Second Review: Catless downpipes & Akrapovic ehxaust

[larkinda]

I went with ultimate racing race cat DP and retained all factory heatshields. As far as I know with catless dp the heat shields are eliminated.
There are a lot of claims to huge power increases from catless but if you run a 200 cel race catted dp like ultimate racing or super sprint the performance gains are the same as catless without the side effects of smell and emissions issues. If you do get a cel from race cat ( 50/50 chance)you can ask your tuner to turn off the co2 code only and leave the sensor on and you'll pass emissions. The sound increase is the same either way because the turbos are really what make the sound on these motors. FYI- with race cat you can really hear the turbo whistle from the exaust-sounds real cool.

[northern2020]

Originally Posted by larkinda

I went with ultimate racing race cat DP and retained all factory heatshields. As far as I know with catless dp the heat shields are eliminated.
There are a lot of claims to huge power increases from catless but if you run a 200 cel race catted dp like ultimate racing or super sprint the performance gains are the same as catless without the side effects of smell and emissions issues. If you do get a cel from race cat ( 50/50 chance)you can ask your tuner to turn off the co2 code only and leave the sensor on and you'll pass emissions. The sound increase is the same either way because the turbos are really what make the sound on these motors. FYI- with race cat you can really hear the turbo whistle from the exaust-sounds real cool.

I retained all factory heat shields with the Akra catless Dp's...hence the choice to use Akra!

Don't buy the notion that the gains from a race-catted dp are the same from a catless dp set up...until you can show some dyno's!!

Any restriction, be it race cats or cheesecloth will restrict gains vs a
Free flow system.

Congrats on your setup, it's a monster!

[MarcG777]

Rboosted717, why do you remoe the catless downpipes when you do your service?

[novablackm3]

hmm I'm noticing a lot of surge in city driving and the loss of torque is very apparent , more so than the gains at top end. stock exhaust with catted dp was actually perfect. On the x5m in city driving most of the time the rpm range in d mode is 1000 to 2000 and will shift into 4/5/6 before you even reach 60.

maybe a tune will help

[Jimshorts]

Originally Posted by novablackm3

hmm I'm noticing a lot of surge in city driving and the loss of torque is very apparent , more so than the gains at top end. stock exhaust with catted dp was actually perfect. On the x5m in city driving most of the time the rpm range in d mode is 1000 to 2000 and will shift into 4/5/6 before you even reach 60.

maybe a tune will help

Interesting... Would have figured some torque gains. Definitley get a tune to get the most out of those DPs. Good luck picking one. All seem pretty good just double check they can tune to your mods and ask them about future tunes if you continue to mod.