PTS Flowbench Forum

I have been trying to make some sense regarding the airflow differences between single and twin scrolls and can't find anything even from the turbo manufactures.
For instance comparing say an AR64 SC against an AR 48 TS as am wanting to change my AR 63 SC to an AR 82TS and logic tells me that if the 82 flows more air on a bench then it will/should produce more top end BUT will be slower spooling up.
Would be great if someone has done this and can post the link

Welcome to the forum Oldie.

There is a lot more to it than just the turbine housing a/r.
How many cylinders feed the turbo, how large those cylinders are, exhaust valve timing, exhaust runner length, total exhaust manifold volume all effect turbine spool and top end back pressure.

Changing only one thing (the turbine housing a/r) may not always have the effect you expect to see if something else or a combination of other things are not quite right.

A flow bench is not going to tell you anything, except that a larger housing flows more air with less pressure drop.

Thanks Tony it's just that there seems to be no info to be able to compare the airflow between different housings.
FE how does one compare say in my case a AR63 Single scroll GT3076 to a Twin scroll AR 78? re spool and boost rise/response.

ATM I have the 63 on a SP manifold and am considering the TS78 but am at a loss as to the end result before I spend/waste my hard earned $$$

Single scroll usually gives less pressure drop at full maximum flow, hence maybe (?) slightly higher top end power.

Split scroll may be an advantage for earlier spool, but the difference can vary from none at all, to considerable.
It depends on how many cylinders feed each turbine, pipe branch lengths, and exhaust valve timing.

If you have the firing order cleverly worked out, a split scroll housing can be extremely helpful in separating groups of cylinders where two or more exhaust valves are open simultaneously.

Every case is different, and the whole thing needs to be thought right through.