clean85owner

I realized my wording later. The hole in the manifold. How big do you port it?

680RWHP12A

hole in the manifold? i dont port the manifold

Furneaux

Can anyone give me any information at all about the Racing Beat Aluminium side housings. We are looking at stuffing a 20b into a 1st Gen RX7 with the added weight of the 20b are these light weight side housings worth the added expense. Does anyone have a 20b with these housing. Any advice gratefully accepted.

680RWHP12A

the aluminum side housings they sell wont work with the 20B motor.. also the 65 pounds of extra weight the 20B carries over the 13B is not worth the thousands you would have to spend if the aluminum housings did fit.

DarkKnightFC

Fuel Distribution Block ???

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I've been looking at running a parallel fuel setup. The current regulator that I have is a single inlet, single outlet Sard Standard Regulator. My question being once I split the fuel line to enter the rails with a Y block, can I join the 2 lines after the rails again thru another Y block, just reversing the flow, into the single entry port on my regulator? Does anyone see any negative side effects to this?
Thanks

Chris

680RWHP12A

this is only really nessisary for high hp syasems( the y block that is into the fuel rails) how much hp are you planning on making? what size injectors are you using? what fuel pump?

DarkKnightFC

Its a walbro pump. Probably 4x720's. Maybe 400hp for now. It will be a little while down the road. The reason I ask is because I have a budget parallel fuel setup in mind. Instead of using SS lines and AN fittings I would be using Seahose( Not sure if you're familiar with it) and Barb fittings to attatch everything. I wouldn't be looking to spend more than $40 give or take a little. I've already got the regulator which I spent $100 on and if I can have the system without buying SS lines and An Fittings and a $150 aeromotive regulator then why not? I'll have as much money wrapped up in my whole system that most people spend just on a regulator.

The seahose looks very similar to our stock oil cooler lines, its high pressure hose thats cloth braided on the outside. I can get it from a parts store here in town. Its rated for some rediculous pressure.

Thanks

Chris

clean85owner

http://www.rotaryshack.com/Products/...sp?intView=100

"89/91 turbo manifold ported and high temp painted

$200.00"

How much do you port it?

Quicker10u

I have just purchased a 83' LE that has a stock motor, but has a RB header, exhaust and a Mikuni 44 on it...The previous owner says that the car runs really rich...What would be a good start for tuning the carb?..What jets would work best to get it leaned out..I am planning on doing some dyno tuning in sometime soon..Just looking for a starting point..

680RWHP12A

what main jet size is in the carb now? i would start by going down a couple of jet sizes.. you could also add a msd box to your leading ignition, that will help burn the extra fuel on top of making more power

680RWHP12A

not much really, i just debur it really.. to help prevent cracking

680RWHP12A

pm sent

Quicker10u

Thanks..I think I am going to get some dyno time at A-spec and use their wideband...The drivability is great the way it is, but I am always looking for that exta few hp..I have upgraded coils and wires..Is it hard to hook up an MSD box to the 12A..I know that it is set up for 4-6-8 cylinders...Can you use the rev-limiter on say a 6AL box?...

680RWHP12A

good, tunining with a wideband is the best way to go!
its very easy too hook up a msd box to a any rotary, you just need the correct wiring diagram as far a using the rev limiter, you would set the 6 al box as a 4 cylinder(cut both wires) and your good to go,however you will need 2 6al boxes for the rev limiter to work.. one for the leading and one for the trailing.. if you install a box just for the leading the trailing will not have a rev limiter and keep on going, not good.. if you get a msd unit and need a wiring diagram please feel free to pm me..

Andy87t2

iTrader: (1)

how do i port the stock wastegate on my s4?

680RWHP12A

take a die grinder, move the wastegate door aside, and grind the dime size hole until its the size of a quarter, or the w/g door flapper....

81WideMariah

iTrader: (8)

allright guys I'm going to have to call on all our rotary knowledge to solve this problem before I take a sledgehammer to my Mikuni PHH44. Here's my issue:

The car runs like a raped ape when I'm accelerating, never experienced the dreaded "Mikuni Bog" once (thank God!!), but once I get to a good cruising speed and try to maintain it she begins to buck, sputter, miss. If i tip the throttle in a little more it clears up, but as soon as I roll back off the throttle it starts again.

Now here's the real kicker, thinking that perhaps this could be ignition related I've rewired the entire system and put in new plug wires and new plugs. Also when I pulled the plugs I noticed that the front housings plugs looked very rich (black, sooty) but the rears plugs looked lean (light brown, flecks of white) ????? Totally lost on an explanation for that one. Now none of these problems existed prior with my stock nikki set-up.

Now for my Set-Up:
81 12a with small port on secondaries ONLY
Holley Red Pump
Profuel Regulator set at 4.5 PSI (verified by inline F.P. Gauge)
8mm plug wires
2xMSD Blaster Coils
RB Header
Full 2.5" Exhaust w/ Borla XR-1 Presilence and Magnaflow muffler
Mikuni PHH44 on Racing Beat 2 Piece mani and plastic carb spacers

Jetting is as follows:

Pilot:67.5 (but have tried 62.5 and 70's and no improvement)
Jet Block:OA
Main Fuel:190 (but also tried 200, and 210's)
Air Corrector:240 (but also tried 220)
Pump Jet: 90

I appologize for the length of the post but I wanted to make sure I listed all the variables so everyone has all the pieces to the puzzle. I'm just not ready to give up on this carb yet so help me out guys!!!! Thanks again.

Ken

Bison Asko

I have a S4 and i just rebuilt the engine. When i did this i removed the 5th and 6th port insert sleeve and blocked off the air control valve. I notice that i have a rough idle and ajusting the AFM makes it a little better. Now the car stalls occasionaly just after is is warm and then cut off once i start it again it stalls. I wanted to know what can i do to fix this problem and if converting it to a carb would give me more power and better mpg

Bison Asko

Based on the condition of the plugs it sounds like a coolant leak into the rear chamber check for the "air bubble" effect at the overflow tank. If she passes that test do a pressure test on the coolant system

Bison Asko

I have a 1986 s4 and i rebuilt the engine. I removed the six port actuation system and blocked of the air control valve. I now have a rough idle and when i ajust the AFM it makes it alot better. I want to know how i can fix this problem.

I also want to run a carb and get rid of the ecu. if i do this would i have to do anything special to the ignition system and would there be any improvment in the performance and mpg

takahashi88

my 88 gtu sounds like its misfiring a little. i ve replaced the plugs, but really have no idea why it would be spitting still. any ideas? also, i realize that your busy with all the other posts, but i haven't seen a reply to mine. i was wondering what the most cost effective hp and torque gains (besides exhaust and intake) are for an n/a engine?

thanks

Gresco

how costly could porting a 4-port 13b 86' be to bore or change to a 6-port and what all would this entail?

Gresco

your ignition is miss firing I suggest a jacobs ignition it should clear up a lot the problems. whats probably happening is the leading and trailing are firing at the wrong time I had the same problem and the jacobs fixed it.

Father Goose

I have a question on oil pressure fluctuation. I have an 85 GSL-SE with a 13B. Recently I've noticed the oil fluctuate from close to 0psi at idle to about 70 at 4000 rpm. I hooked it up t a pressure guage and it seemed to check out ok, is this range normal or do I have an oil pump about to fail?

If it is the pump, how difficult is it to replace? Any helpful tips or instructions?

680RWHP12A

its not the oil pump, replace the sender most likely

is the motor stock?