scion header interchange?

[NichO]

Originally Posted by riceboy

Quote:
Originally Posted by riceboy
do you know if the DC header for the scion will fit the yaris?? i hear that its a nice piece.. and a lot less expensive than the TRD..

It will not, bolts up fine to the block but is not in proper line for the Yaris' exhaust.

THANKS FOR THAT INFO!

[CASTREX]

Weapon R installed a Scion header on a Yaris with BAD results. You can look up for that thread.

[Chris07LB]

Thats because IT DIDNT FIT.

[jmew0ng]

Bummer the headers don't fit... I felt a gain in torque in the echo(w/ scion headers ebay non-brand) It definately felt like it picked up quicker. :x I had stock exhaust with AEM cold air.. HP Wise.. I guess it "appeared" to increase top speed by a little.. but judgement was based on this mild downhill empty freeway (still comparing downhill stock vs downhill with mods) Upped top speed by like 3 mph'ish not too sure.. i just know it almost touched 115

[RossP]

I know theres a header in development, cat back exhaust and lowering springs being developed by a US company atm

[ChinoCharles]

Yeah, you're kind of right. I was probably stoned. Sorry.

[AE86Yaris]

Originally Posted by ChinoCharles

Yeah, you're kind of right. I was probably stoned. Sorry.

there are 2 reason for Individual throttle bodies

1) to help idle a aggressive cam

2) to maximize a aggressive cam

i've driven 4age with ITBS and no cam upgrade and there have a lot less torque than my 4age with stock manifold and no cam. Unless the xA has some crazy camshaft it will see a loss in low end torque. ITBs are for those that only want extreme topend out of there engine, with little or no bottom end to speek of.

so basically stock camshafts have no need for ITBs and therefore it is only for show cars which is therefore linked with being lame, real car guys actually race.

[BulletProofAuto]

there is no "too large" piping diameter for turbo, as for n/a yes there is. i wouldn't go any larger then 56mm for piping with this motor. it seems as though most aftermarket companies are sticking to the 54mm diameter. everything has to do with exhaust velocity, you want optimum velocity...backpressure will only slow it down and force the engine to work harder to pump out the exhaust gases.

[DTM_Yaris]

Originally Posted by john@bp

there is no "too large" piping diameter for turbo, as for n/a yes there is. i wouldn't go any larger then 56mm for piping with this motor. it seems as though most aftermarket companies are sticking to the 54mm diameter. everything has to do with exhaust velocity, you want optimum velocity...backpressure will only slow it down and force the engine to work harder to pump out the exhaust gases.

Im sorry but this post is not quite right.

[soros151]

Yhea, nothing its too big for a turbo. Go ahead use a a 5" diameter piping then.

[heylookitsjames]

just run 18" runners on your ITB manifold and you wont lose any torque

[DTM_Yaris]

Originally Posted by soros151

Yhea, nothing its too big for a turbo. Go ahead use a a 5" diameter piping then.

This one is very wrong. Exhaust theory still applies. Regardless of the fact that it has a hairdryer attached to it.

[soros151]

Originally Posted by DTM_Yaris

This one is very wrong. Exhaust theory still applies. Regardless of the fact that it has a hairdryer attached to it.

Well, u would want the turbo to spool as fast as it can to achieve the boost u want. So there is no lag, if u don't believe me then, do the research, and then answer me back. It may not seem right, but u would need to deal with backpressure in N/A trim. For turbo, flow efficiency is the right point. Why do you think a 2.5" to 3" piping for a turbo tC (2.4) is a good idea? Because u need to let the turbo move the exhaust gasses faster to help spool time, also N/A needs thermal capacity in the piping to retain exhaust velocity, that's why backpressure is still needed. Go turbo... no need for too much backpressure since thermal capacity is there with the gases and temps from the turbo itself.

[DTM_Yaris]

Originally Posted by soros151

Well, u would want the turbo to spool as fast as it can to achieve the boost u want. So there is no lag, if u don't believe me then, do the research, and then answer me back. It may not seem right, but u would need to deal with backpressure in N/A trim. For turbo, flow efficiency is the right point. Why do you think a 2.5" to 3" piping for a turbo tC (2.4) is a good idea? Because u need to let the turbo move the exhaust gasses faster to help spool time, also N/A needs thermal capacity in the piping to retain exhaust velocity, that's why backpressure is still needed. Go turbo... no need for too much backpressure since thermal capacity is there with the gases and temps from the turbo itself.

I've done the research for many years. Actually since 1990. Ive been turbocharging for over a decade and a half. I am pretty sure I have seen and developed a few things in my time.
I think you are misunderstanding the term backpressure. There isn't an internal combustion powerplant in this or any world that wants or needs backpressure to make power.
If there is ANY backpressure in an exhaust system, then there is something wrong. Meaning something is clogged or capped. Completely restricting flow in one direction. Pressure "backing" up towards is original source.

Now exhaust capacity, harmonics, velocity, thermodynamics, etc are completely different terms to concider.
There is absolutely NO rule book on exhaust size or geometry. It needs to be mapped and trialed.
When FI guys discuss large diameter downpipes, it isn't to say bigger is better. On a typical turbo application bigger is NOT better. It is about differential pressure. The pressure on the inlet of the turbine in relation to the exit side of the turbine. The bigger the "downpipe" the better does not work. It makes absolutley no sense, because you still need velocity to get you thru the rest of the exhaust system as efficiently as possible. Of course without limiting capacity. The SIZE of the downpipe will depend on how much airflow you need to process thru the engine. That is the only determining factor. NA or not.

Normally NA engines like to be a bit more conservative on diameter because they need to scavenge thru the ports. Limiting, predicting and "organizing" the exhaust pulses in such a way as to increase volumetric efficiency. On some cylinder head designs with Identical displacement engines, primary runner and collector sizing can vary 1/2 to 1 1/2 inches.

Again there isn't any concrete "this is what you need for na" rulebook on exhaust systems.

[DTM_Yaris]

Originally Posted by soros151

Well, u would want the turbo to spool as fast as it can to achieve the boost u want. So there is no lag, .

It doesn't matter if you have absolutely NO EXHAUST you will NOT get rid of "lag".
It is inherent to the size and design of the turbocharger. It takes heat energy to spin the rotating mass.
Heat energy needs to expand on the turbine blade. Having a two inch downpipe and having a 5 inch downpipe will not get rid of "lag"
Boost threshold (turbo lag) is dependent on the engines ability to produce the required energy to spin the turbine.
Now CAN you decrease the "lag" time slightly with a better pressure differential? Yes you can. If the ENTIRE system that is on the car is restrictive. By increasing the size of the downpipe off the turbo, it can aid in quicker turbo response. Very mildy however.

[soros151]

Well I posted earlier that it would not be wise to use anything TOO BIG, so there u go. While there isn't a guide, there are certain knows in performance. Experience, and reading, and reading and reading and studing helps a lot. Once u have gathered every bit of info, re-read everything and take unbacked knowledge (read: forums) as a grain of salt, yet take them into account like personal opinions and maybe builder tips.

[Notthy[Yaris/S]07]

a friend who has a Yaris HB said to me that I install header to him of xB and single he had to modify cats and to put one high flow and ready


that is what I want to do.....

[Chris07LB]

Get the Megan header MADE for your Yairs.