I am think about getting headers for my 2003 WRX. I was looking at the Aqua Header. I wanted to find out how good this header is.

 

Hard to tell, but it's design is very similar to the "cheaper" header kits on the market. I got a header from Revolutions Motorsports made by KMD and it's the same design 4-1. I paid $575 I think.

However, headers do virtually nothing for you until you are running a larger turbo. On the stock turbo, I barely felt any increase in power and perhaps gained about 300RPM in spoolup. My 1/4mile times only really dropped about a 10th or two.

There is also some debate on SS headers not being able to retain the same amount of heat as the stock cast manifolds. In theory if the heat is retained then the exhaust gas velocity can be kept up and thus will help the turbo spool and spool quicker. But in my case, I did notice the spool up a little quicker after installation.

Whatever, if you got money to burn buy it. But I really think it's something that can wait.

 

If you're gonna get headers, go for equal length or don't do it.

From a Garrett turbo systems engineer:

"As for primary lengths on turbo headers, it is advantageous to use equal-length primaries to time the arrival of the pulses at the turbine equally and to keep cylinder reversion balanced across all cylinders. This will improve boost response and the engine's VE. Equal-length is often difficult to achieve due to tight packaging, fabrication difficulty, and the desire to have runners of the shortest possible length."

Unequal length headers are a waste of your money.

 

I agree. If you're going through that trouble go for he equal length unit. Only one out there is the Maxim Works. They make them for the Prodrive and WRX cars. Here's a picture.

 

I thought that was the only being offered, but after looking at your pic it looks like the wrong pipes have been lengthened. In order for the primaries to be of equal length, the ones on the sam side as the turbo must be lengthened. In your pic it looks like the opposite side's primaries have been lengthened rather than the turbo side primaries. I must be smoking something.

Also, remember that the Maxim includes an uppipe which will save you about two hundred bones.

 

yes you are smoking something. they're equal length.

 

Ahh yes, Keystone had me a bit confused. I see how it works now.

 

who sells the Maxim Works Headers and how much are they?

 

Having seen one of the Aqua headers in person, I can tell you that it is extremely well made. I don't have any other WRX headers to compare it to, but the quality of construction is as good or better than the $2500 Hooker headers on my Corvette, and they are about the best there is.

 

If you take off your stock your stock manifold you'll see a black ring around the surface where it mates up to the block. It's that area you want to port match and blend into the manifold. Would extrude honing help? Who knows. But if you can port match the manifold and blend in the opening to taper into the manifold, you just accomplished what you wanted to do, speed up the Exhaust gas velocity.


Mitch