Post up your turbo of choice for 500+whp in a T3 twin scroll setup. I'm in the market for a turbo!

Ive looked at the GT37 series, BW s200s, but I can't find a good vender. So if you really like a particular turbo, post the link too.

 

Well,on many occasions the "good" vendors are great at what they do and what they give, they just happen to not be the cheapest. So the definition of "good" is subjective.

 

by "good" I mean good prices with good selection and options. I can find garretts everywhere, but not a lot of options for T3 TS.

 

Made 558whp/445trq @ 32 psi w/ the BW S256

 

you won't find T3 divided housings very often except through ATP turbo and their dealers. Your options are limited to the .78A/r. It is not a Garrett housing.

 

Well, at least there are divided t3 to t4 adapters on ebay huh? I guess the only real T3 divided I can find besides the .78 is the GT37xxR setups. Anyone ever try one of those?

 

www.Go-autoworks.com

 

^^^ good site. The s256 ett looks very nice. But for a TS I would like it better if they had a slightly larger divided housing than just a .85~.

The turbine is a good size larger than a GT30r though, and the 70ar housing seems to make the same power as the GT30r .82, but spool slower. BB for ya.

If only they made a 1.15ar divided housing for the GT30r. I bet it would do extremely well. But the T4 1.06 TS is about as big as it gets.

 

A 1.15AR divided housing with that 84 trim smaller turbine wheel will not do extremely well, it will put the turbocharger outside of its best efficiency range, become VERY laggy, and really not do so well. The GT30R was always best as either a midrange torque maker or for twin applications.

Again, you're not going to find options the way you think are available.

You also can't use the BW turbine numbers in the same way as garrett, as the volute sizes are wider than Garrett. For example, the T3 .70A/R turbine housing has a larger volute than the .85A/R.. Math is the same, measurements are different.

 

Well, the 1.15 isn't any bigger than a .82 open housing. It will only flow better because of only 1/2 the pulses going through the turbine scroll. I don't think the 1.06 T4 is going to make that much more power, but will allow you to run a slightly bigger cam.

A 1.06ar divided T4 will generally make power in between a .63 and .82 on this particular 60mm turbine. TS housings generally flow similarly to their smaller open counterparts.

I recently did some testing on the .78ar T3 GT3076r. Found big torque increases, quicker spoolup, but topend wasn't any better than a .63 open housing. The .78 also did not respond well to bigger cams, and made less power.

The turbine flow for the .78 is slightly less than the .63 open housing, so I would expect the 1.15 to perform like a .82. On a 2.0L motor it would be worth testing to see how it reacted to a very big cam.

How come noone has tested a 1.06ar singlescroll GT3076r?

 

I was curious where you measured the diameter of the volute between a .82 and the 1.15 T4 in order to come with this particular conclusion. a true Twin "scroll" is not necessarily an even amount of exhaust pulses going through that system. In a divided housing that is the case they are equal.

1.06A/R GT3076Rs are for those in twin applications that are t4 based from Garrett. that is why they are available in that size. For a single application on a honda, is not that practical with what I've seen from my experience. Others may chime in if they'd like saying otherwise.

 

The .82 open housing is used often with little issue with reversion. The .63 open also has little issue with reversion on my GT3076r turbo. The .78 had tons of reversion issues. Why?

The .78ar housing is measures as total cm2 area for both volutes combined. Therefore, a .78ar really has a .39ar on each side of the divider. This is why it flows less and performs like a smaller housing. Instead of each pulse going through an open .82ar housing, each pulse is only going through half the .78ar turbine housing. Both sides together reflect flow similar to a .63 housing (taking into account flow losses from the increased boundary layer.) The casting finish on the .78 is also horrible, and this could attribute to the higher bp and reversion issues too? Also, I had to cut the bolts down that hold the housing on because they protrude into the ex stream by quite a bit. This could be a flow issue as well.

So they together will flow similarly, but since exhaust gas isn't a steady flow (it's pulses, right?) you can see that the gas has to squish down to the size of a dime in the middle of the volute. I've done a lot of experimenting recently with a GT3076r, and there was a ton of reversion present in the .78 when larger cams were used. Even though the "number" for the housing is larger than the ".63" which experienced very little reversion.

The flange size has nothing to do with the AR so comparing a T3 1.06ar to a T4 1.06ar with the same size turbine will flow exactly the same. The 1.15 just seems like would hit a sweet spot with large cams. I could be completely wrong, but it would be worth experimenting with.

You can see some dyno results of the T2 .64 gt2871r compared to a T3 GT3071r TS and the TS barely makes more power. Even though it has a larger turbine wheel, larger housing etc. I would expect the .78 to flow slightly less than the .63 in the real world.

 

I could be completely off-base with my assumptions of the TS housings, so if I am please enlighten me. The only info I have is the testing I have done myself.

If in fact a divided housing has the rated ar size on both sides of the volute, then something else is causing the reversion issues. Maybe the rough casting or the bolt issue. I would like to see how a T4 1.06 divided would perform.