Exhaust and valves?

[Camaro99]

I am getting a 3" I-pipe installed tomorrow morning with my Dynomax muffler. Some people are telling me that that is way too big of a pipe and that it will float the valves. That sounds like [img]graemlins/bs.gif[/img] to me, but I do not know that much about the valvetrain of motors. From what I have seen it looks like it will not cause any problems. I was just wondering if anyone could confirm of deny that a 3" cat-back system would float valves?

[Dan M]

I have had no problems with my 3" pipes, nor have I heard of any.

Well... except for the occasional SES light from a cheap cat. [img]tongue.gif[/img]

[ August 22, 2003: Message edited by: DrSquirts ]</p>

[Ted]

They don't know what they're talking about. Most people are stupid when it comes down to this kind of stuff. Especially when they act like they know what they're talking about. One exhaust shop told me before that i wouldn't pass emissions if I welded up my cat to the s pipe, as opposed to using flanges???? If the stupid guy even knew anything. Don't ask me, they try to get out of this stuff because they're looking for an easy muffler install to get a few extra bucks. About half the people on this board have 3inch exhaust systems. IMO they're the only good way to go with catbacks.

[ August 23, 2003: Message edited by: Ted ]</p>

[Tyler]

i thought floating valves was due to TOO MUCH backpressure?

but anyways.. i had no problems with my 3inch setup

[FireFighter]

my 3'' is fine and sounds awesome :D

[toast]

The worst you can do is burn a valve and that is only if your are running open manifolds. 3inch should be just fine. [img]graemlins/thumbsup.gif[/img]

[Camaro99]

Update: Well, I went to a shop to get the I-pipe put on and waited 4 hours for them to get to my car. Once they put it on the rack, they said that it wasn't possible to go from the cat size of 2.25" to the 3" pipe. Needless to say I was rather pissed at this bs response to get out of doing an install. So I will be taking it to a different place to get it installed.

That brings me to another thing. I have decided to go ahead and get a high-flow 3" cat and be done with my exhaust for a while. Will this one work? http://store.summitracing.com/default.asp?target=search.a sp&type=bysummitpart&searchtype=both&part=CTO-6007&x=15&y=12
I don't want to buy one that will not fit and was just curious if this one will fit?

[ August 25, 2003: Message edited by: Camaro99 ]</p>

[cero]

that is the same cat im running now, however, i do get that ses light that dr. was talking about. it is a great improvement and my stuff sounds so sweet. the ses doesnt happen very much after you get some miles about 1000. other than that, i have no complaints

edit---just make sure you get a good shop to do all of the work if possible watch as they do it that is what i did so i knew if they took any short cuts

ps dr, what is the ses light from, i know it is from the cat but what is it exactly?

[ August 25, 2003: Message edited by: cero ]</p>

[Arctc Wolf]

valve float is from too high of rpm's, waaay too much backpressure, or too heavy of valvetrain components. u could burn a valve if the exhaust was too free-flowing, such as headers and a 3" cat w/ no exhaust. a 3" cat-back is fine. I've had mine for a year and it's still workin good for me.