Exhaust sound increase - No exhaust swap

[JRex]

Took the TRX over the high end tuner shop in town. Owner and workers have 3 moded Hellcat vehicles, Track Hawk, Challenger Hellcat and Charger Hellcat.

I ordered my QTP exhaust cut outs.

They mentioned a few interesting things, when looking over TRX for performance upgrades.

1) Exhaust piping behind rear wheel has exhaust pressure releases, like GM has, to reduce the amount of exhaust going out the rear tail pipes and lowering the exhaust sound. They said a simple test is to temporarily tape it up with exhaust tape and note the difference in exhaust. Then you could change pipe, if you wanted it lounder.

2) TRX headers are, their term "log headers", due to limited room in engine bay due to suspension location. Don't think there are going to any headers that fit.

Interesting visit.

 

[JRex]

They also asked abut the Easter egg under the hood, Trex eating Raptor.

I asked is air filter box was a big on the other hellcat engines compared to the TRX's. they said no. They also noted on other hellcat applications with K&N upgrade they have gotten 23 to 24 more HP with that mode. They have a dyno there so I assume is was RWHP. Those are the rems most performance mode people talk in.

 

[Bambi]

They also asked abut the Easter egg under the hood, Trex eating Raptor.

I asked is air filter box was a big on the other hellcat engines compared to the TRX's. they said no. They also noted on other hellcat applications with K&N upgrade they have gotten 23 to 24 more HP with that mode. They have a dyno there so I assume is was RWHP. Those are the rems most performance mode people talk in.

Clarification. The shop said that only swapping a k&n filter got them 23-24 hp? And this was proven on a dyno? Without any other mods?

if so you should do it and do pulls before and after on dyno. Post results. I would be really surprised but stranger things have happened

 

[JRex]

From K&N:
K&N 69 SERIES AIR INTAKE
69-2553TTK
17-21 Dodge Challenger / Charger Hellcat
23.59 HP @ 5712 RPM

K&N Blackhawk COLD AIR INTAKE
69-2550TTK
15-16 Dodge Challenger / Charger Hellcat
38.95 HP @ 5713 RPM

I would like to find the air filter flow thru #'s for TRX vs other high flow filters. I dont think anyone knows what the truck is capable of until tried. The size of the air box & filter are 3 times? larger than challenger Hellcat?

K & N only on track hawk 23-24RWHP

They said on track hawk, $2500 pair of heads only gained 25 and made exhaust sound too load to drive as daily driver.

I am sure its all over the Hellcat forums, I just dont have the time to dig it up.

Right off K&N site 23RWHP.
Dynamometer testing verified an increase from 621.05 horsepower to 644.64 horsepower, as measured at the drive wheels, on the same 2017 Dodge Charger Hellcat on the same day, with the only change being the installation of a K&N 69-2553TTK Typhoon air intake system.

https://www.knfilters.com/blog/give...-an-estimated-23-hp-with-a-kn-air-intake-kit/

https://fasthemis.com/i-23893056-kn...2l-srt-hellcat-2015-2016.html?ref=brand:96982

https://fasthemis.com/i-23893824-kn...2l-srt-hellcat-2017-2021.html?ref=brand:96982

 

[Superbrowndude]

Are you mounting the cutouts before the cats or after just curious? I have qtp on a couple of my other cars.

 

[Bambi]

From K&N:
K&N 69 SERIES AIR INTAKE
69-2553TTK
17-21 Dodge Challenger / Charger Hellcat
23.59 HP @ 5712 RPM

K&N Blackhawk COLD AIR INTAKE
69-2550TTK
15-16 Dodge Challenger / Charger Hellcat
38.95 HP @ 5713 RPM

I would like to find the air filter flow thru #'s for TRX vs other high flow filters. I dont think anyone knows what the truck is capable of until tried. The size of the air box & filter are 3 times? larger than challenger Hellcat?

K & N only on track hawk 23-24RWHP

They said on track hawk, $2500 pair of heads only gained 25 and made exhaust sound too load to drive as daily driver.

I am sure its all over the Hellcat forums, I just dont have the time to dig it up.

Right off K&N site 23RWHP.
Dynamometer testing verified an increase from 621.05 horsepower to 644.64 horsepower, as measured at the drive wheels, on the same 2017 Dodge Charger Hellcat on the same day, with the only change being the installation of a K&N 69-2553TTK Typhoon air intake system.

https://www.knfilters.com/blog/give...-an-estimated-23-hp-with-a-kn-air-intake-kit/

https://fasthemis.com/i-23893056-kn...2l-srt-hellcat-2015-2016.html?ref=brand:96982

https://fasthemis.com/i-23893824-kn...2l-srt-hellcat-2017-2021.html?ref=brand:96982

Do the swap and dyno before and after.

 

[JRex]

Are you mounting the cutouts before the cats or after just curious? I have qtp on a couple of my other cars.

I have QTP's on 2019 and have worked flawlessly.

Getting installed after cats back by bed, after X pipe and before mufflers. That way when you hit the FOB button to open exhaust, its just X pipe to open exhaust. Super loud and aggressive. Hit the button again, back to stock exhaust sound for driving in your own neighborhood.

There is no TRX kit for this, you have to order the individual pieces, the by pass electronic cutouts and Y pipes for both sides, but they run on one FOB.

Click a bottom, basically straight pipes, race exhaust, click the other button, normal stock exhaust. Its really a fun toy to have and hand out the ear cracker to any who deserves it.

 

[JRex]

Two notes from performance shop.

After exhaust manifolds, is straight 3" pipe, then to end of cab or so, X pipe, then under bed is 2 tiny mufflers.

After mufflers and before the tips, just behind rear wheels, are 2 exhaust vents, they said it was used to reduce the exhaust flow to the exhaust tips, which decreases the loudness of exhaust. GM does this also. They said a quick test is, they tape it up for a customer and then let them hear the exhaust with additonal flow, which brings more exhaust noise. If customer likes it, they enclose those mesh area or replace pipe with regular pipe.

 

[Bambi]

After cats back by bed, after X pipe and before mufflers.

Why that spot? And did you hear it both plugged and unplugged?

 

[JRex]

No I did not hear it plugged, I ordered the QTP cutouts. They said it makes a difference. This was the first time I ever heard of this, today.

Shop said they just put some type of tape (heat resistance?) around them, long enough for customer to check out the louder noise. Then if customer like it, seal them up or replace the pipe.

It would be a cool video, before and after, with decibel meter.

They said manufacture does to reduce exhaust noise.

 

[2crazy2stop]

No I did not hear it plugged, I ordered the QTP cutouts. They said it makes a difference. This was the first time I ever heard of this, today.

Shop said they just put some type of tape (heat resistance?) around them, long enough for customer to check out the louder noise. Then if customer like it, seal them up or replace the pipe.

It would be a cool video, before and after, with decibel meter.

They said manufacture does to reduce exhaust noise.

Did this happen? Been waiting over 6 months for my truck...so I want something to look forward 2

 

[JRex]

Ordered parts 2 weeks ago, last week they called and got tracking number. Part are suppose to be in this week and install the next week, sometime on the week of 3/15/2021.

 

[echristo]

Ordered parts 2 weeks ago, last week they called and got tracking number. Part are suppose to be in this week and install the next week, sometime on the week of 3/15/2021.

Any update on this? I'm especially curious about the effect from plugging those exhaust vents.

 

[ekaz]

Any update on this? I'm especially curious about the effect from plugging those exhaust vents.

There's a thread somewhere around here about sealing off the exhaust vents...some say its louder, some say no difference.

 

[KnightMare]

There's a thread somewhere around here about sealing off the exhaust vents...some say its louder, some say no difference.

I'm going to do a video about it Wednesday with a decibel meter to see if it really does. And debut the QTP TRX exhaust cutout kit

 

[ekaz]

I'm going to do a video about it Wednesday with a decibel meter to see if it really does. And debut the QTP TRX exhaust cutout kit

Well hurry up with it already, you've been teasing us about it long enough. LOL

 

[jonny_pockets]

Any update on this? I'm especially curious about the effect from plugging those exhaust vents.

I did mine and I feel like there was a difference. At first I only did the back Tri vents because I ran out of tape, later I clamped off all of them and felt it was louder with just the back two closed off. I’m gonna take off the front clamps to see if it if louder with just the back two. For the $40 and 20 minutes it takes I feel it’s worth it

 

[2crazy2stop]

Definitely louder, see Picts. Worth the 50 bucks for sure.

 

[STRADALE]

Definitely louder, see Picts. Worth the 50 bucks for sure.

The high heat tape worked for a little but like w/ @Caliche the mesh screens on the the Resonance Free Pipe just started making holes in the tape. So guess I will go w. the clamps.

What are we looking at there @2crazy2stop, the decibels with the clamps in pink & without in yellow? Is that higher rpms on the left down to idle? Or is that just showing the 93 decibels vs the 101 with the clamps?

 

[2crazy2stop]

The high heat tape worked for a little but like w/ @Caliche the mesh screens on the the Resonance Free Pipe just started making holes in the tape. So guess I will go w. the clamps.

What are we looking at there @2crazy2stop, the decibels with the clamps in pink & without in yellow? Is that higher rpms on the left down to idle? Or is that just showing the 93 decibels vs the 101 with the clamps?

I taped/clamped the left side of the truck and left the right side open. Started it and put my phone on the bumper about the left and right exhaust to get those numbers...at idle. I should have explained, I was being lazy