I want opinions on this idea of mine: Lets take both an "s4 n/a" and an "s5 n/a" rotary engines out of 2nd gen. rx7s.

This is the setup:
1. Bridge-port the 5th and 6th ports.
2. Upgrade secondary injectors.
3. Emissions removal.
4. Wire the 5th & 6th port actuators open or control them manually by cable.
5. Premix, (Ive heard you might need to do something electronically for the oil pump on the s5, corect me if im wrong on this.) Or my idea, just replace the oil injectors with those bolts that have the holes running through them, let the oil constantly "leak" into the combustion chambers.
6. Free-flow exhaust and k&n intake.
7. Another optional mod would be, extra TB plate removal.

This should be a cheap setup. Plan to use stock ecu. Nothing drastic like a haltec. (did I spell that right?)

Want opinions on both the S4 and S5 engines.
Would this work? How would it run? What else would it need? Forgetting anything?
Any comments?

 

Any comments at all? Feel free.

 

I'll read along, this is exactly what I'm doing.
Though I will keep the chokeplates in the TB as it will be for my DD S2.
I'm using the Euro(butterfly-valve) LIM as thats all we have overhere
Stock N322 ECU with T2 secondarys and Apexi S-AFC
Dizzy ignition, possibly DLIDFIS later on

http://www.wankelkim.net/rx7/halfbridge/

I am pretty confident that it will work out.

 

Cool. I was thinking of geting a Apexi S-AFC if I had too.
My brother had one (S-AFC) in his FC turbo befor it got broken into.

Any more comments?? Anyone??

 

Is this going to be a DD ?
In that case, I will highly recommend NOT to go freeflow, sure it will probably gain a few ponies up top, but it will also lose some torque down low where you need it.
That and the fact that you will need earplugs to prevent loss of hearing.

BTW my motor is going in theis weekend/next few weekdays, will let you know how it is when broken in.

 

Daily Driver, Is that what your asking?
Not really, cause it will be my 2nd project car. I had help on my first one just to make shure I did it right. And My "1st project car" is actualy/now my daily driver. This next car will be spare/backup/weekend car.

 

Would it work? Absolutely.

However as many are fond of saying, "a bridge is a bridge is a bridge".

I just started my aux bridge car and it braps nicely. Even if you have the sleeves in tact (I don't) there is going to be exhaust wraparound through the eyebrow port and you are going to get the overlap so it won't be as clean as you think.

The stock ECU won't deal well at all. Any bridge I have had experience with on the stock ECU is horrible.

 

Just another question to satisfy my bridge-port interest: (not necessarily the setup I want to go with) But, any kind of brigde-port whether full or half, how much HP can you get out of em?

 

It varies dramatically. For turb cars, 400HP and up (though 400HP is at the low end). For NA cars that would be considered streetable, 250HP-300HP.

Big difference in power between full and half bridge, no much difference in how the engine behaves (brapping idle, bucking, etc.)

 

OK, so I got the auxillary bridge running today
Idles nice with a decent brap.
As all the seals are brandnew, I have only taken it to 4500 rpm's, now i can actually feel the aux-butterflies open.
All temps are perfect and oilpressure is about 100psi.
Will post a video when my bandwidth is back up

 

My aux bridge idles flawlessly at the stock RPM and drives perfect on the stock ecu with no tunning,...

 

Have You checked the A/F ratios or is the pig-rich stock map just fine?
Im taking no chances, SAFC and 550's to be bought.

 

A dyno is posted in the second gen section, It is a tad lean up top but ran fine. The motor is apart right now due to a corner seal plug falling out not because of detonation.

 

For the lazy
https://www.rx7club.com/attachment.p...hmentid=158746

Not to brag, but my old FC with just a streetport and stock ecu sported 188hp
Im shooting for 200 (obo ) with the aux.bridge

 

I read on nopistons, not to use the rubberplugs in the bridge, they WILL fall out eventually.

 

Do you have the sleeves in place?

 

Yes sleeves in place.

The car would have made a little more, though not quite 200 i dont think, but as you can see on the dyno the 6-port sleeves closed at 7.5k rpm while power was still rising.

The two runs after that were without the sleeves open because i thought i blew up my rpm switch by unpluging it on the fly, but it actuallity the line from the airpump I use to feed the solenoid blew off in the first dyno run.



Also in that dyno I had them opening at 5000 rpm, they now open at 5750.

 

Very true, I just made a thread about this over there too, I thought I was fine, had a good 2/3rds of the plug supported and they still fell out and munched a sideseal on one rotor.

 

The rubber plugs in the corner seals?

 

So a full bridgeported 13b n/a motor with some basic modifications such as a free flow intake, a true dual exhaust, and a ITB with a standalone can do 250-300hp???

The idle should be around 1500rpm right??

I was thinking about going with this setup next year in the spring time, when I rebuild my engine.

Does anybody have a video of a 13b n/a with a bridgeport???? Every video I see is only of a 13bt bridgeported.

 

yes.

 

Right click / save as

http://www.wankelkim.net/rx7/halfbridge/startup.AVI

!!! The high watertemp was because i had forgot to mount the wireingharness ground to the chassis

I have about 130 kilometers on it now, pulling fine up til 5000rpm's

 

Yes. And likely more if you build the engine for more RPM...

You can probably get it down to 1200 or so with some tuning.

 

So for the past 2 days ive been thinking / brainstorming about bridge & street porting. (This happens to me every once in awhile.)

First off, ive been referring to the porting methods diagram, on the rotary engine illustrated site, while thinking about this.

The first thing I want to address is, on N/A rotarys, as far as the Secondary ports go, and as far as doing a "street port", it doesn't seem there is much you can port and "stay within the lines."
So my thought here, would be, it would be better to do a bridge port. Cause you would have more room to work with / you could have more port area. But you would decrease the "safeness" of "staying within the lines".

The second thing I want to address is, Primary ports, any rotary engine, street porting. It seems to me, there is alot more you can port and "stay within the lines", than any other port, like secondarys.
My question is: Is there an advantage to porting the primarys, as far as low end torque gose?
Some might think, just concentrate on the secondarys, cause thats where / when everything happens, its where all the torque & power is. But why not try to increase the low-end a little.

And then for the third thing, I want to address is the mix of both the first & second issues. If I bridge-ported the 5th & 6th ports (aka. aux bridge-port), and street-ported the pimarys, I would think, generally, that engine would be awsome.
Cause I would have that great high-end power with the aux bridge-port, and great low-end power with the street-ported primarys.

But then I think about the whole issue with bridge-porting, that it decreases low-end power a bit. Or would street-porting the primarys, conteract that?

And, im pondering, weather I should go with a aux bridge-port or half bridge-port.
Which one decreases low-end power more.

So once again, any comments, anyone?

 

The low end power loss I think is a myth.
According to my buttdyno I have gained low end torque due to the streetport, but then again my aux.bridge is closed untill the butterfly valves opens the 5/6th/aux ports.
I will get dynoresults as soon as i get some larger seondary injectors installed.