hello, i have a few questions regarding headers which i am planning to get.

i currently have an 04 sti running approx 375hp on the OEM headers, i am looking to replace them after xmas with new ones, i have been doing alot of reading and digging on old threads and was wondering what sort of power/torque increase you might expect from them? lots of different opinions however would it be too much to expect a good couple of hundred rpm spool, + 20 torque?

would you also notice any power increase? some people saying you will only notice a HP increase on equal length ones?

most the sets come with a new upipe to match them and some with the heatwrap, presumably heat wrapping will be better to keep the gasses hot for spooling? also is it worth paying the extra for ceramic coating over heatwrap?

thanks for any help

 

Just get your standard ones ported, (standard STI ones are very good ) have a chat with Harvey

Tony

 

i was contemplating this Tony however future plans might see me goign beyond 420hp so was probably thinking a nice set of 3 bolt headers might be a better option?

 

No not really, the new age parts are much better manufactured than alot of items you can pick up, Harvey is your man to chat with, but if you look at people like Shaun who ran 600bhp (sti headers still i think, just ported), it shows you that you dont need to buy everything that people say are better, alot of parts are not, but chat with Harvey before you go any further

Tony

 

im going back to sti headers from stainless equal length and have seen cars with big power on standard sti so save money and get them ported you wont be disapointed

 

why are you going back out of interest simba? what stainless steel ones did you have on?

 

japspeed mate not so good and too be honest really missed the burble it sounded like a evo japspeed did not last long and cracked even with heat wrap on also very hard to fit but some like them and have no problems my sti headers have just come through the door awesome !!

 

i see lateral do a set of 3 bolt headers with up pipe and heat wrap for about 600 quid delivered, says on there for cars aiming above 380+ , if thats the case why do people buy these if ported OEM will give the same results?

 

I would say it depends how you drive it and plan on driving it. Some fast road driving, hooning around like a chavy loon, or track?

I used standard STI ones and had nothing but gasket failures every time I went on a track day. After that I swapped to RCM ones and did more track days. They were wrapped, one set cracked and the other cracked and melted. Now run RCM but unwrapped and not had any issues at all as they run cooler now.

 

now thats interesting that un wrapped stay cooler i suppose that heat is just moved away by movement of the car

 

That's something I didn't really understand either. Why do people say that the exhaust gases will be kept cooler if thr headers are wrapped. I would hav thought that having the headers wrapped would keep the heat from dissapating?

 

i thought you heat wrapped to keep the heat within the headers and keep the gasses hot to aid spooling?

 

correct

GT2 spec headers with harvey smiths trick uppipe, works for me

 

Harvey sells tubular headers as well as his ported ones but only recommends them for bigger power outputs due to lag

 

so what power are tubular headers recommended to start being used at?

 

I'm running Harvey ported headers and matched up-pipe and they're now holding my car back at 440BHP - need to get a set of tubular with the Harvey Up-Pipe again though.

 

Look on Harveys website or pm him, but I think he rates his headers to over 450bhp. Tubular with Harvey up pipe is a good set up the trick up pipe minimises lag. This is my set up on my V3 STI

 

Classic manifolds are not as good as new age ones, what you need for a classic you dont necessarily need for a newage Still speak with Harvey first before buying on impulse something that you dont need

tony

 

As above, wait until you have talked with hHarvey BEFORE buying.

Mine, running a 2.5 in a classic, uses GT Spec headers from Harvey and a matched up-pipe.

 

cheers chaps will speak with harvey and sort something out

 

I run the std MY01 headers on my Spec C with a std (lightly ported) uppipe. It runs up to 500bhp and 550 torque on a 2.5. I have tried GT spec headers, Gruppe-S headers, HKS headers and a number of different bore uppipes. Some made slightly more power but I have gone back to std headers and ported OE uppipe as that results in the quickiest and most responsive set up by far.