Ltrain925

I知 about A month out from my install of headers with catless x and a bunch of other stuff, know that the long tubes and catless X will smell. What I知 more concerned of is how bad will it smell, I ask this becuse I remember on my C5Z that was heads/cam, supercharge, and LTs with no cats I could literally smell it on my clothes when I got out of the car or later on if i was doing laundry I could smell it on my clothes, I absolutely don稚 want that again. Granted my valve stem seals were shot and my car had a little oil leaking by (which could have contributed to the smell). I can deal with a little smell at a stop light or traffic, just not obnoxiously bad.

How is the smell on these with LTs and full catless X?

LuckyC7Z06

Smells of bald eagles!! Yea it痴 strong but not like you described.

Bill Dearborn

If tuned properly it shouldn't smell. In the old days with carbs you could tell a car that wasn't tuned properly by that smell. Acidy burn your nose smell, too lean; heavy sweet sickening gassy smell that makes you afraid to strike a match, too rich. A lot easier to tune around that stuff with electronic controls. No playing with jets, metering rods, air valve springs, power valves, etc.

Bill

cdh027

Been wondering about this as well. I have main cat delete pipes and corsa catless x ready to install this spring. Hoping its not bad with stock tune?

383vett

I had a C5Z with long tubes and catless xpipe. Great sound but couldn't stand the smell. I put hi flow cats on. Chose not to go this route with my C6Z and C7Z.

Higgs Boson

The C7 doesn't stink anything like LS motors do. Fuel is not injected until after the exhaust valve is closed so nothing is escaping from combustion at idle and low RPMs.

The LS engines inject fuel as long as the intake valve is open and every lope of the cam belches out fuel and stink without combusting during overlap.

Mr. Gizmo

OH THREE Z

I've got a catless kooks set up that has yet to be tuned. The smell is noticeable but not terrible with the windows down in stop and go traffic. I'm scheduled for my bolt on install and tune so I'll see what difference that makes and report back

Higgs Boson

Every engine in the united states of america since the early 90s runs at stoich in closed loop, it doesn't run any richer or leaner than your LS7 or your grandmas toyota civic.

for some reason that I have not bothered to research, the DI engines poop up the exhaust tips vs PI engines even though they both run the same AFR.

now, if you spend a lot of time with your foot to the floor, a boosted motor does run richer than an NA motor during PE.

Chadzilla500

I've got my homemade cat delete pipes, aftermarket x pipe and billy boat fusion mufflers on a stock tune. The smell is there..but its not horrible. My 70 nova and 67 c10 are way worse. The sound increase and tone is well worth it. I would never want cats back on.

Adam Silver05

besides the performance advantage of e85, there is a really cool exhaust smell. I used to hate the exhaust smell of uncatted cars but now with e85 it is actually quite pleasant and doesn't stick to your clothes.

h3mpking

E85 is my exhaust perfume of choice.

John-6717

Just did the LT's and Cat-less X-Pipe and the smell is definitely there. I'm pretty sure there are no leaks and everything is coming out the tail pipes. The exhaust must be entering the car somewhere. Anybody ever try to figure out how the fumes are getting into the car?


We have several older cars and none have cats and I have never noticed this until the Z06. Granted, I didn't have this type of exhaust on another Corvette before, but why would this be different than other vehicles?


And, since the prevailing theories attribute this to going cat-less, this doesn't change the actual amount of exhaust coming out of the tail pipes (composition changes, but the exhaust gas is still there). In this case, the fumes would still be entering the cabin with cats in place, but the smell would be less noticeable.

Higgs Boson

you added long tubes but who tuned your car?

If the headers reposition the oxygen sensors, which they do, the exhaust pulses are slower and take longer to reach the sensors and also do so with different timing, the tune must account for this or your closed loop system may not switch properly around stoich, but slip down the slope to rich-land.

robert miller

Plus MPG is lowered also from what it was. But it you get a good tune on it may get better if you keep your right foot out of it. Robert

3 Z06ZR1

For the 5 hp you get with no cats just get the cats how silly!
Lots of headers and always get the cats.

John-6717

Working on getting the tune arranged. Hopefully next week. However, it still seems odd that exhaust fumes can get inside the vehicle so easily. Having cats or not (or a bad tune) shouldn't determine whether or not fumes make it into the cabin. I can see how the strength of the odor would be affected by that stuff, but how do they get there in the first place?


Did a quick experiment while idling in the driveway this morning. With HVAC system off and the cabin air circulation mode sent to "circulate from within the vehicle", there was no hint of exhaust fumes in the cabin. With the HVAC fan on, the smell returned. Does anybody know where the fresh air inlet is for these cars?

snow

I can tell you this.... I have Kooks Long tubes installed with their cat less X Pipe and Akrapovic exhaust. Had it tuned and I have found that when the temp is cool outside it stinks... sitting at a light in the morning gags you. I have found that if I turn off the climate control and the fan and dont open the window the smell is not as bad. Spoke to my tuner about it and they said it was due to the cooler air temps.

When the car goes in this month for the super charger install we are changing the X pipe to a Kooks race cat. They said it will help but will not remove the smell 100% either...

3 Z06ZR1

ARH's 2 inch with cats no smell.

Ltrain925

Wel I appreciate all the replies, my car goes under the knife end of Jan with the full catless ARH setup, if I find the smell is to bad I’ll just order a set of cats worst case scenario.