Jetn3

Do having open down pipes have any exhaust rasp? Or down pipe to straight pipe (no muffler/bullet) out the back. Any rasp on that?

Wicked69

No. Mine doesn't anyways. Just a little louder. To be honest, even when I am running just off the open down pipes and no mufflers. My car is pretty darn quiet. Here is a video of open down pipes. From inside the car. We are testing the boost. Here we spiked to 30lbs and ran it at 25lbs.

Jetn3

Wicked69, is that open down pipes on twins? Cool vid man! Sounds good.

How about those with a single turbo?

Wicked69

Yes, open down pipes on twins. I don't usually run open pipes because I like it to be really, really guiet. lol However, when I do run open pipes to do some tuning and data logging, most people think it has mufflers on it. Definitely NO drone sounds.

I would think it would be the same with a Single but don't know for sure.

rotary1307cc

iTrader: (5)

quiet is objectionable

anything dumped under the car is going to drive you crazy on the highway

Wicked69

I disagree. I have run mine like that for 2 hr drives and with my stereo playing it doesn't bother me too much. It definitely is better with my mufflers on long drives, but my fuel pump noise drives me way more crazy then open down pipes.

OldGold

iTrader: (1)

It is not bad, really.

Inside:


Outside:

Jetn3

Don't hear any exhaust RASP in the video. Is that how it is person, no exhaust rasp?

rotary1307cc

iTrader: (5)

Lol.... mmmm yeahyeah

Twin turbo c5

Open exhaust for me on my 80mm .I've tried all kinds of different muffler's it just kills the power.

NV Z 28

iTrader: (14)

Really? No drone? I don't mind the noise, its drone that I cant stand. Where does your exhaust dump?

Ryans99ls1

iTrader: (16)

My car is quieter with it dumped right past the kmember than when it had a cutout(pre turbo). No rasp, awesome turbo sound. sounds very good imo. The highway its dead quiet, but im a 6spd and im only turning like 1700 rpm (if that) on the highway. The dumped wastegate is the loudest part. i dont have any cruising vids but this is WOT

OldGold

iTrader: (1)

None whatsoever.

Mike

black4.8

iTrader: (1)

found that any exhaust w/turbo totally kills power. had it dumped under cab, it got little annoying. out the fender now and not bad at all.

Black98s10

Wouldn't dynamat work well for this situation?

RedRocketZ28

iTrader: (19)

Here's mine in car with it dumped by the starter. In OD on the highway it's bearable. I would like to run the exhaust out the back but don't want to sacrifice any power. I will probably extend it back to the axle and put a turndown on it.

Ryans99ls1

iTrader: (16)

i dont have the money to build the exhaust the way i want but idk why more people dont put an e-cutout where the downpipe drops down out of the kmember (where most people dump it). You could wire it to a hobbs switch that opens when it sees a couple psi and closes when you let off. even if you didnt do that, you could use the supplied switch to open/close it. you could even use this as a spot to reduce down from a 4" pipe to a 3" after the cutout and back. obviously when you're running it, the cutout will be open so it wouldnt matter.

RedRocketZ28

iTrader: (19)

I have thought about an e-cutout if I run my exhaust out the back. I had a DMH on my 2000 SS and the damn thing rattled unless I got it closed just right. I would rather spend the money on something else right now instead of exhaust anyway .

PUNISHER TA

iTrader: (13)

I think I heard the DMH cutouts are a bit quicker, but my QTP cutouts are way to slow to be run off a hobbs switch, most pulls would be over before they thought about moving.

but yes, this is what I plan on doing. 3.5" cutout at the fender, and 3" back to the stock catback.

I ran a comparable setup on my N/A 454, dual 3.5" cutouts right off the headers, it was amazing. all the noise/power you can handle with them open, and with it running out the back it was amazingly quiet. (I also ran a 3" E-cutout in my adjustable borla, for extra adjustability, which I will retain.)


Note: I never had an issue with my QTP cutouts (rattling or otherwise)... until the shaft snapped in half... eek.

Tally TransAm

iTrader: (17)

heres an outside of me messing around seeing if i could hook up in front of my shop, short answer is no


inside 40-130 run


took it on a 2 hour each way trip a few weeks ago. didnt drone but wasnt quiet, although i didnt expect it to be. i think the rod end suspension was a larger noise factor than the exhaust