Please toyota/subaru.... everything is perfect, but...

[WingsofWar]

for my function>form,

Twin Non-Sequential Turbo - Titanium True Duals with twin EGTs for metering

or

id do true duals for a track car..but single exit for best street performance.

[chulooz]

"true duals" as in 2 headers going 2->1 on each side? That would be a very unique setup, not sure how I feel about that.

[WingsofWar]

Originally Posted by chulooz

"true duals" as in 2 headers going 2->1 on each side? That would be a very unique setup, not sure how I feel about that.

not that unique, true duals are common in the aftermarket sector for both 13b n/a rotary engines and many V configuration engines, but the price of true duals over single exhausts turns people away majority of the time.

350z

Mustang

Mercedes

GT-R

[tranzformer]

Originally Posted by chulooz

Im with Ichi on this one. A single exhaust will probably be an all around better option for this car. Except for the personal aesthetic opinions but to those I say: Function > Form (within reason of course)

I'm with the two of you as well. No sense in the added weight for me or the added cost. Others might feel otherwise but that is fine too for them.

[chulooz]

Originally Posted by WingsofWar

not that unique, true duals are common in the aftermarket sector for both 13b n/a rotary engines and many V configuration engines, but the price of true duals over single exhausts turns people away majority of the time.
]

I was referencing the engine you are talking about having the exhaust on FB20, boxer 4 now find me dozen of those with a true dual.

Haha, yes i realize many other cars have real/true dual exhasts.

[tranzformer]

Originally Posted by chulooz

I was referencing the engine you are talking about having the exhaust on FB20, boxer 4 now find me dozen of those with a true dual.

Haha, yes i realize many other cars have real/true dual exhasts.

I was thinking the same. I know many 6 and 8 cylinder cars come with true dual exhausts. But are there any 4's that come with a true dual exhaust from the factory?

[bofa]

Originally Posted by ichitaka05

Hm... if that's the case, then isn't that add more weight to the car? Also two separate cat equal to two extra o2 sensors (before cat & after cat)... which means more ecu crap. Also add to that, isn't it gonna cost more for after market parts?

Yep it does have the potential to add more weight, although its entirely possible a true dual made of aluminum or titanium could still weigh less than the stock exhaust.

I honestly haven't done much research on any boxer engines running a true dual setup. If there is in fact a single o2 sensor stock, I imagine the only way to pull it off would be an X pipe in the middle of the system and to mount the sensor there. Maybe we'll get lucky and see two o2 sensors, but I'm not sure that would happen.

[WingsofWar]

Originally Posted by tranzformer

I was thinking the same. I know many 6 and 8 cylinder cars come with true dual exhausts. But are there any 4's that come with a true dual exhaust from the factory?

i think any inline engine that runs a true dual is kinda retarded, because it has a single exhaust bank. I don't think any 4s come with true duals or any flat-4s for that matter even with 2 exhaust banks.

For small engines like the FB20 i don't believe there are enough exhaust gases being pushed out to see any more gains on a true dual setup vs a single exit on a street car. Just added weight.

But once we get to a level of performance achieved in which fuel and engine tuning are more fickle and demanding, a true duals setup helps further monitor engine performance via 2 EGTs or 2 WO2, and provides additional power to each bank separately. But at that point its more like track car status.

Only reason why rotaries benefit from a true dual setup despite being a 1.3 liter is that they physically push an equivalent gas volume of a 2.6L v6.

[WingsofWar]

Originally Posted by bofa

Yep it does have the potential to add more weight, although its entirely possible a true dual made of aluminum or titanium could still weigh less than the stock exhaust.

I honestly haven't done much research on any boxer engines running a true dual setup. If there is in fact a single o2 sensor stock, I imagine the only way to pull it off would be an X pipe in the middle of the system and to mount the sensor there. Maybe we'll get lucky and see two o2 sensors, but I'm not sure that would happen.

some tuners use only 1 bank for Narrowband o2 for stock ECU. But most use a crossover pipe for 02 as well, but for the main reason of Exhaust scavenging, or quasi-static scavenging effect based on the Subarus firing order.

[bofa]

Originally Posted by WingsofWar

i think any inline engine that runs a true dual is kinda retarded, because it has a single exhaust bank. I don't think any 4s come with true duals or any flat-4s for that matter even with 2 exhaust banks.

For small engines like the FB20 i don't believe there are enough exhaust gases being pushed out to see any more gains on a true dual setup vs a single exit on a street car. Just added weight.

But once we get to a level of performance achieved in which fuel and engine tuning are more fickle and demanding, a true duals setup helps further monitor engine performance via 2 EGTs or 2 WO2, and provides additional power to each bank separately. But at that point its more like track car status.

Only reason why rotaries benefit from a true dual setup despite being a 1.3 liter is that they physically push an equivalent gas volume of a 2.6L v6.

I think you are right in that it might not make sense for an inline 4. For a flat 4 though, I guess we'd have to see some tests. As for the output volume it would really depend on the diameter. If performance gains are realized for say, a 3" single pipe, it would be reasonable to expect similar or even better gains from a true dual with ~2" pipes.

[chulooz]

Originally Posted by WingsofWar

for my function>form,

Twin Non-Sequential Turbo - Titanium True Duals with twin EGTs for metering

or

id do true duals for a track car..but single exit for best street performance.

That is my point... why did you say this? true duals are absurd on such an engine.

[bofa]

Originally Posted by tranzformer

I was thinking the same. I know many 6 and 8 cylinder cars come with true dual exhausts. But are there any 4's that come with a true dual exhaust from the factory?

No idea...

And don't get me wrong fellas, I'm not hellbent on a true dual setup, but I guess we at least have something to talk about.

[WingsofWar]

Originally Posted by bofa

I think you are right in that it might not make sense for an inline 4. For a flat 4 though, I guess we'd have to see some tests. As for the output volume it would really depend on the diameter. If performance gains are realized for say, a 3" single pipe, it would be reasonable to expect similar or even better gains from a true dual with ~2" pipes.

The Output volume doesn't depend on exhaust pipe..its the total exhaust volume that the engine puts out. Typically smaller engines don't give big exhaust pulses. Biggest you should ever go on a small engine, small displacement, N/A is a 2.5 in pipe...you can push 2.75 but your risking performance. A 3 inch exhaust will rape your low end torque band and ultimately rob you of power.

[bofa]

Originally Posted by WingsofWar

The Output volume doesn't depend on exhaust pipe..its the total exhaust volume that the engine puts out. Typically smaller engines don't give big exhaust pulses. Biggest you should ever go on a small engine, small displacement, N/A is a 2.5 in pipe...you can push 2.75 but your risking performance. A 3 inch exhaust will rape your low end torque band and ultimately rob you of power.

Yep I realize that... But I have to admit I was thinking of turbo 4 when talking about the 3" pipe (oops). I agree that N/A, 2.5 is probably pushing it. Maybe they will make a turbo version just so we can have true duals (insert I heard there's gonna be a turbo version thread here)