Custom Twin T3/TO4E Set Up
01-31-09, 01:49 PM
#26
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"Stressing the importance of a high turbine A/R, a lot of hotside as you put it, I'm guessing this is to maximize the horsepower output at top end?"
"being dual purpose, how is your turbo response on the street? How do turbine housings affect response time vis-a-vis max output?"
the primary purpose of the larger hotsides is to lower exhaust gas temperature.
the turbine wheels are lightened but still large and heavy. the housing size works fine on the street.
my fd makes 200 rwhp around 4200 rpm. a typical GT42 that puts out the same 84 lbs per minute makes 200 around 4750. check thru dyno sheets and you will see that my midrange is similar to a well tuned GT35r but my top end is similar to a GT42.
this year i am building a new motor that will have an exhaust port that will add lots of midrange. you can greatly effect spool w the exhaust port configuration. i am also adding an intake port that gives me 20 degrees more duration so i should have more top end.
(of course i want more of everything
)
the large hotside is to both exploit the heat coming from the rotary to drive the turbos at all boost levels as well as to rid the engine of excess heat expressed as EGTs. my engine, due to it's larger hotsides, runs 150+ degrees cooler than your typical single turbo setup.
as an aside, there have been 6 twin setups built in the last 6 years and all but mine, i believe, are in the scrap pile. each was built differently... i have about 17,000 miles on my twins and love them.
hc
"being dual purpose, how is your turbo response on the street? How do turbine housings affect response time vis-a-vis max output?"
the primary purpose of the larger hotsides is to lower exhaust gas temperature.
the turbine wheels are lightened but still large and heavy. the housing size works fine on the street.
my fd makes 200 rwhp around 4200 rpm. a typical GT42 that puts out the same 84 lbs per minute makes 200 around 4750. check thru dyno sheets and you will see that my midrange is similar to a well tuned GT35r but my top end is similar to a GT42.
this year i am building a new motor that will have an exhaust port that will add lots of midrange. you can greatly effect spool w the exhaust port configuration. i am also adding an intake port that gives me 20 degrees more duration so i should have more top end.
(of course i want more of everything
)the large hotside is to both exploit the heat coming from the rotary to drive the turbos at all boost levels as well as to rid the engine of excess heat expressed as EGTs. my engine, due to it's larger hotsides, runs 150+ degrees cooler than your typical single turbo setup.
as an aside, there have been 6 twin setups built in the last 6 years and all but mine, i believe, are in the scrap pile. each was built differently... i have about 17,000 miles on my twins and love them.
hc
. You can be sure I'll be contacting you for help . Pretty soon I'm going to switch to dual ball bearing turbos and maybe to the TO4B compressor housings.
01-31-09, 02:00 PM
#27
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i would not spend the money on ball bearings... i consider them overrated and primarily a marketing driven creation. spool is very close between the two.
FYI, journal bearing turbos must have a 360 degree thrust bearing. they do not work well w the 270 degree bearing against the rotary higher egts.
i run TO4B housings and TO4E compressors.
hc
FYI, journal bearing turbos must have a 360 degree thrust bearing. they do not work well w the 270 degree bearing against the rotary higher egts.
i run TO4B housings and TO4E compressors.
hc
01-31-09, 11:02 PM
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i would not spend the money on ball bearings... i consider them overrated and primarily a marketing driven creation. spool is very close between the two.
FYI, journal bearing turbos must have a 360 degree thrust bearing. they do not work well w the 270 degree bearing against the rotary higher egts.
i run TO4B housings and TO4E compressors.
hc
FYI, journal bearing turbos must have a 360 degree thrust bearing. they do not work well w the 270 degree bearing against the rotary higher egts.
i run TO4B housings and TO4E compressors.
hc
02-01-09, 12:48 AM
#29
i would not spend the money on ball bearings... i consider them overrated and primarily a marketing driven creation. spool is very close between the two.
FYI, journal bearing turbos must have a 360 degree thrust bearing. they do not work well w the 270 degree bearing against the rotary higher egts.
i run TO4B housings and TO4E compressors.
hc
FYI, journal bearing turbos must have a 360 degree thrust bearing. they do not work well w the 270 degree bearing against the rotary higher egts.
i run TO4B housings and TO4E compressors.
hc
02-01-09, 03:00 PM
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He is right .. I have a Borg-Warner S472 360 Thrust Bearing turbo on my 1JZ, and it starts to boost @ 3900 rpm. My buddy has Gt35r Ball Bearing on a 1JZ also .. and both at 11lbs.. I walk him by two cars everytime.... Howard, Thanks for all the knowledge you share.. You cant find alot of people that will share this kind of valueable information.. I was thinking of taking my Huffer off and going with a Twin Gt28r kit with dual Tial 40mm wastegates, should be fun!!!
05-09-09, 11:06 PM
#31
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Twin Turbo Set Up for Sevenstock
Hey guys, been a while. I posted up pictures a while back but figured I'd make a new clean thread with updated pictures. I only have a couple of months before Sevenstock, hope I can finish this set up in time. So far, I have half of the manifold built until I can get more piping. By next week, I should be done with the IC and down pipes. I have pictures of the mock up with the IC. My friend had an old intercooler we used to get an idea of how it will look. There is a picture with the manifold half finished. I decided to go with Turbonetics GTK series turbos also. There should be more pictures next week so keep coming back for updates.
Plans:
-Custom twin turbo
-Custom dual exhaust (ripped out my gas tank and building a custom fuel cell).
-Custom twin core v-mount intercooler
Plans:
-Custom twin turbo
-Custom dual exhaust (ripped out my gas tank and building a custom fuel cell).
-Custom twin core v-mount intercooler
05-09-09, 11:09 PM
#32
Looks like you haven't made much progress since last thread
https://www.rx7club.com/showthread.php?t=816239
Good luck on your progress.
https://www.rx7club.com/showthread.php?t=816239
Good luck on your progress.
05-18-09, 04:34 PM
#34
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Here are the pics of the progress, we're waiting for the IC cores from Spearco, I hosted it on a friend's server. Sorry for the big pictures and long wait.
Last edited by spiritrmazda; 05-18-09 at 04:37 PM. Reason: Trying to use server to host up pictures.
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