Thinking about getting the high flow H-pipe from MRT. I currently have the Borla Touring exhaust which is my third axle back I have tried. I def like it the best. No drone. It is just a little quite for me though. Was wondering if anyone out there has this. Not interested in going with headers. I am running the 13-14 TVS with some other mods. Will I make any more power with this? Will I need a new tune? Thanks!
Mrt h-pipe with cats for 07 gt500
- Thread starter KKOSH
- Start date
Yes, your factory cats are better in your application. I am still running my original cats with a good tune. I recently had the mid-pipe off to install a wideband O2 sensor and had the opportunity to get a good look at them, and they are in great shape. If I install a 10% OD lower pulley and/or mono-blade throttle body to further increase boost, I would install an off-road H or Kooks headers with green cats to handle the additional flow, but that would probably force me to replace my mufflers due to the increased noise level.
yes the cats are a restriction, you are better off without them. They get extremely hot so with high boost and high horsepower, your tuner has to dump extra fuel for cat protection. This extra fuel will make it run richer and you will lose power. With catless pipes you lower boost a little bit, which is less stress, and you gain a little power because the system is more free flowing. And you don't have to use that cat protection. If you are running more than stock boost, I would get rid of the cats.
can't really tell unless you are idling in the garage for a while ...
In the state of Illinois you cannot pass emissions without cats. Do not know about MI, but you may have to put them back on and re-tune for emissions periodically.
You can probably pick up 10-15 HP without cats, but I can often tell when I am behind someone without them. Catalytic over temp is frequently turned off in aftermarket tunes. I asked Jon Lund and he told me he routinely turns it off. I had him turn mine back on and asked what impact it might have. He said none unless I am driving it real hard, then it might shave 10 HP to "save'" the cats from melting.
My opinion is that unless you are looking for every last 10th you are better off with cats and COT turned on. Agree that stock cats are the best out there.
If you can find a tuner who can set you up for emissions readiness without cats, it may be possible to run no cats and pass emissions readiness, or so I am told.
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