SS101

iTrader: (2)

i've been told that running open headers isnt good for the valves/valve seats...is this true

thecorrectformula

Yes because this can create excess heat and burn the valves and valve seats. It may not do it right away but after extended use it will put major wear on them. It also deminishes backpressure so if your car isn't tuned for it you'll lose alot of lowend torque.

PhillyCamaro16

iTrader: (1)

You can run them open for a little while most likely with no problems but after a while it will do this:

Phoenix 5.7

iTrader: (7)

is that proven or just stuff that has been said for awhile?

lovescamaros28

When you are running open headers,you have very little exhaust backpressure.Exhaust back pressure is beneficial for complete combustion.
Without backpressure from pipes you can potentially warp your valves because of cold air contacting hot exhaust valves on a vehicle running open headers.I would not even think about open headers on my car.Chances are you are going to end up losing HP if anything due to the conflict with OBD2.

AW794

iTrader: (7)

I dont think you have to worry as long as you are running LT's....

I was open header for 3 months, no issues at all

sunsetta

iTrader: (3)

You will usually warp valves because of the sudden rush of cold air that gets sucked into the extremely hot engine at shutdown.

ArcticZ28

iTrader: (14)

I don't quite buy into the whole warping of the valves with long tubes and open headers. Maybe if you are running no headers at all, it could happen. Your major issue will be with your car running like crap because air from the outside is going to be mixing with your 02's, causing the car to think it's running leaner than it is, and thus dumping fuel and the car running like crap.

mypoorLS1

iTrader: (4)

If you wanna run open headers, put about 18 inches of pipe after the collector to get a good reading from your O2's. You will loose torque down low (at least I did when I tried it) but it will pull harder up top. I wouldn't do it unless it is a race car. Electric cutouts are the way I would go if I ever wanted to run open headers again.

cookba

iTrader: (10)

i have heard the same about back pressure. just put a high flow cat or some pipe behind a cutout and your good.

LS1rulz

iTrader: (1)

You aren't going to get reversion with long tubes. Run 'em.

LSXNV

iTrader: (1)

you wont warp your valves, most of this rumer comes from those in the past who wouldn't keep their headers tight, and that cool air would sneak past the flange and gasket. also the quality of the valves nowadays also help prevent this. in the old days of drag racing, someone found out that adding header extensions would up the horsepower and give more area under the curve in terms of the power curve. some would extend the pipe a ways past the headers collector and paint a white line down the pipe. they would run the engine through its paces and inspect the white stripe. they would then cut the pipe at the point where the paint wasn't burnt. but most have found that 18" of extension past the collector was ideal. some have even made more HP, over open headers, by utilizing an X-pipe. all this has to do with the science of reversion. something i know very little about.

05 GSXR 1XXX

iTrader: (16)

id run alteast 18in or more of stright pipe off your headers just incase it can suck cold air back into..

play it safe.. 4k engine or 20$ of 18in more pipe???

PREDATOR-Z

You'll also burn your 02s
As for valves, it is a possibility, it depends on the header design.

NVR KNO

i run longtubes with my dual cutouts directly behind them. i had to make a custom y-pipe and weld the cutouts to the headers. i also had to move my O2 sensors up farther on the headers to have the space between them. i havent had an issue with them at all yet.... and ive had them like this for i guess almost a year now. i dont daily drive the car but she will sit in the garage with the cutouts still open. i maybe drive the car 2 or 3 times a month at most. runs rich as **** but what do you expect with open cutouts. it does burn O2's up quicker. she pulls hard as crap in 5th gear up top though all the way to 6500rpms.