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U12 Bluebird, Pintara & Stanza => performance and handling => Topic started by: Pure_Sincerity on Apr 12, 2013, 02:47PM

Title: Gearbox options, ratios & final drive Qs
Post by: Pure_Sincerity on Apr 12, 2013, 02:47PM
Since our factory 50v box is gay how will a 32v/70v match up for a ka in a u12 ?

For my build in particular, would the 32v and 70v boxes have tighter gearing for a ka ? I'm hunting down final drives and gear ratios now, ill post back when I find them.

I know you will need:
Pulsar innar LSD shafts, u12 outers
Mock up gearbox mount.
50v housing (part that attaches to the block)
Possibly new custom clutch with different centre spline.

Feedback Chris, Adam, Paul ? Paul you have done it but in revers with a ka box on sr and Chris, Adam, you have all the knowledge and theory.
Title: Re: Gearbox options, ratios & final drive Qs
Post by: SSS on Apr 12, 2013, 03:22PM
Lol, nothing wrong with the 50A/V box, it only needs a decent mechanical LSD. I honestly think it doesn't even need a diff ratio change.
using anything from a 70V is only going to end up in failure.
Title: Re: Gearbox options, ratios & final drive Qs
Post by: Pure_Sincerity on Apr 12, 2013, 04:18PM
No doubting you, but what info do you have behind it in being a good box ? Everyone on PGA recon the 50v boxes are dog shit. Plus Chris has posted multiple times stating
"you're not goin to get anywhere on those ratios"

You're the ka man. What's the info behind it ?
Title: Re: Gearbox options, ratios & final drive Qs
Post by: SSS on Apr 13, 2013, 10:44AM
Ok, so i'll turn the question around to you: what info do the "supposed" experts on PGA have to quantify that it is a shit box?

I don't have any info to quantify that it is a good or a bad gearbox. To me it's not bad, but lack of a good mechanical lsd does not do it any favours either. I don't think the spacing between the ratios is bad either.

Chris said what he did for a reason: the honda motors he has been building are meant to stay in a high rpm band when you are going flat out; this is because they make their peak torque at a high rpm. As a consequence, Honda gear them as such to do this.
My brother's old DC2 Integra Type R is case in point. I used to shift just shy of 8,900 rpm to keep it on the boil.

There will be a limit where you start making a lot of torque (ie in a turbo setup), and you will start breaking components.

Look at Lgee's U13 as a prime example, lots of torque, and he has shredded 3rd gear many a time; because it was the weakest link in the chain.

There have been past members that did SR swaps into the u12 and used the 32 / 70 series pulsar boxes, and they used to shit gearsets even thinking about jumping on the loud pedal. BruceTI's blue TRX (SIRTRX's old car) had this problem, and he was only pushing 200ish kw at the wheels through it.
AFAIK, Kranz has not had that issue with his hybrid 50 series box at all.

Compared to something like, a Hollinger or Xtrac sequential 6 speed, simply there is no comparison. Hollinger or Xtrac hands down, because they are dedicated race boxes.

I'll say it again: Apart from installing a good mechancial or clutch pack type LSD, stuffing around with gearboxes in the U12 is going to be a waste of money, money that could otherwise be spent on making more power.
Title: Re: Gearbox options, ratios & final drive Qs
Post by: noss on Apr 13, 2013, 03:01PM
also fwiw, sirtrx ended up going with a par gearset that had straight cut 1 & 2 gears. maybe 3 as well i'm not sure. it was removed from the car when he sold it though.

likely the gearbox only died because someone was driving like a tard. i have busted a KA gearbox once, because i thought it was a good idea to launch at 4k rpm all the time. it was an expensive lesson at the time. 2nd gearbox i still drove hard but i didn't to spastic launches.

i would say a few people on pga would fit into that category when it comes to broken components.
Title: Re: Gearbox options, ratios & final drive Qs
Post by: Budgie on Apr 13, 2013, 04:24PM
The PGA guys would have no idea about the 50V boxes, they don't use or run them in their cars!! They use the 32 boxes, blow them up, then put PAR or PPG gearsets into them.

The 50V FWD box is virtually identical to the AWD, which was designed to handle alot more torque (in the turbo U12/U13 and the GTiR). The 32 box/gearset was never fitted (to my knowledge) to an AWD car.
Title: Re: Gearbox options, ratios & final drive Qs
Post by: SR20ME on Apr 14, 2013, 12:42PM
This is interesting for me as I have with my sr20det a SSS N14 gearbox. So what model is that? (still new to Nissan stuff)

I think if you drive the car extremely hard and floor it at the lights with the clutch the gearbox will blow itself up. You drive it on the street and are smooth in gearchanges it may survive or at least for a lot longer.

Is there a gearbox I can use for the SR20DET besides the N14 OR N15 SSS. Going down the PAR path means about $5,000 for a straight cut set plus they are really noisy gearboxes of course, due to straight cut.
Title: Re: Gearbox options, ratios & final drive Qs
Post by: Budgie on Apr 14, 2013, 05:17PM
That's a 32 series box mate.
Title: Re: Gearbox options, ratios & final drive Qs
Post by: SR20ME on Apr 15, 2013, 09:25AM
Okay

So I have been doing some research. The 70 series boxes have been known (in the USA) to handle really good amounts of power (up to 400HP). They come out in the N16 1.8L manuals but the bellhousings don't fit and it is some work to get them to match up at least to an sr20. To a KA motor it would be more of a challenge I might imagine.

With the 50V box, how hard is it to match this to the SR20 motors? I don't what to change this now as I just had a custom CV shaft done and am guessing the 50V boxes would mean I'd have to get custom shafts done again as well for both drivers and passenger side? If I blow up the 32 series gearbox which I am told will happen if my tune and power levels are reached 180 to 200fwkw then I'll have to look into that.

What were the 50V boxes fitted in? Our U12 KA versions and GTI-R?
Title: Re: Gearbox options, ratios & final drive Qs
Post by: Kranzy on Apr 15, 2013, 09:59AM
I am running a 50's series gearbox in my SR powered pintara.

U12 SR18DE bellhousing (imported from NZ, Dozer might be able to help here)
U12 KA gearset and outer casing (LSD)
u12 KA LSD drive shafts (standard shafts work fine)

I managed to source parts to then run an awd clutch...info here:
http://www.antrx.com/smf/index.php/topic,13726.msg282885.html#msg282885

I was originally running an exa clutch to suit the flywheel size, with a modified centre to fit the ka spline. The clutch, worked well at the start but really struggled with the power of the motor. I ended up replacing it as it was slipping and I thought I had got to the end of its life, it actually warped the clutch plate so much it was rubbing on the metal of the disc not the clutch material (full face paddle clutch) The awd clutch, which is the same as the skylines etc is amazing, I actually feel like im driving a car with a bit of power as the clutch is so strong.

Also as Adam mentioned the KA internals have stood up to 5+ years of punishment in the car and dont look like giving up, syncro's are a bit iffy, but they've been like that since I had the KA in the Ti before the conversion.


Title: Re: Gearbox options, ratios & final drive Qs
Post by: SR20ME on Apr 15, 2013, 10:41AM
I am running a 50's series gearbox in my SR powered pintara.

U12 SR18DE bellhousing (imported from NZ, Dozer might be able to help here)
U12 KA gearset and outer casing (LSD)
u12 KA LSD drive shafts (standard shafts work fine)

I managed to source parts to then run an awd clutch...info here:
http://www.antrx.com/smf/index.php/topic,13726.msg282885.html#msg282885

I was originally running an exa clutch to suit the flywheel size, with a modified centre to fit the ka spline. The clutch, worked well at the start but really struggled with the power of the motor. I ended up replacing it as it was slipping and I thought I had got to the end of its life, it actually warped the clutch plate so much it was rubbing on the metal of the disc not the clutch material (full face paddle clutch) The awd clutch, which is the same as the skylines etc is amazing, I actually feel like im driving a car with a bit of power as the clutch is so strong.

Also as Adam mentioned the KA internals have stood up to 5+ years of punishment in the car and dont look like giving up, syncro's are a bit iffy, but they've been like that since I had the KA in the Ti before the conversion.


I'm on PGA a bit at the moment because of questions around my build and the sheer number of guys with sr20 modifications. They don't rate the 32 gearbox (fair enough). Not much talk about the 50 but they regard the 70 as the best choice. Like Pure_Sincerity, there isn't a tonne of information about maximum power ratings on these gearboxes.

Kranzy, what sort of power are you making with the 50 series box?? Are you 180 and above? Don't know what mods you have etc except you are running a T25?
Title: Re: Gearbox options, ratios & final drive Qs
Post by: Kranzy on Apr 15, 2013, 11:15AM
Ive never had it dyno'd so not 100% sure on the figures. Its mostly stock, with a T25g at 10psi and a tune. I would estimate between 160-180kw.
Title: Re: Gearbox options, ratios & final drive Qs
Post by: SR20ME on Apr 15, 2013, 04:37PM
Ive never had it dyno'd so not 100% sure on the figures. Its mostly stock, with a T25g at 10psi and a tune. I would estimate between 160-180kw.

Okay, thanks Kranzy. Appreciate the info.
Title: Re: Gearbox options, ratios & final drive Qs
Post by: Budgie on Apr 15, 2013, 10:10PM
There are also a few FWD SR20DE powered imported U13 Bluebirds popping up on gumtree in QLD at the moment, so it wouldn't surprise me if you could find a complete FWD SR20DE 50 series box from an imported U13 somewhere up north at a wreckers or something.
Title: Re: Gearbox options, ratios & final drive Qs
Post by: pedro666 on Apr 16, 2013, 11:59AM
my 70 series(g20) should be here in a couple of weeks, from what i have found out the box ratios from the b15 are better for N/A and the 2002 g20 are better for turbo. i will try and find the final drive ratios, and the differences between the 3 series, i have them somewhere. the main one was the 3rd gear in the 30 series, and a helical Torsen limited slip differential for the 70.
Title: Re: Gearbox options, ratios & final drive Qs
Post by: SSS on Apr 16, 2013, 05:51PM
and a helical Torsen limited slip differential for the 70.

Winning!
Title: Re: Gearbox options, ratios & final drive Qs
Post by: chr1S on Apr 16, 2013, 08:18PM
Ok this is my two cents,

After having been exposed to various Honda gearboxes (standard civic/integra all the way to type r and custom tighter gear sets) I would not waste my time making a hybrid from a Pulsar, or whatever - unless you make a custom bell housing and mate that to a Honda ITR box (good enough for 500whp all day long).

When I had my U12 and looked into gearboxes, I had someone in the states willing to start a group buy for Quafe LSD's, and had a quote from PAR to make me a custom gearset with a 4.7 FD. This was only because I wasn't convinced the 4.1 (i think) CA20 FD was going to work good enough for what I wanted (2.6L, 9000rpm) - I honestly can't remember the quote, I think it was something like ~4k and considering it was a dogbox with custom gearing I thought this was the best option - but I wasn't going to spare much on the car at this point in the build, I had the engine in check with the BC stroker and the whole shitbang, for a street car I wouldn't do it.

I know there is some simulation software out there that doesn't show a measurable difference to quarter mile times for varying FD values, which I find hard to believe, I have a paper that was based on FSAE simulations and varying FD (to validate quick shifters) and it did demonstrate there was a crossover point where you start going backwards as the gearing is simply too tight. If I were to run my old integra with the K24 and a standard Accord Euro gearbox and drag race my identical car with a Type R gearbox, I would get walked, simple as that.. and people have proven this at the drags on multiple occasions.

The tighter gearing you go, the more force you apply at the contact patch, hence why most Hondas sit there bashing the limiter in first/second gear (wheelspin) - to achieve the maximum amount of long. acceleration, you need ~10% slip ratio (not tyre slip ratio, actual driven ratio) so you won't be anywhere near this if you're power limited from you're gearing. Now becareful here, I'm not implying that you should gear your car so you wheelspin in every gear, that would be silly - or impossible on low levels of power. But regardless of turbo or NA I think the KA box is simply too long.

http://www.youtube.com/watch?v=CSRXSShotl0

http://www.youtube.com/watch?v=tx3n2XXWjy0

This video will give you an idea of how tight the OEM K series and B series (Standard) Honda Type R gearbox is.

Title: Re: Gearbox options, ratios & final drive Qs
Post by: pedro666 on Apr 16, 2013, 09:39PM
damn those vids make me want to get the vet on the road even more.. watched this after , funny as..
'Mamma mia'
http://youtu.be/FTTyYUT9QJE (http://youtu.be/FTTyYUT9QJE)
the previous gearbox, cvt hyper m-6 also had helical lsd.
I found the final drive ratios for the 70 series..  4.1 FD out of the G20 and a 4.4FD out of the B15.

Title: Re: Gearbox options, ratios & final drive Qs
Post by: SSS on Apr 17, 2013, 11:18AM
Ok this is my two cents,

After having been exposed to various Honda gearboxes (standard civic/integra all the way to type r and custom tighter gear sets) I would not waste my time making a hybrid from a Pulsar, or whatever - unless you make a custom bell housing and mate that to a Honda ITR box (good enough for 500whp all day long).

When I had my U12 and looked into gearboxes, I had someone in the states willing to start a group buy for Quafe LSD's, and had a quote from PAR to make me a custom gearset with a 4.7 FD. This was only because I wasn't convinced the 4.1 (i think) CA20 FD was going to work good enough for what I wanted (2.6L, 9000rpm) - I honestly can't remember the quote, I think it was something like ~4k and considering it was a dogbox with custom gearing I thought this was the best option - but I wasn't going to spare much on the car at this point in the build, I had the engine in check with the BC stroker and the whole shitbang, for a street car I wouldn't do it.

I know there is some simulation software out there that doesn't show a measurable difference to quarter mile times for varying FD values, which I find hard to believe, I have a paper that was based on FSAE simulations and varying FD (to validate quick shifters) and it did demonstrate there was a crossover point where you start going backwards as the gearing is simply too tight. If I were to run my old integra with the K24 and a standard Accord Euro gearbox and drag race my identical car with a Type R gearbox, I would get walked, simple as that.. and people have proven this at the drags on multiple occasions.

The tighter gearing you go, the more force you apply at the contact patch, hence why most Hondas sit there bashing the limiter in first/second gear (wheelspin) - to achieve the maximum amount of long. acceleration, you need ~10% slip ratio (not tyre slip ratio, actual driven ratio) so you won't be anywhere near this if you're power limited from you're gearing. Now becareful here, I'm not implying that you should gear your car so you wheelspin in every gear, that would be silly - or impossible on low levels of power. But regardless of turbo or NA I think the KA box is simply too long.

http://www.youtube.com/watch?v=CSRXSShotl0

http://www.youtube.com/watch?v=tx3n2XXWjy0

This video will give you an idea of how tight the OEM K series and B series (Standard) Honda Type R gearbox is.



Like I said on bookface mate, U12's are cheap. Buy another one!

Tighter spacing between gears will help, but ultimately it's the FD that defines torque output to the ground.

I will look into it further, I still have to pull down one of the VLSD boxes I have to see if that Quaife LSD will work. If it does, i'm adding it to my xmas list.