kdanie

I have been thinking about this little engine quite a bit lately and have some thoughts on what it needs to be a better performer. I would like to get some input from all of you on what you would want from a header, remember that even the best header is still a compromise and until someone can design a computer controled variable (elsastic) header the best that can be done is target a specific range of performance and try and minimize the compromises in other areas.

So, the choices are:

A bolt on header (mates up to stock exhaust in the stock flange location) just like the others on the market. Inexpensive but hp gains would be much smaller.

A header that maximizes peak power (good for bragging rights and drag racing) that may not fit with the stock location exhaust flange. If max peak power is your goal, a complete custom exhaust would be required anyway. More expensive but much larger gains than the above header.

A header that maximizes midrange power with little/no sacrifice in top end. It would not reach as much peak power as the above header but would have a broader torque band. Not good for bragging rights but more fun to drive every day. This header would also require a complete custom exhaust to work correctly.

Basically just tell me what you really want from the header.

ken

showpaojoe

i don't know about the other guys but if its proven, then i'm down to do a complete exhaust. i don't know which group i'd be in though, most likely the fun to drive one with better torque. i guess you can't have the best of both worlds

GruntStyle

i will pick number 2 for 1000 alex, if we are going to have to get a custom exaust for max and midrange, i would rather have max

TheRedBox

Im all about top end.

Sorry if I'm biased. Those turbo DSMs sure do make you that way.

eric_m

i'm all about drivability.

sorry if i'm biased, but after driving a wrx with a lot of turbo lag and a lot of top end, i just want the thing to go as soon as possible, not work it's way up. top speed is all but useless in everyday driving anyway. especially on the scions where the gearing limits top speed to 120-130 at the max.

just my opinion.

2fixA

yeah, i'll peg for option number 3, it'll be a more everyday experience, and it isn't as if you don't go through the band to get to the top faster...

stellarhavoc

I 2nd that motion.

kdanie

So, it looks like only a few people really care anything about a header..... I'm surprised!! Well, maybe it's just that some of you don't know what you really want in a header. I could TELL you what you need but that wouldn't make you think/learn.....
ken

scionaraxb

I want a header the splits 1&3, doesn't come loose all the time, is Carb legal, won't leak all the time, won't rust through, won't have the paint burn off in the first 5 minutes, and won't cost an arm and a leg.

There, now make that for me please. (otherwise I'll just leave it stock)

2fixA

oh yeah, also a ceramic coating would be hella good... I've seen some measurements of the exhaust temp w/ and w/o a coating... if we can keep it hot and moving I'm all for it..

also if you mean the wide power band performance I assume you will be creating a tri-y style header versus a 4 into 1, which if I recall my headers correctly, has a much more narrow power band and focuses more upon high end power..

on top of all this I assume some amount of tuned length will go into this design so we can harness the power of a resonated evacuation of the exhaust gasses?

but this is all a matter of theory, the hard part comes in engineering all of this into a usable piece...

is that what you were wanting in a "knowledged" header response?

HemanC

I would opt for option 3. As long as someone can install it for me.

kdanie

EVERY mild steel header should be ceramic coated, it WORKS and quality headers are too much work to build to do it too often.

Stainless steel transmits 200 times less heat than uncoated mild steel but ceramic coating can still help them too.

Here's what I have found in 35 years of messing with engines: We spend hours deciding on what cam to run, compression ratio to set it at, intake modifications, cylinder head modifications, what ignition system to run and a bunch of other details then we bolt on an over-the-counter header and think we are done. Huge mistake, we just left a bunch of HP on the table we didn't even know we had available!

2fixA,
The old try-Y headers were touted as producing a wider/flater power band but this is not always true. A lot of dyno testing has proven that the CORRECT 4-1 header will better it in HP and torque. CORRECT is the key here. A modern 4-2-1 header is a far cry from a try-y but still not ALWAYS the best.

Here's some info straight from 2 of the best modern header designers in the country with experience in drag, NASCAR, TRANSAM and SCCA. A "fully developed" stepped 4-1 header is only worth about 1% increase over a "fully developed" single dia. 4-1 header. A "fully developed" 4-2-1 header is only worth about 2% over a "fully developed" 4-1 header. OK, what does "fully developed" mean? To get the maximum benifit from a header it must be designed for each specific engine combination using modern computer engine simulations and constructed using modern concepts such as merged venturi collectors. The header must then be dyno tested and refined, THEN taken to the track and refined again.... How many companies do this? Very few, if any! Heck, very few race teams do this (but consistant winners do!). Adjustable primaries and replaceable collectors are a huge help in development.

I am positive I could design and build a header for these little engines that would work so well it would REQUIRE a completly new intake system and programable ECU to make it run but the power gains would be considerably more than anything currently on the market. Did I mention I build custom headers for fun???

The possibilities boggle the mind.... A truely quick Xa with 4 individual throttle bodies and velocity stacks instead of that plastic intake we get from the factory, a fully scienced out 4-2-1 stainless header and custom exhaust to the bumper. Say....150hp (more with a compression bump and cam change) at the wheels?? SWEET!!


OK, back to reality...
The real key now is to design a header that works better than anything else on the market but doesn't confuse the ECU so much it can't function, and at a reasonable cost and relitively easy installation. That's a pretty big job and will require some serious R&D to do well.

ken