hey dat, these early attesa systems were really cool. they use a hydraulic clutch for the front drive engagement, similar to like a brake caliper in function. there is a hydraulic pump in the rear of the car to pressurize it & apply this clamping force & it's controlled by a computer, but intercepting it is not hard.
with no pressure in the system it's rwd.... then, depending on how much pressure there was fed to the transfer it could lock the front anywhere from 0% full rwd, all the way up to a full 50/50 lock, which is 100% locked awd. there was even a gage on the dash showing reading real time 0-50% front lock which was pretty cool too.
some drag racers have gutted the whole computer/pump system & instead use an emergency brake lever connected to a hydraulic cylinder, like a master cylinder or a clutch cylinder etc... do the burn out in rwd, then pull the lever to engage awd lock, then after launch mid track the awd can be released too by pushing the lever back down...
now there are a lot of options for aftermarket stand alone programmable center dif control computers available to control the factory hydraulic pump too, do luck was one of the first to do one in japan I think back when these cars were new & there pretty cool. you have a few dials & switches, you could switch from rwd to automatic sense awd to full lock awd right from the dash. in auto sense mode you can also dial in the engagement depending on a lot of factors like g force & various other inputs... you can actually dial in understeer & oversteer of the car depending on how much fwd engagement there is.... this is fun:smile (2):
I will probably have to use a stand alone center dif control anyway because there is no such thing from nissan as an HR powered stick shift vehicle with AWD, don't exist, so the "correct compatible " ecu for my application is non existent. unless I can get one of the ecu programming guys to merge the awd logic to the stick shift rom, I'm most likely going to have to just run a stick shift ecu & awd will most likely now need to be separate stand alone control. in a way that's cool because I can now have full control from the dash like the do luck controller has... theres one controller out there that uses the wrx dif control knob too, custom center diff control computers are big in the subaru crowd I think
so now I need to get a bell housing that will line up with the HR engine, & then cut the front part of it off. I'm going to then need to cut the front off of the stick tranny & weld the front of the HR housing to it. because the only stick version tranny that's available for the HR engine is the 6mt & it's bell housing is also part of the whole transmission housing, this means that I needed a whole 6mt tranny from an 07 & up g or z just to cut the front of it off...
there is also the possibility of using an automatic transmission bell housing. the automatic transmission bell housing does unbolt from the automatic transmission & is a separate piece, but I winded up getting a whole used auto tranny to take the bell housing from too, I'll have to do a lot of measuring & calculating to figure out which bell housing is best compatible with which stick tranny but at least now I have all the pieces I need to play .
so now it seems I have a total of 4 transmissions, that I will eventually attempt to cut up & turn into at least one, but hopefully 2 custom awd stick shift transmissions, to be compatible with nissans latest large bell housing bolt pattern. this is pretty cool, imagine even a late model awd m or g with FI laying down power like the old school gt r's & getting all attesa like with a awd stick :tongue (2): like a poor mans gt r
why hasn't this been done before?:smile (2):
now what sucks though is I just gotta resist playing with all these new toys too much until my headers & turbo swap is done & running:frown:... I'm going to have to build a whole mess of an alignment jig to get precision alignment in building these transmissions too.... prolly start it's own thread when the aluminum starts flying
with no pressure in the system it's rwd.... then, depending on how much pressure there was fed to the transfer it could lock the front anywhere from 0% full rwd, all the way up to a full 50/50 lock, which is 100% locked awd. there was even a gage on the dash showing reading real time 0-50% front lock which was pretty cool too.
some drag racers have gutted the whole computer/pump system & instead use an emergency brake lever connected to a hydraulic cylinder, like a master cylinder or a clutch cylinder etc... do the burn out in rwd, then pull the lever to engage awd lock, then after launch mid track the awd can be released too by pushing the lever back down...
now there are a lot of options for aftermarket stand alone programmable center dif control computers available to control the factory hydraulic pump too, do luck was one of the first to do one in japan I think back when these cars were new & there pretty cool. you have a few dials & switches, you could switch from rwd to automatic sense awd to full lock awd right from the dash. in auto sense mode you can also dial in the engagement depending on a lot of factors like g force & various other inputs... you can actually dial in understeer & oversteer of the car depending on how much fwd engagement there is.... this is fun:smile (2):
I will probably have to use a stand alone center dif control anyway because there is no such thing from nissan as an HR powered stick shift vehicle with AWD, don't exist, so the "correct compatible " ecu for my application is non existent. unless I can get one of the ecu programming guys to merge the awd logic to the stick shift rom, I'm most likely going to have to just run a stick shift ecu & awd will most likely now need to be separate stand alone control. in a way that's cool because I can now have full control from the dash like the do luck controller has... theres one controller out there that uses the wrx dif control knob too, custom center diff control computers are big in the subaru crowd I think
so now I need to get a bell housing that will line up with the HR engine, & then cut the front part of it off. I'm going to then need to cut the front off of the stick tranny & weld the front of the HR housing to it. because the only stick version tranny that's available for the HR engine is the 6mt & it's bell housing is also part of the whole transmission housing, this means that I needed a whole 6mt tranny from an 07 & up g or z just to cut the front of it off...
there is also the possibility of using an automatic transmission bell housing. the automatic transmission bell housing does unbolt from the automatic transmission & is a separate piece, but I winded up getting a whole used auto tranny to take the bell housing from too, I'll have to do a lot of measuring & calculating to figure out which bell housing is best compatible with which stick tranny but at least now I have all the pieces I need to play .
so now it seems I have a total of 4 transmissions, that I will eventually attempt to cut up & turn into at least one, but hopefully 2 custom awd stick shift transmissions, to be compatible with nissans latest large bell housing bolt pattern. this is pretty cool, imagine even a late model awd m or g with FI laying down power like the old school gt r's & getting all attesa like with a awd stick :tongue (2): like a poor mans gt r
why hasn't this been done before?:smile (2): now what sucks though is I just gotta resist playing with all these new toys too much until my headers & turbo swap is done & running:frown:... I'm going to have to build a whole mess of an alignment jig to get precision alignment in building these transmissions too.... prolly start it's own thread when the aluminum starts flying
