i bought an N/A s5 recently with full headerback straight piped exhaust, with the O2 sensor unhooked, i read something about someone blowing their motor due to the straight pipe not having enough back pressure and i guess it was running too lean or something like that? i'm not sure, but i really wouldn't like to blow my motor.. and i've never heard of this happening until i read that thread.. i was wondering if hooking up O2 sensor(because mpg) would maybe make it run lean and blow? what do you think?

 

Turbo engines with no exhaust and a fuel cut defencer run to lean and blow.

With an NA, no worries. If someone claims that, they aren't very bright and probably did something else wrong.

 

Im running straight pipe. But runs better with at least a good exhaust. Seem to have better power with at least 0.50lbs of back pressure

 

Not on an S5 n/a, but you will **** off yourself and everyone around you. Don't do it.

 

So your pretty much saying if you have a FCD with a downpipe and exhaust it will blow the engine? thats not what I hear

 

Well ya heard wrong. Or msiread.

 

Hrm... I have a Turbo motor, 3" catless N1 Style exhaust from front to back.. FCD built in to ECU. I had not heard that this was a recipe for exploding apex seals...

So Do I need to add a boost controller?

 

This is only for the turbo engines not N/a. I believe that your in the clear.

 

The only thing you will blow is your eardrums..

 

Lol

 

that would help, but more fuel would be a plus as well

 

Did you conveniently leave out a ported wastegate?

 

i noticed this too. my S5 feels like it makes more power with the cats vs straight pipe under 4500rpm.

however its not because it wants backpressure, but i think because the stock ecu tune doesn't work very well @wot under 4500rpm with the straight pipe* if you tuned the ecu with the straight pipe it would make more power.

as for blowing the engine, the S5 NA runs so rich that its fine, if anything it runs a little richer when its opened up.

*going WOT, it feels like it makes noise, but doesn't go anywhere, so its either too lean, or its too rich and not enough timing or something, i didn't check. it was also too loud and too stinky so i put the cat back on it....

 

My car stinks Bad. I mean Just backing into the garage and shutting car off smells up the house. I never have a tailgater. I am always looking in my rear view to make sure no cop is smelling my exhaust. Cause that could be bad. Its funny though I will get a tailgater very rarely then after 5 seconds they back off and then go around. they never hang out

 

What? 5 seconds??? Get 2 step now nobody does it. Hahaha

 

It will be deafening. You'll hate yourself for doing it after a week or so.

 

yes, burning gasoline smells. since the rotary engine emits more unburned hydrocarbons than a normal piston engine, it will smell like its rich, even if its not.

 

Too much boost, not enough fuel. If you have the supporting mods, it would be acceptable. An FCD just tricks the stock ECU into thinking it is running less boost than it actually is.

If your ECU has one built in, I'm assuming an Rtek, then you have some way to control the fuel. So you're in the clear.

 

I was thinking about headers on my n/a fc3s but i also heard that it can be bad for the engine? dont know who to believe

 

A straight pipe makes ur car smells like ****, thats the biggest reason why i sold the full rb set that came with the car.

 

If you have a good pair of mufflers (ie stock or RB), the sound levels can be semi-tolerable with a straight pipe alone, but the highway drone gets annoying. Toss in a header, and all bets are off.

A full RB exhaust does not use a straight pipe. It'll have a presilencer, which is not at all the same.

No.

Where the heck do these rumors come from?

 

Well, just saying i cant stand anything without a cat ... it smells bad. :-)

 

I had a true dual header to two glass packs and a set of FlowMasters. Never got any smell.

 

well i have an sdj header(gangster) straight, and i mean STRAIGHT *** pipe from that to a RB muffler.. i was just wondering if connecting the O2 sensor would hurt.. thanks.

and F*CK yes its annoying driving more than 1 mile at a steady rpm.. it almost puts me to sleep sometimes driving 15 miles to/from work.. its like a loud humming lullaby hahaha

 

i feel like a noob for asking but are headers hard to install?, i can imagine the bolts would be a bitch to get off from getting so hot