ok I’ve been doing tons of looking and I’m trying to figure out what’s best placement for catalytic converter behind a turbo? I know most people place the O2 sensor about 10-15” behind the turbo, but how far down can the cat go before they no longer burn up the unused fuel?

 

Best placement for a catalytic converter is in the recycle bin, especially on a turbo car.

That being said, on all turbo vehicles I have see the converter is in the same location as non turbo models.

 

Most of the time I would totally agree about using catalytic converters. But I’m hoping that between the cats and efi that I can daily drive it again and not smell like gas when I get home. But I’ll give that a try thank you

 

Put the cat as close to the turbo as you can, and the O2 in between. No need to put the O2 downstream.

 

I hate stinking of exhaust after driving. When I changed to E85 that made a huge difference in that aspect.

 

Yeah idd love to run e85 but here in SoCal there few and far between. so it good old 91 pump gas what I’ve got. But I’m hoping the cats will work cause I will be doing a front fenders exhaust as well

 

I am honestly surprised you can tag/insure/drive something with twin turbos out there in Commiefornia.

 

Yeah, you can and there strict out here. but my truck is old enough they don’t bat an eye it. Even though it’s not required. I’m converting it to efi and putting cats on it. so it runs better and doesn’t reek of gas. I also just want to do a good job on the exhaust system, so cats and O2 sensor do there jobs properly. I’m thing about placing the O2 sensor 10” down from my turbos and the cats 2” behind that. it’s just hard to make sure cause everybody junks there’s so there not much about proper placement on a custom system.

 

You could be causing yourself tuning issues running a cat not to mention back pressure issues.
It might be a good idea to tune it without
A cat since your going efi before complicating stuff. What’s the worse that could happen running a cat you clog up the cat and blow a head gasket if your tune is wrong.

 

Hu I never thought about that. So it might be worth it to make a test pipe, tune the engine in. Then see how the cats change things after. I’m also not to concerned about to much back pressure. I’m only going to be running low (5-7 psi) boost and 5500 rpms max I’m sure the engine will be capable of more but that all I want to run

 

Famous last words. Kinda like hold my beer lol. I said that too. I remember my first boost gauge went to 20psi and I said I would never run that much boost. Now I have datalogs with 30psi on them.

 

Naw I’m sure the truck is going to be fast enough for spirited canyon runs. My engine is a 489ci big block Chevy, with twin 72 mm turbos and I’m running a tko600 trans with gm truck 12 bolt so I know if I go to far I’m going to be breaking something