Cpt.Joe1983

Anyone know what kind of hp boost i would receive completely eliminating cats? When i deleted all 4 on my viper i picked up 49hp. Just curious if anyone has done this to a 65 model v12. And please dont tell me about the loud noise. Because i love it. Also i plan on doing a ecu tune from Speedriven at the same time.

eaks

The tune will yeild the highest results.. I do not have any dyno numbers but I can tell you that when I picked my car up from the shop after doing the catless downpipes I could feel a bit of a difference (although possibly mainly because of the sound).. When I got home I flashed the tune I had for my cl65 with catless downpipes and intake and upgraded IC pump and once that was done there was a huge difference. I have had a hard time booking dyno time so I dont have any numbers but you will get a huge gain from downpipes and tune on the v12 tt. I am not sure about the s65 but the w215 cl65 everyone says the coils will go shortly after a tune.. I tuned mine last year and am still running on the original coils (I did order the newer type and have them sitting in a box in the garage for when/if the original ones fail)..

RaceHorse

Downpipes will add a lot of power, but a custom intake is needed. I went from 562whp to 645whp on the same EC tune, both on 93 octane. I have since added a double pump trunk tank setup to go along with my supplemental HE. You will gain a significant exhaust note, I didn't touch the mufflers since it sounded good to me with just the cats removed. I think a custom intake is a must, it allows the turbos to spin freely making more power in the higher RPMs. If you notice a few companies are already providing catless downpipes for the V8TTs. It has really helped them get a lot more power out of those motors too. I hope that helps.

RaceHorse

Hey do you have any pics of your set up? I'm interested to see other variations of one offs. I'm assuming you made something similar to mine, grabbing air from in front of the radiator.

VMAX7

Any videos of your cars in action gentlemen?

Cpt.Joe1983

Yes, i love videos and pictures 😍

BlownV8

I have straight pipes, upgraded intercoolers, upgraded BOV's, downpipe, and straight through exhaust on my SL600. The sound is pure evil. Just so freaking sick. Really sounds like a race car. One of the best sounding exhausts I've ever heard.

The6ix

Hey, I'm new to the forums. Can you send me a video or email me a video of your exhaust? I have no mufflers on my SL600, but I'm thinking about going catless down pipes. Could you send me a video of cold start, revs, and accelerations? alp_sal@aol.com

Dr Matt

You guys are making me think harder about deleting my cats, could be the difference between running more 10.7's or breaking the 10.6 barrier......

I just got tired of the catless exhaust smell on my last toy. The exhaust sound without mufflers is just about right for me so I'm afraid it will be too loud straight piped.

martinp

Matt, I would recommend against it. I have Kleemann headers > Eisenmann back boxes with just pipework between. After standing at the back of the car for 15 secs your eyes start to water and your clothes even pick up the smell. Not pretty...

I'm getting hi-flow/sports CATs fitted to mine this month to clean that up, only 2 rather than the OEM 4 setup though.

Can't say anything about the V12 version although I assume it would be similar but the choice is ultimately up to you guys!

leodangelo

I have to agree with martinp. I installed catless down pipes on my CL65. The fuel smell is so strong I can no longer park in my garage. If I start the car in the garage the fuel smell fills the house. I am looking to have high flow cats installed.

The sound is awesome. I have some recordings somewhere that I will try and find. Startup is loud enough to get my neighbors to come over and ask what's going on. Driving normal is fine (not too loud in the cabin). Full throttle acceleration is pure evil.

-LeoD

fastlife23

Please post up!!!!!! My 93 stroked and blown fox body has a an off road pipe and driving it around for more than 5 mins gives me a fumes headache. It's really annoying and then I stink like a pump jockey all day

RaceHorse

I guess I'm the odd ball tolerating the burning eyes. My car is not a daily driver, so I can handle a few minutes of fumes before heading out for some fun on the rare occasion . There is no drone or stink inside and when it's warm and ready the car is all business, much more then most would expect. I look at it like the bite from the first sip of nice scotch, both put a nice smile on my face. It was in the low 40s today and WOT resulted in wheel spin at 60-70 MPH. There is a lot of power to be had on the V12TTs by going catless.

fastlife23

can someone please post a vid of their cl 65 straight piped? considering doing this.

Dr Matt

Don't feel lonely Rich, I drive mine daily and park in my garage every night but I'm still thinking about yanking my cats. Love to drive one straight piped before I do it, but that's probably not going to happen. Where do you live anyway, ��

AMG-Driver

In my opinion a good compromise is to go with Quality 100cell cats in the downpipes (with EURO 4 coating to achieve smog emmission test). They are good for 20 HP and there is no smell from the exhaust, which in the SL is even more important, when the roof is down.

The most additional HP then comes with a big dual cold air intake from the front, like RACEHORSE did on his car.

If you prefer a more "stock looking" intake in the SL, the SL65 BLACK Series intake is also much better than from factory, but you have to relocate the ABC-Control-Unit and some lines of it, and this is quite a big job to do - but it has been done on a few cars in Germany.

RaceHorse

I don't have a video, but I have heard videos of others, search youtube for any catless V12TT. They sound almost identical to stock on video since you can't sense loudness. In person its just louder.


I'm 1 hour north of New York City. You are welcome to drive mine if you find yourself on this side of the country. Its one expensive test drive, probably cheaper to swap the cats back if undesired. LOL However, the offer still remains.

fastlife23

Will do thanks guys