Im not sure how the efr 7670 would do with 2 cats, a quiet exhaust and quiet intake.

The tiny stock primary turbo can spool through all that and make decent boost/torque from 1,500rpm on.

My efr 7670 with 3.5" exhaust with just a straight through muffler and 12" long 6" base velocity stacked inlet still didnt quite have the boost/torque from idle to 1,500 as stock sequential with 3" dp and intake.

Remember, every journalist ever writing about the rotary says it has no torque because it has little rotating mass and not much torque from idle to 1,500rpm.

No big deal for a race car; but you feel it at every single stop light in a street car. We learn to drive it, but everyone notices it first time they drive a rotary.

So, Mazda was trying to make torque off idle on the 13B.

 

You don’t need two cats

 

Of course not. Dont even need one.

Im pointing out how the efr 7670 would have infeeior deiveability over the tiny stock primary turbo if it were saddled with all the restrictions Mazda had to have in place to sell the FD then.

Even with the advancements in turbos a smaller turbo is much less sensitive to all the restrictions of the stock FD.

 

Did you get them installed? How do they feel?

 

I am patiently waiting also

 

Any updates?

 

Would love to know what decision was made, any updates?

 

he’s taking it to another level with twin EFRs

https://www.rx7club.com/build-thread.../#post12576097

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