Nameless Performance Equal Length Stepped Header

[Calum]

Originally Posted by XPR Small Block

i just know with v8s a "Shorty" header creates more lowend torque vs. a long tube header which makes more topend i would assume the same thing would apply here

Pretty well all of the rules of thumb have been thrown out the window with this engine. We've had Visconti reporting almost no difference between 91 and 93 octane, Nameless made more power with a 3 inch exhaust vs. a 2.5, Full Blown has made over 520 whp on a stock longblock, two tuners that I know of have reported making the most power at over 12:1 air/fuel ratio and running a safe AFR of high 11's on pump gas with turbo'd engines... Just throw all of your preconceived notions straight out the window.

[FR-S Matt]

Originally Posted by Calum

Pretty well all of the rules of thumb have been thrown out the window with this engine. We've had Visconti reporting almost no difference between 91 and 93 octane, Nameless made more power with a 3 inch exhaust vs. a 2.5, Full Blown has made over 520 whp on a stock longblock, two tuners that I know of have reported making the most power at over 12:1 air/fuel ratio and running a safe AFR of high 11's on pump gas with turbo'd engines... Just throw all of your preconceived notions straight out the window.

So basically what you're saying is this engine is an enigmatic beast?

[Calum]

Originally Posted by FR-S Matt

So basically what you're saying is this engine is an enigmatic beast?

Everything we've seen so far has pointed to just that.

[FR-S Matt]

Hmm, looks like I'll be taking the plunge on the 3" DP/OP and hopefully a 3" midpipe with a beefy resonator. I'm so indecisive, lol.

[Mars2]

With almost 250 crank Hp we start to be close to the point where a 2'5 exhaust start to induce some restriction. So A couple of sharp bend could make it hapen sooner.
This graph is with Crank Hp not WHP

[Mars2]

Sorry that was to explane that I'm not surprise 3" exhaust make more power than 2.5"

[Acree]

Where did you find that chart?

-Acree

[d1ck]

Originally Posted by Mars2

With almost 250 crank Hp we start to be close to the point where a 2'5 exhaust start to induce some restriction. So A couple of sharp bend could make it hapen sooner.
This graph is with Crank Hp not WHP

This doesn't take the thermal efficiency of the engine into account. An engine with a higher thermal efficiency will produce more HP for a given exhaust flow rate.

[mad_sb]

Originally Posted by FR-S Matt

Hmm, looks like I'll be taking the plunge on the 3" DP/OP and hopefully a 3" midpipe with a beefy resonator. I'm so indecisive, lol.

Ha.. Jason almost had me talked into the 3" yesterday.. I went ahead and ordered the 2.5 but am waiting on them to test the 2.5 midpipe and revised axleback.

[FR-S Matt]

Originally Posted by mad_sb

Ha.. Jason almost had me talked into the 3" yesterday.. I went ahead and ordered the 2.5 but am waiting on them to test the 2.5 midpipe and revised axleback.

Yeah, I'm going to talk to him again. I'm not afraid of the 3" system. I just need a good resonator and a 3" midpipe to go with it. It will be easy swapping to turbo later.

[johnbradley]

Originally Posted by Dimman

I disagree. The 'regression' around the dip between runs is ECU. The dip itself is an acoustics artifact.

Originally Posted by mad_sb

Yeah, the dip is a combination of compromises NOT just the tune. There are only so many variable you can adjust in the tune and by this point the combination of tuners have touched them all on various cars and no one has eliminated the dip.

This header design and tune combination has already turned a big chunk of what was the dip into a mound of torques... I stoked to see the finished product and how it performs.

I agree with these guys. After having done some extensive naturally aspirated tuning with Hondas in the last 2 weeks, dips like those are present in LOTS of applications. Oddly enough playing with the actual intake pipe length and diameter made the most differences on those.

Originally Posted by Skywgn1

I would like to know how the ECU handled the header without the tune. Are there graphs and actual figures?

I meant to have gotten that done but didnt remember in time...next time though.

Originally Posted by Calum

Pretty well all of the rules of thumb have been thrown out the window with this engine. We've had Visconti reporting almost no difference between 91 and 93 octane, Nameless made more power with a 3 inch exhaust vs. a 2.5, Full Blown has made over 520 whp on a stock longblock, two tuners that I know of have reported making the most power at over 12:1 air/fuel ratio and running a safe AFR of high 11's on pump gas with turbo'd engines... Just throw all of your preconceived notions straight out the window.

I can tell you there is no power loss running NA between a 12.0:1 and a 13.5:1. On a turbo motor you will always make more power lean but with Subaru head design thats a bad idea for #3 and #4. I have made best power on most Subaru drag race tunes at a 12.5:1 but I would never leave it there on the street.

[johnbradley]

Originally Posted by Dimman

When I'm looking at the AFR, what exactly am I seeing? Is the straight dotted line the 'target' and the wavy solids the actual?

Dynojet lets you set a "safe" limit line if you want. That particular one is a 12.5: and is more for a quick visual reference if I am lazy and dont want to get out of the car to stare at the screen.

[reeves]

Originally Posted by johnbradley

After having done some extensive naturally aspirated tuning with Hondas in the last 2 weeks, dips like those are present in LOTS of applications. Oddly enough playing with the actual intake pipe length and diameter made the most differences on those.

Hope this isn't too far off subject, but would a CAI intake with longer piping work better than a short-ram intake? As far as making the most difference to minimize the dip? Or is it negligible?

[naikaidriver]

Originally Posted by reeves

Hope this isn't too far off subject, but would a CAI intake with longer piping work better than a short-ram intake? As far as making the most difference to minimize the dip? Or is it negligible?

This is WAAAYYYY off subject but honestly, new intakes (whether CAI or short ram) don't do anything for the torque dip. In fact, there are some intakes that make it worse without a tune.

If you want to eliminate the dip, it looks like your choices are, forced induction, header and tune, e85 tune.

Scott