PekkaH

Have anyone change their original whole cat back system to full 3" ? There might not be any benefits because the original AMG cat back is 2,75" for what I know.

Renntech sells just back boxes and claims that jus changing those there is 10hp benefit. https://www.renntechmercedes.com/ind...8-cls53-detail

Friendrich motorsport sell whole 3" system https://www.ebay.de/itm/393395018943...oAAOSwYVVgyJwZ

I have E63 AMG catback now in my car and I can switch it to that Friedrich motorsport if I just want to do it. But what do you guys think is that stock AMG cat back so free flowing that there are no benefits to change it bigger? Like reducing back pressure etc. ?

vdubpower

what are u gonna with 10 hp

PekkaH

Do nothing with just 10 hp.

I was comparing the RENNtech back box 10hp gain to FULL 3" cat back possible gains if some one have try full 3".

sickSVT

You probably wont see any gains unless you're running big boost. It'll probably just have a deeper sound.

If anything I would have a local shop delete the mufflers or buy a kit like this.

https://quicksilverexhausts.store/pr...ctions-2012-on

PekkaH

Thanks, im really close to go under 11s on 1/4 mile so a little desperate man.

I.T. Guy

It's always that last little bit! What time are you at now? What mods?

Take out the spare tire and jack and all that trunk stuff
Only run 1/4 tank fuel
Pressure down rear tires to lower PSI
Take out all the floor mats
Don't eat lunch

PekkaH

Lool. nice thoughts . I have try all those already. Only not the floor mats, but I have weighed those and are 1.9kg. lool.

But seriously I have still one mod to do and see after that if I can get under 11s with my m278 with pump gas and no meth. Now its like hitting to the wall..

I will post some Dragy soon.

PekkaH

PekkaH

PekkaH

And now I have install the Blackboost intakes and done the job! M278 engine Shooting brake goes under 11s on 1/4 mile with just pump gas, no ethanol blends or WMI. Very special thanks go to Blackboost intakes and my tuner Motorbit on Finland. Real great tuner that man!

brutus_tx

Glad to see that the intakes provided you with sufficient air to get you into the 10's! That's a testament to your tuner. I'm keen to see if they can leverage the improved air from the BlackBoost intakes to tweak the tune even further now, assuming your fueling can cope with demand.