sikbrik

Actually, a short-tube 4-1 does exactly what you said...high RPM power gains. A 4-2-1 is really going to bump your midrange, 3000-5500 RPM a bit more SO out of the available options it seems the 4-2-1 would be better.

The part of the theory that was left out is long-tube 4-1 (especially true equal length) headers. These are going to boost power from off-idle up to about 3500rpm. Peak HP numbers won't be as high as the 4-2-1 but avg torque "under the curve" will be about the same and 1/4 mile times are likely to be within a tenth of each other.

Around town will be nicer with the long-equal 4-1, though.
Dragstrip might be nicer with a short 4-1.
Auto-x might see some benefit from a 4-2-1 since a lot of time will be spent in the midrange.

Like d0tSplit said, It all depends on what you want to use the car for.

sikbrik

oh, and since the 4-2-1 in this instance is BARELY a real 4-2-1 (meaning that the secondary length looks to be about 3" at most and that resulted in shorter primary tubes), it's probably not that much of a noticeable difference at all.

x2theB

Can somebody provide me a complete list of Manufactures for Headers for xB's along with pricing. Thanks!

AleXb

I agree with that..... its about time someone said something that makes logical sense... lol..... NOT TO DISS ANYONE.....


-AleXb.

killerxromances

He didn't, but i will. Toyota hasn't matched Honda's performance in years. Honda is ideal for an autocross environment, top end power, high revs, generally light weight depending upon what model. The Spoon Fit ran identical times as a stock nsx, what does that say for Honda? Sure, comparing two different cars within Honda's line up, but i've never seen Trd take a xb/xa and run it through tests against a Supra. Why? Because Toyota and trd doesn't take performance like Honda does. Am i saying Toyota's are bad cars? No, but class vs. class you will usually find Honda has a performance edge over Toyota. All aspects guys, cornering, acceleration, brakes, everything. The only car Toyota has right now that could be really considered as a performance coupe/car is the tC, and imo thats a joke. Way too heavy, way too top heavy, not designed for performance at any angle.

killerxromances

Oh, as for the 4-1 vs. 4-2-1 stuff. I have yet to see a 4-2-1 header for the xb make any more difference than a 4-1. 4-1 makes more top end power, makes more whp than wtq. 4-2-1 makes low-mid end power, and i've seen some dynos where they make more wtq than whp.

Also, lets not forget that a header alone will do absolutely nothing. Pair it with some other mods, and thats where the best gains will be. This has been discussed over and over, i could go into much more details but i'm exhausted, and i've got a lot on my mind.

*Absolutely nothing meaning very little gains*

x2theB

Can the DC Header for xA fit the xB?

hotbox05

yep it fit's yaris , echo , xa , xb

evilBOXevil

4-1 or 4-2-1....
I think that if you had a really free flowing exhaust that, maybe, a 4-2-1 would work well for you- But most people on here have an axleback exhaust.
If you did a whole header back exhaust, then I'd say go for the 4-2-1, but if your running on a stock catalytic (which would be everyone in California), you're getting plenty of backpressure-so go for the 4-1.
I feel like the purpose of the header is to open things up a bit. If you're thinking of the 4-2-1, in order to keep some backpressure, on these cars- you might as well save your money and stay stock.
I am god, and I do know everything-but this is just my opinion.