The Automatic Thread - Questions

[turboedsloth]

Manual valve body. Easiest way

This.

I'm in the process of building an auto up at the moment to go behind my 26/30 to test out. Will be using a full manual valve body

[tripsteady]

Manual valve body. Easiest way

This.

I'm in the process of building an auto up at the moment to go behind my 26/30 to test out. Will be using a full manual valve body

What kind of process is involved in using a manual valve body? Not a straight swap I imagine?

[steve200b]

Best you give mv autos a call in Adelaide they are good guys and good work

[tripsteady]

Best you give mv autos a call in Adelaide they are good guys and good workyeah

yup , know who they are , getting my shift kitted valve body upgrade from them

[steve200b]

I had a r34 box built by them very happy with the result

[turboedsloth]

What kind of process is involved in using a manual valve body? Not a straight swap I imagine?

Not 100% straight swap. I am using 1-4 full manual which will be easier to install rather than electric 4th

[zoomzoom]

Not 100% straight swap. I am using 1-4 full manual which will be easier to install rather than electric 4th

Id like to see that. I've seen a video of a manualised skyline where the driver appeared to flip a switch to engage 4th gear. Looked really awkward and inconvenient for driving on the street. I was under the impression that a manualised valve body still only had 3 positions for forward gears, meaning OD had to be an alternate control.

I guess you also lose things like the lockup converter (unless you have manual control), and variable line pressure (runs full pressure all the time?).

[sonicz]

I guess my only question is how are people holding 300rwkw on the stock clutch plates? My Auto box cant hold lockup on anything past 6psi on boost. If I set the boost to 12 psi, anything more than a 1cm of pedal press results in massive transmission slipping and the car not accelerating. The engine seems to cut power and wait for the auto box to catch up and then bounces of the rev limiter until I release the accelerator, then it shifts and the process starts all over again. My car is 3x faster on the lowest 5psi than 12psi.

Have I just been unlucky with my trans? I must've spend over $600 trying out various Automatic fluids and the thinner the fluid the less slip there is but its still useless.

Edited January 24, 2014 by sonicz

[Trex]

That does not sound good

[scotty nm35]

There is no material left on your clutch packs, the auto is in need of a rebuild. You can either swap a S/H box in there, or rebuild it at a trans specialist at a cost of 3 or 4k.

[GTSBoy]

Simsmetal.

[sonicz]

Yea figured. Seems crazy people spend 3-4k on Auto rebuilds though. Manual conversion would be much better and cheaper unless you have a thing for unreliable transmissions that cost you power and fuel.

I guess I will drive drive gingerly along at 5psi. Too broke to do otherwise. Actually the transmission shifts smoothly and works well if if you dont exceed about 6psi and I guess about 200HP which is what I estimate the engine puts out at that psi.

Whats to say if I buy another used auto transmission it wont be in a similar condition to mine? Theres no way to tell the condition of the clutch plates. I guess thats why I always find it weird people just take for granted the Nissan turbo boxes are tough and can handle power well when my experience with every Auto box I have ever owned has been lousy. And its always the same problem. Worn clutch plates that cant hold power.... People just don't change Auto trans fluid and they just drive it till it dies or sell it to a sucker like me just before it busts.

Edited January 24, 2014 by sonicz

[steve200b]

I still have the lockup converter in mine but the highest stall speed you can have is 3000rpm the convenience of the overdrive comes down to the user and the driving style. I only use od over 100km and the clutch for reducing trans temp on the highway

These two buttons are my controls that's where my hand sits when driving so not an issue for me

[turboedsloth]

Whats to say if I buy another used auto transmission it wont be in a similar condition to mine? Theres no way to tell the condition of the clutch plates. I guess thats why I always find it weird people just take for granted the Nissan turbo boxes are tough and can handle power well when my experience with every Auto box I have ever owned has been lousy. And its always the same problem. Worn clutch plates that cant hold power.... People just don't change Auto trans fluid and they just drive it till it dies or sell it to a sucker like me just before it busts.

A basic tell tale on auto condition is the colour and smell of the oil. You're actually meant to service autos every 12 months 20000kms to maintain them well.

The turbo boxes can be built strong you've just got to do it right

[scotty nm35]

Yea figured. Seems crazy people spend 3-4k on Auto rebuilds though. Manual conversion would be much better and cheaper unless you have a thing for unreliable transmissions that cost you power and fuel.

I guess I will drive drive gingerly along at 5psi. Too broke to do otherwise. Actually the transmission shifts smoothly and works well if if you dont exceed about 6psi and I guess about 200HP which is what I estimate the engine puts out at that psi.

Whats to say if I buy another used auto transmission it wont be in a similar condition to mine? Theres no way to tell the condition of the clutch plates. I guess thats why I always find it weird people just take for granted the Nissan turbo boxes are tough and can handle power well when my experience with every Auto box I have ever owned has been lousy. And its always the same problem. Worn clutch plates that cant hold power.... People just don't change Auto trans fluid and they just drive it till it dies or sell it to a sucker like me just before it busts.

You would have exactly the same issue with a manual box, as the stock clutch wouldn't hold much either. Considering I have two twin plate clutches here worth $2500 each, and they aren't anything special, make sure you add that to the cost of the manual conversion to get it to hold similar power.

All you had to do was put a shift kit in and it would have lasted...

[sonicz]

You would have exactly the same issue with a manual box, as the stock clutch wouldn't hold much either. Considering I have two twin plate clutches here worth $2500 each, and they aren't anything special, make sure you add that to the cost of the manual conversion to get it to hold similar power.

All you had to do was put a shift kit in and it would have lasted...

People get away with a lot less than $2500 to replace a clutch, and for just above stock power levels even the cheapest clutch would last long enough for me and would certainly be a lot better than the mess you are in if your auto box is not working right. An auto box rebuild is the same 3k+ cost no matter what and most people either replace them with another used box that also has the original clutches, or scrap the car. Point is almost nobody touches an auto, its just driven till it dies.

IMO Manuals are just simpler, work better, hold more power, deliver more power, are better on fuel, have a lower chance of slipping, and are cheaper to fix if something goes wrong, and any mechanic can do it.

Most used cars that are manuals seem to have no slipping for the power the car comes with. It rare to see, and I see a lot of used cars, and if its there it just means the clutch has not been replaced for a while. Whereas in autos I see slipping clutches all the time.

Most people don't feel it because there is still partial engagement. Slipping is pretty obvious on a manual, most people just know to replace the clutch and they actually do it. In autos its almost unheard to do anything to it, so it doesn't even cross peoples minds. Not to mention clutches are serviceable items on a manual, whereas in an auto they are not.

How many clutches have been replaced on a manual compared to an auto, even if we account for the difference in automatic vs manual cars?

I personally don't know a single person that has even changed the oil in their automatic, let alone change the clutch plates, whereas almost everyone I know with a manual cars has had their clutch changed at some point. The only place I see people doing anything to automatic gearboxes are the odd forums users that are cashed up and chasing power for the drag strip.

On top of this if you have a friend or know how to do the work yourself, its feasible to buy a $500 clutch and fit it yourself. An auto box needs pixies and fairy's to be serviced i.e its almost impossible to do yourself, nor would you want to.

Gee that sounded like a rant didnt it. Sorry!

Anyway, just for future reference, when I fit a new auto box, can you tell me the best place to get my hands on a shift kit and who to take it to to have it fitted in Sydney?

[sonicz]

You would have exactly the same issue with a manual box, as the stock clutch wouldn't hold much either. Considering I have two twin plate clutches here worth $2500 each, and they aren't anything special, make sure you add that to the cost of the manual conversion to get it to hold similar power.

All you had to do was put a shift kit in and it would have lasted...

People get away with a lot less than $2500 to replace a clutch, and for just above stock power levels even the cheapest clutch would last long enough for me and would certainly be a lot better than the mess you are in if your auto box is not working right. An auto box rebuild is the same 3k+ cost no matter what and most people either replace them with another used box that also has the original clutches, or scrap the car. Point is almost nobody touches an auto, its just driven till it dies.

IMO Manuals are just simpler, work better, hold more power, deliver more power, are better on fuel, have a lower chance of slipping, and are cheaper to fix if something goes wrong, and any mechanic can do it.

Most used cars that are manuals seem to have no slipping for the power the car comes with. It rare to see, and I see a lot of used cars, and if its there it just means the clutch has not been replaced for a while. Whereas in autos I see slipping clutches all the time.

Most people don't feel it because there is still partial engagement. Slipping is pretty obvious on a manual, most people just know to replace the clutch and they actually do it. In autos its almost unheard to do anything to it, so it doesn't even cross peoples minds. Not to mention clutches are serviceable items on a manual, whereas in an auto they are not.

How many clutches have been replaced on a manual compared to an auto, even if we account for the difference in automatic vs manual cars?

I personally don't know a single person that has even changed the oil in their automatic, let alone change the clutch plates, whereas almost everyone I know with a manual cars has had their clutch changed at some point. The only place I see people doing anything to automatic gearboxes are the odd forums users that are cashed up and chasing power for the drag strip.

On top of this if you have a friend or know how to do the work yourself, its feasible to buy a $500 clutch and fit it yourself. An auto box needs pixies and fairy's to be serviced i.e its almost impossible to do yourself, nor would you want to.

Gee that sounded like a rant didnt it. Sorry!

Anyway, just for future reference, when I fit a new auto box, can you tell me the best place to get my hands on a shift kit and who to take it to to have it fitted in Sydney?

[turboedsloth]

People get away with a lot less than $2500 to replace a clutch, and for just above stock power levels even the cheapest clutch would last long enough for me and would certainly be a lot better than the mess you are in if your auto box is not working right. An auto box rebuild is the same 3k+ cost no matter what and most people either replace them with another used box that also has the original clutches, or scrap the car. Point is almost nobody touches an auto, its just driven till it dies.

IMO Manuals are just simpler, work better, hold more power, deliver more power, are better on fuel, have a lower chance of slipping, and are cheaper to fix if something goes wrong, and any mechanic can do it.

Most used cars that are manuals seem to have no slipping for the power the car comes with. It rare to see, and I see a lot of used cars, and if its there it just means the clutch has not been replaced for a while. Whereas in autos I see slipping clutches all the time.

Most people don't feel it because there is still partial engagement. Slipping is pretty obvious on a manual, most people just know to replace the clutch and they actually do it. In autos its almost unheard to do anything to it, so it doesn't even cross peoples minds. Not to mention clutches are serviceable items on a manual, whereas in an auto they are not.

How many clutches have been replaced on a manual compared to an auto, even if we account for the difference in automatic vs manual cars?

I personally don't know a single person that has even changed the oil in their automatic, let alone change the clutch plates, whereas almost everyone I know with a manual cars has had their clutch changed at some point. The only place I see people doing anything to automatic gearboxes are the odd forums users that are cashed up and chasing power for the drag strip.

On top of this if you have a friend or know how to do the work yourself, its feasible to buy a $500 clutch and fit it yourself. An auto box needs pixies and fairy's to be serviced i.e its almost impossible to do yourself, nor would you want to.

Gee that sounded like a rant didnt it. Sorry!

Anyway, just for future reference, when I fit a new auto box, can you tell me the best place to get my hands on a shift kit and who to take it to to have it fitted in Sydney?

You could not be any further from the truth. If people didn't like spending money on autos, my carpark wouldn't be as full as what it is

[steve200b]

most people haven't been in a car with a built auto, once you have you won't mind spending the money once on a good auto. only issue with an auto is you can't kick the clutch but i like my car with the built auto a lot better than when it was 5 speed

[tripsteady]

transcooler + shift kit from mv automatics should hold 280rwkw and last. Tons of guys on the forum are making decent numbers with just that. Also the auto skylines usually are less abused than their manual counterparts