You are wrong in this case. While an engine is essentially an air pump, the more air you pump thru the more fuel added and thus the more power.
I see all the talk about you must have all 3, intake, exhaust and header to see the power..
Well everyone is forgetting one major part... The head. It can only flow so much. So adding larger tubes on either side won't do anything except make you lose torque. Toyota has optimized this engine at the factory. All you are doing is lightening your wallet.
Now headers can help if designed correctly and that involves a long tube unequal flow. This creates a scavenaging effect which helps draw gases from the exhaust ports. The shorty headers are worthless.
Don't let the size of the ports fool you.. It only matters if the heads can flow enough cfm to utilize the larger pipes.
Just because they make headers and intakes, exhauts doesn't mean they work. Its the way they make their living..
Now if you are talking about a V8 , there is always room for better manifolds and pipes... but this 1.5L puppy is already optimized from the factory.. all you are doing is changing the torque curve... for the worse.
Get an exhaust for the sound... thats all its good for... Intake also for the noise... try and find a long tube header that is designed for the car... if you do, you wont be paying $60.. but it will at least do something besides making your walltet lighter

 

intake, header, and exhaust do help. yes they change the torque curve but usually for the better. since your transmission regulates more of your torque than your engine does. have to rember torque is just a measure of revolution in ft pounds. toyota didn't optimize this engine for power we all know that it was optimized for gas mileage. yeah porting could make it better but still if it didn't make difference in adding this stuff why would toyota even consider selling it as factory accessories? if it doesn't really do anything. every time i've added and intake its helped my low end torque and some of the uper end power. honestly an engine dyno doesn't lie.

 

well the heads must have slightly more flow than needed stock...... cause i/h/e gives hp and tq.

 

lose torque. I dont think so. Why would just an intake make power on the dyno if what you claim is true.

Take for instance the stock intake hose. The black ribbed one. The ribs in this tube are not designed for power. They are there to reduce intake "noise." Removing these a.k.a. aftermarket intake tube will increase h.p. and t.q. numbers because the flow is much more direct. Also what about the stock intake setup do you really believe that that U shaped pipe and that lousy snorkel are gone be better for torque numbers.

Don't take me wrong a modded head will still help alot with bigger h.p. applications i.e. f/i or a built bottom end. But or someone going with simple boltons i/h/e is a power making combo. Not big power but power none the less.

 

Okay.. Everyone is talking here but no one is saying anything except hotbox thats actually true.

4-1 header: General loss of torque in the bottom end, gain of torque and whp in high rpm range. With the xb, 4,000rpm+ is when you notice the most gains.

4-2-1 header: General gain of torque in bottom end, gain of whp in lower-to-mid rpm range. With an xb, you will notice most of the gain between 2,200rpm and 3,500rpm. Usually you don't see a loss of whp or wtq on the top end with a 4-2-1, but your power and torque curves do change.

i/h/e will benefit you the most, compared to one or the other. The head isn't as restrictive as some of you are putting it. The 1nz head is fairly close in design and actual size of the 1zz head. Which overall, its not that restrictive. No head is that restrictive from the factory, even a geo metro will see both whp and wtq gains with i/h/e. Which is probably one of the worst motors in a car in usa.

Stop reading off google and start learning from real life numbers and from people who actually have experience with building motors, light or heavy builds.

 

These cars ARE optimized from the factory, but not for peak horse, they are tuned for fuel economy, emissions and engine noise.
Change out intakes, headers and exhausts and you will affect power, power curve, noise, emmisions and fuel economy

 

You need to pull your head out of your ___ and learn something other than the hype you hear from the aftermarket dreamers who are only interested in your money.
I build and test engines for a living and most likely have been doing so before you were a wet spot in someones jeans. So throw your money away and believe what you want, you would probably only waste it away on worse things anyway

 

Whew....it's getting warm in here.

 

Yeah i must not know what i'm talking about. Nevermind i built a 231whp n/a gsr prior to owning the box, nevermind the countless times i've helped with friends cars ranging from easy head swaps to full motor swaps. Yeah, lets not talk about that i must be one of those guys that just listens to what other companies say.

We are talking about three basic bolt ons, not rocket science. You believe i'm wrong? Show me one car, any car that lost power with i/h/e, or showed no gains all. Show me one. I can show you hundreds of dyno sheets that prove that i/h/e does make a difference, usually a 10-15whp increase and wtq depends on what the set up actually is. But lets not talk about that mr. i've been around for years and i know exactly what i'm talking about. All i ask is for you to show me one car, one motor, that lost power or remained the same with just i/h/e. You show me that and we will go from there. Otherwise you can just stop feeding off non-sense about make believe, and stop trying to tell newbies what works and what doesn't.

By your logic, a head swap would do nothing. After all, the rest of the motor is "ideally tuned" from the factory for performance and because everything else is more restricted than the new head, it must cancel everything out. Hm, now that i think of it. Stand alones must do virtually nothing. Infact, almost all performance parts on the market today must do absolutely nothing unless you just rebuild 100% of the motor. By that time, and thousands of dollars later, you must see a gain of some sort.

Anyone that trys to argue that i/h/e (as simple as they are) do absolutely little to nothing is just absurd.

 

Not to jump in the middle of a fight, but honestly, I've come from a background similar to yours, though my teg stuck with a b18b and an auto tranny, but it made 170 whp on an auto without the spray, true race motor, but that argument is for another day, also hit 245 whp on a 50 wet, running rich. I've also built a 330 whp eclipse GST on 93 octane, but again another argument. The point is you're just like I am an over glorified part swapper, sticking to a label you like forcing it upon others. You've listed no real reason that the dc sports header is any better. I wanted to get a motor built to handle 500 hp all day for a few years, and only take it to 400 or so, for a very simple reason, major head work, and lightened lower end. I didn't get a lightened lower end the way the deal worked out, however people running more boost, timing and higher octane had trouble being consistent with me for these reasons, and theirs way to much detail to argue about it here.

I'll interject here with a comment about OBX at this time and point of what I know. I have purchased a set of headers, for a different car, which are branded by them, as well as a cat back. Apparently OBX Racing finds the companies that make exhaust, and buys from them. Don't believe me look up the headers from obx racing for a subaru 2.5 RS, and then go to http://www.rallitek.com and look at their header design, you will see very, very slight additional changes. such as a better spot for the 02 bung, and that the old one the manufacturer made was merely plugged with a stainless steel oil pan bolt. Also looking up a few other products made by OBX they have done the essential copycat method, which I stated above with a few others, (acura integra included.) Now the question to ask, is which company did the R&D to the 4-1, and in the end copied. Go a step further, and do the same for the 4-2-1. I'll lay $50 on the exact same product, with the product re badged by OBX; bear in mind I'm not a betting man, and have ____ed off people to the point that they'd pay so I'd leave them alone. I don't' believe OBX makes anything themselves, however I do know that what people are paying $750 w/o shipping for a full exhaust for my scenario, I got for $575 shipped, and I only have to live with three tags. I will not lie, Support through OBX is horrible, but its a racer's dream to get the exact same thing only cheaper, and the truth is if it was made buy the same company it will have the same problems, I just won't be able to get it fixed for free easily.

Now from my standpoint, the only advantage a DC sports has over an OBX or megan racing is the fact the dc sports tag usually always has a carb number, and I highly doubt the OBX does. This only matters in a few states.

You're whole argument on why OBX is better hasn't prove anything, and from what I know, I will share. The gains you see from bolt-ons are almost pointless for the cost. I've seen old heavy v8 monte carlos doing 13.5 in the quarter no nitrous on a carburetor. It had 3:78:1 gears, a stock cam, and a ton of head work, and mid style headers, with open true duel exhaust. Before the head work the car went 14.2 and the car went 13.2 after the carb was re-jetted. so to make make matters best scenario, this work was all done from a Wednesday to a Friday, in south Florida, during the summer. The gains for bolt-ons are extremely minimal when coupled to a stock motor, but getting that little extra always helps in the performance. I dont' know anyone that's willing to spend the time with a 1.5 to get the best gains out of the head itself, lots of money a good machinist and multiple heads along with a good flow bench will prove it.

Btw: I've seen pacesetters make more power then dc sports on the old j-bodies and Saturn's as well. After they got some head work, they ended up switching to a dc sports to take advantage of the extra bits. The fact is its all combinations of parts and lot of math. The XB crowd doesn't' show the same urge as what I've seen in other cars, however the fact is no truth has been given yet, so there is not a real answer to the initial posters question.

The goal to accomplish next is find out who makes the 4-2-1 and 4-1 that dc sports are buying form. I did not find out this knowledge first hand, but the source I got finding out that it was a true clone even presented the factory's name which was confirmed Rallitek worked with in the past.

Might I also add that since DC sports had been bought by the same people that own AEM, I think the R&D has gone up, but I also believe the products actual quality has gone down. On my teg, I had an old stainless 4-1 header, which was never a problem and I had purchased a 4-2-1 after they were sitting next to aem, and it was replaced 2 times due to cracking. I won't bash the company and I would recommend it to many people honestly, but I don't' feel you're mind is open enough to comprehend the fact that their may be better for a stock application out there, or even a better combination then what is in your mind atm. When people say its one way only it usually means the good out ways the bad, and that's definitely not the case. I've also seen people go faster for cheaper, and grenade a week later. Trick is find someone with a next to identical setup, and see what they dyno in as similar environments as possible. A race can also depend on driver, and I've seen many scion owners who think they can drive, and might be decent, but you never know how good they can actually be unless you watch them periodicly to see how they improved in technique, so a race isnt' my proof here. On that note even if the 4-21 takes milisconds differnece to go a higher rpm faster, when its a fwd vs fwd almost identical, you can bet your tail who's going to win when you shift the same speed and times. the extra horsepower will early in the band will provide a flatter torque curve, which the spike at the end won't overcome until you tlak of actually topping out your car. Where are you goignt o get an xb to trap over 100 mph in the quarter? I doubt it will ahppen wihtout forced induction.

Later,
Jerry Powell

 

Hate to be a 2nd consecutive post:

First lie to dispell a 4-2-1 vs a 4-1 should lose on peak power unles the 4-1 is a horrible design. 4-2-1 is a gain through the band hoping to make a flatter torque curve. Last time I got to drive the XB, when I power shifted, it shifted below vvti engagement. I know I can make one faster then yours in a quarter or a turn, without FI, if I stuck to a 4-2-1 and you to a 4-1, if we shared all information based on that. You're playing a peak power is faster. It saddens me that you once owned a teg and hadn't learned hw to properly use power.

 

Oh one more bit, unless monsotr motor works changed their header design, they are not the clone OBX used.

 

Beyond being ridiculously hard to read, absolutely nothing in your post was substantiated. Just a whole bunch of rumors and innuendo that, as far as this forum is concerned, have no basis in reality.

The most reliable information you have to go buy when buying after market parts is a companies track record. If the company has a track record of producing sub-par, inexpensive parts, what is the likelihood that this will change specifically for a market as small as the Scion xB/xA?

It has been said again and again in this forum, not to expect much of a gain on our cars even with an intake, header and exhaust. To expect more than a couple horse power for each is unrealistic. In the end it all comes down to quality. And the best judge of a companies quality is their track record. Sure, brand A and brand B headers might both produce 3 hp, but which one is still going to be functioning properly in a couple of years? Whose flange will begin warping? Whose welds will crack?

For my money it is worth paying the difference for a quality part from a company I trust to know that I am not going to have to worry about repair or replacement in a couple of years. If not sooner.

 

you must be retarted. if you're shifting below vvti then you never see any power........

 

I'm simply going to say this: VVTi does not engage. It's constantly variable. I think you're confusing VVTi with VVTLi or VTEC. The xB has VVTi.

 

Well the tone of the exhaust seems to change slightly above 4800 consistantly for me. I was going by sound and watching the tach in an empty straight for a dead stop, but I'll get the datalogger out, and see where the car starts cahnging its reactions to the metered amount of air to find out more. Interesting changes many theories, but ramping up airflow still doesn't change much.

People laughed at me with my mitsu when I was looking for a custom built header years ago, but no-one laughed when it made 80 ft pounds of torque extra 2500 rpm's earlier then the cast manifolds in a turbo situation. Think what you will, and thanks for pointing out its continously variable, it explained a few of its driving habbits I couldnt' understand before.

 

i think he's a lil slow......

 

ummm a tubi turbo manifold and a cast turbo manifold are sooo much different than 4-2-1 and 4-1 headers on an xB

 

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this is where i step in and say stop the baby name calling before this thread is locked. I don't care who started it, just let it end.

EDIT: This thread is locked.