Attention: TDR Forum Junkies 
HT3B's twins 18 22 23 26 27 cm housings open and divided?
I'm thinking of building a mild set of twins with a hybrid Hx 35 12cm and an HT3B or BHT3B.
I have found out that there is an 18cm undivided housing (Mostly avalible in Europe), 22cm undivided housing, 23cm divided (comon), 26cm divided (also comon), and 27cm divided and 27cm undivided (comon I think on Big Cam 400s)
Im going to keep the HX 35 12cm because I don't want to loose it's responsiveness and low end efficiancy. Most of my driving is well within the range of my HX 35 and no I don't really need twins - it is just for fun and for pesky gassers that come close to hurting my pride. I have more power than I can use up to about 2300 RPM or so and thats when it starts to choke. I would like to go up to about 3200 rpm and use the power up there where the torque is not so high that it tears up my drive line. It is just for short bursts because otherwise I'm going too fast.
About 700 ft lbs is the max my clutch will handle before it slips. I had one that held alot more before and I riped the hub out of it and I figure I'm lucky I didn't break my trans input shaft.
My Max Hp will be about 425 if I can hold 700 lb ft of torque up to 3200 rpm and most of the time it will be way less.
I plan to keep boost below 50 and more like 40+ and leave my timing at 15* for now because most of the time I will be below 1600 RPM and I don't want to O ring yet.
I think I want one of the smaller housings so that the big turbo will actually be doing something instead of just idling all the time.
I hoping to get a balance between them in the lower - mid range and have the waste gate almost open in the upper range.
This will, I'm guessing, act more like a truck with a small turbo for the bottom end and a big turbo for the top as opposed to the high HP guys that are looking for big boost and are more concerned about compounding.
The 22cm undivided is going to cost me almost $200 extra over a 23cm divided and I'm not sure it is worth it. I could smooth the corners off on the divider in the turbine housing to make it flow around it a little smoother.
I do have an external turbonetics waste gate I think I will use so I can have a low boost pressure most of the time and a higher one for spcial times.
Do you guys with twins run your EGT probe in the exhast manifold?
See my signature for engine Mods.
Comments on the divided and undivided housings and any other comments apreciated.
I'm thinking of building a mild set of twins with a hybrid Hx 35 12cm and an HT3B or BHT3B.
I have found out that there is an 18cm undivided housing (Mostly avalible in Europe), 22cm undivided housing, 23cm divided (comon), 26cm divided (also comon), and 27cm divided and 27cm undivided (comon I think on Big Cam 400s)
Im going to keep the HX 35 12cm because I don't want to loose it's responsiveness and low end efficiancy. Most of my driving is well within the range of my HX 35 and no I don't really need twins - it is just for fun and for pesky gassers that come close to hurting my pride. I have more power than I can use up to about 2300 RPM or so and thats when it starts to choke. I would like to go up to about 3200 rpm and use the power up there where the torque is not so high that it tears up my drive line. It is just for short bursts because otherwise I'm going too fast.
About 700 ft lbs is the max my clutch will handle before it slips. I had one that held alot more before and I riped the hub out of it and I figure I'm lucky I didn't break my trans input shaft.
My Max Hp will be about 425 if I can hold 700 lb ft of torque up to 3200 rpm and most of the time it will be way less.
I plan to keep boost below 50 and more like 40+ and leave my timing at 15* for now because most of the time I will be below 1600 RPM and I don't want to O ring yet.
I think I want one of the smaller housings so that the big turbo will actually be doing something instead of just idling all the time.
I hoping to get a balance between them in the lower - mid range and have the waste gate almost open in the upper range.
This will, I'm guessing, act more like a truck with a small turbo for the bottom end and a big turbo for the top as opposed to the high HP guys that are looking for big boost and are more concerned about compounding.
The 22cm undivided is going to cost me almost $200 extra over a 23cm divided and I'm not sure it is worth it. I could smooth the corners off on the divider in the turbine housing to make it flow around it a little smoother.
I do have an external turbonetics waste gate I think I will use so I can have a low boost pressure most of the time and a higher one for spcial times.
Do you guys with twins run your EGT probe in the exhast manifold?
See my signature for engine Mods.
Comments on the divided and undivided housings and any other comments apreciated.
Last edited:
might as well get one from piers not much more!
