New V70 owner: advice needed!

[bananarama]

Originally Posted by griston64

I wouldn't let Kwik Fit anywhere near my exhaust !!

I was only messing around with you guys. I learnt the hard way many years ago; never again.

[Tatsfield]

Can't let the comment about loud after market systems go unchallenged. Bespoke exhaust system can be provisioned to meet any spec that the owner chooses. I had a V6 coupe on which I had the exhaust modified to allow more flow through the catalysers. It was very noisy so I invested in a stainless system made up with an extra free flow silencer to deal with the extra sound. The car went like a bat out of hell and if pushed hard under acceleration would snarl, but in ordinary street use it was as quiet as it had been when it came out of the show room. One day at a car club meet I was demonstrating to some other owners something under the bonnet and started the engine. I completely forgot to turn it off and later standing at the back of the car opening the tailgate was surprised to feel the exhaust on my legs. The after market system was a quiet as a mouse even though it snarled like a big cat under heavy throttle action. A sensible stainless after market system will smooth out the flow, give you the sound level that you choose and last a lifetime. What's there not to like?

[griston64]

Originally Posted by Tatsfield

Can't let the comment about loud after market systems go unchallenged. Bespoke exhaust system can be provisioned to meet any spec that the owner chooses. I had a V6 coupe on which I had the exhaust modified to allow more flow through the catalysers. It was very noisy so I invested in a stainless system made up with an extra free flow silencer to deal with the extra sound. The car went like a bat out of hell and if pushed hard under acceleration would snarl, but in ordinary street use it was as quiet as it had been when it came out of the show room. One day at a car club meet I was demonstrating to some other owners something under the bonnet and started the engine. I completely forgot to turn it off and later standing at the back of the car opening the tailgate was surprised to feel the exhaust on my legs. The after market system was a quiet as a mouse even though it snarled like a big cat under heavy throttle action. A sensible stainless after market system will smooth out the flow, give you the sound level that you choose and last a lifetime. What's there not to like?

I had a Milltek resonated system on my old V70 which was pretty quiet but gave a nice growl under acceleration with the 5 pot engine

[simboc2004]

The Jetex exhaust growls nicely through mid range acceleration and at start up, but isn't intrusive in the cabin. Just what I wanted.

But, boy, has it freed up some power... and made that power delivery much smoother. I'm guessing the standard single box (on my car) must have been quite restrictive. i also have a freer flowing ITG air filter

[bananarama]

Originally Posted by simboc2004

i also have a freer flowing ITG air filter

Is the factory filter that much of a bottle neck?

[Tatsfield]

I believe that free flow cotton/oil filters offer greater through flow for very long periods of time installed at the cost of not filtering quite as finely as factory spec which are reasonable when new but get progressively more clogged which is why they need to be regularly changed.

Can't speak for the Volvo but previous cars with cotton/oil free flow filter panels showed about 1 or 2 extra BHP and synergistically complimented free flow exhaust systems either of which were good but together they were much better than either was on its own. You have to make the decision regarding filter efficiency but I know of no case where K&N have had to pay out on their insurance against their filter damaging any car engine.

[bananarama]

I'm just surprised the factory filter would be that much of a bottle neck because the box and filter are pretty big, and the engine is not (for example) a high revving VTEC.

I'm no expert and have only had one experience: On the old Golf I had a BMC CDA which sounded great but (I'm pretty sure) offered no performance improvement.

[Tatsfield]

You do raise a doubt in my logic. My previous cars were petrol engined and it is possible that diesel engines do not suffer from such restrictions although logically at some point in the rev range a restrictive filter might reduce the induction rate. To fess up, I put in Polestar in my D5 but am happy with the original filter and original twin silencer system as the engine provides more than enough power for my usage.

[pjm84]

Originally Posted by Tatsfield

I believe that free flow cotton/oil filters offer greater through flow for very long periods of time installed at the cost of not filtering quite as finely as factory spec which are reasonable when new but get progressively more clogged which is why they need to be regularly changed.

Can't speak for the Volvo but previous cars with cotton/oil free flow filter panels showed about 1 or 2 extra BHP and synergistically complimented free flow exhaust systems either of which were good but together they were much better than either was on its own. You have to make the decision regarding filter efficiency but I know of no case where K&N have had to pay out on their insurance against their filter damaging any car engine.

I had an ITG filter on a tuned TD5 Defender. Over time the oil from the filter coated the MAF sensor and it only became noticeable due to a slight misfire. Once I found the issue I cleaned the sensor and put the paper filter in....wow what a difference.

D4 is now Polestared. Only a small drive back from the garage but instantly noticeable. Sounds different as well. Picks up a lot more freely and then takes off where the D4 stifled itself. Badge is now white

[Tatsfield]

I opted not to have the badge. I just like the fact that the tank is more capable than stray BMWs and Audis think it is.