Exhaust Advice

[georgeleedom]

I am looking for advice on what size down pipe and exhaust to get for my '99 s70 GLT - low pressure turbo. I am not taking it to the track, but hoping to build a competitive street car. I am hoping to stay with the LPT, but would consider changing the turbo if I don't get the power I want.

Thanks

[Oreo931]

3" downpipe to 2.5" cat back. (you can go bigger on the cat back if you want)

[Falcone]

I'd do a full 3 or a full 2.5, depending on your future plans. I'm not a fan of downstepping.

[mdlimy]

I'd do a full 3 or a full 2.5, depending on your future plans. I'm not a fan of downstepping.

I agree but I would go with a 3", you are going to want a muffler/resonator or even a couple and that itself is a slight restriction so the 3" would help balance that out a bit, in short a 3" would yeild best performace and not need upgrading when a higher flowing turbo is installed.

[Mesoam]

2.5 the whole way

[drin850]

Whatever the OBX system is

[Kit Vexed]

not to thread-jack, but i got the iPd 3" dp and race cat, but already had the Eurosport 2.5" cat-back system.. went to the autoshop and picked up a 3"-2.5" reducer piece and man - 1/2" difference looks pretty extreme?? im worried about it bottle necking and really f-ing up the exhaust flow.. but what else could i do?? anybody ever mix and match 3" - 2.5" from different companies?? what did you do?

[nocturnal7x]

Whatever the OBX system is

OBX is 3" downpipe then 2.5" after the middle pipe to the tip.

[nolanator]

the difference between full 3" and tapering to 2.5" would be negligible with the power you are making. i've looked into quite a few tunes/datalogging/dynographs for other cars (specifically subarus) and have found that until you are hitting big numbers, the flow isn't obstructed enough by the piping size alone to make a noticeable difference. i'd assume this would be the case for volvo as well.

[Turbosleeper]

OBX is 3" downpipe then 2.5" after the middle pipe to the tip.

Definately a thumbs up for me.

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