AZ EVO IX MR

iTrader: (10)

my twin scroll 40r is almost done, i will post dyno numbers asap

evolved83

iTrader: (2)

yea i would like to know about when the testing will be as well geoff

homemade wrx

had a typo and edited it...meant to say same, not single a/r...if all things are the same spec except one is twin scroll and the other is single...the single would have better top end...but the twinscroll would be my choice as it would be better throughout the rest of the powerband...

pkradgreek

iTrader: (3)

there is a big trend towards twin scrolls with the automotive manufacturers. that must mean something in terms of drivability. It's obvious it helps smaller displacement engines that naturally lack high torque generation. I don't think you'd necessarily need something like this if you were taking about larger displacement engines. Interesting to see the set up on the new skylines.

trinydex

iTrader: (12)

need is a relative word

vortech_g35

iTrader: (4)

Hot!

Jspec EVO VIII

iTrader: (9)

Love those Full Race kits! Just waiting for the results.

4G63DSM

Looks sweet, but remember you have to have a twin scroll turbine housing for this to be beneficial. That makes it a very pricey kit..
On the other hand Full Race's welds look so F*cking amazing and perfect it might be worth it! DOubly so, when the BR crew approves their designs...
I would be surprised if identical cars, one a regular 35r on a cast mani, and the other atwin scroll 40r spooled the same.... twin scroll or not, you still need a lot of hot exhaust gasses to spin a monster like a 40r... claims like that make me very suspicous...

SHow me some data!!!

LT1runner

iTrader: (8)

IT is kind of interesting that noone (company wise) will show a straight up back to back comparison. Have as close to identicle header shapes as possible, one single scroll, and the other twin scroll. Go for the same size hot side, one single and one twin scroll. Maybe a single is better with a smaller hot side, and a twin is better with a bigger one, I don't know. I don't think it's really in the interest of any company right now to show out right definativly which is better, or which company can do twin/single better. Think about it. All of this talk and opinion going back and forth, and noone has posted or produced any solid numbers/results. There is more than one way to make boost/power, but the people who can't do these test are the people who most want to know which is better the most. I know these types of test are really hard to do, and you may wind up proving yourself wrong.

So the question is, is twin scroll better than single when concerning 4 bangers? Is this depending on how much money you have. Is the increase spool you may get from a move to a twin scroll worth it in dollor amounts. Does twin scroll allow you to comfortably move to a bigger turbo without all the lag of a single. Is twin scroll even worth it on turbos smaller than 37r's? So many questions.

spdracerut

iTrader: (2)

Mistu and GM would say that twin scroll is better since both the 4g63 and turbocharged Ecotec come with twin scroll turbo/manifold designs from the factory

LT1runner

iTrader: (8)

But that's for a stock powerband they don't mind warrantying. I do understand the larger framed turbos come twin because they are mde with deisels in mind. Not small engines. Now can small enines benifit from twin scroll. Sure, but at what price is the is someone willing to spend? If you spend that cash, how many rpms does that cash buy you. Spool at 300rpms on a 35r for example. Is 300 rpms worth it for ruffly 2000 more bucks. To some sure, but if you're on a budget, and no matter what going to a 35r, are you going to regret getting a single scroll kit?

spdracerut

iTrader: (2)

Ah, but the question that you ask can be applied to every single thing known to man My answer is that you better be content with what you can afford!

If you can only afford the single scroll... well, there's no issue. If you can afford the better/more expensive option, I personally always go for the better stuff.

If I could afford to fly first class, I would, but I can't

LT1runner

iTrader: (8)

Hell, that's probably the best answer of all of these posts I've read yet. To that I say true indeed, true indeed.

scorke

iTrader: (18)

LT1 runner one flaw in your logic is that there are no equivalent hotsides so the test can never really "perfect"

Scorke

LT1runner

iTrader: (8)

Yes, I understand that. But when you don't have "equivalent hotsides" you have to get as close as possible. Just like the header design. You won't get an exact header, even up to the collector, but you may be able to get it so close that the difference doesn't count for much. At least I hope someone can. But who would do it? Which company do you think will do it. It seems it would be in the interest of Fullrace to do it.

TS 40r at 30 psi, and at 40 psi.
SS 40r at 30 psi, and at 40 psi.

Show the difference in logs and dynos plots. Let the public deceide where to spend money. If twin scroll is way better, that may drop the price of single scroll kits