finnigan5823

iTrader: (4)

whats best?

currently have ported headers

on my v5 typeR= 2.5 bottom end,v5 heads,td05/06 20g,550's etc etc

mapped by andy F( 418bhp/420lbft)

anyway whats you lots thoughts on GT SPEC equal length tubular headers?

will it make my car spool up quicker or more power?

or am i best off sticking with my ported headers?

cheers. finn

shepster

iTrader: (2)

More power captain, have them on mine and are worth the expense.
You should see good gains from them on your specs.

MaDaSS

Stick with the ported. I do not see how you will gain any spool up at all changing to tubular, if anything it will go up the revs, like mine did. Speak to Harvey before you do anything with your spec. He will give you honest advice. He helped me as best as he could, and if i had known him years ago i would be thousands of quids better off now.

finnigan5823

iTrader: (4)

thanks for the reply's

will speak to harvey tommorow

its his headers which are on car now

but once read somewhere that gt spec headers wer the ones to have

am sure harvey will no best

Juice

at what power level should you consider changing the headers.?

what are the standard headers good for? and if they are changed to aftermarket ones, what advantages and disadvantages would be seen?

dunx

iTrader: (3)

It should make more mid and top end power, imho.

As for spool a 2.5 should mask this nicely ?

dunx

MaDaSS

Harvey really is the man to ask about all this.
All you need is ported OEM ones until you get above at least 350 to 400 bhp.
Tubular rob you of low down torque. I know because i have em. Tubular will lose some of the burble if they are slightly unequal, and lose a lot of the burble if equal headers.
Although, i bloody love the howl mine makes now at high revs! LOL. Awesome sound.
Mine are GT Spec II, ceramic coated headers.
Now i have recently had my up pipe changed back to a smaller diameter one, all to do with spool up, etc, and it made a noticable difference.
Dont just post on here, you need to speak to someone knowledgable before you waste your money.

Juice

thanks for advice, ill send harvey an email now

garetgax

iTrader: (3)

ive the same spec but with 740cc phase 2 injectors. looking to go for a second map on e85 and wondering about main bearings and engine safety parameters at high revs etc during trackwork. Wondering if i should look to replace the crank witha nitrided one and acl bearings or is it safe at the 400 ish mark. I assume as well that a sti 6 speed can cope with 400 ftlb torque on a consistent basis. If im remapping on e85 though wondering where the limit is before i need to look at a full rebuild.?

harvey

iTrader: (48)

On a 2.5 (not 2 litre) around 420/420 and with a good 05-06 20G you are around the point when a change from ported to tubular is worthwhile. However, I have now developed a special 3 bolt flange up-pipe to run with the GT Spec headers and the response and spool and mid range torque will blow you away. Everyone who has had one fitted in place of the O/E GT Spec up-pipe has raved about it.
Paul : I can do you a good deal on a set of GT Spec 3 bolt flange tubular.
The special up-pipe is £139, stainless, slip jointed DEI wrapped and new Subaru studs.