or fork or whatever it is that snaps and rebuild it but still wanna know if its worth even thinking about

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If you want better fuel economy, seriously, just speed everywhere in 5th gear.

 

SR20DET 180Sx, old car got ~8L/100km, because I'd smash it at the lights, 1st, 2nd, and drop into 5th, pretty much. Consider cruising at 2-2.5 in 3rd or 4th, versus same rpm in 5th. Your motor is doing the same amount of work, but the car's travelling faster/further.

 

With a slipping clutch (shifting before 2800), economy went to 12-14L/100km, because I wasn't speeding at all, because it was an effort enough to just get it up to speed.

 

Edit: the standard gearbox is pretty well suited to the NA SR. If you're thinking of working things out so you have a lower cruising RPM, you're going to find that it's a dog, simply because the motor doesn't have enough torque to get things going. Being an underpowered motor, you've got to rev it to get anywhere, which means using fuel. Gearing isn't going to get you out of that problem.

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It'll cost more than any fuel you'd use. I did 1000km a week for 8 weeks when I bought my last car, so fuel economy/pricing would be noticeable. But not everyone's as big a nutjob as me, so forking out $1000 for a gearbox, and then spending 2 weeks chasing up bits and pieces to make it fit, and then getting the speedo working properly because what you read on a forum didn't work, and plus labour, etc. How much fuel are you using, really? Strip some weight from the car, and that's a headstart, and won't cost anything.

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If you want better fuel economy, seriously, just speed everywhere in 5th gear.

 

SR20DET 180Sx, old car got ~8L/100km, because I'd smash it at the lights, 1st, 2nd, and drop into 5th, pretty much. Consider cruising at 2-2.5 in 3rd or 4th, versus same rpm in 5th. Your motor is doing the same amount of work, but the car's travelling faster/further.

 

With a slipping clutch (shifting before 2800), economy went to 12-14L/100km, because I wasn't speeding at all, because it was an effort enough to just get it up to speed.

 

Mind you, what you said above is a good point, however remember you're driving that off boost which is probably where you're saving your fuel whereas DE's are alot different and need a different approach remember smashing it in 1st and 2nd means about 8 seconds later waiting slowly for the revs to build :lol: But i get what you're all getting at and i do plan to adapt my driving so im not at the pump every second day.

 

Edit: the standard gearbox is pretty well suited to the NA SR. If you're thinking of working things out so you have a lower cruising RPM, you're going to find that it's a dog, simply because the motor doesn't have enough torque to get things going. Being an underpowered motor, you've got to rev it to get anywhere, which means using fuel. Gearing isn't going to get you out of that problem.

this is definetly NOT what i want to do hahah - i currently have a 4.375 ratio diff(soon to be 4.363 R200..) which is causing the high idle, I understand getting a 3.9 would make taking off sluggish as all hell but lower my idle at the top end-

What i am thinking is as per http://nissans15.com/spec.htm Gear ratios are taller and closer together From 1-4 then 5th is the same as 4th and 6th is even lower than 5th in the 5 speed so i will kill two birds with 1 stone:

Higher gearing from 1-4 where I NEED it

Lower gearing in overdrive which i also need

the above is my reasoning for getting a S15 trans

 

 

Strip some weight from the car, and that's a headstart, and won't cost anything.

That is true, However i dont want to run a stripped interior and roll cage like every other P plater in a N/a S13 >__

 

i would do all the work myself and have a hoist i can do it on so doing the conversion wouldnt be a difficult job just gathering the parts would be the fun part- Which means i need to know excatly what i need for the conversion to do it as efficiently as i can

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Honestly forget about it, as said above if you want fuel economy by diesel vw

 

We don't drive these cars for their fuel economy

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Honestly forget about it, as said above if you want fuel economy by diesel vw

 

We don't drive these cars for their fuel economy

I am strongly contemplating a s15 gearbox conversion for the taller gears/ better economy in 6th..

 

half of me wants the 6 speed for economy other half is for the taller gear ratio's and sheer extra gear haha.. great read that tho cheers mate

 

 

Higher gearing from 1-4 where I NEED it

Lower gearing in overdrive which i also need

 

Mate honest to god, How many times do i need to say that fuel econnomy is NOT the only thing im looking for I do understand these things guzzle fuel and i am merely trying to find ways to lessen the blow because the plan is to keep the car over the next 4 years while on my P's So $1000 today will save me X ammount over 4 years time. so yes, i do believe its worth it ALSO with the taller gear ratio's the car will be quicker off the mark and quicker up to speed and if you haven't driven a SR20DE believe me it fails at these two things.

 

INB4 Further fuel consumption comments (unless they're actually helpful)

 

Thank you!

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Let's say you save 20 bucks a week that's $1000 a year you'll save $4000 in 4 years the gearbox and parts will be close to $1500 so you've saved $2500 bit of a waste you could save more than that by reducing weight just romping the spare tyre, tools, any clutter in the car that's not needed having the stock wheels with decent tyres on the car , removing the subwoofer if you have one if you have a bodykit remove it and go back to stock, and never driving above 2500rpm

 

I don't think it's quicker off the mark it seems the same as my 5 speed s14 and s13 I used to own

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the only gain you would get is the satisfaction of saying "i have an s15 box". then people will reply those are weak, 5 speed it better etc etc. i don't really see a gain in doing it.

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the only gain you would get is the satisfaction of saying "i have an s15 box".

hit the nail on the head

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I can see your point in considering it though. With my S13, going 100km/h on the freeway, in fifth I'm sitting on a little bit under 3000rpm. So I'm left pondering the fact that the additional gear would be beneficial. But hey, is it really worth all the hassle?

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I can see your point in considering it though. With my S13, going 100km/h on the freeway, in fifth I'm sitting on a little bit under 3000rpm. So I'm left pondering the fact that the additional gear would be beneficial. But hey, is it really worth all the hassle?

 

So what? I sit at around 2900rpm in 6th doing 100km's and iv got 3.9 ratios at the ass end.

 

See what were getting at.??

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I have a 6 sp in my s15 now and you can feel that it won't stand up to the punishment that a 5 sp will take

Oh f**kofff you can. Load of shit. Love how the 6speed got a bad name coz of some people and the way they drove and now every kid on the block has jumped on the bandwagon because they have read all the threads about this and that. Now saying oh no, no, no, they are just weak - period, on every occasion a 6speed is mentioned. People do 300rwkw+ with them, people use them for drift. Your just contributing to a mass exaggeration.

 

Having said that the 6speed gears/ratios are better suited for drift and circuit, and it can defiantly take the punishment of an atmo SR.

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I have a 6 sp in my s15 now and you can feel that it won't stand up to the punishment that a 5 sp will take

Oh f**kofff you can. Load of shit. Love how the 6speed got a bad name coz of some people and the way they drove and now every kid on the block has jumped on the bandwagon because they have read all the threads about this and that. Now saying oh no, no, no, they are just weak - period, on every occasion a 6speed is mentioned. People do 300rwkw+ with them, people use them for drift. Your just contributing to a mass exaggeration.

I've owned an s13 s14 s15 2x r32s and an r33, and I'm possitive that the 6sp feels more flimsy than the 5 speeds

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Great to know you've owned all those cars. My mother has owned over 10. She probably knows better then both of us.

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I'm just saying that I'm not jumping on a bandwagon in regards to the s15's gearbox, and that my opinion is based on the comparison to other Nissan turbos

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I agree with suspop I don't think its a weak gearbox however it is a lot more complex than a 5 speed in roughly the same container so I'm sure it would have narrower gears and thinner forks for sheer space constraints so I'm sure it would be weaker than the 5 speed. however I think its a good box and I'm sure if a lot of people can run ~200kw through It it can survive

 

that being said this thread has become one big arguement which is not what I wanted all I wanted was a few more details for the conversion before I attempt it- and stig, when/if it shits itself feel free to say I told you so.

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the only gain you would get is the satisfaction of saying "i have an s15 box".

 

Pretty much, its not like you own a lambo or something.

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I'm not saying you'll break yours, its behind a nonturbo engine, to you I'm saying it's a massive waste of money cause your doing it to save money on petrol,

 

I was arguing with suspop, cause he saying I'm going with the crowd saying the box is weak when I basing it on my opinion of how the box feels,

 

Suspop: have you driven an r33 in good condition for more than an hour? The gearbox feels tough as nails

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