Quote Originally Posted by Daox
Yup, that header was designed for 1.5L Tercel engine.

I'm absolutely sure the tubes should be that long. Long tube headers are always superior to shorty headers. Look on any race car. The longer tubes give you a broader torque band than short tubes. I've read the recommendation for a street car to never go shorter than 32". I think this header is 34" or 36" IIRC. They're also equal length runners which is another good design practice.
Thank you Daox,

Very informative answer. I've heard about equal length design (which is what xiaogary's header for our car looks like...) I haven't measured the actual length, but from what I understand, xiaogary's header which replaces our stock header and cat is not much more than 24", but definitely not 32" or 34"... Is there a way for us to go longer than that? Would it be practical? Are the gains from xiaogary's headers actually the best we can do or can we go with a longer cat-delete header for more gains?

Also, they say that 4-2-1 is a better choice for smaller engines (like aveo and tercel engines)... what's your opinion on that?

Thanks ahead for all the answers.

P.S. I understand that this may not be the most appropriate thread to ask these questions (but it already had a picture of headers in it ) so if you need to, feel free to move this post where it belongs better.