Dave D

I am collecting parts to put together a rotary Miata(with an E-Prod-type look/flaver)and looking at a few engine possibilities.Here are the options:

1.12a with some large(pretty large)streetport irons I got for free

2.12a with some bridgeport irons (from same source)for free although the port job is borderline safe.

3. 12a P-port that someone I know has apart and wants to sell cheap.But it was from a drag racer(is there really a difference betwen a p-port for drag and road racing?).

This is all to be done on meager buget as my GT1 car eats up most of my $$$$$.I was just toying with this project idea for some of the smaller tracks we go to here in the northeast(Pocono,Millville,Limerock,Beverrun,and Summit).

I also would like suggestions for induction.I have 2 Megasquirt units bought on the cheap so F-injection is an option although TWM throttle bodies are pricey.BTW-class rules are out the window as this will run in NASA's PT-class where mods are assesed points for class bump-ups.

I'd like some outside opinions

Thanks,

Dave D.

j9fd3s

you might wanna look at the classing real quick, in the PT the poeripheral port is like 40 points, although with the E prod tyre setup and miata weight, that might be ok.



the PP puts my 81 rx7 from like PTF to PTB



doing efi on the p port is a good idea. i think the difference between drag racing and roadracing is prolly in the tuning?

Dave D

The classing would not be much of an issue-1.the car at around 1750-1800lbs with an E-prod type susp. and a mild rotary would be a little rocket ship and 2.I'm the NASA Northeast Chief of tech,so I doubt there would be much of a classing issue(unless I ran away from most in the class)as we are pretty laid-back in the competition dept.,most just come to have fun.

Re. the PPort,I was worried about the high revs/narrow power band being an issue in longevity/maintenance.I would like the motor to be reliable.I heard that a PPort can sometimes be more "flexible"in rev range and reliable than a big Bridgeport.Is this somewhat correct?I guess I would need to limit the revs to<9,000 longevity.

Dave

heretic

A peripheral port is far more flexible than a street port of comparable power.

j9fd3s

ha, we do timing and scoring for norcal nasa. i only mention the pt thing, cause the PP puts my 1st gen in a pretty fast class, faster than i'm gonna be able to run it.



i think at 1800lbs its gonna be a rocket with a PP.

banzaitoyota

That why my new RX@ is going to NASA!! Lesss BS than the secret squirrel car club

Dave D

So if I understand this correctly,1.a PPort is just a PPort,not much difference if it's for drag race or road race?The diff may be in fuel induction/headers choices?And2. due to the port timing,the PPort IS moe flexible in the rev range than a SP?I kind of had an idea that was the case,but being new to this rotary world,I was not sure.But can a PPort be run at reasonable revs for longevity?I would not mind tearing the unit down in the winter for apex seals,inspection,etc...but if would have to come apart 2-3 times a season,that would be a bummer. What's a reasonable rcipe for a 12a PPort?(hardend sta. gears from a turbo,oil pumps?,induction?,apex& corner seal type?,etc..).

I really appreciate any help/advice,

Dave D.

Lynn E. Hanover

The street port would be the most reliable. Maybe 229 HP at 9,000 RPM.



A bridge port with 38 MM chokes maybe 245 at 9,400 RPM



A Pport maybe 270 HP at 9,500 RPM



Fuel injection I cannot help you with I only have carbs.

We have raced at Pocono, Lime Rock, And Summit point. I went to a drivers school at Summit.



Lynn E. Hanover

j9fd3s

yeah its pretty laid back, which is nice.