I4UnderPressure

iTrader: (33)

I was just browsing Buschurs website where they sell a turbo kit with a cast manifold designed to work with mitsubishi turbos. What are the advantages/disadvantages of these style turbos vs. a stock twin scroll style? I did some research but couldn't find a clear cut answer.

RapedApe

iTrader: (2)

Buschur's cast manifold is designed for single scroll turbos which are less expensive. Twin scroll spools faster, but requires a twin scroll manifold. A TS turbo and TS tubular manifold are almost $3k for the two. I'm sure you saw that Buschur's cast HTA 35r kit is $3,400 for everything.

turbo addict

iTrader: (2)

if you are looking at a stock TS or a buschur single scroll there is not going to be that much difference. If you go to a t3 or t4 you have the option of different turbine housing sizes to get the turbo to respond where you want it to. If it were me I went with a t4 and have many options on the turbo that I have. The dsm housings are usually only one size and you are stuck with that. I can explain further if you need. kinda sleepy now though.

I4UnderPressure

iTrader: (33)

Ok, that makes sense. So is it "financially" better for some due to the higher price of twin scroll? Or can the mitsu turbos make more power up top? Just seeing if there was any advantage to this over a twinscroll besides $$$.

cij911

iTrader: (14)

You keep saying Mitsu turbos, what do you mean - the stock 8 or 9 turbo? The larger turbos from Garret or Precision turbos, flow more air than the stock turbos, so will yield better peak numbers but will suffer low end loss. You really want to select the size turbo based upon your needs and setup.

Twin scroll (which the OEM design is) will give you better transient response, but won't show its benefits on the dyno. Twin scroll is more expensive to design and build, but is the route that all the OEMs have gone (it is better from an engineering perspective). That said, depending on how you use the car and your setup, a standard setup may be more than adequate.

Call Dave B. and talk to him about your goals / uses, and he will steer you in the right direction.

RapedApe

iTrader: (2)

Some believe that TS setups give a little away on top end. I personally don't believe that. There aren't a whole lot of cars running aftermarket TS setups and posting results vs the same turbo in a with a single scroll housing and manifold.

If it were me, and it's gonna be, I'd only go TS on a 35R or bigger turbo. Anything smaller spools fast enough for me anyway.

turbo addict

iTrader: (2)

again it depends if you are talking about a mitsu single or twin scroll or a garrett,bw,etc. It will cost more because you will need a new manifold for the garrett manifold, but you have the option of different a/r housings. with the mitsu's you get one or maybe two and that is it. also with the mitsu you will be limited on power over a garrett housing, (smaller than the garrett).

For another thing, if you look at the garrett twin vs a single scroll. the twin will spool faster with a good manifold (that keeps the exhaust pulses separate, does the same as a headder over a log manifold).

One thing that you need to consider is that when they make the twin scroll, is that they usually dont count the metal in the divider of the scroll. So for a given size the volute area will be smaller. (a .68 a/r single will flow more than a twin but only by a small difference though) you can often get away with a next size up twin and get close to the same spool as the smaller single with the more flow.

Kinda wordy but I hope that it helps;-)

turbo addict

iTrader: (2)

many of the supra guys have done back to back. It is usually shop dependent on what the particular shop likes. but generally the twin spools faster. sometimes the single will peak higher. but as I said yu can always go to the next size up.