T-4 divided flange.
12-30-2015, 09:05 PM
#1
6 Second Club Moderator
Thread Starter
iTrader: (7)
Join Date: Sep 2002
Location: Lombard .IL
Posts: 3,682
Likes: 0
Received 0 Likes
on
0 Posts
T-4 divided flange. Has anyone tried removing the divider? If so has anyone tried having them ported? Any gains? I'm thinking about doing it to mine.
01-01-2016, 01:11 AM
#2
TECH Apprentice
I got the twin bw82 with 87mm turbine , 1.25 ar divided
methanol
smooth the edge off oh housing , not to a knife edge but
spool up was smoother .
not maxed them out yet
6.2's 1/4 @ 2300 lbs
methanol
smooth the edge off oh housing , not to a knife edge but
spool up was smoother .
not maxed them out yet
6.2's 1/4 @ 2300 lbs
01-01-2016, 01:01 PM
#3
Why would you want to remove it? Cutting it back slightly and knife edging (dull knife edge anyway) it is what I've seen the "pros" do to help with laminar flow. I don't see how porting the inlet does anything? The exit volute diameter remains the same. It would be similar to running a larger hotside than necessary pre-turbo. It isn't going to change back pressure, just slow down the air. Thats the last thing you want to improve "spool-up".
01-01-2016, 08:11 PM
#5
6 Second Club Moderator
Thread Starter
iTrader: (7)
Join Date: Sep 2002
Location: Lombard .IL
Posts: 3,682
Likes: 0
Received 0 Likes
on
0 Posts
I can't see how it helps for max performance. Always looking for a edge. I have to run the t 4 to be legal in my class with a weight break. The inside of the housing is rough, thought it would help to smooth it and remove that divider?
01-02-2016, 06:23 AM
#6
9 Second Club
But removing the divider is just turning it into an open scroll ? So why not just get an open scroll housing ?
Presumably your pipework leading to the turbo isnt divided either ?
Presumably your pipework leading to the turbo isnt divided either ?
Trending Topics
01-05-2016, 05:30 AM
#12
9 Second Club
This is much easier to do on a 4cyl motor than it ever will be on an 8cyl motor, but some say isolating each cylinder bank on a V is helpful too....I dont really see it other than perhaps if it helps maintain gas velocity using smaller tubing for each bank.
Tial made V band inlets so people could install their turbos with V-bands for easy fitting/removal.
01-05-2016, 01:13 PM
#13
On The Tree
Join Date: May 2014
Posts: 123
Likes: 0
Received 0 Likes
on
0 Posts
i don't know why on earth you would cut the divider out of a divided flange... just buy a undivided flange? Why did you buy a divided flange if you have a single scroll turbo to begin with? Maybe i'm missing something?
As I understand it:
A T4 divided flange should flow the same as a T4 undivided flange. The exhaust volume the motor produces under WOT is a relatively consistent scale. The restriction is the turbo, not the flange. So increasing the size of the flange or pre turbo piping will just slow the velocity of the exhaust down resulting in slower spool.
As stevieturbo (sort of) said, the whole point of a divided flange is to run a twin scroll turbo. The whole point of a twin scroll turbo is to group cyl's together by valve event so back pressure from one cyl isn't breathing into another cyl as the exhaust valve opens thus reducing back pressure, allowing the motor to rev faster thus spool a turbo faster...etc. Same basic principal as long tube headers on a non turbo motor, keep the cyls isolated
As I understand it:
A T4 divided flange should flow the same as a T4 undivided flange. The exhaust volume the motor produces under WOT is a relatively consistent scale. The restriction is the turbo, not the flange. So increasing the size of the flange or pre turbo piping will just slow the velocity of the exhaust down resulting in slower spool.
As stevieturbo (sort of) said, the whole point of a divided flange is to run a twin scroll turbo. The whole point of a twin scroll turbo is to group cyl's together by valve event so back pressure from one cyl isn't breathing into another cyl as the exhaust valve opens thus reducing back pressure, allowing the motor to rev faster thus spool a turbo faster...etc. Same basic principal as long tube headers on a non turbo motor, keep the cyls isolated
01-05-2016, 01:57 PM
#14
9 Second Club
For your first questions...I've no idea why people buy housings they dont need.
A T4 divided flange with a larger number will flow the same as an undivided with a smaller number. From what I understand the divider simply takes up space in that respect making it flow less.
Whether the restriction is the "turbo" or not....bad wording. The restriction is either the turbine wheel, or the turbine housing.
Sometimes there just seem to be more divided housing options so I guess if you want much larger you'd need to opt for the divided housing, and larger again, machine that divider away altogether.
A T4 divided flange with a larger number will flow the same as an undivided with a smaller number. From what I understand the divider simply takes up space in that respect making it flow less.
Whether the restriction is the "turbo" or not....bad wording. The restriction is either the turbine wheel, or the turbine housing.
Sometimes there just seem to be more divided housing options so I guess if you want much larger you'd need to opt for the divided housing, and larger again, machine that divider away altogether.
01-07-2016, 09:44 PM
#16
6 Second Club Moderator
Thread Starter
iTrader: (7)
Join Date: Sep 2002
Location: Lombard .IL
Posts: 3,682
Likes: 0
Received 0 Likes
on
0 Posts
Twin scroll is largely about isolating valve events in the pipework to reduce effects of backpressure re-entering the cylinder.
This is much easier to do on a 4cyl motor than it ever will be on an 8cyl motor, but some say isolating each cylinder bank on a V is helpful too....I dont really see it other than perhaps if it helps maintain gas velocity using smaller tubing for each bank.
Tial made V band inlets so people could install their turbos with V-bands for easy fitting/removal.
This is much easier to do on a 4cyl motor than it ever will be on an 8cyl motor, but some say isolating each cylinder bank on a V is helpful too....I dont really see it other than perhaps if it helps maintain gas velocity using smaller tubing for each bank.
Tial made V band inlets so people could install their turbos with V-bands for easy fitting/removal.
01-08-2016, 05:02 AM
#17
9 Second Club
TBH I considered it on mine....but if anything it would probably have made things more awkward.
I can just unbolt turbo/manifold as one piece very quickly. It'd be far harder and pointless to unbolt the turbo.
But V-Bands definitely are great and does put the whole divided scroll aspect in the bin for those wanting to use them
I can just unbolt turbo/manifold as one piece very quickly. It'd be far harder and pointless to unbolt the turbo.
But V-Bands definitely are great and does put the whole divided scroll aspect in the bin for those wanting to use them
Last edited by stevieturbo; 01-08-2016 at 05:10 AM.
01-08-2016, 07:43 AM
#18
I'm not sure how picky your sanctioning body is on "grey area" rules but why not take your current t4 housing, chop off the flange, and weld your vband of choice on. It's still "technically" a t4 housing just with a different flange. I doubt it would be allowed but it doesn't hurt to check.
01-08-2016, 12:06 PM
#19
6 Second Club Moderator
Thread Starter
iTrader: (7)
Join Date: Sep 2002
Location: Lombard .IL
Posts: 3,682
Likes: 0
Received 0 Likes
on
0 Posts
I'm not sure how picky your sanctioning body is on "grey area" rules but why not take your current t4 housing, chop off the flange, and weld your vband of choice on. It's still "technically" a t4 housing just with a different flange. I doubt it would be allowed but it doesn't hurt to check.
01-08-2016, 12:18 PM
#20
9 Second Club