Most of the larger turbos that i have seen induce more lag at lower RPMS, and make less power than stock down lower, and the power gains don't show until much much later in the RPM band where the power just suddenly ERUPTS.

For drag, this isn't quite as big a concern, but for us trackers, it seems that a more responsive turbo, even if it make less peak horsepower, would be better suited for out needs.

This may be a poor analogy, but when looking at the gains for Vishnu's stage 2 and 3 for the regular WRX, the bigger IHI turbo makes more power and torque at ALL points in the RPM band over the stock turbo, which is obviously the optimal result.

Now, why can't a turbo do this for the EVO?

My thoughts thusfar have been that perhaps given that they are both 2.0 L engines, the IHI for the WRX (and as well the 16g for the EVOs) are about the most optimal turbo that one can use while not losing anything down low.

I am, however, hoping that this isn't true, as i would love to see a turbo that can make more hp all throughout. I, and im sure many others, would buy the kit in a heartbeat if there we're no sacrifice involved.

 

You cant have your cake and eat it too. Bigger turbos are laggy. Its that simple. Bigger turbos make more power cause they can move more air. Making the exhaust side move more air is what creates the lag. If you create more backpressure on a big turbo so it spools up quick you end up with two demons. Backpressure at high boost levels becomes excessive. And if the turbospools too fast at low rpm you will induce compressor surge.

In short. Smaller turbos are more fun on street cars. There really is no substitute for a fast spooling turbo on the street. And its absolutely necessary on a autocross car.

I am saying there isn't a better turbo than the 16g. So far I haven't seen anything that would make me trade the 16g for a bigger turbo if a had an EVO 8.

I am anxious to see the results from these bigger turbo kits every vender is coming out with. I think you will see the very same results dsm fanatics already know.

 

Its the one that comes on the car a Vishnu stage 1+ will give you at least z06 power Look into keeping the stocker as long as necessary its a fine unit

 

As 94AWDcoupe points out, bigger turbo equals more lag. It takes longer for a larger compressor turbine to spin up. Ball bearing designs reduce lag as well as anti lag systems, but there is no turbo that I'm aware of that delivers linear boost throughout the entire rpm range. Vishnu's results relative to equal power distribution has more to do with Shiv's tuning expertise than the design characteristics of the IHI turbo.

The twin scroll big 16g on the EVO's is a pretty good compromise and has netted experienced tuners mid 11 second runs with proper supporting mods. You probably have the best turbo for your specific needs. Just add a stage 2 or 3 Buschur or Vishnu kit and it could get real scary coming out of turn.

Speedlimt....

 

There is a technology out there, not widely know or used yet.
It's the Aerocharger Variable Area Turbine Nozzle (VATN).
It uses movable vanes that control the speed of the turbine. It acts like a small turbo down low and a big one up top. You don't even need a waste gate!
check this site: http://www.aerocharger.com/vatn1.htm
There is much more info out there on them.
Garrett is also working on an electric version, along with air bearings and sheet metal housings.
Turbos are becoming more mainstream and thus more technology and improvements.

 

Very promising stuff but still some major $$$$$$$$$$$$$

 

Their big system (6000), doesn't quite meets the Evo's needs. They are only good for about 540cfm and 2.0 PR. Maybe in the future?
I think Garrett will come up with something before Aerodyne.

 

I do believe we have a turbo set up that will give you more bottom end and a lot more top end as well.



It is our RnR L1R. It uses a 50 trim compressor wheel along with a T04E compressor housing. That along with our equal length manifold will give you stock like spool with a lot more top end power. The turbine housing is the best in the business as well. It is built by PTE who are known for their trubone housings.


That particular kit was a huge success with the DSM's and I believe it will also catch on with EVO owners who want more than the stock turbo, manifold can give them.

 

But thats exactly my question. I understand that bigger turbos are tend to me more laggy, but with the way Vishnu tunes their WRX's, you CAN have your cake and eat it to, which leads me to believe that the 16g, or the IHI for the wrx may just me the optimal turbo for the car.

 

Remember that excludes a restrictive pre turbo cat as well as a downsteam cat as well as a big mouthed downpipe as well as a restrictive IC pipe as well as being able to run good amounts of part throttle boost at lower throttle levels through tuning- whew all of coure really hurts spool on a stock wrx

 

Those IHI turbos on the WRX's only spool like stock because they don't have the restrictions the car comes with from the factory. A WRX on stock turbo with no cats will spool faster then any other aftermarket turbo.

We can probably get an aftermarket turbo that makes more power and spools like stock, but it would never spool as fast as a stock turbo with no cats, downpipe, catback, etc. Some of these new ball bearing turbos have great spool up to go with big power.

 

The WRX is a laggy engine to begin with, keep that in mind. Nothing like a 4g63. Getting that car to spool with anything on it is like pulling teeth from a chicken. (For you city guys, chickens don't have teeth. haha) The car even with the stock turbo is a big disapointment in the spool up department.

The Aerochargers are junk. They can't make big HP numbers and that is why even though they have been available for what seems to be about 10 years nobody uses them. Stay away from that option.

The stock turbo on the EVO is just a great piece. Like it has been said, several guys have gone 11's on it, we have gone 11.65 at 117.88 mph on it, nothing to sneeze at. I would suggest for an all around blast of a car to drive just bolt some of our Staged upgrades on it and have fun.

David Buschur
www.buschurracing.com

 

You got that right. Waste of time.

 

The newest R35 GTR Skyline is reputedly going to come with motor assisted spool, but that's just rumor until something shows up.
Like they said, the flat Subaru motors won't spool turbos very well. The stock WRX car has 3 cats and a suboptimal stock turbo to pile onto the fire. It is no wonder that Shiv (and other tuners) can give you more power everywhere. The EVO comes with a highly developed turbo and a very well engineered layout. The only reason to change it out is to use a unit with more flow potential and consequently more lag. The only way to get more power without lag is if you can improve the technology or design of the system. There is very little room in that department with the EVO.

Mark
www.Quantum-Racing.com

 

You sir, are a vishnu chearleader.

There haven't been a lot of graphs posted with upgraded turbos and the ones that have been i believe are a bad example. Lag is overrated and that is very hard to understand until you own a large turbo or ride in a well set up car. I'm not talking about a 3037 turbo with a .87 ar hot side either. What rpm do you see full boost at stock? With a t3t4 50 trim (not even dual bb), you can achieve full boost by 3500 to 3800 rpms. Not only that, but boost becomes posative with about 8-10 psi before you hit 3000 rpms. That turbo is also moving much more air than stock. The 16g only flows 505 cfm (550 for big 16g) but the 50 trim flows 730 cfm (all nubers rated at 15psi). That's a huge difference.