EXHAUST HEADERS... CHEAP ONES ON EBAY...?

ye jamie they are cheap for a reason they are crap they crack every where usually near joints just before the welds had a set for one of my cars that looked like them and thats what happened
 
Yeah figured as much... :icon_rolleyes: Out of curiousity, did you notice any difference power wise or quicker spool up from em Dec...?
 
it made mine worse jamie but i was a bit green at the time and was fitting them with a td04 on a standard wrx ,tbh it would be an advantage on a track car or a big power car where it could be mapped in for better spool low down and for better flow at high revs ,so it has advantages and disadvantages :dontknow:
 
Hey Jamie

If you want to know more about headers stuff, contact Harvey Smith on Scoobynet, He's a guru..
What he will probably tell you - tubular headers are suitable for only 400+ bhp cars as they delay the spool but add a couple of horses.

for up to 400 bhp the stock original headers are good enough. I've ordered and fitted the ported headers with matched up-pipe from Harvey.. and it was a really good, worthy mod imo. :thumbsup:
Turbo spool has significantly improved.

oh, and stay away from this cheap, cracking ebay stuff :icon_hang:
 
@ Dec... Cheers :thumbsup:

@ Codders... Cheers for the info too.... I'm initially only aiming for 360/370... so if the standard headers are good for that... is there anything to be said for changing the up pipe..? Also can you strip the heatshielding off standard headers and wrap them with heat wrap to keep the temps down....? :dontknow:
 
JAMIE-TYPERV6 said:
@ Codders... Cheers for the info too.... I'm initially only aiming for 360/370... so if the standard headers are good for that... is there anything to be said for changing the up pipe..? Also can you strip the heatshielding off standard headers and wrap them with heat wrap to keep the temps down....? :dontknow:
Click to expand...

That's exactly how they come from Harvey.. without heatshield which is usually on the crossover pipe... and DEI heatwrapped :thumbsup: You can do it yourself too..


The Up-pipe is plug and play under condition you have standard turbo. If you have different one, the up-pipe will obviously have to be appropriate to match it. :thumbsup:

manifoldf.jpg
 
Get rid of those heat shields :thumbsup:

Generally heat wrapping is a good idea.
Following the rule no1, which says what's cold should remain cold (intake), and what's hot should remain hot (exhaust).. heat wrapping the exhaust manifold not only isolates it from cooling system, intake, etc., but also enhances exhaust gases flow. :thumbsup:
 
Jaime ur standard manifold and ported up pipe would be perfect for up to 400... or twinscroll set up, which is fast spooling, good for 500 but will loose burble.

What ever you do dont buy the cheap sh*t, imagine a piece breaking in header, going through turbo and into your engine... not cheap anymore :icon_hang:
 
Headers definitely need a remap to get the best from them - you need more fuel and advance during spool up to bring spool point lower down the rev range. As above, no point really until you get to swapping the turbo. However, once you've gone that far (turbo and mappable ECU) then decent after market headers will provide more power than ported stock headers above 5k or so...at the expense of slight later spool, and loss of the scooby burble (replaced with an addictive banshee scream if running decat and 1.2 bar over 6k!).

Richard
 
@ Codders....

I've being doing a bit of research on the Harvey's OEM modded headers and some good gains to be had from them taking into account the power levels I'll be aiming for. So I've decided to give DIY porting and polishing the headers a go, followed by removing the headshield and then by wrapping them. I've been checking out a few good threads where this was carried out and it seems fairly straight forward.

Flow matching them will be the only thing I won't be able to wet carried out... but I assume opening up the ports and polishing them is bound to improve the flow of the stock headers somewhat.
 

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Porting is kind of flow matching anyhow - aim to have a slight lip between the joints, such that in the direction the gasses are flowing, the opening gets a little bigger as it passes through a joint. I'd actually do it all in one go though - wrapping the OE headers also improves spool as it retains heat which is the power that drives the exhaust wheel (make sure you wrap the up-pipe too).

Richard
 
Is this what you mean bout havin the opening larger as it passes through a joint Richard....? :ponder2:
 

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Exactly Jamie, although I would not open out the left hand hole quite so large. Imagine it with water flowing rather than air, then imagine there being little fish in the water. You want to get the fish to the turbo as undamaged as possible...if that makes sense, LOL! It was how someone explained it to me many moons ago...

Richard
 
I looked into this a bit too Jaime, and at first look, i seen that the opening in gasket was alot bigger than opening on headers, but its not a good idea to widen the header ports too much, i was advisd to just open the up by around 2mm, and taper that down along header around 4mm, essentially just tapering it a bit. On you diagram above, with gas flowing left to right, i wouldnt taper out the left side at all, just taper out the right side a bit so you can funnel in more.

If you measure the i/d of your head exhaust port and the i/d of header openings they should be around the same, the gasket is a good bit bigger i/d

I have a few pics, not great quality, i didnt go down the route of polishing at all as i allowed the will be soothed up fairly quick
This pic i have the left port done and gasket left over it... shite pics i know
DSC00265.jpg


This one the port on right i have done and have the gasket left in place
DSC00264.jpg
 
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