I have now driven 6 or more 03 /04 STi and STi PPP and find that nearly all the engine character of the earlier STi4/5/6 type era has gone? - Can this be recaptured by sensible mods to exhaust - where did characteristic throb go?? - These cars are UK and not equal lenght manifolds and presumably all earlier and later cars ran some level of Cats? - I wont forget the low rev throb of an STi 5/6 R - I need to recapture this on an STI PPP (03) -suggestions?

 

The new STI's (i may be wrong) have equall length exhaust headers, which although improving performance, gets rid of a lot of that distinctive impreza burble that comes from the old styleeee ones having unequal length headers.

It's all to do with the timing of the exhaust gasses from each cylinder hitting the turbo

James

 

hmm - certainly sounds plausable however I understood that the manifold issue only aflicted the type c import twin scroll trbo model

 

The new UK STI's DON'T have equal length headers.

 

True, they DONT

Fit a blitz nur spec R, & you will get a hell of a lot more than throbbing from it

 

i think its the number of CATS that the new generation have. I have an 04 sti and its sounds great with my Firestorm on, burble etc.

With the standard exhaust on you could hardly tell it was a scooby!

 

I have a 02STi Type UK and had a Power Engineering sports cat exhaust sytem fitted 18 months ago. This gave a nice burble at low speeds and from the outside sounded like a Classic Scoob with the old H&S Scoobysport system. At higher revs the air induction noise tended to swamp the exhaust noise. Therefore I have just had a H&S Afterburner Vortex backbox fitted in place of the PE backbox and this makes quite a difference and is louder at all revs. It deepens the exhaust note whilst still retaining the burble at low revs. At higher revs there is more of a howl and the exhaust noise now largely swamps the induction noise.

Also blipping the throttle from idle gives the odd pop and bang.

Alan

 

Agreed the standard 03/04 is much quieter thus less of the burble. As others, I guess this is a combination of the CATs and the muffler(s). A friend of mine purchased a very cheep OEM second hand center cat, removed the little kitten from inside and refitted it - his burble has now returned - back to normal operation!
-Steve.

 

thanks for comments chaps and kitten carers - I have driven with PPP upgrade which includes sports cat down pipe + their system, however just seems to roar / drone - very little character or detail - I think it was the scoobysport back box I liked on the earlier car. - I am not looking for volume (its an age thing + lots of years of driving TVR!) just the cackle pop and throb - you know - low revs in high gear and ..... 'bob....bob...bob!!' V8 type throb...

keep the suggestions coming..

 

get a tsl group n backbox,it sounds rumbly at low revs and howls at high revs
but is not that intrusive on long drives-i should know as i have a wife and 2yr old girl and if they were not happy I would know about it
martin

 

thanks - do you get that v8 style throb at low revs high gear with windows down?! - Presumably I could just swap the PPP rear box for it