STOCK 08 GT-B tb STi on the DYNO - 182.6awkw

by **GTSPECB STI** » Wed May 20, 2009 6:47 pm

Actually the GT mufflers are very similar to the design of the sti quads with the exception of the tips. Both huge triangular shaped bodies with small in pipe. I know because I have taken a set of stock mufflers off a MY08 Gt Spec B and replaced them with a set MY07 Tuned by STI quad tips. Better sound but still damn restrictive both of them.

You are correct that the dump pipe is the most restrictive followed by the centre pipe with its horrible flat shaped resonator and then the y pipe and muffler combo.

by **STiLADYLIBERTY** » Wed May 20, 2009 6:52 pm

senator wrote:
STiLADYLIBERTY wrote:
senator wrote:nice work

what mods???????????????????

thanks , its completely OEM "tuned by STi" .

It says fairly good thing for the low backpressure STI twin mufflers IMO

I would like to confirm the ratios for an 08 6sp and also the rear diff type if anyone can tell me ?

stock... mmmmmm

just imagine what a tbe, high flow air filter and aftermarket tmic can do????

mmm , I hear ya . a few more easy kws to be gained when the need arises. Id do the fuel pump and possibly injectors in particular if going further with such mods.

by **GTSPECB STI** » Wed May 20, 2009 6:56 pm

the stock fuel pump and injectors will handle those mods easily with safety to spare trust me.

by **STiLADYLIBERTY** » Wed May 20, 2009 7:02 pm

GTSPECB STI wrote:Actually the GT mufflers are very similar to the design of the sti quads with the exception of the tips. Both huge triangular shaped bodies with small in pipe. I know because I have taken a set of stock mufflers off a MY08 Gt Spec B and replaced them with a set MY07 Tuned by STI quad tips. Better sound but still damn restrictive both of them.

You are correct that the dump pipe is the most restrictive followed by the centre pipe with its horrible flat shaped resonator and then the y pipe and muffler combo.

yeah , I guess the mufflers would be close to there max flow characteristics at around 180kw ?? I mainly kept it stock cause the wife likes it quiet , plus we`ve been down the full S/S TBE and catless up pipe road on my 04XT which I loved but it was painful on long trips .
and for $$$ per kw / bang for buck I opted to spend 1k on a tune instead of 1k for some difference in exhaust note alone.

really happy with it tho` , a great starting point if nothing else

by **GTSPECB STI** » Wed May 20, 2009 7:04 pm

totally agree that a good tune is the best bang for buck improvement you make to our cars. I had my car open source tuned prior to doing any exhaust mods and it made a big difference to mine.

by **tangcla** » Wed May 20, 2009 7:04 pm

Curious to know how much extra noise changing the centre pipe and Y-pipe would generate, if I kept the stock mufflers...

by **STiLADYLIBERTY** » Wed May 20, 2009 7:23 pm

tangcla wrote:Curious to know how much extra noise changing the centre pipe and Y-pipe would generate, if I kept the stock mufflers...

hmmm , me too . I intended to run a 3" TBE back to the factory mufflers .

I guess the mufflers should keep it pretty quiet regardless , spool up might still be a little louder with a S/S dump Id say

by **GTSPECB STI** » Wed May 20, 2009 7:33 pm

I ran the phat dump pipe to the factory system at first, a bit more noise but not too much and the sound was not that great. Then I replaced the centre pipe and y pipe and kept the sti quads. Bit more noise and some power increase but not a nice note to be honest. I then replaced the sti quads with hitechs and I can tell you the power increase was noticed and the sound was so much nicer without any drone or anything now. I love it.

by **tangcla** » Wed May 20, 2009 8:04 pm

STiLADYLIBERTY wrote:I guess the mufflers should keep it pretty quiet regardless , spool up might still be a little louder with a S/S dump Id say

The downpipe definitely changes the note. I had an AVO downpipe on stock mufflers, it sounded tinny and raspy as.

by **blacknwhite** » Wed May 20, 2009 8:16 pm

I had the Phat dump and centre with the stock cans in the time between selling the Hitechs and getting Phats muffs, and it was ....horrible, felt after the Hitechs like a broom was up its bum

by **STiLADYLIBERTY** » Thu May 21, 2009 7:31 am

blacknwhite wrote:I had the Phat dump and centre with the stock cans in the time between selling the Hitechs and getting Phats muffs, and it was ....horrible, felt after the Hitechs like a broom was up its bum

ouch

by **SMI77** » Thu May 21, 2009 9:44 am

I would like to confirm the ratios for an 08 6sp and also the rear diff type if anyone can tell me ?

STi 6spd man ratios, with tbSTi having the short shifter:-
http://www.subaru.com.au/models/liberty ... tions/all/

...and the diff is:-
http://en.wikipedia.org/wiki/Torsen_differential

by **swingn** » Thu May 21, 2009 11:26 am

How come your Dyno Sheet's don't have Pulse on them?

The figures do seem a bit high IMO, but as Jim Boy said, it's all about the improvement from the base reading

So good work

by **Arith** » Thu May 21, 2009 12:33 pm

swingn wrote:How come your Dyno Sheet's don't have Pulse on them?

I think Rod mentioned something about Pulse's dyno being out of action that day so they had to dyno his car at another place down the road.

I don't want to get into any disputes, but I think the increase is due to the tune, not to the low pressure of the STi mufflers compared to the stock cans. You still have that huge centre muffler to contend with as well, so the restrictions from the stock setup are two fold.

by **swingn** » Thu May 21, 2009 2:34 pm

Arith wrote:I think Rod mentioned something about Pulse's dyno being out of action that day so they had to dyno his car at another place down the road.

Ahhhhhhh... If that's the case I think the figures may be a little inflated.

Gain is still awesome though from the base reading

But the actual numbers are a wee bit too high IMO.

STOCK 08 GT-B tb STi on the DYNO - 182.6awkw

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