whatme Posted January 5, 2006 Report Share Posted January 5, 2006 OK, well I was considering buying but i have now decided there are bigger performance gains to be had. The thing is i still dont want to choke off my engine if i get a higher psi chip for the car. So caught between saving money and wanting performance i looking into the exhaust cut-out valve. It seems just about perfect for me (being able to keep the sleeper look right up until you blow them away) and it costs so much less than an exhaust that i could by a chip with the extra money. Im wondering what the downsides to this are considering the fact that i wasnt able to find anything about someone putting one on. Can anyone help clear up why no one seems to like them very much? Thanks Link to comment Share on other sites More sharing options...
the underlørd Posted January 5, 2006 Report Share Posted January 5, 2006 http://volvospeed.com/vs_forum/index.php?s...15109&hl=cutout^^ relevant info for ya. Link to comment Share on other sites More sharing options...
NataSS Inc Posted January 5, 2006 Report Share Posted January 5, 2006 www.quicktimeperformance.com/QTECElectronic cut out. About the best you can buy. Lots of the V-8 guys use them and they are pretty trick. Run around town with it closed till its needed and then flip the switch and its open.I would hope you would see gains with it open. Especially on a turbo, the less restriction the faster the turbo will spool alot quicker. Link to comment Share on other sites More sharing options...
whatme Posted January 5, 2006 Author Report Share Posted January 5, 2006 that helps a little bit but doesnt really talk about any down sides. If i go with it ill relocate the o2 sensors so they are before the cutout so that fixes the problem. I heard somewhere that it kills low end power. is that true, and if so how bad? I was mainly just wondering if there was anything really bad about it i should know before i go ahead and do it.thats pretty Darn sweet. So then what size should i go with for it? I only have a stock down pipe right now but i plan on buying one later so that makes it kinda tough.....Would there be a problem with having a 3 in cut out come from stock downpipe then be sized down to stock exhaust? Link to comment Share on other sites More sharing options...
NataSS Inc Posted January 5, 2006 Report Share Posted January 5, 2006 that helps a little bit but doesnt really talk about any down sides. If i go with it ill relocate the o2 sensors so they are before the cutout so that fixes the problem. I heard somewhere that it kills low end power. is that true, and if so how bad? I was mainly just wondering if there was anything really bad about it i should know before i go ahead and do it.Yes, you will loose a little low end but will more than make up for it as soon as the boost builds. Just foot brake it at a stop to start building boost then floor it. Or start in low gear, just be ready to shift.Oh, and the interior noise levels will skyrocket. If I was going to use one of these I would put it about 1 foot behind the O2 sensor. Running one to close to an O2 sensor can cause problems with if for some reason air gets to it.These things make a HUGE diffrence on late model Fbody's. even stock ones.thats pretty Darn sweet. So then what size should i go with for it? I only have a stock down pipe right now but i plan on buying one later so that makes it kinda tough.....Would there be a problem with having a 3 in cut out come from stock downpipe then be sized down to stock exhaust?Bigger the better. I would wait till you get a larger diameter down pipe.Also forgot to mention that you MIGHT get a little exauhst leak with this. Its almost impossible for the valve to completely seal the cut out. Nothing bad but annoys some people. My buddy had one and complaint of a faint leak. But I could never hear what he was talking about. Link to comment Share on other sites More sharing options...
whatme Posted January 5, 2006 Author Report Share Posted January 5, 2006 my understanding was that if you didnt put the o2 sensor before it then the ecu would do the same thing as if an o2 sensor failed. and i dont really see how air could get to the 02 sensor if it was behind the cutout since the only time it would be open the exhaust pressure would keep it from getting in. The problem i was talking about with the 3 in was adapting the exhaust to go from what ever diameter the downpipe is, i only know its less than three inches, to a 3 inch section then back down to a 2.25 inch exhaust, though i guess that would mainly be a problem of having a competent person put it on.You said the cabin noise skyrockets. How bad do you mean? like i dont want to get a real bad headache whenever its open or actualy hurt my hearing. Like just a little bit louder than straight pipes or a whole lot louder? Link to comment Share on other sites More sharing options...
the underlørd Posted January 5, 2006 Report Share Posted January 5, 2006 a whole lot louder? exhaust dumping out underneath where you're sitting. Link to comment Share on other sites More sharing options...
whatme Posted January 5, 2006 Author Report Share Posted January 5, 2006 ok then so lets put my scientific quantification system to this. Is it "wow that ringing noise in my ear almost completely blots out the sound of the engine now..." loud, or "Holly crap i cant stand this!!!" loud, or maybe "Where are my earplugs!!!!" loud, or how about "Dang, that sounds good but im glad i dont have it like that all the time..." loud. What i mean is will it be bad enough as to be unberable for driving short distances or at WOT. I mean i know there will be drone beyond drone but is it going to be so bad that its almost unberable? Link to comment Share on other sites More sharing options...
NataSS Inc Posted January 6, 2006 Report Share Posted January 6, 2006 "Loud" is very subjective. I run a 11.5:1 compression 347inch LS1 with a BIG cam out headers, right into a "4 pipe that exits on the right side of the car through a NASCAR boom tube. Yeah, its freaking LOUD but it sounds killer and I have never heard one bad thing from someone about how it sounds. At 7500 rpm it literally sounds like Dale Earnhart Jr. is coming down the street and you can be heard a LOOOOOONG ways away. Its earsplitting at WOT. But just cruising around is still pretty loud and will make my ears ring for the rest of the day.The cut out, when its closed will sound just like your car does now. But when its open, its open exauhst. Its going to be a hell of alot louder than stock. But your not supposed run around town with it open all the time. Your neighbors wont like you and the cops will LOVE you. The cut out is for those unplanned "meetings" with felow car enthusiast at stop lights or on the freeway in a show of force. It might be the thing that lets you edge them out. I wouldnt doubt it if you pick up a couple 10ths at the drag strip with it. And I garantee your trap speeds will be faster.I have heard volvos on open exhuast at WOT (being around the At Speed car) and it sounds sweet. I have seriously considered putting one of these on my car but until I get a larger downpipe I dont want to spend the money.And there should be no drone at all at WOT. Drone only shows up under maintenence throttle, 1/4, 1/2 throttle etc. Link to comment Share on other sites More sharing options...
whatme Posted January 6, 2006 Author Report Share Posted January 6, 2006 well if your ears are ringing for the rest of the day that may not be a good thing....as in major hearing damage...but anyways, see i dont know then...ive heard an open exhaust on a volvo and it does sound sweet and it wasnt insanely loud in the car, but then again, as mentioned above, the tip of the exhaust will be right underneat you. I want to be able to ride atleast a short distance with it open, i mean around a mile or so but not much more than that. I also dont want to have to wear earplugs to keep from getting a major headache...i wouldnt think it would sound much louder than like, for example, someone running a 3 in exhaust with only a single straight through muffler...but then again what do i know.... Link to comment Share on other sites More sharing options...
NataSS Inc Posted January 6, 2006 Report Share Posted January 6, 2006 Its not going to be that loud with a 5cyl. Yes, it will be considerably louder than normal but for just short jaunts it will be fine. You will probably catch yourself running around with it open more often than you think. Link to comment Share on other sites More sharing options...
whatme Posted January 6, 2006 Author Report Share Posted January 6, 2006 ok, well i have decided to buy one.the thing is i cant figure out where to put it. It seems like there is not enough room between the flex joint on the down pipe and the cat to put it there, and if i did it would be angeled downward and the valve would blow all the hot gas all over the forward/botom of the car.I gues could go with putting it after the cat but that seems like it would nulify the majority of the benifit.So this leaves me with only one option i can think of; when i have the cut of put on, have the shop cut of a length of pipe and move the cat further down the piping and weld a new pipe in its place. I would then put the cut out valve where the cat was.Anybody have any suggestions? Link to comment Share on other sites More sharing options...
JHEIII874T5M Posted January 7, 2006 Report Share Posted January 7, 2006 Your solution will work perfectly. The reason it feels so much louder is b/c it's dumping directly under you. I ran open downpipe for about 2 months driving around 60 miles/day in the city, Ben did the same for a couple of weeks... it's fun as hell, but with the exhaust directly under you the cabin has a bit of a fuel/fume smell along with it being rather loud. However, at least in my car, it droned less open downpipe than it did out the back of the car with a magnaflow magnapack on it. Link to comment Share on other sites More sharing options...
fromtheshadows Posted January 7, 2006 Report Share Posted January 7, 2006 most of my exhaust noise is at low rpm off boost. As for killing your low end I doubt it will as the engine in its NA form gains little down low from a larger exhaust. I think this is much better than a str8 dump, fumes on a boost actuated valve shouldnt be too bad since youre moving pretty quickly on boost, The main downside I would be concerned about is the heat dumping directly below you could burn you up, no? A side exit pipe would look sic. Oh and in this state its totally illegal. I would flange it up for sure so you could make the fix it tickets go away without the headache. Link to comment Share on other sites More sharing options...
VolvoFan Posted January 7, 2006 Report Share Posted January 7, 2006 I've got a QTEC cutout on my car. The exhaust is 3" from the turbo back, through a high-flow cat, and then it takes a 90 degree turn towards the passenger's side of the car where the cutout is, then out through a boom tube. When the cutout is closed, the exhaust necks down to 2.5", goes through an IPD muffler, and over the rear axle where it splits again into two 2.25" pipes and goes out through a couple of glasspacks with stock C70 tips attached to them. Sounds great closed, and even better open. Because it dumps out just before the passenger side wheel well, I don't have a problem with excessive noise or exhaust fumes in the cabin. Definitely makes a difference at the strip.For more info, just search -Jon Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.