Clutch upgrade. A12

[njoz1200ute]

What clutch do you all reccomend on a high powered A12 turbo motor? 

 

200hp shooting for ?

[Mattndew76]

Post this on Datsun1200?

[njoz1200ute]

I did as well

[datsunfreak]

On 11/20/2018 at 3:45 PM, njoz1200ute said:

What clutch do you all reccomend on a high powered A12 turbo motor? 

 

I used a Centerforce clutch on mine, but they don't seem to offer one any longer...

 

SPEC makes good stuff and they list several options?

 

Stage 2 street: https://www.specclutches.com/691484/

Stage 4 race: https://www.specclutches.com/701254/

Edited November 23, 2018 by datsunfreak

[njoz1200ute]

Thanks DF.

 

I also found this one.  I was thinking of buying it after the holidays

 

https://californiaclutch.com/product/nissan-stage-2-clutch-kit-package?v=7516fd43adaa

[njoz1200ute]

The SPEC stage 2 looks nice too ?

[afracer]

Go for an ORC clutch, 190mm, includes lightweight flywheel for around $800 shipped. Spec clutches are stock pressure plates with a different disk depending on which 'stage' you get 

[njoz1200ute]

$800 blows the budget.  But sharing the link and the rest of the advice is important and appreciated 

[afracer]

LOL you said budget! HAHAHAHAHA don't kid yourself. If you're building a 200hp A12 turbo you'd better be willing to drop coin where it matters or you're wasting your money and time as well as the time of everyone trying to help you out. 

 

ORC 209D-NS1012-SE is approx $700 plus shipping or ORC 209D-NS1012-RC is approx $1000 plus shipping. You choose your vendor

https://www.blackhawkjapan.com/products/orc-orc-209d-ns1012-se-3

 

Http://www.rhdjapan.com

 

[datzenmike]

Go automatic. The 3N71B from a 280zx turbo is stout enough just swap an A series removable bell housing on. A bit more work would be the L4N71B from an '83-'84 Maxima. The 3N71B bell is close but won.t work. You would have to cut the A series auto case bolt pattern off and weld it on. With mods to the shift body it's capable of holding 600 HP and has an overdrive 4th gear. Get a 4.375, 4.625 or even a 4.875 differential and the overdrive and acceleration in all gears is improved.

[datsunfreak]

23 minutes ago, datzenmike said:

Go automatic.

 

 

And while you're at it, go ahead and have your testicles removed and change your name to Shirley...

[datzenmike]

Ha ha ha... no seriously. When you get up in HP they make more and more sense.

 

Always select the correct gear based on vehicle speed and throttle input

They never over rev the engine shift points.

Never miss a shift. No hand eye coordination needed.

Easier on drive line components because it's always in gear.... no sudden 6k clutch dumps.

No high wear components to replace.

Faster shifts than a standard.

Line pressure, modulator valve and valve body springs and check valves can be 'modified' for even harder clutch engagements to get that 'chirp in second'.

The 280zx 3 speed has a higher stall speed torque converter, more clutches and plates.

 

[datsunfreak]

41 minutes ago, datzenmike said:

Ha ha ha... no seriously. When you really get into drag racing they make more and more sense.

 

Fixed.  :)

[powerbench]

Which A series tranny can even hold 200 hp, assuming it's making in the neighborhood of that in torque. Would a 63a even handle that without blowing up?

What rear end is being run? 190H?

 

[datzenmike]

The '82-'83 S110 gen 2 and the '84 S12 gen 3 200sx were H-190 diffs with disc brakes and narrow enough for a B-210. ('85 and up were IRS) Gearing wasn't great but truck gears and side gears could be swapped in. These were coil spring but could be converted to leaf. Very strong.

 

If you weld aluminum a 71B could be used with an A series bolt pattern put on.

 

This is starting to add up in cost and you haven't even started on the engine yet.

[afracer]

The saving grace for any high power A series is the weight of the 1200 will help a trans live longer. I'd bet a good condition 63A would hold up ok for a bit behind a 200hp turbo A series where the torque and power aren't going to hit hard at a lower rpm. So long as shifts and launches are gentle. 

Edited December 6, 2018 by afracer

[datzenmike]

Torque is what they are rated by and torque is multiplied by the lower gears in a transmission. I always wondered why the H-190 was rated at almost 300 ft lbs on a less than 100 ft lb L20B.  First would be either just under 300 or 350 depending on the transmission. Then there's there's tires. Small enough they spin and limit the load placed on everything else.

[datsunfreak]

8 hours ago, powerbench said:

Which A series tranny can even hold 200 hp, assuming it's making in the neighborhood of that in torque. Would a 63a even handle that without blowing up?

 

6 hours ago, afracer said:

The saving grace for any high power A series is the weight of the 1200 will help a trans live longer. I'd bet a good condition 63A would hold up ok for a bit behind a 200hp turbo A series where the torque and power aren't going to hit hard at a lower rpm. So long as shifts and launches are gentle. 

 

FWIW, I've seen these broken by a mild L20b with "aggressive" driving...

[powerbench]

Way back in the day I maybe made 100 hp  and could break a 60a, ( usually the rear end first ) . My buddy has a quaffe tranny behind his roughly 180hp a15 track 1200 car and his friend has one behind his 200ish horse power 510 .....and the 510 has broken it twice now.( My buddy is now scared to take the car out now because of how much the tranny cost and watching his friend break his twice)

 

[powerbench]

On 12/6/2018 at 8:15 AM, afracer said:

The saving grace for any high power A series is the weight of the 1200 will help a trans live longer. I'd bet a good condition 63A would hold up ok for a bit behind a 200hp turbo A series where the torque and power aren't going to hit hard at a lower rpm. So long as shifts and launches are gentle. 

I can see this being true , but the first time out stop light racing  and they spool the turbo up to take off , parts may start going towards the ground. Whats the point of building a 200hp motor if your going to be gentle with it. If I'm making power ,I'm using all of it .

[datsunfreak]

Well, this has gone a bit off the original topic, so...

 

 

It sounds like to me your going to spend triple the money, break lots of unobtanium parts, and all just to make the same power as a stock CA/SR would. ?

 

Edited December 8, 2018 by datsunfreak

[datzenmike]

A 200 hp engine should include a 200hp drive line. Your H-145 is at least 1/3 what you need and the 63A barely handles an L20B.  If you're drag racing it, you have to expect stock A series transmissions and differentials to break from the abuse. Drag racing on stock parts is basically... abuse.

 

When an architect designs a skyscraper they start at the top floor and work downward. This assures that each floor is strong enough to hold up what's above it. Your differential and transmission will tell you what engine you can safely use. The H-145 is good for less than 100 pounds of torque. You need at least an H-190. The 63A can just barely adequate to support an L20B. A 71B or better yet a 71C with the A series bolt pattern cut off and welded on would be better.

 

 

[njoz1200ute]

In actually an architect.

 

The rear is a H165.

 

5 speed 60a.  

 

The previous version of this A12 turbo motor which had around 140hp did fine on the 4 speed and the H165 it had.  The problem qas the clutch slipped bad.  Im using the same rear but 60a 5 speed this time around

[Dguy210]

On 12/8/2018 at 11:09 AM, datzenmike said:

A 200 hp engine should include a 200hp drive line. Your H-145 is at least 1/3 what you need and the 63A barely handles an L20B.  If you're drag racing it, you have to expect stock A series transmissions and differentials to break from the abuse. Drag racing on stock parts is basically... abuse.

 

When an architect designs a skyscraper they start at the top floor and work downward. This assures that each floor is strong enough to hold up what's above it. Your differential and transmission will tell you what engine you can safely use. The H-145 is good for less than 100 pounds of torque. You need at least an H-190. The 63A can just barely adequate to support an L20B. A 71B or better yet a 71C with the A series bolt pattern cut off and welded on would be better.

 

 

 

I've owned 2 63A transmissions, one behind a very stock L20b (521) and the other behind my relatively mild A14 in the B210. I developed a serious whine on 5th behind the L20b in only a few years that required a rebuild and I'm starting to get some noise on the one behind the A14 after 7 years and I'm reasonably gentle with my stuff overall (I have broken one h150 after about 16 years). So I don't really consider them that robust a transmission at this point, even behind an A.

 

I think Mike's idea of a 71 swapped to A series front end is on the mark. I know the 720 2wd 5spd shorty will fit in a 1200 (manual tunnel) with some BFH convincing and is stock length so that seems like it might be a good candidate.

 

[datzenmike]

The 71 is used on the '79-'83 non turbo 280zx so reliably good for 180 hp. You would need an A series automatic or 4 speed for the bolt pattern or make an adapter plate. The input spline where it rides in the pilot bushing is probably larger that the one on the 63A. So maybe an A series pilot turned down larger to fit the 71B? I don't know if the clutch disc spline on the A series matches all other Datsun inputs... maybe. Then you need the 63A clutch and PP.