1600cc Turbo gets a larger Throttle Body

[nbuscemi]

As those of you who follow me in these forums know, I love using OEM parts (VW or otherwise) on my EFI-Turbo Bug. I've been rocking a TB from a 91-95 Ford Escort 1.9L mounted to a custom make intake. I recently got my hands on a TB from a 2004 Mazda Miata 1.8L. Not only is the Mazda TB larger, it gave me chance to rethink the intake manifold. The Ford version consist of a 1-5/8" center cention splitting off to two 1-5/8" runners. (see picture). The Mazda version has the 1-5/8" runners sharing a common plenum (something the Ford version lacked). I haven't done any dyno pulls or data lags yet, but they are in route.

Enjoy...







-Nick-

[V8Nate]

Looking sweet! Fingers crossed for improved performance!

[nbuscemi]

My issue is power before boost comes in... or the fact that the turbo takes FOREVER to spool up. Im hoping that a better flowing intake plus the soon to come larger up-pipe (1-5/8" to 2") decreases the boost threshold. Im not after more peak HP (though would be nice) I'm looking for power to come in sooner in the RPMs.

-Nick-

[Schweg]

Looking good! interested to see the dyno reaults

[buguy]

How much larger is the new one? I had a 50mm on my 1600 and i could make 30+ psi of boost at like 50% throttle (maybe even less). Makes boost duty tuning challenging. Even on my 2054 that same 50mm will make full boost at somewhere around 65% throttle. I always thought a smaller tb might be better. I could be way wrong though. A smaller one could be a choke point higher in the rev range.

[nbuscemi]

I'll have to measure them again, the numbers escape me at the moment. I took the car for a short drive today and it felt 1,000% more responsive. Perhaps its the TB or the larger volume on the intake manifold. The previous version had that poor engine breathing through a 1.635" pipe... now it its twice that! More solid data to come...

-Nick-