NA 6 port half bridge build (zenki FC)

Tougemonster · 08-24-2012, 11:13 AM

Hello all.. so my original motor blew a coolant seal in winter storage (-45 below @ 96,xxx) a few years ago.Im second owner bought with 70,002 miles with all records including all oil changes, gas fill ups, you name it. Even got the window sticker and dealership brochures.Chassis is tip top.A friend of mine gave me a new(used) motor. It lasted 800 miles some how... seized on start up.

This is my only pic of it now(My gf doesnt know how to work buttons)

This is how its suppose to be (exept this is an SE)

So now i have started a rebuild on the stock engine(I think she got mad at me for tossin in a used motor).

I should be able to re use the hard seals. But im not sure about 3 piece seals on a half bridge. Any insight? Im not sure they are even 3 piece but i am assuming so because its an S4

Im trying to run a stock ECU as judge ito has done it and I have seen how fast it was(RIP)(youtube)
To my knowledge he ran stock primary inj @460cc and S4 turbo secondary@ 550cc

I have found no more info as of yet, I PM'd him tho

Mods so far i have done 20k miles on this setup to try to learn chassis dynamics and polar movement at the limit of grip with low power
Tein drift spec coil overs 8kg front 6 kg rear (too stiff)
AWR chromoly lateral rods
AWR rear control arm spherical bearing
AWR camber links (didnt break :0)
Racing Beat DTSS eliminators
Poly bush A arms
Racing beat sway bar end links
AC/PS/smog delete (finding elec pw steering pump)
CAI off a ford diesel (still not enough airflow)
Hawk Hps+ pads (suck)
Short shifter
S5 tranny
S5 tails

Stuff im adding while i build(Already have, or free ish)
I have a full stainless dual roadrace setup im running paralell for about 113-118 inches( not sure how to tune this yet)
Mazdatrix heim joint endlinks
Mazdartix bumpsteer/angle tie rod ends
Tanabe Sustec strut bar
Stich weld
Chassis/engine harness diet
Sound deadening removal (keeping ugly maroon interior cus it makes my tornado grey silver look PIMP)
S5 bumpers and trim(keepin it black)
Shimmed LSD

Stuff Im adding later
Adjustable sway bars
Heim joint ball joints
Full cage and Huge diet
Fuel cell and auxiliaries to support
Urithane stiffening foam
NA Rtek?
Gilmer belt drive
Crown Vics
Downforce?
80s Boatflake gunmetal paint?

K so enough of all that, gettin down to business.
Can i use stock ECU and 3 piece seals?
Would switching the direction of a worn in apex seal with corner piece towards the center iron mess stuff up because it was bedded in rotating the opposite direction?

And finally does longer piping (118") boost low end or high RPM? Or shorter (113")
Im shooting for a Helmholtz resonance effect at around 5500 rpm
Anything else? AFM mods?

Tougemonster · 08-25-2012, 10:43 AM

Mainly im asking about 3 piece seals in a half bridge and stock ECU running it? Now you dont need to read the whole post?

reddozen · 08-26-2012, 05:04 PM

I would have to agree.. stock ecu and 3 piece apex seals sound like a disaster for any kind of bridge port...

Tougemonster · 08-28-2012, 06:54 AM

Yeah ive already been talked out of 3 piece seals. Im still wondering about rtek 2.0 for NA tho. But then i still have to use the afm which is a restriction. Or i could use a RB weber dellorto uim. It fits on a stock 6port lim. But i really dont wanna go carby

RETed · 08-28-2012, 09:53 AM

Stock ECU is too much of a restriction.
In fact, the stock intake manifolds are a restriction.
If you really want the BP to breathe, you need to redo the whole intake manifold, period.
This is why a lot of the BP's go carbs with some kinda aftermarket intake manifold.
Expensive is FI + ITB's.
This is not a cheap project by any means if you want to extract all the power potential of the set-up.
For the money you end up spending, you could be making a lot of power with a turbo set-up...

-Ted

Tougemonster · 08-28-2012, 10:52 PM

Bummer.. looks like I might have to give up the brap and just clean the ports up the bit.
I'll try to get a S4 turbo 4 port and full bridge that and leave the 6 port be for now.
I do have two 6 ports, so I could put the new parts on stock or pineapple street port. Then half bridge the spare, throw it in and try to dyno tune with Rtek, see what happens.
Id like to experiment with 6 ports as they are cheap to free, and easy to find.

And thanks for the input guys. I know i dont have many posts here, I spent alot of the time on the "other forum" I've had my FC for about 10 years now, had a couple AE86's and a RA65 before that. Not quite a noob, so thanks for not being harsh, I'll always be learning and will never quit asking questions

N.RotaryTech · 08-29-2012, 08:30 PM

So I was trying to figure out if I should post my experience with this. I believe that not many have done what I have done. So I figured that maybe my fluke of an experience with this might not be practical. But since you mentioned that you have another motor, Yes! You should bridge-port it.

Ok enough of me sounding like a pompous ass.

I should find where I posted this info before.
Since I don't feel like going through it again Ill provide cliff notes.

This is what I did:
Half Bridge Port S4 Motor.
Stock S5 ECU.
550cc primary injectors (S4 turbo injectors), Stock secondaries (460cc)
Lots of tweaking the Throttle Body.
Got it Running!
Really Fun to Drive.
Coolant seal failure as thousand miles later. (My fault with rebuild.)

Ill dig up more info on this later.

Or you can just search my posts.

Later.

Tougemonster · 09-01-2012, 04:41 PM

I watched you vids and build up post.I'm going which much smaller bridge and unblended into secondary 5th and 6 ports.
Keepin the bridge on the secondary seems like its going to be alot easier time it.

Im going to use a pineapple street port for the primaries and aux ports,
I'll use the template to extend the secondary at the bottom, but not towards the housing, cus i need space for the bridge.

And you should try switching your 550s on your secondaries instead of primaries since you have huge port that most likely get more air, hence need more fuel. Just a theory, makes more sense in my head anyways.

This is how Judge Ito set his up, and Im going to try the same way

Do you have an AFR gauge or anyway to tune fuel?

88turboii · 09-03-2012, 03:05 PM

i helped him "tune" it on stock ecu.. it wouldnt idle with factory 460's, b/p need a ton more fuel. with 550's it idled nicely around 13.5 AFR. it was just a pain to start as it would flood out without a fuel cut switch

imo going turbo is better than porting

Tougemonster · 09-04-2012, 08:49 PM

Well hopefully with smaller ports and no aux bridge I can get it to idle on 460's
I only need it to work to drive to another shop to park for the winter, then ill install some type of standalone. I still have to find out who can tune what here in Montana

Tougemonster · 12-01-2012, 03:21 AM

So i kinda jus did my own thing cus everyone told me it wouldnt work well
I made a template using the pineapple large streetport for a 6 port
the template has a 32mm bridge on the secondaries only,its chamfered to about 34mm
the bridge is 5.5mm wide and the port goes to 1.5mm from the coolant seal and the housings are notched to match
Im still on a stock ECU i went with rebuilt injectors and used 550cc/min secondaries
I used cnc'd atkins aux port sleeves and just leave em open for now
all the intake runners were smoothed of casting crap TB was ported
I posted most of my buildup on the other forum.
http://www.rx7club.com/build-threads...ki-fc-1009424/

http://youtu.be/JcGz6iHgXb0

N.RotaryTech · 12-01-2012, 02:54 PM

Congratulations!
I took a look at your thread.
Sounds good.
That speed run was sick. I didn't know na fc's could reach 100mph Uphill!

Have fun with it.

diabolical1 · 12-01-2012, 09:20 PM

impressive, sir.

Tougemonster · 12-02-2012, 02:47 AM

hah thanks guys. wasnt really a speed run though.
I wont really know what it can do till i adjust the throttle body so it opens all the way.
500 more miles to go

chibikougan · 12-03-2012, 12:48 AM

Proud..

My car is getting more holes in it.

Damnit I think I am the only one without my car going again!! Well except Granpa. He does have it towed over by his house finally though. I should see if he wants me to take his Rotary parts out for him.

I don't have my AFR meter anymore either. Someone over there has a dyno

One on Higgins http://www.usdieselparts.com/

Also dynojets in billings,bozeman, and big sky

08-24-2012, 11:13 AM	#1
Tougemonster Meat Popsicle Join Date: May 2010 Location: Missoula, MT iTrader: (0) Posts: 31 Rep Power: 0	NA 6 port half bridge build (zenki FC) Hello all.. so my original motor blew a coolant seal in winter storage (-45 below @ 96,xxx) a few years ago.Im second owner bought with 70,002 miles with all records including all oil changes, gas fill ups, you name it. Even got the window sticker and dealership brochures.Chassis is tip top.A friend of mine gave me a new(used) motor. It lasted 800 miles some how... seized on start up. This is my only pic of it now(My gf doesnt know how to work buttons) This is how its suppose to be (exept this is an SE) So now i have started a rebuild on the stock engine(I think she got mad at me for tossin in a used motor). I should be able to re use the hard seals. But im not sure about 3 piece seals on a half bridge. Any insight? Im not sure they are even 3 piece but i am assuming so because its an S4 Im trying to run a stock ECU as judge ito has done it and I have seen how fast it was(RIP)(youtube) To my knowledge he ran stock primary inj @460cc and S4 turbo secondary@ 550cc I have found no more info as of yet, I PM'd him tho Mods so far i have done 20k miles on this setup to try to learn chassis dynamics and polar movement at the limit of grip with low power Tein drift spec coil overs 8kg front 6 kg rear (too stiff) AWR chromoly lateral rods AWR rear control arm spherical bearing AWR camber links (didnt break :0) Racing Beat DTSS eliminators Poly bush A arms Racing beat sway bar end links AC/PS/smog delete (finding elec pw steering pump) CAI off a ford diesel (still not enough airflow) Hawk Hps+ pads (suck) Short shifter S5 tranny S5 tails Stuff im adding while i build(Already have, or free ish) I have a full stainless dual roadrace setup im running paralell for about 113-118 inches( not sure how to tune this yet) Mazdatrix heim joint endlinks Mazdartix bumpsteer/angle tie rod ends Tanabe Sustec strut bar Stich weld Chassis/engine harness diet Sound deadening removal (keeping ugly maroon interior cus it makes my tornado grey silver look PIMP) S5 bumpers and trim(keepin it black) Shimmed LSD Stuff Im adding later Adjustable sway bars Heim joint ball joints Full cage and Huge diet Fuel cell and auxiliaries to support Urithane stiffening foam NA Rtek? Gilmer belt drive Crown Vics Downforce? 80s Boatflake gunmetal paint? K so enough of all that, gettin down to business. Can i use stock ECU and 3 piece seals? Would switching the direction of a worn in apex seal with corner piece towards the center iron mess stuff up because it was bedded in rotating the opposite direction? And finally does longer piping (118") boost low end or high RPM? Or shorter (113") Im shooting for a Helmholtz resonance effect at around 5500 rpm Anything else? AFM mods?

08-26-2012, 05:04 PM	#3
reddozen Gold Wheels FTW Join Date: Mar 2008 iTrader: (0) Posts: 744 Rep Power: 17	I would have to agree.. stock ecu and 3 piece apex seals sound like a disaster for any kind of bridge port... __________________ My Cars: 1974 RX4 Coupe 1991 FC3S RX7 - Sold 2003 ZZW30 MR2 (Rotary swap after RX8) 2004 SE3P RX8 (20B Swap in the works)

08-29-2012, 08:30 PM	#7
N.RotaryTech Home-brew Rotary Join Date: Feb 2008 Location: GooseCreek SC iTrader: (0) Posts: 552 Rep Power: 17	So I was trying to figure out if I should post my experience with this. I believe that not many have done what I have done. So I figured that maybe my fluke of an experience with this might not be practical. But since you mentioned that you have another motor, Yes! You should bridge-port it. Ok enough of me sounding like a pompous ass. I should find where I posted this info before. Since I don't feel like going through it again Ill provide cliff notes. This is what I did: Half Bridge Port S4 Motor. Stock S5 ECU. 550cc primary injectors (S4 turbo injectors), Stock secondaries (460cc) Lots of tweaking the Throttle Body. Got it Running! Really Fun to Drive. Coolant seal failure as thousand miles later. (My fault with rebuild.) Ill dig up more info on this later. Or you can just search my posts. Later. __________________ '89 RX7 GTU, half-Bridge-port S4/S5 NA, E6K, Full RB exhaust, weekend warrior. '83 RX7, The "this might take awhile" project. '87 RX7 GXL, Rest In Pieces. '98 Subaru Impreza Outback-sport, rx7 rescue vehicle, down for repair. '94 Ford Ranger, daily.

09-01-2012, 04:41 PM	#8
Tougemonster Meat Popsicle Join Date: May 2010 Location: Missoula, MT iTrader: (0) Posts: 31 Rep Power: 0	I watched you vids and build up post.I'm going which much smaller bridge and unblended into secondary 5th and 6 ports. Keepin the bridge on the secondary seems like its going to be alot easier time it. Im going to use a pineapple street port for the primaries and aux ports, I'll use the template to extend the secondary at the bottom, but not towards the housing, cus i need space for the bridge. And you should try switching your 550s on your secondaries instead of primaries since you have huge port that most likely get more air, hence need more fuel. Just a theory, makes more sense in my head anyways. This is how Judge Ito set his up, and Im going to try the same way Do you have an AFR gauge or anyway to tune fuel? Last edited by Tougemonster; 09-01-2012 at 04:43 PM.. Reason: make it eaier to read

12-01-2012, 03:21 AM	#11
Tougemonster Meat Popsicle Join Date: May 2010 Location: Missoula, MT iTrader: (0) Posts: 31 Rep Power: 0	So i kinda jus did my own thing cus everyone told me it wouldnt work well I made a template using the pineapple large streetport for a 6 port the template has a 32mm bridge on the secondaries only,its chamfered to about 34mm the bridge is 5.5mm wide and the port goes to 1.5mm from the coolant seal and the housings are notched to match Im still on a stock ECU i went with rebuilt injectors and used 550cc/min secondaries I used cnc'd atkins aux port sleeves and just leave em open for now all the intake runners were smoothed of casting crap TB was ported I posted most of my buildup on the other forum. http://www.rx7club.com/build-threads...ki-fc-1009424/ http://youtu.be/JcGz6iHgXb0 Last edited by Tougemonster; 12-02-2012 at 02:48 AM..

08-25-2012, 10:43 AM	#2
Tougemonster Meat Popsicle Join Date: May 2010 Location: Missoula, MT iTrader: (0) Posts: 31 Rep Power: 0	Mainly im asking about 3 piece seals in a half bridge and stock ECU running it? Now you dont need to read the whole post?

08-28-2012, 06:54 AM	#4
Tougemonster Meat Popsicle Join Date: May 2010 Location: Missoula, MT iTrader: (0) Posts: 31 Rep Power: 0	Yeah ive already been talked out of 3 piece seals. Im still wondering about rtek 2.0 for NA tho. But then i still have to use the afm which is a restriction. Or i could use a RB weber dellorto uim. It fits on a stock 6port lim. But i really dont wanna go carby

08-28-2012, 10:52 PM	#6
Tougemonster Meat Popsicle Join Date: May 2010 Location: Missoula, MT iTrader: (0) Posts: 31 Rep Power: 0	Bummer.. looks like I might have to give up the brap and just clean the ports up the bit. I'll try to get a S4 turbo 4 port and full bridge that and leave the 6 port be for now. I do have two 6 ports, so I could put the new parts on stock or pineapple street port. Then half bridge the spare, throw it in and try to dyno tune with Rtek, see what happens. Id like to experiment with 6 ports as they are cheap to free, and easy to find. And thanks for the input guys. I know i dont have many posts here, I spent alot of the time on the "other forum" I've had my FC for about 10 years now, had a couple AE86's and a RA65 before that. Not quite a noob, so thanks for not being harsh, I'll always be learning and will never quit asking questions

09-03-2012, 03:05 PM	#9
88turboii destroy, rebuild, repeat Join Date: Feb 2008 Location: Charleston, SC iTrader: (0) Posts: 395 Rep Power: 17	i helped him "tune" it on stock ecu.. it wouldnt idle with factory 460's, b/p need a ton more fuel. with 550's it idled nicely around 13.5 AFR. it was just a pain to start as it would flood out without a fuel cut switch imo going turbo is better than porting

09-04-2012, 08:49 PM	#10
Tougemonster Meat Popsicle Join Date: May 2010 Location: Missoula, MT iTrader: (0) Posts: 31 Rep Power: 0	Well hopefully with smaller ports and no aux bridge I can get it to idle on 460's I only need it to work to drive to another shop to park for the winter, then ill install some type of standalone. I still have to find out who can tune what here in Montana

12-01-2012, 02:54 PM	#12
N.RotaryTech Home-brew Rotary Join Date: Feb 2008 Location: GooseCreek SC iTrader: (0) Posts: 552 Rep Power: 17	Thats how you do it! Congratulations! I took a look at your thread. Sounds good. That speed run was sick. I didn't know na fc's could reach 100mph Uphill! Have fun with it. __________________ '89 RX7 GTU, half-Bridge-port S4/S5 NA, E6K, Full RB exhaust, weekend warrior. '83 RX7, The "this might take awhile" project. '87 RX7 GXL, Rest In Pieces. '98 Subaru Impreza Outback-sport, rx7 rescue vehicle, down for repair. '94 Ford Ranger, daily.

12-02-2012, 02:47 AM	#14
Tougemonster Meat Popsicle Join Date: May 2010 Location: Missoula, MT iTrader: (0) Posts: 31 Rep Power: 0	hah thanks guys. wasnt really a speed run though. I wont really know what it can do till i adjust the throttle body so it opens all the way. 500 more miles to go