NA mods to make big #s?
 

I got a bunch of NA engine parts sitting around so I got this urge to build myself a nice high powered NA engine. Can someone please help me out with mods that are good for NA 13Bs that I do not already plan on doing.

What I want to do so far is:
-Street port using 88IntegraLS's templets
-Remove 5th and 6th port sleeves and put that stuff Bruce uses in his rebuild video to make a nice ramp for the air
-RB header with pipe straight to some sort of performance muffler (single exhuast)
-K&N cone filter
-Port intake manifolds
-Smooth out TB and TB mod also
-Rats nest removal
-Weight reduction

Those mods say on a base s4 with moderate weight reduction, would you say id be in the 14s at least? What other mods can I do to boost the power level up and NO forced induction this is staying NA.. I already have a TII with heavy mods.

Any advice is welcome

Thanks

You just desciribed my motor :D I used 88´s templates with good results.
Ill be building a true dual system for my baby when I come home from the LeMans.

You could put in a 4.3:1 diff to get better acceleration

How much powe would you say your making with that setup? Is the stock fuel system plenty for it? Any 1/4 times or 0-60?

All I would suggest is to not remove the 6 port sleeves so as to keep the stock six port system operational, and put an S-AFC on the list. I think the gain in low end torque outweighs the gain you might see in the upper revs. A cold air box for your K&N would also help, or you could build a true cold air induction setup. Hmm . . that's about it for NA performance. It just takes good porting, intake and exhaust, some air/fuel tuning, and light wheels / tires (my 300zx wheels and 225/50 tires cost me .05g in first gear) / chassis. A light flywheel is also good for autocrossing or road racing.

One of these days I will do a real exhaust for my car and get an SAFC, and make a trip to the local dyno. It would be nice to see 170ish on 87 octane. :)

I saw a thread where mazdaspeed7 was debating how the sleeves are just a restriction when you start doing bigger mods. I can see how he is right. I mean there isnt very much lost without those sleeves and im sure there is a lot lost up high with them being a restriction. Its also hard to make them work with aftermarket exhaust system, due to lack of backpressure.

88IntegraLS... would you consider your ports moderate? light? or towards the monster side?

I just purchased a header and presilencer (Cat replacement pipe) from rb, if you bye the correct presilencer then it will come up with the backpressure tube. It's my understanding that it should have enough backpressure to actuate the 5/6 ports.

I'll keep you updated.

*I am currently gonna keep the stock catback until icemark comes out with his catback system.

Also, search for extrude honing, under the name "Icemark", there a great way to pick up power, but it's a bit pricey.


https://www.rx7club.com/showthread.p...extrude+honing

or keep your sleeves in and do a bridge or j port to you 5th and 6th ports

I have the eurospec. motor which is kindda different from US--Solenoid operated butterfly valves instead of rotating sleeves, dizzy(mechanical) ignition there is no EGR ports to screw up flow and it comes stock with 4.3:1 LSD:)
That makes for quite a benefit powerwise, im guessing around 200FWHP and I still need to tune the SAFC.

somewhere in this thread is a few pics of my ports
https://www.rx7club.com/showthread.p...hreadid=258319

I really dont want to shell out a lot of money on this car, its more or less my daily beater. Just so I dont have to drive my TII everywhere, but I want the NA to have some power too. RB= expensive, this is a budget car, all the money got invested in the TII...

power = money = power

Unfortunatly, they go hand in hand. Most of your power gains will come from intake and exhaust work through porting our opening up restrections. No magic wand here.

Question for all; Are K&N Cone Filters just as good as say, the HKS or other brand of cone filters?

Pretty sure euro-spec cars came with 10 less HP then fed spec.

We must do things a bit differently over here. When someone wants a "nice high powered NA engine", they don't waste their time with streetports. ;)

I consider my ports medium/medium/large (primary/secondary/aux). I don't consider any decent street port to be monster. Brige or peripheral ports are wild ports IMO, but street ports are for people who want a nice streetable power band.

Until I see a dyno sequence done with six port sleeves and without, I'll stick with my sweet, broad power band and hypothetical 5 less top end horsepower due to the "restriction" caused by the sleeves / actuator rods. Keep in mind the simple fact that the sixth port is fed by a runner which also feeds the secondary port, so there isn't a great deal of pressure wave tuning possible on the aux because the runner was probaby sized for the secondary ports. You can't tune the runner for both ports because they have wildly different closing timing. The only optimization possible with the secondary runner is for the secondary port before the auxes open up. If the auxes are open below 4k, you lose this pressure wave tuning (tournament effect).

Now, if you fabbed a custom intake manifold with six separate runners, each being tuned in length for their respective ports and desired power band, I could see some merit in removing the sixth port sleeves, but for use with the stock intake manifold, I don't see any reason to remove the sixth ports. I have seen a few threads by people who have removed the sleeves / disabled the aux port actuators and wired the ports open, where they regretted ever messing with the aux sleeves. I have yet to see anyone post that they got any kind of usable power gain by removing the sleeves.

But I'm sure I see the six port NA engine differently than most people who modify them.

there was actually a lot of people that have wired open their ports. When I went to autox, i felt like the only rx7 guy there that still has the ports working like stock. Everyone removed them all together or wired them open.

Maybe you should try to just wire yours open and see how the power is. Then you can inform us with your results.

https://www.rx7club.com/showthread.p...threadid=19552 here is the thread that talks a lot about removing the sleeves. We all know mazdaspeed7 has one of the fastest NA FCs if not the fastest. See what he has to say about the sleeves.

He's also tuned for top end power, not power all over the band. You should see his latest street port. There are pix of it at the other rotary forum in the porting section somewhere. That might be more of what you're after if you want peak power and not power under the curve.

I guess I misunderstood the goal of your project. If I were going for just peak power on an NA I would just do a bridgeport. I wouldn't mess around with a street port. The goal of my ports were to make a very streetable and well rounded engine, with the same power band, just steeper. Wiring open the auxes and doing a bridgeport or just very large street port will give you a Vtek power band, which isn't for everyone.

And\or the factory ECU :o:

Any proof of that?

:bsflag:

Well just cuz I dont have proof doesnt make it BS.. that BS flag was unnesessary.

Please explain to everyone how having your auxiliary ports open all the time can have any positive effect on performance (since they're open at high load anyway).

We all know it can't, but I want to hear your explanation anyway...

hehe my explaination? uhh dont really have one, just agreeing with mazdaspeed7 about the fact that those sleeves can cause turbalance, and restrict air flow. MANY have also said that having ports open all the time is almost unnotacable in the low end, but you will be 100% that your ports will be open at over 4k rpms. Plus say you are racing when are you actually in low rpms anyways? You launch from high rpms, then shift at redline, you still end up in higher rpm range when shifting at redline.

order some RB lightweight rotors :)

Then my NA will end up costing me more than my TII ever did but 10000x slower.