Twin Scroll Turbos?? Monster Spool.. FACT or FICTION???
May 1, 2010, 09:26 PM
#32
Then you'll have to compare the same car with the two different setups. You'll also need to actually drive them, as I can illustrate two similar setups with similar dyno plots, but the difference behind the wheel is vivid. Why? Because the dyno doesn't plot TP changes vs. time, and that makes a difference. Of course, if one is interested in a few seconds of WOT in a straight line, it isn't really important.
May 1, 2010, 09:26 PM
#33
So this is where I agree with Mike and say I am unimpressed with the twin scroll setups I have seen. Everything is a sacrifice for what you want, which direction is the powerband to the left or the right?
I can make a single scroll 35R spool fast, its called a .48 or .63 housing. Obviously it loses out the top but then you use a .82 or 1.06 and get the top end back. I dont think there is really such a thing even with the TS housings that gets you both. We definitely didnt see it on the 42R. It seems all the ones I have seen are choked like a small A/r single scroll. You might be able to fine tune the difference more and get something between a .63 and .82 but in the end you are running a 1.06+ TS housing and getting negligible increase (200 rpm) over just doing the single scroll.
Ted, we can set torque vs time of run if we want on a DJ.
I can make a single scroll 35R spool fast, its called a .48 or .63 housing. Obviously it loses out the top but then you use a .82 or 1.06 and get the top end back. I dont think there is really such a thing even with the TS housings that gets you both. We definitely didnt see it on the 42R. It seems all the ones I have seen are choked like a small A/r single scroll. You might be able to fine tune the difference more and get something between a .63 and .82 but in the end you are running a 1.06+ TS housing and getting negligible increase (200 rpm) over just doing the single scroll.
Ted, we can set torque vs time of run if we want on a DJ.
May 1, 2010, 09:29 PM
#37
So this is where I agree with Mike and say I am unimpressed with the twin scroll setups I have seen. Everything is a sacrifice for what you want, which direction is the powerband to the left or the right?
I can make a single scroll 35R spool fast, its called a .48 or .63 housing. Obviously it loses out the top but then you use a .82 or 1.06 and get the top end back. I dont think there is really such a thing even with the TS housings that gets you both. We definitely didnt see it on the 42R. It seems all the ones I have seen are choked like a small A/r single scroll. You might be able to fine tune the difference more and get something between a .63 and .82 but in the end you are running a 1.06+ TS housing and getting negligible increase (200 rpm) over just doing the single scroll.
I can make a single scroll 35R spool fast, its called a .48 or .63 housing. Obviously it loses out the top but then you use a .82 or 1.06 and get the top end back. I dont think there is really such a thing even with the TS housings that gets you both. We definitely didnt see it on the 42R. It seems all the ones I have seen are choked like a small A/r single scroll. You might be able to fine tune the difference more and get something between a .63 and .82 but in the end you are running a 1.06+ TS housing and getting negligible increase (200 rpm) over just doing the single scroll.
Ok Im really out.. Get back to this later.. Thanks!!
Mike
May 1, 2010, 09:29 PM
#38
not that i want to get to involved here but i drove the NYC bad bish. stupid fast i must say. this was when the hta82 came out. it was laggy for my taste. but now that i have TS the TS stuff is way more responsive on the street and between gear shifts or down shifts ''then WOT'' all happen much more rapidly. thats the point of TS.
as for it not holding up top. IMO there is not enough options out there to help a mid sized turbo 35r to 40r to hold up top. some companies sell a TS t3 .78 back side for a 35r. thats like a .48 in open scroll. lol stupid if you ask me. TS needs the biggest back sides available and there just is not many options out there. and the options that we have ''pte'' there castings suck. i would rather make my own out of cardboard.
as for it not holding up top. IMO there is not enough options out there to help a mid sized turbo 35r to 40r to hold up top. some companies sell a TS t3 .78 back side for a 35r. thats like a .48 in open scroll. lol stupid if you ask me. TS needs the biggest back sides available and there just is not many options out there. and the options that we have ''pte'' there castings suck. i would rather make my own out of cardboard.
Good stuff though!
May 1, 2010, 09:34 PM
#42
not that i want to get to involved here but i drove the NYC bad bish. stupid fast i must say. this was when the hta82 came out. it was laggy for my taste. but now that i have TS the TS stuff is way more responsive on the street and between gear shifts or down shifts ''then WOT'' all happen much more rapidly. thats the point of TS.
as for it not holding up top. IMO there is not enough options out there to help a mid sized turbo 35r to 40r to hold up top. some companies sell a TS t3 .78 back side for a 35r. thats like a .48 in open scroll. lol stupid if you ask me. TS needs the biggest back sides available and there just is not many options out there. and the options that we have ''pte'' there castings suck. i would rather make my own out of cardboard.
At the end of the day, to each their own...
May 1, 2010, 09:35 PM
#44
I was thinking to myself JB was going to prove me wrong here too.. I guess your findings were about the same.. You also brought up a great point.. this turbo i show above had a .82 AR.. Imagine it in .63.. I have made over 700 with .63 6262's too so i know they dont choke much.. I believe Dynoflash did as well with Suman's car a while ago.. Thats what made me open my eyes to the .63. he did it before me.. I usually go .82 for " Street Testing " to kill the wheel spin...
Ok Im really out.. Get back to this later.. Thanks!!
Mike
Ok Im really out.. Get back to this later.. Thanks!!
Mike
May 1, 2010, 09:40 PM
#45
Do you have a specific thought on how you want it tested? I'll have a TS car on the dyno wednesday that I can compare to my car if it gets on the dyno on monday. The TS car will be there for sure though, so I can make this happen fairly close in the test. Both are 35Rs, both are MIVEC with S2s, I am 2.4 and he is a 2.0L. I believe he has the .96 A/r TS housing.
We can post the dyno in time and the log with TPS at a given time interval. Since the RPM reference will need to be used as well we can do the graph both ways and then post the log. I think we will find the transient response at a given rpm value is going to be pretty similar from something like 40-50% TPS depending on what the starting point rpm is.
Please outline the test conditions and we'll try to follow them as closely as we can. To equalise the displacement difference I am thinking something like 4k for starting rpm?
We can post the dyno in time and the log with TPS at a given time interval. Since the RPM reference will need to be used as well we can do the graph both ways and then post the log. I think we will find the transient response at a given rpm value is going to be pretty similar from something like 40-50% TPS depending on what the starting point rpm is.
Please outline the test conditions and we'll try to follow them as closely as we can. To equalise the displacement difference I am thinking something like 4k for starting rpm?