hey guys. i have a little motor building project going on that i thought i'd share with you. all suggestions and feedback will be nice and accepted.


its a 6 port s4


start with a pretty big street port, S5 intake manifolds (ported), custom intake in the fender, atkins re-build kit, remove emmisions , TB mod and port, light weight flywheel, exedy or ACT stage 1 clutch, TII trans driveline diff. and half shafts...

i was trying to get 180-200 hp out of this. let me know what you guys think

 

depending on how big your port is depends on how much horsepower you'll be able to put down, and the ported intake manifolds should help quite a bit, for custom intake are you talking about a custom cold air? tb mod and port will help a lil so thats good, that clutch should get the power down the floor better with a lightweight flywheel so those all seem like good ideas, weather you get 180 hp is yet to be seen with all this, i'd like to see dynos when your done. and exhaust system with headers will help as well and it will add up in the end

i think its a good plan and id like to see all that youre able to do with this, keep us posted with how its going and what ends up from it

 

Sounds like a plan! If you tune it right, you should have no problem hitting your power goal.

When you say "ported" manifolds, what exactly are you referring to? I've done a whole lot of work on those things (both good and bad) in the past to see what works and doesn't so I'm curious to see what you want to do.

 

its going to be a large street port. for exhaust i'll be running a pacesetter header straght pipe (2.5") exiting through twin borla mufflers. for tuning i'm still having trouble deciding. is there anything made purposly for N/A tuning?? i dont know if there is many people around me that would/could tune my car so i would be doing it myself. i need something user friendly.

i was just going to port them out a little bit and port match the gaskets if necessary. do you have any write ups on intake mani porting or what worked the best?


yeah i was going to make custom cold air that runs from the motor straight across into the fender. i saw on here someone beat me to it... oh well

 

for the N/A all you need is the rtek 2.0, which is very user friendly and all you need in order to do tuning. and i could be wrong but i think the pacesetter close the 5th and 6th ports so the best choice would be the racing beat which does not

i gotcha, well id like to see the setup when its finished, pictures and all

 

Do not gasket match! This is a huge mistake that way too many people make. The problem isn't that the runners are too small in this area. The gasket is too big. If you gasket match, all you did was enlarge the runner area in this location alone. That means you'll slow the air down and then speed it back up again after it passes this point. It takes energy to change the speed of air. You can however halfway gasket match. What this means is that you can enlarge the lower side but not the upper. This doesn't really affect flow going into the engine. It does however provide a dam to help block reversion. I know someone is going to come on here and claim that you need reversion in order to take advantage of pressure wave tuning in the intake manifold such as with VDI on the S5 engines. The phenomenon is still there on all engines. It just has dual tuning locations on the S5. However this is an acoustic tuning phenomenon and we aren't stopping that. It works.

I'm also sure someone will come on here and tell you your Pacesetter header is crap. True there are better designs out there but that is a very effective piece compared to the stock crap manifold. Go ahead and use it. It won't fall apart in a couple of years.

The intake idea with the filter location would work fine. The air would be cooler. You don't get a "ram" effect from any other system anyways.

EDIT: The Racing Beat header won't help actuate the aux ports any better than any other header. The tube is on their pipe that goes where the cat is. It's not on the header anyways.

 

blackedoutFC3S I would have liked to get the racing beat header but brithers bought me the pacesetter for christmas you cant beat free.

rotarygod i see what mean about slowing and speeding up the air. i will definatly keep that in mind when i start my porting. when i port the bottom side should i go in as far as i can?

i will post pics as i get the chance to. right now i have the motor takenapart and i am cleaning it up trying to make it like new. thanks to both you guys for your input

 

you guys seem to be forgetting S5 high comp/light rotors? might also be an idea to install some RB street/race bearings and a slightly higher pressure oil press regulator.

 

i thought about the S5 rotors... when i looked for some they were like 600 bucks. just something i wouldnt be able to afford if i wanna get my motor built in a decent amount of time. those bearings and oil pressure regulator could be done. i'll have to look into that stuff

 

when you say 180-200hp, you mean at the engine right?

 

Someone here tested on a 12A and found the Pasesetter to *cost* 10hp relative to the stock exhaust manifold.

Someone on the no-pistons forum did a street port 6-port engine and found the stock exhaust manifold to only cost 15hp at the top end relative to a Racing Beat header. (Something like 180 and change vs. 195hp)

I guess what I am saying is, I'd use the stock manifold before wasting money on a Pacesetter. And I used to *use* Pacesetter, but only after some porting of the collector. Shoulda bought something better.

 

I'm going to go on a rant here so be prepared! I am not personally attacking Peejay either. I actually like the guy! (but not THAT way!)

I had a Pacesetter for a long time and still do own it. For the money, it's hard to beat. Whoever tested one and found it to lose power was either a liar with a motive to discredit it's gains due to a personal hatred (which I would say it probably most likely) or had some real bad issues on his motor. There is a 0% chance it will lose power to the stock manifold. There is a 100% chance that it gains. I know from experience. Is it the nicest thing out there? Nope. But it works and it's cheap. That's justification enough to use it for some. For others, it isn't good enough. That doesn't mean it's all bad though. You need to realize that many RX-7 owners WANT the best but are then too cheap to pay for it. RX-7 owners are a creative bunch that's for sure. Unfortuately many of them make the same mistakes over and over and over again after everyone before them has failed. The community is full of people that give poor advice with no experience to back it up and just pass on hearsay to others who then try it with poor results. As as example look up bridgeporting 6 port engines, S-AFC's, bigger, bigger, bigger, etc...

15hp is ALOT of power for something to be hurting. That's not even funny and a very good example of how the stock manifold is a piece of junk. You can make it give more peak power than it does by cutting off the outlet of it and replacing it with a 2.5" sch 40 weldable 45 degree elbow. I've done this too. It'll increase the top end nicely but low to mid power isn't all that much better. A header, even a bad one, has an advantage over even the best flowing modified stock manifold in that it will give more average power over more of the load range of the engine. There is more to power than full throttle. In fact I'd argue that full throttle dyno runs are probably the least useful information that you can base any comparison off of. It's true though but sadly what most people look at when it comes to comparisons. Dyno charts sell product and allow you to brag or bench race. A dyno is a useful tool but only doing full throttle runs tells you little important information.

Yes there are better options than the Pacesetter. There is no denying that. There are also better options than the Racing Beat header or even the SDJ header which for some strange reason everyone thinks is the holy grail of RX-7 headers. Gail per dollar, it's hard to beat a Pacesetter. Do not buy one if you intend to buy a better one later though. Save your money and wait a bit longer until you can get what you want. Relatively speaking a better one isn't much more expensive.

Rant over.

 

i think on an fc, the main restriction is the cats, not the manifold. also, especially on the s5, the ecu doesnt really help you either.

ive seen s5's with the stock manifold dyno within 2hp of the car with headers, and that was 2hp MORE (142 to 140). at that point you can tell who had the healthier engine....

the big gain we found was going from 12 to 13afr, it was like 15hp/10lbsft, and that was with the haltech, stock ecu (measured it in a few s5's) in the low 11's/high 10's over 6000rpms.

but thats just on the dyno, and you're right about that!

 

rotarygod, I think there may be an issue regarding quality control.

The first Pacesetter I got (the one I bought brand-new) had a very cramped collector. The two pipes merged inside the collector until they were about an inch apart. Highly restrictive, the hole was smaller than one of the pipes. Spent a LOT of time with a die grinder, ruining a new burr, cleaning up that junk. Then I had to fix all the bolt holes which were not only too small but not quite where they needed to be.

The Pacesetter that came with my silver car was not nearly that bad. I ran a 15.6 with that car with a stockport. It didn't look like the person who installed it had to modify it in any way.

So maybe the guy who found that it took his 100hp engine to 90hp got a bad one, and you got a good one.

 

i was talking about 180-200 to the wheels



i guess you missed the part where i sadi i got the header from my family as a christmas present.
i dont care that most poeple think they are a poor header. i have no prblems with it. after installing the header and removing my cat i have noticed a little more power....

 

I think it will take more than that to see 200 wheel, but I'll be following closely. It seems a lot of people do almost the exact same thing and range from 140wheel to 195wheel. I hope you're successful.

 

It is possible that there is a QC issue with the Pacesetter. That's always a possibility. Mine wasn't pretty at the collector, but it could have been much worse. Since the questionable result was on a 12A, I'd be very curious to see what the afr's were before and after the header. I had such a dramatic power difference on my 2nd gen when I originally installed mine that I have no doubt the afr's changed quite a bit. Fortunately an afm can account for any additional airflow and adjust accordingly. A carb however can not. I'm wondering if power went down not due to the header being crap but rather from the afr's changing to something suboptimal from that jetting. I'd like to see the carb rejetted. It is a common problem to have people install things and if there is no immediate gain, they hate it. We've seen this happen many times with Holley carbs. Someone installs it, expects it to be perfect and then it's not since it isn't jetted properly. They trash talk it and downplay it rather than fix it. This too is a possibility here.

By no means am I defending Pacesetter as a great product. Having used one and seen some nice gain from it, I just like to dispell the myth that it isn't useful. Mine sure as hell was!

 

Carbs DO adjust for airflow.

It should be noted that the same testing session saw 120hp from a Racing Beat header.

On my cars, you got more power by taking fuel OUT. The Nikki just dumps fuel at the top end because the venturis are so small and the boosters so efficient.

 

now i see why you gave me that pacesetter pete! lol

 

That's the one that I did 15.6 with a stockport! Maybe I'm giving you the Holy Grail of Pacesetters or something

If you do take the flange off (good luck with that, it's all perma-rusted!) I want to see the collector area. I was having thoughts of just cutting the collector off, cutting through the excess internal tubing in the process, and then welding it back on, but I didn't have a chop saw and a welder. If you had that kind of stuff then you could do that...

 

turns out...

 

This is a bit off topic but still concerns power gains for an NA with a header.

What about a true dual system?

I have the opportunity to get a true dual system at a decent price. Are there any real gains in a true dual system? I thought I read a post by Rotary God in another thread that stated the true dual system disrupts the pressure wave. The FSM only shows this effect in the intake and ignores any effect the exaust is having.

I would like to here more about this.

 

depends on how well acoustically the true dual system is tuned.

 

Trying to get back on topic here. I'm sure he will need more than that to get to 180-200 hp at the wheels. I have noticed though that it seems like the more experienced rotary builders seem to be able to get to that number on an N/A build much easier and with less modifications than someone who has done a lot of research and is working on their first or second engine.

I'm with Rotarygod on the headers though. Although I absolutely despise pacesetter headers because of their cheap manufacturing and poor quality the longer runners compared to the OEM "thermal reactor" design should offer a significant gain in exhaust removal and scavenging. Most people in the talk forums have a fairly amature concept of wave tuning, reversion, etc and how to minimize reversion while maximizing the wave tuning. Reversion may be almost impossible to eliminate but is surely not needed.

Looking on the intake side, a lot of what it takes on the intake side to building power is to maintain momentum and conserve energy. Again like previously mentioned port matching can be a bad thing if you are not careful to maintain a constant velocity. As for port matching only the bottom, only the top, or partially all the way around I haven't built many rotaries to know what they like (although I have worked on many piston race engines) specifically but there are some things to keep in mind. Having the intake manifold runner slightly smaller than the port will help promote fuel mixture (if there is fuel already mixed with the air) and help combat reversion farther into the intake manifold. On the other hand most engines like a 2% decrease in runner diameter as they reach the valve/port opening. So having the intake manifold runners slightly smaller where the flange bolts to the housings will cause a slight amount of loss in velocity. Matching only the top or only the bottom (or even the left or right side) will have different effects at different engine rpms, and will combat reversion and fuel that has dropped out of suspension differently. Changes on the long turn radius of the port will affect high rpm more and changes to the short turn radius will have more of an effect on low rpm operation.

Since this is a 6-port engine I would look into one of the methods of tuning when the ports open and do some porting to them. Kahren has some posts with pictures showing his port work on N/A engines that have been dyno proven to make power in the 180-200 whp range.

Also in my professional experience with porting cast iron I've found one of the best port finishes comes from using a grinding stone after you've gotten the shape you want. Just make sure you use a trueing stone with it.

P.S. Don't mention Aux Port Bridging to Rotarygod, he'll completely flip out. lol.