advice on exhaust fumes...

[redfirepearlgt]

I know this sounds petty but here goes.

Any of you guys running FI and no cats take notice of how strong the increased exhaust smell is on your car? I am contemplating pulling the cats and going to a offroad pipe and GT500 exhaust to find some more HP. I added LT's and OR/X to my 2005 as my last upgrade and the exhaust was rather harsh. harsh enough you could start the car, get out, walk inside and carry the smell with you. It was a BIG turn off for the MRS. And she likes to be called MRS by the way. I am also trying to determine if the custom cams on that car added to that issue, or if it is mostly due to removing the cats. I expect some increase as I was around before cats were on cars. Just trying to get some petty 411. I really feel like I should be wearing my fuzzy pink slippers while inquiring about this LOL! JK!!!

So as absurd as this sounds, could I get some feedback on how intense the exhaust fume smell increased on your Forced induction car when you went off road midpipe? Thanks.

Again I know this is petty sounding but I do like having my wife go with me when I take the car out. So it's petty...........but its not so petty if you get my meaning.

 

[5lho]

I get it, that's why I hold off. This isn't a '69 Chevelle here. I like the fact I can start it up in the driveway and not gas out the whole house. I'm making 520 horse on a hundred shot of ntrous through the stock cats, I ran stock cats and exhaust behind the V3 I had on my last S197, making ~550 horse, no problem.

 

[stkjock]

It's "advice" so I changed your title and moved out of tech.

 

[sdleo29]

I love the smell, lol

 

[BruceH]

Keep the cats, you can make more than enough power with factory cats. I made 699rwhp with a 4.6 3v, factory cats, and a Procharger D1. This was with E85. That's another suggestion, run E85 and the exhaust will have a nice sweet smell. I've also had plenty of setups with a 4.6 that ran on gasoline and made well over 550rhwp. IMO once you go above 525rhwp the extra power becomes exponentially useless in a car that will see a lot of in town driving.

My suggestion is that you do your research and focus on those with real world experience. Factory cats work great but make sure your tuner keeps the cat and exhaust valve protection turned on in the tune. Some will turn it off. Turn off cat protection and they can get too hot. This forum has seen aftermarket cat failure. The cause is always blamed on the cat but I'm not sure that's the reality. There is a reason the factory tune has a parameter for cat protection logic. Just like there is a reason the factory tune keeps the knock sensors active, etc.

I like to compare to what works for factory cars. Do you ever hear of a stock GT500 with a stock or FRPP tune having cat issues? No. Why not? I think part of that has to do with the tune. I also think the stock cats are more robust than most aftermarket cats but I have no way of doing the testing required to prove that theory.

 

[travelers]

It's "advice" so I changed your title and moved out of tech.

I was going to give him a smart ass comment till I read you changed it and moved it.....

As for a good answer, are you talking about a 2005 or the 2014 in your sig?

If the '14 loose the cats and get a good tune as mine is clean and doesn't smell at all, that I know of. The coyotes really breath better without the cats. I installed the ARHs with off road H before the 2.3 whipple. made a difference and with the whipple even more. But no real noticeable smell.

 

[stkjock]

I was going to give him a smart ass comment till I read you changed it and moved it.....

As for a good answer, are you talking about a 2005 or the 2014 in your sig?

If the '14 loose the cats and get a good tune as mine is clean and doesn't smell at all, that I know of. The coyotes really breath better without the cats. I installed the ARHs with off road H before the 2.3 whipple. made a difference and with the whipple even more. But no real noticeable smell.

But should he lose the cats and not loose them I think.

 

[BruceH]

Ahh, so you aren't forced induction. When you were asking for advice from people with forced induction I assumed it was because you were too.

Seriously, think about E85. People have even passed sniffer test emissions without cats when they were running E85. The exhaust smell is nice imo, nothing like a mostly hydrocarbon based fuel.

 

[07 Boss]

Cams are always going to give you fumes at idle because the motor is sputtering and missing. A lot of extra unburnt fuel makes it into the exhaust. but I bet a bunch of it is due to not having cats. I happen to like that smell. Brings back fond memories. But if the ball and chain don't like it you might want to weld a couple in there for her.

 

[redfirepearlgt]

I was going to give him a smart ass comment till I read you changed it and moved it.....

As for a good answer, are you talking about a 2005 or the 2014 in your sig?

If the '14 loose the cats and get a good tune as mine is clean and doesn't smell at all, that I know of. The coyotes really breath better without the cats. I installed the ARHs with off road H before the 2.3 whipple. made a difference and with the whipple even more. But no real noticeable smell.

Thanks. And yes its on the 14. The 05 was two cars ago. Sounds like you have a similar setup as mine less exhaust.

It's "advice" so I changed your title and moved out of tech.

Mighty kind. And I appreciate the education. I was not aware "chit chat" was a synonym for advice. I mistook it for being a synonym for gossip.

Thanks for moving it. I'll keep that in mind the next time.

Keep the cats, you can make more than enough power with factory cats. I made 699rwhp with a 4.6 3v, factory cats, and a Procharger D1. This was with E85. That's another suggestion, run E85 and the exhaust will have a nice sweet smell. I've also had plenty of setups with a 4.6 that ran on gasoline and made well over 550rhwp. IMO once you go above 525rhwp the extra power becomes exponentially useless in a car that will see a lot of in town driving.

My suggestion is that you do your research and focus on those with real world experience. Factory cats work great but make sure your tuner keeps the cat and exhaust valve protection turned on in the tune. Some will turn it off. Turn off cat protection and they can get too hot. This forum has seen aftermarket cat failure. The cause is always blamed on the cat but I'm not sure that's the reality. There is a reason the factory tune has a parameter for cat protection logic. Just like there is a reason the factory tune keeps the knock sensors active, etc.

I like to compare to what works for factory cars. Do you ever hear of a stock GT500 with a stock or FRPP tune having cat issues? No. Why not? I think part of that has to do with the tune. I also think the stock cats are more robust than most aftermarket cats but I have no way of doing the testing required to prove that theory.

Appreciate the 411 Bruce. I do know that VMP keeps the knock sensor active on my tune. It is limited add only 2.0 degrees of timing but can pull out as needed on days such as yesterday if IAT2 temps, cylinder temps, detonation or other issues arise that timing retardation can remedy. I will check on the cat and exhaust valve protection though when I speak to them on Monday. I datalogged a decent pass last evening (as decent can be in 3500DA at a track at 492ft) and need to send it to them to see if we can add a little more timing down low to come out of the hole a little better.

E-85 is great stuff and if I was doing just a car for competition only I'd go that route. I plan to stick with 93 Octane because of its availability in comparison but more so because of its efficiency in MPG.

Thanks for the tech 411 on the tune...I mean advice.

Ahh, so you aren't forced induction. When you were asking for advice from people with forced induction I assumed it was because you were too.

Seriously, think about E85. People have even passed sniffer test emissions without cats when they were running E85. The exhaust smell is nice imo, nothing like a mostly hydrocarbon based fuel.

She gets help from a meat grinder. If you get the meaning

 

[travelers]

It's "advice" so I changed your title and moved out of tech.

Thanks. And yes its on the 14. The 05 was two cars ago. Sounds like you have a similar setup as mine less exhaust.

Yes other then the possible brand of headers, I have the GT500 mufflers also and no cats. I do have a Lund tune for my setup.

 

[BruceH]

Thanks. And yes its on the 14. The 05 was two cars ago. Sounds like you have a similar setup as mine less exhaust.



Mighty kind. And I appreciate the education. I was not aware "chit chat" was a synonym for advice. I mistook it for being a synonym for gossip.

Thanks for moving it. I'll keep that in mind the next time.



Appreciate the 411 Bruce. I do know that VMP keeps the knock sensor active on my tune. It is limited add only 2.0 degrees of timing but can pull out as needed on days such as yesterday if IAT2 temps, cylinder temps, detonation or other issues arise that timing retardation can remedy. I will check on the cat and exhaust valve protection though when I speak to them on Monday. I datalogged a decent pass last evening (as decent can be in 3500DA at a track at 492ft) and need to send it to them to see if we can add a little more timing down low to come out of the hole a little better.

E-85 is great stuff and if I was doing just a car for competition only I'd go that route. I plan to stick with 93 Octane because of its availability in comparison but more so because of its efficiency in MPG.

Thanks for the tech 411 on the tune...I mean advice.



She gets help from a meat grinder. If you get the meaning

Ok, I get it now. I'd still keep the factory cats but that's me.


I would of never mentioned it if I knew VMP was doing your tuning. The last thing a good tuner is going to want to hear is that someone on the internet thought they might be doing it wrong, lol.

I also was thinking in terms of a 3v, I have no idea what parameters are set up for a 5.0.

I would agree with the MRS though, I'm not a fan of unburned hydrocarbons myself. I must be the only one on this site who lived through carbureted motors, points distributors, breathers, and no cats who doesn't miss it a bit. All those crankcase and gas fumes when driving in traffic, dismal power production for cubic inches (or horrible street manners for anything modified to make more power), rotten mpg, changing ignition components all the time, spark plugs not lasting because of leaded fuel and the unpreciseness of a carburetor/vacuum points distributor. Don't miss it at all.

I think we are in a golden age of musclecars right now. But I digress.

 

[redfirepearlgt]

Ok, I get it now. I'd still keep the factory cats but that's me.


I would of never mentioned it if I knew VMP was doing your tuning. The last thing a good tuner is going to want to hear is that someone on the internet thought they might be doing it wrong, lol.

I also was thinking in terms of a 3v, I have no idea what parameters are set up for a 5.0.

I would agree with the MRS though, I'm not a fan of unburned hydrocarbons myself. I must be the only one on this site who lived through carbureted motors, points distributors, breathers, and no cats who doesn't miss it a bit. All those crankcase and gas fumes when driving in traffic, dismal power production for cubic inches (or horrible street manners for anything modified to make more power), rotten mpg, changing ignition components all the time, spark plugs not lasting because of leaded fuel and the unpreciseness of a carburetor/vacuum points distributor. Don't miss it at all.

I think we are in a golden age of musclecars right now. But I digress.

I'm with you on that. While I am old enough to know that 351C 4V stands for 351Cleveland four barrel (4 ventricle) I will take the modern day technology over old school. I like the old stuff but you said it. We are in a golden age...the next gen if you will. I like change...on certain things. This is one of them.

I think for now I will stay that was as well. I just need a little work on getting out of the hole which may be simply adding a little more timing on the bottom end and ultimately a Circle D 2c or 3C next spring should resolve the issue completely.

 

[joedls]

LOL. That smell is how I make my car "wife-proof".

 

[redfirepearlgt]

LOL. That smell is how I make my car "wife-proof".

I think I just pee'd while i was laughing!

 

[skwerl]

If VMP is tuning your car then I wouldn't worry about it. Just mention to Justin your concerns and he can adjust your tune accordingly. If you want to run aftermarket cats and not burn them up, he will make it so. If you want to run no cats and still make it so the wifey doesn't complain about the fumes, he can make that happen as well.

 

[redfirepearlgt]

^^^ Agree 110%. Amen and pass the biscuits if you please. Best group of out of state boys I have ever worked with.

 

[skwerl]

^ They are local to me. I've even been blessed with the opportunity to share a meal or two at the Starkey's dinner table. Did you know they have SIX kids?

 

[hockeygod]

At what boost level generally do you have to worry about blowing out the cats?

 

[bunits19714]

I noticed the fuel smell more when I was catless na, I am fi now and run a mixed gas of 110 leaded and 93 and it doesn't smell nearly as bad- barely noticeable and I have a nose like a blood hound( I couldn't stand it na and almost switch to e-85 cause of it) I don't know if it is all attributed to the blend and lack of benzene and other additives that stink or if it is because when I went fi I was dyno tuned and when I was na I was emailed tuned with no log revisions just some minor tweeks per verbal info. _ Meaning my af ratio is more dialed in. marine gas has no additives and airplane fuel doesn't have all the chemicals in it that make it stink those are some other choice to mix with your 93- My car isn't a dd and only sees about 3500 miles a year. And race fuel is actually more readily available than e-85 actually. 6 different station with in 15-20 minutes.