Nameless Performance Equal Length Stepped Header

[fknlo]

I'd love to be able to do a full exhaust setup that adds good power but isn't too loud. I'm not 16 any more, being able to stay somewhat low key is important.

[jamal]

Wouldn't it have been way easier to just take a perrin header, cut off the end, and put on a new bend and collector?

[Dave-ROR]

Originally Posted by jamal

Wouldn't it have been way easier to just take a perrin header, cut off the end, and put on a new bend and collector?

Uhhhmm why would they do that exactly?

[jedibow]

Originally Posted by arghx7

20 mega pascal is about right for peak pressure on a modern system with side-mount injection. Systems with center mounted injectors will go a lot higher. The fuel pressure is trending higher to meet tightening particulate emissions standards. That makes me think the stock DI injectors are nearly maxed out after all. The crank angle window for injection is narrow.

I think it would be possible increase port injection beyond the cutoff point to increase fueling needs, however it would be hard to tune, but yes that would be to bad if the direct injectors are already maxed out. I wonder how HKS increased the fueling needs for the supercharger setup?

[jedibow]

Originally Posted by Symbiont

Personally, I'm looking for a system that does the following (in order of importance):

A) Makes power and torque
B) Hopefully helps smooth out the dip o' death
C) Sounds aggressive, but not too loud
D) Looks fantastic
E) Saves some weight

This will be for daily driving and a bit of canyon carving. Track use will be almost non-existent on this car.

By the way, I can pretty much guarantee that the dip is not a placebo effect or imaginary (not sure what the actual numbers are, though), you can definitely feel it in day-to-day driving.

The most likely cause is cam phasing, which is why Dimman mentioned it, until camshafts are produced for this engine NO bolt-ons will remove the torque dip, but the nameless setup has made it better.

Remember that once you change cams you will have to make sacrifices, it will either be smooth midrange, low end pull, or highend power, not all three.

Taiman, would you please update everyone on how the torque dip has changed since the exhaust intall, and what your current driving impressions are regarding said torque dip?

Thank you

G

[Dimman]

Originally Posted by Symbiont

Personally, I'm looking for a system that does the following (in order of importance):

A) Makes power and torque
B) Hopefully helps smooth out the dip o' death
C) Sounds aggressive, but not too loud
D) Looks fantastic
E) Saves some weight

This will be for daily driving and a bit of canyon carving. Track use will be almost non-existent on this car.

By the way, I can pretty much guarantee that the dip is not a placebo effect or imaginary (not sure what the actual numbers are, though), you can definitely feel it in day-to-day driving.

I think they've hit everything except B which we may see some positive results on with alternative configurations.

As for the placebo comment, I understand it is real. I'm just speculating based on gearing and rpm drop, not having driven one yet, that under 'soft' and 'hard' driving it wouldn't be too apparent.

Some insight on how it is noticed, and under what conditions, could help with figuring out a solution.

[Dimman]

Originally Posted by jedibow

The most likely cause is cam phasing, which is why Dimman mentioned it, until camshafts are produced for this engine NO bolt-ons will remove the torque dip, but the nameless setup has made it better.

Remember that once you change cams you will have to make sacrifices, it will either be smooth midrange, low end pull, or highend power, not all three.

Taiman, would you please update everyone on how the torque dip has changed since the exhaust intall, and what your current driving impressions are regarding said torque dip?

Thank you

G

The cams and exhaust acoustics are inter-related. So there is a chance that alternative headers can sort out the dip. We may only need AVCS control rather than replacement cams.

[serialk11r]

Originally Posted by Dimman

The cams and exhaust acoustics are inter-related. So there is a chance that alternative headers can sort out the dip. We may only need AVCS control rather than replacement cams.

I think it would be more intake header dependent, no? Doesn't matter how good your exhaust scavenging is if the intake acoustics don't match. Would probably need AVCS adjustment along with fuel/ignition to suit the new volumetric efficiency local max, and turn down the intake cam advance in the previous local max torque range since scavenging efficiency has been reduced there.

[Dimman]

Originally Posted by serialk11r

I think it would be more intake header dependent, no? Doesn't matter how good your exhaust scavenging is if the intake acoustics don't match. Would probably need AVCS adjustment along with fuel/ignition to suit the new volumetric efficiency local max, and turn down the intake cam advance in the previous local max torque range since scavenging efficiency has been reduced there.

Not really. They can act by themselves or together good or bad.

An exhaust pulse will create a pressure drop at the exhaust valve when it arrives. Bigger pressure difference will reduce effort to extract gas out of the cylinder. But matching it to overlap and coinciding intske side lengths we can now get a pressure increase on the intake side as well. But there can actually be such a thing as over-scavenging too...

So what the acoustic tuning can do is spread around or gather together torque in the rpm range. Which goes back to my old BMEP obsession. It's not just about peak BMEP, but also how far it drops over how many rpm. And acoustics plays a major role in that. In this case remember I was originally not too impressed with the BMEP numbers, before we got dyno graphs. But the fact that the low peak is nearly the same as the main peak shows how much they've spread it around. Now we just have to gather it up at 5500+ and get some slightly longer duration cams, and this will be getting close to that TRD 3SGE...

[Symbiont]

Originally Posted by Dimman

I think they've hit everything except B which we may see some positive results on with alternative configurations.

As for the placebo comment, I understand it is real. I'm just speculating based on gearing and rpm drop, not having driven one yet, that under 'soft' and 'hard' driving it wouldn't be too apparent.

Some insight on how it is noticed, and under what conditions, could help with figuring out a solution.

The thing that bothers me is an upshift around 6k RPM or so under hard acceleration. The engine lands right in that dead zone, and the car feels as though something tugged on its bumper and slowed it down a lot. Then it slowly picks back up as you work out of that zone.

Shifting at 4kish or 7kish pretty much negates the issue as you avoid that zone altogether, as long as your high RPM shifts finish before the engine RPM drops too much.

Really, you'd notice this the most on a track or area where you can't always control your shift points. In street driving, it is 100% avoidable... but I don't want to have to avoid anything.

[R/TErnie]

OP,
Have you dyno tested any other header designs? Seems like you just dyno tested against the OEM piece...

Also LaCenter washington is a small place. You work for ETS previously?

[Symbiont]

Originally Posted by jedibow

The most likely cause is cam phasing, which is why Dimman mentioned it, until camshafts are produced for this engine NO bolt-ons will remove the torque dip, but the nameless setup has made it better.

Remember that once you change cams you will have to make sacrifices, it will either be smooth midrange, low end pull, or highend power, not all three.

Taiman, would you please update everyone on how the torque dip has changed since the exhaust intall, and what your current driving impressions are regarding said torque dip?

Thank you

G

Right, I don't expect it to go away completely, but smoothing it out a bit would be awesome. Honestly, I love the low-end grunt of the engine, but the 'twin peaks' are always on my mind when driving aggressively.

I really don't want to do much with the cams. I probably won't do more than an I/H/E and a tune, with a possible change in the suspension later on down the road.

[Coheed]

Originally Posted by R/TErnie

OP,
Have you dyno tested any other header designs? Seems like you just dyno tested against the OEM piece...

Also LaCenter washington is a small place. You work for ETS previously?

Since there are no designs yet developed, all tests are against the OEM piece. Development will continue.

[Coheed]

I'm a sucker for big power. I'll take some big cams

I'd like to nail around 220whp or so for now. Once a tuning solution is available i'd like to play with this.