EvolutionM - Mitsubishi Lancer and Lancer Evolution Community - Official Boomba 75mm Big Bore Throttle Body Review and Dynotesting by TTP!

With the many changes and tests we have run on the 2005 Evo VIII thus far, we reached the point in our build where we believed the next bottleneck in the system would be the stock throttle body.

With the last segment of our reviews being the addition of the Magnus Motorsports V5 Cast Intake Manifold, the next smallest orifice in the system seemed to be the throttle body. About this time Boomba had their CNC machine cranking out all kinds of billet parts for many different vehicles.

Kris @ Boomba asked us to take a close look at their new Boomba 75mm Throttle Body for the Evo 7-8-9 pictured here:

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Upon opening up the box, we were impressed with the packaging, finish and attention to detail put into this unit.

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Taking an inventory of the items included with the purchase, we had an interchangeable stock manifold spacer, two sets of bolts for use with or without the stock spacer, and an inlet adapter for the full 3.125" inlet or the factory 65mm inlet. A 75mm composite gasket was also included for the manifold side.

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An optional Boomba intake manifold spacer for the Mustang throttle body bolt pattern was also included in order to mate up to the enormous Magnus V5 Intake Manifold.

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One of the excellent designs of the Boomba throttle body is the high pressure O-Ring on the back of the throttle body to adapter plate connection. This insures an airtight seal at ridiculously high boost pressures.

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If you are using the larger 3.125" inlet flange, all you have to do is remove the four small allen head screws to release the O-Ring sealed flange on the intake pipe side. It is a very well engineered unit, easy to work with.

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One issue we did initially run into was that the adapter plate for the Magnus Manifold fit the Boomba holes perfectly however.....

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The the Magnus V5 Intake Manifold throttle body flange and phenolic spacer gasket was 5"x 5" and the Boomba Adapter Plate was 4" x 4".

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After snapping a few pictures off and emailing them to Kris@Boomba, he had the newly cut adapter plate reworked and overnighted to us at TTP, so that we could resume our testing.

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As you can see above in the picture, the Boomba orifice is much larger than the stock unit.

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Here is a picture of the Boomba 75mm Throttle Body installed. Only red was available at the time, but it has a unique look to it. :)

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Here is a close-up of the 3.25" to 2.5" reducing 90* coupler we used to retain the INJEN intake and intercooler pipes kit. We opted to use the 75mm throttle body flange on the Boomba 75mm Throttle Body.

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From a different angle.

Anyhow, what most of the members of this site are looking for are the hard data numbers of how this Boomba 75MM Throttle Body actually performs so here goes...

The baseline run was made on the stock throttle body with 2.75 outlet to stock inlet size and below is the run shown:
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The after test was done on the Boomba 75mm Throttle Body with 3.125" flange and 3.25" to 2.5" 90* reducing coupler. With no tuning changes, there were notable gains of 17whp or so and about the same in tq in given rpm ranges.

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In the end, the Boomba 75mm Throttle Body is a superbly crafted piece, fits well, is designed well, holds insane amounts of boost, has a nice base idle adjustment screw and added about +17whp and the same in torque to our own test car.

With all of that said, the biggest benefit we have seen in day to day driving is throttle response! The Evo is faster responding now with the larger throttle body. It is a pleasure to drive with less lag time for the car to react on throttle position changes.

All in all, we like the Boomba 75mm Throttle Body and recommend it to anyone wanting to get the most out of their Evo.

TTP