V12Godspeed

Well I have been contemplating the idea of doing a full 3 inch exhaust...but why spend the money when I could do an Electric cut out system on the beast and keep my good exhaust.. I think there are some good power to be made by relieving some of the back pressure...any thoughts

retardedmunk

I am down for this mod. Let's find a manufacturer

alx

i would rather not as the stock setup is calculated for specific backpressure of the exhaust.

removing the backpressure might result in overspinning the turbos and maybe overboosting if the wastegates cant compensate.

i dont know enough about the car, but the setup is complicated and i would rather not play with this.

maybe vadim can comment on it better

alex
few cars

V12Godspeed

Actually you could use the QTP's or DHM cut outs...and just have someone make a 3 inch down pipe something like this...and Viola!

Summit might have them and just bolt on the Electronic cut outs...I think we need 3 inch because our exhaust is 3 inch till it reaches midsection breaks into 2.75

http://cgi.ebay.com/ebaymotors/Hedma...1%7C240%3A1318

V12Godspeed

Well I took care of this by talking to a few people before making a decision...according to vadim he said it was a good idea. I also spoke to my tech and said it would be good to relieve backpressure...If i do it I will by doing a before and after dyno and post it.

There are a few V12 owners running around with a 3 inch exhaust and nearly no mufflers almost....they gained a few ponnies.

Dsmed

The only issue with cut out on the V12s is there is no room before the cats. And putting cut outs after the cats will not get you the gains that you are looking for. Unless you relocate the cats further back its not worth it.

V12Godspeed

Hmmm...I see your point I will try maybe some high flow cats, but the idea is to put them after the cats.

alx

nah... just gut the cats, run o2 sims behind them so ecu is happy.

change oil before annual emissions test. it will pass unless you are in one of the states that has roller emission test then it is questionable...

running dumps after the cats will mostly defeat the hp purpose methinks unless you go for sound...

the only subjective objection i have is that i have heard open header v12 and it did not sound very nice... the turbos might hush it a bit, but the sound was.. meh..


alex
few cars

V12Godspeed

I will definitely consider gutting them...do you know where I could find simulators? it is tought to trick the ECU...

Exotic-metal55

I would just get the CL65 tune and not hack up your exhaust over small HP gains.. The tune on a 65 is like 100 HP and 200 TQ range! Then look to cooling mods..

At least you only have one set of cats! If you just had to get power from the Exh. then I would look for restrictions in the turbo down-pipe area first.

Vadim @ FD

I am looking to do them on my S600 as well.

As far back pressure, ECU has very wide control over wastegates. I do not forsee any problems.

As far as power, IMHO about 5-10RWHP. Stock exhaust is very decent.

As far as sound, I have pulled mufflers off on mine and it does sound mean. Definitely too loud for everyday, but this why cut-outs make the most sense.

Dsmed

Ebay sells the simulators, most tuners shop carry them. Price is between $25-50 each. Or some people have had good luck with O2 extenders, those are $10-15 each. getting rid of that sorry excuse for a H-pipe and installing a reall 3 inch X-pipe would also help.