Jill's Baby

[ToranaGuy]

Your in for a world of fun with your little "mighty girl".

In regards to the exhaust, I have a 2.5 inch system on my mighty boy, with one hot dog & one sports muffler, with twin outlets & twin chrome exhaust tips. It's too noisy to be honest. Some of the guys from the last Albury cruise can attest to this lol.

Sounds great, but could be quieter. I have a f8b & I will be fitting a turbo to it, that will quieten the exhaust down a bit.

I still run the stock pipe under the engine (for now, will be a turbo dump pipe later), ending at the firewall where it's flanged out to 2.5", and there it bolts to the rest of the system. I had this system made as a replacement for the broken stock system in the belief that I won't have to upgrade it again when I get the turbo on.


Cheers

ToranaGuy

[Billie]

2.5" on a 800cc engine? Would lose abit of hp with that.

[Brayden]

Yeah agreed, even 2" is too big for anything under a litre.

[ToranaGuy]

2.5" on a 800cc engine? Would lose abit of hp with that.

Yep 2.5" on a 800cc engine. Has the head ported & will be getting a turbo. Leaning towards the GT15 size.

That's what I thought, that it would loose hp/torque down low. I suggested a 2 inch system to the exhaust shop, then my future plans (turbo), and they suggested I went with a 2.5" system. Have not found it down on power compared to the crappy stock exhaust. It also drives much better down low than with an open engine pipe, dumping at the firewall, maybe it's due to the small stock engine pipe I still have? Have not had it on a dyno to see actual numbers tho. Maybe it does have a little less power down lower in the rev range than a 2 inch system would have on it?

Remember, I have a stock cast iron manifold & stock engine pipe, so up to the firewall it's still stock size, then it becomes a 2.5" system. When it get's the turbo it will be as big as it will ever need to be. I didn't want to spend up on a 2 inch system & then replace it with something bigger down the track.

Above all it is too noisy currently, and If I wasn't planning on boost, it probably would be too big, a 2 inch or 2 & 1/4 would probably be better on a n/a F8b.

Cheers

ToranaGuy

[Billie]

On my suzuki x-90 i took the resonator and muffler out and ran straight through. Really loud. Put a muffler back in it, runs better, revs quicker. Needs back pressure to run. Thats a 1.6 16v with 1.75 inch exhaust. Its the noise that makes it feel quicker, I thought mine was, until i got the muffler back on. Even a turbo 1.0 would only need a 2 inch system. Not that turbo systems need back pressure, but the amount of flow would need just 2 inches.

[Brayden]

The need for backpressure on a 4 stroke engine is a myth. Scavenging on the other hand is very important.

[Billie]

Thats the word I was looking for.

[ToranaGuy]

The need for backpressure on a 4 stroke engine is a myth. Scavenging on the other hand is very important.

That's what a number of well known performance exhaust shops told me as well, when I questioned them about sizing for the ute. Shops that have fit exhausts to some very powerful car's, very quick car's.

Trust me, it's faster with the new exhaust. You can feel the engine rev much more freely, and it picks up speed quicker, tested with car performance app on my HTC phone. It's also more economical too.

Cheers

ToranaGuy