I know this might sound stupid, but did anybody try to do a tt 4 clynders?

 

lol

 

I'm sure its been done before.. But I suspect the reason you haven't seen it is due to the confines of the engine bays on most cars, and likely any experiments that had been done probably didn't offer the desired results.

 

It's been done with DSM's before....never had any results to show any significant advantage...

 

I believe Doug'd Dynopower built a twin T25 turbo'd 2g a few years back. It didn't seem to perform any better than a 20g or so. I think he did run 11s with it.

 

only advantage would be spool up, but BB turbos kind of have that problem beat anyway

 

There was a huge discussion on DSMtalk some time back. I believe there was even some testing...with, as stated above, negligible results. The semi-consesus was the no matter how many turbos you have, you're still running the set boost...15 psi is 15 psi....not 30 cause there're two turbos. Equal pressures flowing the same direction from multiple sources do not compound.

 

you could go w/ the RX-7 route and do sequential turbos. That would allow for earlier boost response w/ the bigger second coming online later. The thing is that it was not particularly reliable. Most serious RX-7 tuners either switched to a single large turbo.

It seems that the EVO could use a little help below 3500 RPM, but I don't think the added complexity of a second turbo is the answer. An ECU upgrade and a cam would probably be a better (and cheaper) approach. But my application (autocross) is probably different than yours.

 

I think the perfect engine for the twin turbo setup is the Subaru boxer. One turbo on each side sitting right off the head. Less piping to the turbo, so it should be pretty effecient. I believe they do a twin turbo set-up on the B4 (JDM Legacy)

 

There's technology available that would be better suited if you want to lower the spool.. I've been working with a Titanium wheel turbo (and OE Japanese unit)

I've seen one other interesting application of a twin turbo setup on a truck, it is a double compressor, the second turbo compresses the air AGAIN after its compressed by the primary turbo.. I don't know if the experiment ever worked out though.

 

You mean a supercharger/turbocharger combination? I've seen that too, it worked out pretty good.

 

twin turbo on our cars??!! WHY?

 

Twin charge

 

JDM Legacy is sequential turbo believe it or not. I know because my best friend had one here in Cayman. It uses the IHI VF18 and VF19 turbos.

 

putting twins on a boxer isn't really a new idea, since the boxer is basically like a v engine it's always "easier" to put twins on a v engine setup... cuz otherwise tubing gets all complicated.