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Wuz up fellas, Ive been on this website awhile but I cannot find a good thread on Headers, performance gains w/ them... etc... Could some one please fill me in or at least direct me to a good thread about Headers for our STI, thanks.
 

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DS1 performance has done a header shootout on WRX, modded WRX, STI, and a modded STI. It should be published come Jan, Feb in (I forget) magazine. Mag name was like performance, style, and something if I remember. In that they have Borla, Gruppe-S, GT spec, HKS, etc up to 8-10 headers. From everything that I have heard, GT- Spec II seams to be the best power adder. There is a GT-spec III prototype that was tested too though. I'm sure this will be posted on Nasioc. I'll post the link when I get home.
 

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Hey JJ!

Im ordering the new GT Spec headers from Dan (not confirmed, but supposedly the Spec 3 models), but anyways... they are very nice and are very good priced. Gains were about 1-2whp lol , but about ~15wtq (which is where it counts , that and Dan's car is pretty maxed out as it is.). Im sure guru can tell you more, but I will definitely be getting a set. I also liked the fact that they helped the knock threshold and also seemed to balance and smooth out the A/F ratio. Very nice pieces.

Robert~
 

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whoa... i might have to hold out then. Although my price range probably wont be up there for anything past the GTspec 3 anyways :( ... anyways, nice write up :) cant wait to grab that mag.

Robert~
 

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i gbot the gt spec Ii very happy with them...keeps the same boxer sound...hks downpipe...stock exhaust....267whp 8)
 

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from what dan showed, those headers wont do much in the HP department... (1-2whp) but gains of like 15-20wtq! Which is awsome.

Robert~
 

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Turbo Insulation Kits

from what dan showed, those headers wont do much in the HP department... (1-2whp) but gains of like 15-20wtq! Which is awsome.
Dan's results were severely limited by the VF39. Think about it like the WRC cars that are restrictor limited to 300HP. These cars make much more torque than normal (300ftlbs) because they are airflow limited to a certain HP. The VF39 also does this on the STI. If (when) Dan gets his bigger turbo, he will realize similar HP gains of the headers.

Remember that HP = rpm x T(torque) / 5252. So if you make X torque gains, you will probably make similar HP gains unless you are being limited by airflow.
 

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Squeaky seat

Yes I know, thats why I said i was excited by the 15-20wtq gain... then with even a bigger turbo the gains would grow.

Robert~
 

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They might be the same as some other company's dyno #s ;) they're known to copy people.

Robert~
 

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With what my Jet-Hot coated GT-Spec Gen. II's did for my WRX wagon's torque curve - I can't wait till I put them on the STi...

I just need to get done with my data logging and then go into my mods step by step - I am not going all out at once this time.

Log, log, log.
Then this month Aquamist system 2d goes on along with the AquaXEDE.
After that start on the exhaust.
 

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Yup, same here man, the Jet Hot GTspec 2 headers will be going on my car as well soon.

Robert~
 

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DeltaDash? Any one have info on it?

i have the gt spec headers and they are really nice. tons nicer than my friend who had the borla ones.
 

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I have the hks hedder on my sti and had it on my older wrx. Did not get to dyno but in both cases the upper rpm pull was increased nicely.
 

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I had a 02 WRX basically STG4 (18G) + TMIC and completely catless running a WBO2 etc...

I did a GP-MOTO 4-2-1 equal length header as my last mod and it boosted my MPH in the 1/4 from 103.9 to 106.3 so that means at least a 20-25whp gain, never dynoed it though. This was on same boost and same tune (a/f and timing) as before the header. So basically the header is a good mod.

Only downside was that particular header had so much plumbing that the piping rubbed the stock plastic guard that sits under the engine and burned a 1x3" hole through it. And gave the exhaust note a much higher pitch and a somewhat tinny sound... basically didn't sound too good anymore IMHO ;), but it did give me some really good power.
 

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And gave the exhaust note a much higher pitch and a somewhat tinny sound... basically didn't sound too good anymore IMHO , but it did give me some really good power.
Thats why I wouldnt get the equal length headers... the extra 5whp or so over normal unequal length headers (gtspec) is not worth it for the loss of the deep boxer rumble.

Robert~
 
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