i was at autozone today picking up new headlight bulbs for my 99 prelude. the guy at the counter was asking wut kind of performance mods am i doing. I said i would like to put on a header, and then he laughed. He said how i would be stupid for doing that because vtec engines need back pressure to get the best preformance. is this true?
i was always thought that free flow was better than any kind of restrictive exhaust manifold

 

You should never discuss anything with any employee at AutoWeDontKnowShitZone. Simply pick up your part, pay for it, and leave. No conversation.

 

The guy has no idea what he's talking about. Back pressure is a word thrown around a lot with exhausts, but seldom understood. Search for the threads on here about 3" exhausts on Prelude's and how they made power everywhere on a nearly stock motor. If you want to be nice, print off the dyno graphs, give it to the guy at AZ and tell him to stop spreading lies and learn what he's talking about before he gives more bad advice.

 

Better yet, search Google for "back pressure myth" and you'll get about 10 sites that explain it fully.

 

Tell him that Hondas don't have 8 cylinders. His understanding of air pumps (engines) is based solely on limited knowledge of normally aspirated V8s.

 

He is wrong.

 

AutoZone? More like VATOZone

 

dont flame me for this but... isnt a little bit of backpressure good for low end torque? but it would rob high end power right?

 

thats funny man !

 

no. do as kronn says and find the stuff written by blake

 

I agree, even though I shop there, I have more knowledge than autozone tools.

Like today, I need batteries with cold cranking amps of 620 and 32 degree cranking amps of 820. The guy was sitting there telling me that this isnt the right battery, and pointing at the screen.

I told him, just because its on your screen doesnt mean it's true.

They can be helpful, but beyond replaceing OEM equipment, they can help you.

 

You can go too far with an exhaust that's too big, or trying to run a header that's designed for something other than what you are doing with the car. There are certainly header designs that will produce more torque at lower RPM than other full-race headers, and this is why you hear about people who favour four-into-one headers, and others who geneally favour four-into-two-into one headers.

The trick is to do your research, and pick a header design with a good reputation and with proved performance suited to your application.

 

yea im gona have to agree that there is some truth to it... while back i had a custom 3"strait back exhaust and noticed it pulling more at very high rev/speeds, ended up gettin a 2.5" and it definitely gets off the line quicker now

 

go back and tell him