My 03 STI

TD05 18g Turbo
HKS SSQV
3" Decat (think it goes to a 2.5" at the bottom)
Standard PPP Mid pipe
ProDrive muffler
Ported and polished headers
Gems ECU
Running 312whp

The car is a little too quiet for me so was going to replace the resonated ppp mid pipe.

Do I go 2.5" or 3" will it make more less power or noise with 3"?

 

Anyone?

 

Can't be 312 WHP can it? Wheel horse power?

Personally I'd stay with the 2.5" pipe size you have and just go for de-resonated centre section. MAY not need a re-map as ECU might fuel correct enough.

 

Many thanks for reply, think i will stick with 2.5"

As far as power goes, all I am going on is this Dyno that came with the car



Was taken at AME on their hub dyno so the print out is at the wheels power

 

Ah right. Makes sense. a Hub dyno is not strictly WHP figure. As the name suggests it's a figure at the hubs and does not take into account energy lost through tyre friction etc.

Still, looks like the car is fun!

 

Ah cool everydays a school day :-)

Rough guess then what the above dyno would be at the fly? I'm hoping the GEMS should deal with the new mid and not need a remap. I have a wide and AFR gauge in the cab so can keep an eye on it

 

Very difficult one to answer that.