V12Godspeed

I am thinking of either removing the cats completely or Gutting them internally and leaving them in place. What are people doing these days? Thanx

V12TTenthusiast

I got 3 Inch Catless on mine, but my whole exhaust is custom made 3 inch all the way around

shardul

iTrader: (1)

cut the cats out and weld a 3" pipe in place with 02 bungs

RaceHorse

This above, or downpipes... Ask yourself, "will there be a time and place where they are needed for emissions?" I'd find a decent exhaust place and have downpipes made in house. I think its difficult for real accurate fitment without the car on site. In the end the price will be about the same. Also, you will need to ditch the stock airboxes if you already haven't. My car ran out of breath in the higher RPMs, spitting out the exhaust faster than it could draw air in. While you are at it, are you going to remove the flat spot towards the back where the support is located? I kinda wish I had, I'm sure its not a big difference, but it just looks bad after everything else is nice and big.

V12Godspeed

Yep, got an intake system. Once engine goes down, will do the downpipes as well. Thx

V12Godspeed

Can someone suggest a simulator or any kind of trickery to trick the CEL? I will get tuned once everything is done. Thx

V12TTenthusiast

I used those 90 degree elbow 02 simulators off vivid racing, did the trick

Dr Matt

Tuner should be able to turn off rear O2's in the tune. Not a good idea to drive around with all the mods you have planned without a tune so just have them do that in the initial tune.

V12Godspeed

She will get tuned for sure, Thx

Great Thanks.

V12TTenthusiast

Taking it off tune isn't 100%, I had Jerry do mine and it still popped up time to time, to get rid of it for sure I had to do those 02 simulators to top of what Jerry did in the tune

V12Godspeed

Do you have the link? Cant seem to find it. Thx

V12TTenthusiast

My bad it wasn't vivid racing it was summit racing this is the link

http://www.summitracing.com/parts/vp...FQQT7Aodr1gARw

V12Godspeed

Thanks a lot.

V12TTenthusiast

You'll prob need to get 2 of them 1 for each side and when you use the washers, I think I used the middle size of the set of 3

RaceHorse

I have the 90's also. I have NOT had the tune adjusted for the 02s running without the cats. Under normal hard pulls the light doesn't go on. If I do a long highway pull I will get the CEL even with the elbows. It happened even easier with the stock air boxes. If You haven't done anything yet I'd consider having an extra bung welded in place for data logging.

V12Godspeed

Thanks. Yes, will be putting in an A/F logger.

adamls2

Does anyone have the speeddriven cat-less downpipes, or any other cat-less setup for that matter? I'm very curious to hear the sound difference vs stock. Really want to pair this with my muffler delete. Would appreciate any input!

eaks

I have the speed driven catless downpipes and am super happy with them. I originally told the shop to cut my mufflers off but they called me after they had the downpipes on and said they would recommend keeping them on as it really changed the sound already. I went and fired it up and love the sound with my mufflers still on.. Sounds deadly at startup, a nice rumble at idle and when you get into it it sounds great and the best part is there is no drone at highway speeds..

shardul

iTrader: (1)

i have catless setup with no muffler and it is real loud. I plan on putting the mufflers back on

adamls2

Thanks for the input guys. I'm assuming the catless dp is similar to the muffler delete effect.

Shardul, i'd love to hear a sound clip or something! It's hard for me to have too loud of a setup, haha. How loud would you say it is insude the car, compared to just the muffler delete? ( if you had it like that before the catless)

Thanks!

RaceHorse

I think the hard part is exhaust mods on the V12TT just make it a little louder without any change in tone. Sound clips don't do any justice it needs to be heard/experienced in person. Its a smoother firing pattern than a V8 so you won't get the same throaty sound that you hear from a V8 with an exhaust. That's a huge part of the appeal to me. These cars are very unassuming, silent killers to many cars on the road.