quiet exhaust

turbonick · Post by **turbonick** » Thu Mar 04, 2010 4:39 pm

yeah, i'd like to run a full open 3" turbo back, but around here the cops are #*@&$^@#*(^$ ya no...

so, i was trying to figure out a quiet exhaust for the neon. again, it's a '00 neon undergoing an '04 srt-4 swap. i was thinking 3"DP with electric cut out (how is that with a stock turbo? big spike and a lot of boost creep?) with the stock '00 neon exhaust behind it... or should i get the rear from an SXT or something? i want to keep the car as quiet as i can for legal issues and so people aren't suspicious of the car when they hear it. going for sleeper status here... but i dont want to put an exhaust on it that will actually be TOO restrictive for the motor. hence the 3"DP with a dump so if i want to rip on it, there wont be so much backpressure. im thinking the car might sound pretty nice without being loud and still be ok for the motor with 3"DP, high flow cat, resinator, SXT rear section.

any opinions and input would be great. both good and bad. i need help with this

thanks,
nick

acr · Post by **acr** » Thu Mar 04, 2010 4:58 pm

when the hear they hear the blowoff valve, you won't have the sleeper advantage...

stdlystdmufn · Post by **stdlystdmufn** » Thu Mar 04, 2010 5:38 pm

its better than hearing the whistle from the turbo at idle.

Post by **occasional demons** » Thu Mar 04, 2010 6:11 pm

The blow off can be routed into the exhaust.

You could still go 3" to the rear, just put a 3" inlet/outlet muffler back there. It wouldn't need to be a whisper quiet one, as the turbo is going to do a lot of the quieting chores for it. Something with a nice rumble on an N/A application, will be relatively quieter on a turbo set up. The axle back may need to be fabbed, as I doubt there is a 3" pipe pre made to fit a SE/SXT muffler configuration. The cut out would still be an option for all out powah.

stdlystdmufn · Post by **stdlystdmufn** » Thu Mar 04, 2010 6:29 pm

you can route the blow off to the exhaust like the old MAF turbos had

DoubtedNeon · Post by **DoubtedNeon** » Thu Mar 04, 2010 11:53 pm

couldnt u just use a stock bov off of the srt? im assuming this is an srt turbo (think u said that anyway) u could route the bov into the exaust like occasional demons said. thats prolly ur best bet.

I actually have a stock "bov" laying around here, 2 actually.

turbonick · Post by **turbonick** » Fri Mar 05, 2010 12:21 am

ya its all stock. route it into the exhaust???? never heard of that.... i was thinking of getting a block off plate, running my hks ssq but putting the recirc insert in it and welding the tube in the intake at a steep angle towards the turbo to try and keep the noise out through the filter to a minimum. plus it might help keeping the turbo spooled if between shifts, it's getting a burst of air to the inlet.

can someone explain the exhaust thing tho? sounds interesting

Post by **occasional demons** » Fri Mar 05, 2010 12:31 am

The noise from the BOV is being directed to the exhaust, where it would be drowned completely. Your idea sounds interesting, but you might get a weird noise as the air hits the fins. Just like hitting a spinning bearing with compressed air. It might be very loud.

stdlystdmufn · Post by **stdlystdmufn** » Fri Mar 05, 2010 12:34 am

i said intake because i knew some DSM owners that were upset that they couldn't hear their BOVs (its funny how styles go round and round)

edit: p.s. its like im a little kid making a mess on the forum and occasional demons is like my dad cleaning up all my mistakes (its cool though cus im learning in the process

)

turbonick · Post by **turbonick** » Fri Mar 05, 2010 12:41 am

[quote="occasional demons"]The noise from the BOV is being directed to the exhaust, where it would be drowned completely. quote]

so you're not saying plumbing it into the exhaust? im wicked confused lol

stdlystdmufn · Post by **stdlystdmufn** » Fri Mar 05, 2010 12:42 am

pretty sure he means to plumb it into the exhaust

turbonick · Post by **turbonick** » Fri Mar 05, 2010 12:45 am

no i really am confused lol how do you plumb it into the exhaust without the exhaust pressure feeding back into the bov? or melting things?

Post by **occasional demons** » Fri Mar 05, 2010 8:52 am

I hope the back pressure does not exceed the pressure coming out the blow off valve. You would have other issues. It could be plumbed into the exhaust after the cat if it was a problem. If back pressure is more than 1or 2 psi when easing off the throttle, let alone while accelerating, something ain't right. If the blow off is going to be much more active when the throttle is shutting. Unless you haz one monster turbo. There are reed valves? that they used for the '70's style emissions to introduce air into the exhaust. You could incorporate one of those if you were that worried.

esteinmaier · Post by **esteinmaier** » Fri Mar 05, 2010 9:40 am

Don't route it to the exhaust. It will promote surge at best, melt stuff at worst. Stock turbo cars all route it back into the intake pre-turbo. Or you can do what I always wanted to do and rubber-band a duck call to the outlet, and then people will never have any idea it's a BOV.

stdlystdmufn · Post by **stdlystdmufn** » Fri Mar 05, 2010 9:45 am

esteinmaier wrote:rubber-band a duck call to the outlet

Post by **occasional demons** » Fri Mar 05, 2010 9:47 am

Well, that shoots the sleeper mode out the er, pipe.

turbonick · Post by **turbonick** » Fri Mar 05, 2010 10:37 am

esteinmaier wrote:Don't route it to the exhaust. It will promote surge at best, melt stuff at worst. Stock turbo cars all route it back into the intake pre-turbo. Or you can do what I always wanted to do and rubber-band a duck call to the outlet, and then people will never have any idea it's a BOV.

i had a "honey do" whislte i found at the dollar store in the wedding section on my shadow. duct taped it to the RFL. it was like a giant coach whistle without the ball inside it. it sounded like a cop car when i was cruising around, when i ripped on it, it actually sounded pretty sick lol

i think i am just going to do what i mentioned before, put the ssq on it with it routed back to the intake close to the turbo. i think thats my best bet at keeping the turbo car noises to a minimum. i am going to run a cat and resinator after the DP so that should keep the spool noise from being noticeable at the end of the exhaust. i thought of a new setup yesterday....

3"DP (idk if it will go down to 2.5 or stay 3 all the way back) high flow cat, vibrant ultara quiet series resinator, with a single exit "can" style muffler. figured i could put a silencer in it if i want, and it would have a decent tone without being loud and... kids around here might think im "rice" and try to mess with me with their honda's and eclipse's... then... see ya.... lol