hello everyone,my lj turbo 186 is at the stage to be painted and rego soon.i have a fully done up trimatic 2800rpm stall convertor.my car only revs to 5500 rpm.my question is would it be worth while installing a trans brake in my torana,will there be a lot of benifits using it.i will be racing it at the drags.what rpm can i have the car on when using the trans brake when drag racing.can i go over the stall of the convertor or not.thanks jason.
trans brake
Started by
_ljxu1torana_
, Aug 25 2011 12:55 AM
5 replies to this topic
#2
dattoman
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Posted 25 August 2011 - 10:05 AM
I was once told you couldn't transbrake a trimatic
But that was a long time ago and maybe things have changed
Stall speed will depend on engine build specs and convertor size
But that was a long time ago and maybe things have changed
Stall speed will depend on engine build specs and convertor size
#3
_Bomber Watson_
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Posted 25 August 2011 - 05:57 PM
I have a transbraked Trimatic Datto.....
Jason, basically works like dumping the clutch on a manual.
Chances are so long as your stall is the correct size for your engine (ie not stalling up before the turbo makes boost) then you will be launching below your stall speed to allow a bit of converter flare....But im yet to experiment with setting mine up so thats just what i have been told.
Cheers.
Jason, basically works like dumping the clutch on a manual.
Chances are so long as your stall is the correct size for your engine (ie not stalling up before the turbo makes boost) then you will be launching below your stall speed to allow a bit of converter flare....But im yet to experiment with setting mine up so thats just what i have been told.
Cheers.
#4
_OLC383_
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Posted 25 August 2011 - 07:57 PM
Hi Jason,
What type of set up you looking at using, an MSD 2 step which use's a "pill" which are set at different rpm (200rpm increments) would be best & easiest to change, BUT there lowest pill rpm by memory starts at 3000rpm, although they do make an adjustable pill which ranges from 1000 - 3000rpm by means of a small grub screw in the side of the pill, that is adjusted while the car is running to set the required rpm,
There are other brands that work on a dial set up but i dont know how low the rpm range goes down to,
Or you could hook the trans brake up with out any 2 step set up & hold it flat out, it will only go as high as the convertor will stall to, that way will also let you know how much stall the convertor acctully has,
Just make sure your convertor is set up for a transbrake, as a transbrake will put alot of pressure on the convertor & destroy it quickly if not set up correctly,
I run a stall convertor with 5000rpm stall although i only have 3800rpm set up as my launch rpm which seems to suit my application the best, also depending on the track conditions i might drop the launch rpm by a couple of 100rpm.
Just my thoughts
Wayne
What type of set up you looking at using, an MSD 2 step which use's a "pill" which are set at different rpm (200rpm increments) would be best & easiest to change, BUT there lowest pill rpm by memory starts at 3000rpm, although they do make an adjustable pill which ranges from 1000 - 3000rpm by means of a small grub screw in the side of the pill, that is adjusted while the car is running to set the required rpm,
There are other brands that work on a dial set up but i dont know how low the rpm range goes down to,
Or you could hook the trans brake up with out any 2 step set up & hold it flat out, it will only go as high as the convertor will stall to, that way will also let you know how much stall the convertor acctully has,
Just make sure your convertor is set up for a transbrake, as a transbrake will put alot of pressure on the convertor & destroy it quickly if not set up correctly,
I run a stall convertor with 5000rpm stall although i only have 3800rpm set up as my launch rpm which seems to suit my application the best, also depending on the track conditions i might drop the launch rpm by a couple of 100rpm.
Just my thoughts
Wayne
#5
_ljxu1torana_
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Posted 25 August 2011 - 11:29 PM
hi wayne,i am using mallory 685 cdi,which has boost retard,two stage rev limiters,no pills.it has a led window to make the settings,also digital.having a cgi,transbrake is new to me.when i go to the drags i want get of the line as quickly as possible.i will be using either 235/50/13 slicks or 215/60/13 slicks,3.08 diff ratio.my car only revs to 5500rpm.i have done some testing when the car was registred over the quater mile distance.back then i had no cdi.i was changing gears at 5000 rpm in first gear at roughly the 80 metre mark changing in to second gear at roughly the 200 metre and crossing the line at 4800rpm.this was done on 205/60/13 tyres.i had to feather it of the line for about the first 20 metres before that i could put the foot down.it was accelerating very quickly through every gear.this is only on 14 psi of boost.i will be using 18 psi at the drags.i found a speed calculator on the net i type in all of the info and said i would be doing about 117 mph at 4800 rpm with this set up.i dont know if these calculators are correct or not but it does feel very close to 117mph.thanks jason.Hi Jason,
What type of set up you looking at using, an MSD 2 step which use's a "pill" which are set at different rpm (200rpm increments) would be best & easiest to change, BUT there lowest pill rpm by memory starts at 3000rpm, although they do make an adjustable pill which ranges from 1000 - 3000rpm by means of a small grub screw in the side of the pill, that is adjusted while the car is running to set the required rpm,
There are other brands that work on a dial set up but i dont know how low the rpm range goes down to,
Or you could hook the trans brake up with out any 2 step set up & hold it flat out, it will only go as high as the convertor will stall to, that way will also let you know how much stall the convertor acctully has,
Just make sure your convertor is set up for a transbrake, as a transbrake will put alot of pressure on the convertor & destroy it quickly if not set up correctly,
I run a stall convertor with 5000rpm stall although i only have 3800rpm set up as my launch rpm which seems to suit my application the best, also depending on the track conditions i might drop the launch rpm by a couple of 100rpm.
Just my thoughts
Wayne
#6
_OLC383_
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Posted 26 August 2011 - 05:46 PM
Hi Jason,
On my Moroso slide rule 117mph equals roughly an ET of 12.75, are the slicks your using drag slicks or street radial slick,
With the 2 stage limiters, i'd be using 1 as a max rpm for saftey in case it ever free revs the max rpm limiter will stop it over reving maybe set it around the 5600-5800rpm range & the other limiter would be the transbrake launch rpm, some thing you'll have to play around with, depending on convertor stall speed, turbo spooling,
most importantly is not to sit there to long on the transbrake to long or you will cook the gearbox,
Wayne
On my Moroso slide rule 117mph equals roughly an ET of 12.75, are the slicks your using drag slicks or street radial slick,
With the 2 stage limiters, i'd be using 1 as a max rpm for saftey in case it ever free revs the max rpm limiter will stop it over reving maybe set it around the 5600-5800rpm range & the other limiter would be the transbrake launch rpm, some thing you'll have to play around with, depending on convertor stall speed, turbo spooling,
most importantly is not to sit there to long on the transbrake to long or you will cook the gearbox,
Wayne
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