twinscroll/singlescroll TURBO SHOOTOUT -- full-race / VE engineering / vivids dyno
Feb 12, 2009, 09:23 AM
#62
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[QUOTE=Full-Race Geoff;6682194]just finished installing the .82 a/r T3 singlescroll hta35 on the car, pg 1 updated will dyno tomororw morning[/QUOTE
So did you guys use the single scroll manifold for the test? I asume the original Buschur setup on the car came with the single scroll Shearer mani? Do you still have it laying around or was it sold.
So did you guys use the single scroll manifold for the test? I asume the original Buschur setup on the car came with the single scroll Shearer mani? Do you still have it laying around or was it sold.
Feb 12, 2009, 09:41 AM
#64
So did you guys use the single scroll manifold for the test? I asume the original Buschur setup on the car came with the single scroll Shearer mani? Do you still have it laying around or was it sold.
Maybe these quotes will clear it up for you. Running a single scroll turbo on a twin scroll manifold should not affect the results. It looks like Geoff is doing his best to comply with everyone's requests.
Hi ron, were not going to try and mimic backpressure to determine which housing to run, we only have so much time so we will test the setups that are considered the "standard" and go from there. .63 a/r is too small and a waste of time imho. the runner dia is another point of debate, as we use a different runner dia for our twinscroll vs singlescroll headers. if people can agree on one methodology, we'll test it this week. if you and dave would rather supply a shearer header/turbo/downpipe for us to test the singlescroll stuff with i would be honored.
Last edited by Mr. Evo IX; Feb 12, 2009 at 10:09 AM.
Feb 12, 2009, 01:51 PM
#67
Page 1 update has pics of original setup. The original manifold looks like a coated cast manifold.
Maybe these quotes will clear it up for you. Running a single scroll turbo on a twin scroll manifold should not affect the results. It looks like Geoff is doing his best to comply with everyone's requests.
Maybe these quotes will clear it up for you. Running a single scroll turbo on a twin scroll manifold should not affect the results. It looks like Geoff is doing his best to comply with everyone's requests.
However, I seem to remember lots of companies making huge claims about how a true shallow angle merge collector is paramount in making power. A twinscroll manifold does not provide this shallow angle collector. Are we going to see similar results where people initially used the divided turbine housings with undivided manifolds and made claims of the turbos being complete crap.
I also have several books on the topic and at least with regards to flow coefficients and reversion prevention, a shallow angle merge collector is a big deal.
It seems like this test is focusing on optimizing for a twinscroll setup and tossing a single scroll on afterwards?
Last edited by 03whitegsr; Feb 12, 2009 at 01:54 PM.
Feb 12, 2009, 03:22 PM
#68
03whitegsr, maybe it's a catch22. However, I agree with your previous post. I'd rather see 2 optimized setups tested. Of course that would mean another manifold change and more variables which I'm sure the testers would like to avoid. Plus, if Geoff used his T3 single scroll manifold, the claim would be that runner size was not equal. So he's damned if he does, and damned if he doesnt.
Feb 12, 2009, 04:41 PM
#70
It appears that the use of the twinscroll manifold on the single scroll turbos is so that runner diameter is mantained and so that the manifold is essentially a constant... lots of companies making huge claims about how a true shallow angle merge collector is paramount in making power. A twinscroll manifold does not provide this shallow angle collector. Are we going to see similar results where people initially used the divided turbine housings with undivided manifolds and made claims of the turbos being complete crap.
undivided manifold + divided hsg = fail
undivided manifold + undivided hsg = pass
divided manifold + undivided hsg = pass
divided manifold + divided hsg = pass
we're doing the best test we can. if anyone else would like to do their own test more properly than us feel free!
Last edited by Geoff Raicer; Feb 12, 2009 at 05:47 PM.
Feb 12, 2009, 09:37 PM
#71
They have a shallow angle merge between the two paired cylinders, but it's not really a shallow angle merge collector. I have no idea if it matters or not.
I just seem to remember from a few years back that certain companies were making the claim that their manifolds were superior because they used a "proper" merge collector. The manifolds became the "standard" in a few communities before later being outed in exchange for superior divided manifolds.
I understand that testing undivided T3, divided T3, undivided T4, divided T4 all with fully optimized setups is pretty much impossible with this kind of test. I was just making sure I understood what exactly was being tested.
I just seem to remember from a few years back that certain companies were making the claim that their manifolds were superior because they used a "proper" merge collector. The manifolds became the "standard" in a few communities before later being outed in exchange for superior divided manifolds.
I understand that testing undivided T3, divided T3, undivided T4, divided T4 all with fully optimized setups is pretty much impossible with this kind of test. I was just making sure I understood what exactly was being tested.
Feb 13, 2009, 10:43 AM
#74
They have a shallow angle merge between the two paired cylinders, but it's not really a shallow angle merge collector. I have no idea if it matters or not.I just seem to remember from a few years back that certain companies were making the claim that their manifolds were superior because they used a "proper" merge collector. The manifolds became the "standard" in a few communities before later being outed in exchange for superior divided manifolds. I understand that testing undivided T3, divided T3, undivided T4, divided T4 all with fully optimized setups is pretty much impossible with this kind of test. I was just making sure I understood what exactly was being tested.
Feb 13, 2009, 11:31 AM
#75
So you feel (or have tested) that the use of an undivided turbo on a divided manifold will not impact performance?
Awesome test by the way. I'm sorry if it looks like I'm taking anything away from the test. I'm just trying to fully understand your test and any implications that may araise from the testing method and assumptions used.
Awesome test by the way. I'm sorry if it looks like I'm taking anything away from the test. I'm just trying to fully understand your test and any implications that may araise from the testing method and assumptions used.