Thanks for all the good N/A info so far guys. I'm seriously considering cutting a street port into my spare S4 block and seeing what I can run with my mostly RB exhaust (no header yet), cone filter, and the S4 intake manifolds (I'm considering the S5 switch).

Will the stock S4 tranny, clutch (mine is stock form, less then 5k miles on it), and rear end (GXL LSD) take the extra power with any major problems? This is my DD so I'm trying to avoid too many complications when I drop this engine in. Hopefully careful planning (I'm in no rush) will help me with that.

 

 

awesome graphic

 

Why does the NOx increase so much at stoich? sry for the n00b question.

 

Do a good header first. You'll get far more power from a good header on a stock port motor than you will from porting and a stock cast iron manifold.

 

Lean best torque is usually somewhere around 13.3:1 for most four stroke motors. There are variables but that's a good place to start for max power at high load and WOT.

14.7:1 is the theoretical peak of chemical efficiency of the burn. Some engines can burn much leaner mixtures for improved mileage. Again, there is no set rule as there are many variables.

 

Yeah, I was hoping to put off buying a header until I got my street ported motor ready to rock. I'm putting a price list together right now because I'm definatly going to go with the S5 intake as well. I already have most of my emissions knocked out, so the only thing that would become complicated is getting the VDI to work at the correct time, which isn't a huge deal.

My biggest concern is how much the S4 LSD drivetrain can take before you have problems turning gears into mush and clutch slippage issues. My tranny and clutch are in great shape right now, but I'm not sure where their limits are.

 

Treat them right and they last a good long time without problem. The diff especially. Put drag radials on it and pound the strip and you will break something.

 

I'm still here. Are you still doubting my dyno chart? I'm trying to determine what my next upgrade should be, if I need a standalone to handle timing and fuel, or just get a piggyback fuel system and do the timing myself.

I have a timing light with advance on it. I want to use it to advance my timing by 10 degrees like C. Ludwig recommened. I set the light on the first mark on my pulley and set the advance to 0 degrees. Then I turned the advance until I reach the second mark. The advance showed 60 degrees. The real distance between the 2 marks should be 15 degrees. I think this means that if I want to advance my timing by 10 degrees, I should set my timing advance to 40 (10 degrees * 4 (rotary timing correction)) and adjust the CAS until the first mark (20 degrees) lines up with the peg. Does this sound correct?

 

i have an s4 na streetport also, but im using s4 internals.. im hoping to hit like 180 whp max with headers and full 2.5" exhaust with a collector and an safcII , and whatever other mods i can do, engine will be mild ported and ill also have a lightweight flywheel and dual friction clutch

 

that 185 hp that speedsource is quoating is that with the stock manifold??

 

whoops

 

Yes. That's for a legal ITS motor which is a completely stock motor from the AFM inlet to the exhaust ports with the exception that the 6-port sleeves can be removed legally. They quote 175whp on the stock ECU and 185whp with their Motec setup. I know a guy that just completed the install on the Motec and is suppose to dynp at some point. I'm very curious.

robertb, the best thing to do is put another mark on the pulley and reference from that. Since the leading plugs are firing in wastespark you're getting an ignition event every 180* of the crank. You're timing light most likely can't filter that 2nd event per rev and that will screw with your advance **** settings. So what you're truely seeing might not be what is indicated on the ****. Some of the pulleys are actually 360mm in circumference such that 1mm equals 1* making it easy to add very accurate marks. Just pull the pulley off, measure the circumference, and divide the circumference by 360*. That will give you how many mm or 1/10th of an inch, whatever unit you measure in, that equal 1*.

 

Yes.
Either the dyno chart is "fudged" or the dyno isn't calibrated and reads high.
Icemark hit 174hp at the wheels, and it's one of the highest 13B NA dyno out there.
kahren built a custom intake manifold but kept the stock TB producing 177hp at the wheels.
Some other guy (from another forum) claimed over 180hp, but it was bullshit.

I have never seen a stock ECU hit you numbers.
You're not even running a fuel controller, which makes it even more unbelievable.

So how did your dyno numbers suddenly jump almost 10hp?


-Ted

 

That is a good question, but without a list of their modifications there's no way to compare. Your previous point about there being no crossover dip at 3800 is interesting. Sometimes I feel it, sometimes I don't, sometimes the motor misfires erratically all over the rev range.

I have no reason to fudge the chart. Since the A/F ratios that I got during this round of testing are somewhat consistent with the testing I did a year a ago with a friend's wideband (David Lane), I do intend to have a rotary experienced tuner have a look. The ratio is consistently rich.

 

well i want to get like 170rwhp what are the major things you need to get to make more hp ? i

already getting rb collector , 2.5" piping 4" tip, mild streetport, dualfriction clutch, rb light steel flywheel im guessing that will get like 150-160 at least to the wheels

with msd ignition, coldair intake, throttlebody mod, safcII ... how much hp would i see ? another 15-20whp ?

what else could i do to make more hp? i dont really believe in taking out the actuators/rods idea, i like my low end...not unless my car was a ' race car ' which mine is not

 

Basically, there is no way the car can make more than 180hp at the wheels with the stock ECU, period, even with a properly calibrated DynoJet.

You're running larger secondary injectors with no fuel controller; the stock ECU already runs the stock 460's overly rich.
There is no way in hell adding the 550's will automatically run close to proper AFR's to make best power.
I think the dyno graph is off by as much as 30hp.


-Ted

 

I don't know that the graphic is totally accurate. NOx emissions rise and fall with combustion temperature. The hotter the combustion, the more NOx. Usually the more lean, the hotter the combustion, and that graph makes it look like combustion cools off the leaner you get.
As for the "Torque" curve on there, your Torque is completely dependent on Volumetric Efficiency. At peak VE, you have peak Torque.

 

it could be just one of *those things* that happened...
i.e. i have personally seen a bone stock s2000 trap 103mph...................

 

That's just for S5's right?

 

Either or...
Please remember I did say *STOCK ECU*.


-Ted

 

While we're debating NA power, would you get the most power from a full s5 intake, or s5 upper and s4 lower, because I've seen both. I seem to remember seeing that the s4 lower was good for more air flow.

 

the s4 and s5 lowers are essentially identical as far as the intake passages go. The differences are in the emissions related passages... S5 has a exhaust port under the intake primaries that the S4 doesnt have.

more information here:
http://www.pengaru.com/forums/index.php?showtopic=52

 

ted you mean a stock port?

because i think otherwise, if its ported.
https://www.rx7club.com/showthread.p...5&page=1&pp=15

 

^^^^ Still the champ and my inspriation 195 whp out of an NA FC