Rotary Response and Racing

Flow Bench - Tech findings.

Air flow rates for FD3S intake manifold have been generated....

Comparison tests between a stock and modified intake manifolds show improvement in air flow not much as mazda has done a good job in this area also....

Testing shows a 6% total increase in air flow through a modified intake and dynamic chamber...this equates to bolt on horsepower

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02/01/01-03/12/01

All parts tested are 1993 FD3S US Fed spec

Preliminary test runs of a modified intake manifold and dynamic chamber indicate that there could be a reasonable gain in air flow made for a reasonable cost. Flow bench shows that bigger is not necessarily better.  

Tests were made on the YAW flow bench. All tests were done at 20in of H₂O vacuum.

• FD3S Intake manifold

FD3S intake system, factory stock and flow ported engine housings

Base Flow was 85% for stock IM on non ported new FD3S housings. 

90% flowed IM on stock housings

92% Stock on flowed housings

97% flow ported IM on flow ported engine housings. 

Bench rates:

• Stock lower manifold LIM : 92% 

• with dynamic chamber UIM: 89% 

• Modified lower manifold: LIM 97% 

• with dynamic chamber  UIM:    93% 

These are only the first tests on this manifold and by the results found, it is optimistic that further improvements can be made. Even so 6 to 8% with an affordable price tag right now looks very feasible. 

This does not take into account the increase in the effects of the upper dynamic chamber. 

• Engine Housings

Air flow tests on modified engine housings show small improvements.   The stock Mazda housings are very efficient - 87%-90%

Intake ports achieved 98% flow, Exhaust ports 100% on the bench

As it shows now a 15% to 17%  increase overall  in air flow seems obtainable

Mazda has made this power plant very efficient. Nothing like the earlier motors. Especially the hard to flow six-port motors. So any improvements now are going to be small. It is when you add up all the 5%'s here and 7%'s there that we are seeing excellent results. There are now completed packages on the road. Improvements have been smoother running, cooler running and better fuel consumption in daily driving. Although the last can be subjective do to heavier right feet. And bigger smiles on the face.

1993 R1 modified induction, cleaned up ports in housings, clean up oil system ports, PFS intercooler, intake, silencer, Bonez downpipe, PFS engine management system, CenterforceII, Jacob's wires, Redline water wetter and , Redline two-stroke race oil added to fuel. All stock otherwise. Suspension upgrade recommended is TEIN. Modifications to engine compartment to better facilitate the extraction of heat.

Turbo lag- doesn't happen. Smooth through all transitions.

This package is emissions legal, fast, and fun to drive.

Please email for more information and to get on a mailing list so you can be notified when the new findings are ready. email sales@rotaryresponse.com subject: FD3S INTAKE

Mazda has made the flow ratings on the RENESIS motor and intake are even better. This means that any improvements to be found are going to be minimum and much more expensive. That is the nature of performance. Going from 65% to 85% is easy and cheap. 85% to 98% harder to find and more expensive. Finding that last 2%....priceless

August 05, 2009

Rotary Response  <>  Rx for your 7

Tucson, Arizona 85716

1986                  6/2008