im not looking for anything in particular, im bored so im posting this and you can just throw out any comments or info or whatever....

i have an 83 GS and this basically what my plan is for my setup...

12A Half-Bridge Intake & Extend Ported Exhaust
RB Race Rotors
Hardened Stationary Gears
Carbon Apex Seals
DLIDFIS
Jacobs Ultra Ignition Coils
RB Exhaust
48 Weber IDA

Tokico Illumina Adjustables
not sure what springs to get yet
SE Rear End & brakes
X Drilled & Slotted rotors
Semi metallic pads

yadda yadda yadda

 

Electric fan?

4.44 rear end?

 

oh yea, i said yadda yadda yadda cause i knew i would forget something . yea electric fan is going in too as well as no emissions which is already done.

can you give me a little more info on the 4.44 rear end? the stock is 3.91 right? what do you usually get it off of?

 

Why go half-bridge with that setup? You won't get as much power as a full bridge and you'll still have all the low-rpm issues because the overlap's still there.

Half-bridge is useful when using the stock apex seals because you can flip the seals around on the second rotor and cut a nice big bridge and matched housings into the secondaries.

It also makes more sense to run a four-barrel with staged secondaries for a half-bridge.

 

I can't remember which model exactly but the 4.44 ring and pinion where used in some Mazda vans and commercial vehicles.

 

so until i hit my powerband, my idle/low end will be just as bad as with a full bridge? what is the approximate difference in powerband between the two. ive heard a full bridge starts at 6k, is this true? what about half? full bridge would be very fun im just worried about daily drivability issues.....when it comes down to it i will probably do it anyway just because my love for brap is too great

 

It depends on what intake setup u use. If your using a 4bbl like a Nikki, why not go half bridgey? Youll run on the SP primaries till your in the mid range when the secs open. Sounds good to me. I wouldnt do a half BP with a 2bbl.

Hey, ditch the idea of using stock igniters if your going all out like this. Get an MSD or Jacobs. They are much more powerful, specially at hi rpms.

If your gonna go an SE rear, you better do the front too of the brakes will be mismatched. Either front SE suspension, or adapt FC 4 bolt brakes.

 

would a holley 600 work for a half bridge 12A or is it too big?

for some reason i remember reading that someone was having problems using msd boxes on rotaries, but i know a lot of people use them so I am probably remembering wrong. doesnt jacobs have stuff specifically tuned for rotaries?

yea i said SE rear but i am really planning on swapping the rear, and the entire suspension and braking system

 

I dunno what the airflow requirements are for a 1/2 BP. Id imagine a carb somewhere between 450 and 600. So the Holley 600 should work.

Having problems with MSDs on rotaries huh? If that was true, most road racers would never finsih their races.

 

lol i knew i had to be wrong but for some reason that got stuck in my head somewhere along the line. which do you think is better, MSD or Jacobs?

also what about drivability? revhed mentioned that the idle and low end will be just as bad with a half bridge as it would with a full bridge, is this true? see, im going to be a senior in high school and the 7 is my only car because i dont want to have to pay for any more insurance. ive never driven any bridgy before so i dont know what to expect with the low end.

 

The only real reason to go with DLIDFIS is for cost reasons. You get most of the benefits of MSD for little to no cost with DLIDFIS. It cost me $30 CDN to do the swap, FYI. If you're planning a real hummer like the one detailed, get the Jacobs rotary or the dual MSD box setup.

 

I have no experience with Jacobs. Probably similar to what you get with an MSD. Which is good.

I'd like an explanation of the 1/2BP being bad down low as well. As I see it, when the your running only on the primaries mostly, your basically running a SP, till the secs open up, then your on all 4 ports.

 

yea, i think if i run a 4 barrel with SP primaries i think it will be very streetable. also, i will also be able to suprise people with the top end, cause the brapage will be hidden

 

i think thats a good idea.....best of both worlds

 

Well more of a compromise, but most things are.

 

do you think 230 at the rear wheels is a reachable goal if tuned well?

 

I think 230 at the wheels is shooting a little high. I might be wrong but I'd bet you'd end up probably around 200. Either way thats really good for a N/A 12A.

I'm not trying to start a flame war here, but I'm just curious. If you are doing all this why did you pick a 12A over a 13B?

 

i heard that a properly tuned large SP 12A can put out 200 at the wheels but i could be wrong also, lol .

well this is my first project which means it is my first rx7 project so id like to start out with a 12A just so I can have alot experience before i move on to the 13B and 20B ( ) .

after i get everything else done, what do you guys think about installing a nitrous system with a small bottle, since i cant afford to do a turbo system right now .

 

LOL for your setup the only thin you would need to go with a 13b would be the racing beat 12 -> 13B mount and the 13b intake manifold and header. Assuming you havent bought anything yet, all you need to get is the adapter.

 

i might do the swap if i can get a good deal on an engine

 

Just because the throttle is closed and the port isn't flowing any air doesn't mean there's no overlap. The exhaust port still "sees" the intake cycle because of the bridge so you still have the exhaust gas dillution at idle and low rpm. A half bridge will brap just like a full bridge. That being, you'd think the powerband should come on earlier than a full bridge though due to better velocity through the primaries.

 

how long is my motor gonna last if i take care of it with the half bridgy?

 

i was reading stuff over on the second gen forum and they said that the 6 ports are bad candidates for a half or full bridge because of their flow characteristics. if thats true then for best results i should get a 4 port which means i need a TII, FD, or Cosmo motor. rather than spend that kind of money on a new engine i would rather stick with the good ol' 12A for now.

 

i know i said i cant afford a turbo setup but what if i got all used turbo stuff, like get an s4 turbo, etc.? this way i would be able to afford it, what do you think? a half bridge turbo 12A . do you think the s4 will flow enough for my high powerband? can i make these work? id love to have a turbo half bridgy to drive through college (i know i wont finish it before the end of this year)

 

i changed my mind about the turbo, because since im gonna have carbon seals then it wont last long, and this car has to be my daily driver so instead i am gonna go n/a until i can afford to have a different daily driver. i am gonna go half bridge first, then if maybe upgrade to full bridge later. i should be able to take alot of the people around here with a half bridge so its good enough for now, even tho theres a little voice in my head screaming "moe POWAH!!". it should be plenty of fun for a 17 year old. on the top of my list is this 16 yr old kid with an eclipse gsx. its got the bodykit, rims, etc. he thinks its da **** with his super loud bov, but hes running the stock turbo at stock boost levels and claims he beat a modded wrx lol.