Inetba

So I've read with over 2* overlap you start to smell exhaust and gas coming from your car really badly.

My question is, If I had a catted Y pipe with an exhaust cut out AFTER the catalytic converter, how much overlap could I run before you start to get that exhaust/gas smell. I would want the exhaust cut out as close to the catalytic converter(s) as I could get it to help promote flow if that influences anything.

I would prefer not being able to smell gas/exhaust at all sitting at a light or in a parking garage.

Thank you for your help!

zracer323

iTrader: (12)

A catted y-pipe with no cutout would be your best bet if you don't want any exhaust smell. Or get an electric cutout that you can close when you want to.

Inetba

Alright, assuming I had a catted Y, NO cut out, and a gmmg exhaust, about how much overlap could I run before I start smelling exhaust?

BigBirdLS1

This is a tough question to answer. What you mentioned already are factors that would dictate the severity of the gas smell. The overall size of the cam and of course most importantly the tune will make or break the smell.

Inetba

So wait, what if it was a small cam but it had a large overlap? Would that have a bad smell?

Or a large cam with negative overlap?

Which one would have a stronger smell or would they be equal?

TImmy_Jones

iTrader: (4)

Just run the exhaust AT LEAST over the rear axle and you will eliminate most smell (even with an ORY) unless you are idling for more than a few mins in one spot, or backing up.

Inetba

Seriously? That's such good news! The whole reason I was avoiding the big cams is because I didn't want the car to smell like it was going to break any minute!

Awesome.

TImmy_Jones

iTrader: (4)

Seriously man, see if someone has an ORY around you....I never rode in a car without cats before and it stinks when I back up (car occupies space where my exhaust was being spit out) and when I idle...but other than that, no real smell.


One thing to consider is if you have a garage...I would honestly switch to a catted Y if I had to park indoors, that would stink like hell.

Seriously, find someone around you with an ORY and see if you can check their car out. I could see where dumped under the car (pre-axle) would smell, but mine literally goes over axle and dumps out and I get zero smell, even rolling at a few MPH up to a light or stop sign.

I don't think the people behind me like it too much...

brcampbe

iTrader: (1)

Sometimes you just can't avoid the smell. I have the TSP 228r cam with a 110LSA and it's overlap causes my exhaust to smell like gas pretty good. I even have a catted Y and it still stinks. Good tune too, but that only eliminated the cam surge and stalling. I imagine if I had a 114LSA it would stink a lot less.

TImmy_Jones

iTrader: (4)

Any concern of a clogged cat, or two with a setup like this?

SOMbitch

iTrader: (8)

Never bothered my cats Timmy. Almost 50K on them two different motors...

OP....My cam has 20* overlap @ .050 and the only time I smell it is when I pull it in a garage etc.... My exhaust runs out the back and I never smell it at stoplights or even when backing up...

PowerShift408

iTrader: (44)

There's not a set amount of overlap that will generate the smell of fuel. However, even with a stock cam, a catless exhaust will generate the smell. It's not a strong smell, but different people have different tolerances to these things. I was blessed with a pretty limited sense of smell since birth so it's never been something that I've had an issue with. The best advice I can give you is to try and find a local with a catless exhaust and go for a ride and see for yourself.

BlackScreaminMachine

iTrader: (17)

The tune of the car can/will have a big effect on exhaust smell as well as having CATS or no CATS. Also to consider is timing and heat range of the plugs.