Sorry about yet another "How much power" type post but I've searched and found nothing...


My question: How much HP can I expect to gain from a ported (which level of porting?) FI 13B with a stock intake and exhaust? And how much of a power gain could I expect if I added a non-restrictive intake and exhaust to the ported motor? How much power can a 13b gain from a better ignition? Does anyone have any *real* before/after porting hp numbers? I think im looking for about 200hp but are the mods I've listed going to give more or less power than that? How much torque to rotarys gain from mods like these?

Thank you


-Jeremy

 

I think with a big street port, it would be possible to hit 200hp.

Now if you were to rip out all the FI non-sence and slap a Weber or 2 on there

 

I don't think a 6 port 13B is going to hit 200hp with a street port and intake/exhaust mods...

Firstly you can't do a "BIG" street port on the 6 port. It can be ported, but it's not nearly as big a difference as it is on the 12A's.

I would think 180HP max... But that's only a guestimate...

 

I think 200 FLYWHEEL hp is quite possible, but 200 REARWHEEL hp would be substantially tougher. If you went with the best of the best intake/exhaust and got a decent streetport, then did a few cheap mods to free a few more stranded hp, you could hit the goal.

 

Let me throw a quick question in.

What is the percent increase of horsepower from the stock port to the street port for the 12a and 13b?

 

A typical 'street' modified port 12A would give an increase of 15-18% in horsepower if all other components did not change.

For example an optimised stock port- with carby, exhaust and inlet, fuel pump upgrade will give you a realistic 155hp. Rebuilding with a 'street' port will give you about 185hp.

In the case of a 13B, add about another 15% to both configurations

The problem in using quoted figures is many dynos only give comparative results as they are never accurately calibrated. So measured results between different dynos are misleading and can vary plus or minus 20%. A well known RX-7 owner recently did a serious carb upgrade, he changed his tuner and the new dyno showed power had gone down!

 

Paul Fitzwarryne - thanks that's what I needed.