Aveo header with pics!

[xiaogary]

I am in the progress of making a 4-2-1 header + flexible pipe which will bolt up the original center exhaust silencer at the 2 nut flange. Meaning you will need to keep your 4-1 cast iron header + cat + flexible pipe section. And replace the whole front portion with this 2 piece set up.

I am trying it now. Apparently, I feel more torque. And rpm rises faster from 0-80km/h and from 80-120km/h. I am trying out 120km/h and above to see whether it does choke up and cost higher rpm to be more restricted. But my butt feel tells me, its much more responsive. And can feel the amount of torque and g-force pulling immediately whenever I step.

For 4-1, its more smoother of course, for those who prefer less back pressure. Not that the 4-2-1 has lots of back pressure, but it does have a bit more than 4-1. So its different feeling altogether and different people have different preference for amount of back pressure they need according to their driving habits and style.

[khan4rtist]

bump, any updates on that 4-2-1 header?

[subachad]

back pressure = bad
exhaust velocity = good

As for the CA thing, weld some nuts or brackets on there so you can use your stock heat shield. That will go a long way to appearing stock.

[tidus10]

final price shipped to USA?

[LarsBud]

98 octane, man that’s what my BMW R60/7 needed in Germany, can’t get that in Canada. I always had to add octane booster to get it to fun right.

I Canada:
I'm paying around 95 to 90 cents a L.

[thehunterooo]

ima get that 4-2-1 when i get my money on aug 29th!

maybe he finished it?

[xiaogary]

bump, any updates on that 4-2-1 header?

I had been using it for 4 months plus on my car. Feels more torque than my 4-1 header. Good for peope who rev and change gear at 2.5k to 3.5k.

Above 4k feels a bit choky, but of course its not as choky (restrictive) as original exos which starts to feel choky at 2.5k. Its still very much free flow and power releasing. Just that the 4-1 can rev freely all the way until red line. 4-2-1 will feel more back pressure compared to 4-1.

4-2-1 is more torquey, 4-1 is more free flow and rev to red line freely.

But as a rating, if back pressure is a scale of 0 to 10, original exos set up is 10, totally no exos (without header, cat, mid silencer, rear muffler) is 1.

4-2-1 backpressure rating will be abt 5.
4-1 back pressure rating will be abt 3.

The above rating is for my car without cat, with straight thru mid silencer, and straight through rear muffler.

For a car with orginal mid silencer (also straight thru also) and semi flow rear muffler, the rating will need to add 2 pt. Meaning 7 and 5 respectively.

But back pressure is not a good gauge for exos. A good exos flow is a free flow with adequate back pressure (least resistance higher exit speed). Meaning, not meaning free flow is good. It need high exos exit speed. Too low back pressure will also have low exit speed.

I would say the 4-1 is good for both auto and manual also. Although some auto drivers will prefer the 4-2-1 more due to higher back pressure.

[XJCasper]

Screw backpreasure.

I want best hp and torque.

4-2-1 or 4-1?

[thehunterooo]

i see, ill just buy another 4-1, but next month when i get my money

[tidus10]

i see, ill just buy another 4-1, but next month when i get my money

another?