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

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 significant gain in air flow made for a reasonable cost.

Runs made on a flow bench using of a FD3S intake system mounted to FD3S intermediate and rear housings. 

At 20in of H₂O vacuum the flow was 97% with open non ported new FD3S housings. 

 Stock lower manifold: 92%   loss of 8%

with dynamic chamber: 89%  loss of 11%

Modified lower manifold: 97% loss of 3%  

with dynamic chamber:    93%  loss of 7%  

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. 

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

As it shows now a 15% to 18% increase overall  in air flow seems very obtainable

Mazda has made this powerplant 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 TIEN. 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. Which is bad news for tinkerers that want to sell porting as a money making proposition. It does mean 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 95% harder to find and more expensive.

June 04, 2007

Rotary Response  <>  Rx for your 7
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