Have you ever compared side by side an EVO mass and a 2nd gen mass? Just looking at the two your first guess would be the 2nd gen mass flows more air. the openings are clearly bigger. Yet the evo mass outflows it by quite a bit. The reason is the evo mass while smaller flows more air because there are less divisions inside. The flow loss from the division in a hotside is no different. All the top drag racers on the planet would be using twin scroll housings if they flowed better than single scroll. but on the contrary all the top dragsters use single scroll housings.

I am not saying garrett engineers dont know what they are talking about, I am just saying the advantage of twin scroll is not as big as some would suggest. And from what I have experienced and gathered from very knowledgable racers is twin scroll is in most cases not very big difference and usually not worth the effort.

you only have to compare the performance of the the evo 3 turbo to the performance of the evo8 turbo to show the twin scroll is not doing a whole lot. Curt Brown just recently made 455whp on an evo3 turbo in his 91awd using e85 fuel. and dont forget the evo3 turbo has a compressor housing the size of a donut.

 

i can speak from experience that a stock 2.0 with a 35r/.63 on pump/meth is a fantastic street setup.

unless you're drag racing the car constantly and running race gas, i don't see a need to even consider a 37r........

i just don't see why anyone wants a street car that will be daily driven in which the powerband doesn't start until 5500+........

Regardless of how high you can spin the engine........what does it matter? it's a daily driven street car.........and IMO a powerband is well worth giving up a few extra horses.

It seems like since the evo turbo aftermarket has increased people have gotten somewhat immune to turbo lag. It doesn't seem to be an issue anymore because many people have gotten so used to and accepted the idea.......

which is cool........

but to read posts on this forum and have people say "A 35r is not laggy at all".........

common......it's a very laggy turbo, especially with the .82. Granted we've all accepted how much we love the power it makes and being an owner of one i can say it's well worth it......

But even on my 2.3 i wouldn't even consider a larger turbo..........unless i wanted a drag car.........

IMO it's about balance.......not 1000rpm's worth of insanity.........

 

So the only 8sec Evo's in the States use what? I'll give you a hint GT42. What type of housings do GT42's use?

Maybe not worth the effort to drag racers who care more about upper rpm power, and will never see rpm below 6K, but the people asking these questions drive their cars on the street where the difference is very pronounced from my experience.

Comparing anything that Curt Brown does to a normal or even exception car builder/racer is not a good comparison. He is apparently an allien sent here to make us earthlings realize our ineptitude .
With that exception I've never seen an Evo3 turbo come close to the Evo8 turbo - especially in regards to pump gas hp. Using your example, one could easily say that his 10.59 in a heavy Evo plattform on the Evo8 turbo is a good arguement for the twin scroll.

 

If there was a tried and True GT35R Twin Scroll, i woudl buy it, it seems like the best street setup there is.

 

Who specifically? I'm not familiar with "dragsters"

 

Sorry to be off topic but does anti-lag work with the 3076, 35r, and 37r?

 

Wow, yes, anti-lag has nothing to do with what turbo you use, and the 3076 comes in ball bearing (r designation) too

Scorke

 

must roll fenders.

 

Firstly, unless you yourself have driven, built, tuned, or dynoed a twin scroll setup vs a single scroll all you have to share with us is a guess just like anyof us could make.

Top Dragsters never rev below 4-5k RPM and never are at partial throttle, although I agree with you that maybe in all out extreme situations a non divided housing will make more power, for those of us that drive the cars in real life, and not theoretically, the gains and advantages of using a twin scroll are huge, and very noticable according to both Drifto(walker), TedB, and Geoff from full-race, all of whom have tried both divided and undivided, they have dynoed, driven, and tuned them and they all believe that there is a serious advantage.

94awdcoupe-when you test, dyno, and tune a divided vs undivided housing then you can doubt why they are better or worse

Scorke

 

Well sorry I don't know as much as you but I was really curious because Mines used this on their evo and I just wanted know why people didn't use this method.

 

Talked to hondaguy, dude who wanted it saturday backed out, he is shipping it out today/tomorrow I believe so we can do it this week/weekend.

Scorke

 

Check out the Ecotecs in NHRA ProFWD and Hot Rod drag racing classes. They have won repeat championships and are consistently the fastest cars in their classes (despite rules stacked against them). Both cars run twin scroll.

When you ask the GM Racing guys they say they tried the cars with and without twin scroll.

Like everyone else, they run a boost builder / stutterbox on the line. They settled on twin scroll because they can reach their desired launch boost on the line easier. They can get by with a less-aggressive boost builder setup, which in turn results in less stress on the engine.

 

good deal.

 

And I know for a fact most NHRA SFWD run twin scroll as well

 

I wouldn't think a twin scroll would be that effective in an allout drag car as they are just in one narrow powerband and WOT, not for spoolup and driveability.