Wow, that could be a confusing title. After spending a few years in e46/e36 land, I am returning to my rotary roots. I have an FC shell that is getting prepped for FP solo duty in the garage.

My question is this; what engine housings should I start with given that porting is open in my class?

I have a very fresh stock 6 port engine currently in the car, but according to forum lore this is a bad engine to port.

I do have a budget restriction, I cannot afford to call Mr. Mederer and have a Kiesel motor built. I do however have lots of time and a die grinder, I just need to know which set of housings has the most porting/power potential. Any comments will be welcome!


Elliot

 

Wow, post count requirements are STRINGENT!

 

I haven't read the rules in a while... But don't you have to start with whatever was on the car originally? I don't think you can use turbo housings, but you might be able to use 4 port housings from an FB.
If the RX8 was listed "on the same line" would we be able to start with (or swap in) the Renesis?

 

The way I read it, any combination is legal, but must remain n/a.

 

i think my friend is running FP with a 1st gen, and he put a 13B bridgeport in it, so i'd imagine engine swaps are ok, but you should double check that.

the combo you want depends on what intake you get to run, if you must run stock NA intakes, then i'd probably do a street port.

if you can swap intakes, then go 4 port and a bridge, like Mr C.

 

You are correct.... I like the sound of an FD block with RX8 rotors and match the header and intake to the port timing.

 

(clarification)

The FD ports (especially the center plate) have the largest port castings.

 

Intake and exhaust are free... aka: full custom, if you want

 

Just re-read the rules. Where does it say you can use the plates from an FD?
The way I read it, if you are running an FC, you can run a 13b or a Renesis (appendix A, pg 219). And you are allowed to bridge/perif port it.
The FB and the RX-8 are actually more flexible since they're allowed a 12a, 13b, or the Renesis.
Any place else in the rule book when it mentions the FD or TurboII, it specifically calls out the engine as being "turbo". So I don't think you'd be allowed to mix and match parts between the turbo/non-turbo.
I'd love for you guys to prove me wrong. I haven't built my engine yet, so the more options the better.

 

why F around, go P port! set it up right and you can tow with it

 

renesis rotors wont net you anything if used in 13B peripheral exhaust port housings. The rotors are slightly smaller thus it's basically a wash in compression ratio (plus there is a whole set of problems with apex seals). Use the lightweight S5 high comp rotors with a 13B block if going N/A.

And yeah, ideally if you can use an FD block with S5 N/A rotors that's your best foundation...

 

What kind of powerband do you get with the pp approach?

 

I have not run one myself so i couldn't say. I have had numerous conversations with my engine builder about what is the best platform for an N/A motor using stock parts and we both agreed on that.

Talk to Rob at Pineapple Racing. He has done more than a few of those...

 

I talked with a fellow Prepared car friend last night and he agreed with my interpretation of the rules. But he added that we could probably get them to add the allowance to use FD plates.
With some of the newer cars coming into F Prepared (Boxster, S2000), they might be more willing to do something that keeps the older cars competitive.

 

mine, which is a 12A built to the specs in the competition book, except with mufflers, and its all corked up.

@2500rpm it feels like it makes as much as a stock 12A@ its torque peak, then it comes on. based on how it pulls on my friends car (i know, i need to dyno it), i'm making about 180rwhp@6500rpm. i figure it should do about 220-225rwhp@9000ish once i get the intake/exhaust right.

my other yard stick is my other friends FC, the P port is in a really light 82 Rx7, but it just wastes the FC in a straight line

the only real penalty is noise, which i believe is solvable. part throttle low rpm drivability isn't great either, it like it when you're decisive