Truck felt slower after exhaust mod, so I tried out my new dragy…

SILVER SLED · April 17, 2022

So I’ve known about the phenomenon of a loud exhaust making the same vehicle seem slower. So worrying that my muffler replacement may be hurting performance I finally decided to set up my new dragy. Knowing the truck is sitting about 150 lbs heavier than when I went to the track where it ran a 13.61 I was hoping for a 13.7ish. The first run went 13.69, so I was pleased and didn’t believe the new louder exhaust didn’t hurt performance. I decided to do run more run for the heck of it, launch at a little higher rpm and it ran 13.59. So now I’m thinking maybe the exhaust actually helped performance. Who’d a thunk that.

KARNUT · April 17, 2022

8 hours ago, SILVER SLED said:

So I’ve known about the phenomenon of a loud exhaust making the same vehicle seem slower. So worrying that my muffler replacement may be hurting performance I finally decided to set up my new dragy. Knowing the truck is sitting about 150 lbs heavier than when I went to the track where it ran a 13.61 I was hoping for a 13.7ish. The first run went 13.69, so I was pleased and didn’t believe the new louder exhaust didn’t hurt performance. I decided to do run more run for the heck of it, launch at a little higher rpm and it ran 13.59. So now I’m thinking maybe the exhaust actually helped performance. Who’d a thunk that.

All the people I’ve hung with over the years including myself had the opposite sensation. The same effect can be said that smaller cars with a firm ride feels faster cornering than a larger one at the same speed. A stick shift vehicle seems faster than an automatic. The more you stimulate the senses the bigger the excitement.

TNTSierra · April 17, 2022

9 hours ago, SILVER SLED said:

So I’ve known about the phenomenon of a loud exhaust making the same vehicle seem slower. So worrying that my muffler replacement may be hurting performance I finally decided to set up my new dragy. Knowing the truck is sitting about 150 lbs heavier than when I went to the track where it ran a 13.61 I was hoping for a 13.7ish. The first run went 13.69, so I was pleased and didn’t believe the new louder exhaust didn’t hurt performance. I decided to do run more run for the heck of it, launch at a little higher rpm and it ran 13.59. So now I’m thinking maybe the exhaust actually helped performance. Who’d a thunk that.

It does because the flappers cover 50% of the airway in the stock exhaust. I picked up .2 to .3 tenths by adding my Corsa Catback and S/B intake. Depending on the running. That is just by an app on phone. They do make a difference. I’ve said it on the last 2 trucks I did both these aftermarket accessories for. Yes seat of the pants felt way better. Drivability was better, and the sound was intoxicating!

SILVER SLED · April 17, 2022

4 hours ago, KARNUT said:

All the people I’ve hung with over the years including myself had the opposite sensation. The same effect can be said that smaller cars with a firm ride feels faster cornering than a larger one at the same speed. A stick shift vehicle seems faster than an automatic. The more you stimulate the senses the bigger the excitement.

I noticed it first when swapped transmissions in my 69 Dart in my dads garage. I had to cut the exhaust in front of the muffler. It sounded terrible after that and felt like it was making a lot of noise just to get down the road and seemed slower. My dad said once you get the exhaust fixed it will be fine, and it was. This truck exhaust was louder than I wanted originally. Same sensation as in my Dart for me. I’m now getting used to exhaust-replaced muffler and flapper valve with straight through muffler, kept resonators-and honestly kinda like it. Maybe just me.

SILVER SLED · April 17, 2022

3 hours ago, TNTSilverado said:

It does because the flappers cover 50% of the airway in the stock exhaust. I picked up .2 to .3 tenths by adding my Corsa Catback and S/B intake. Depending on the running. That is just by an app on phone. They do make a difference. I’ve said it on the last 2 trucks I did both these aftermarket accessories for. Yes seat of the pants felt way better. Drivability was better, and the sound was intoxicating!

I still have my S&B intake to install yet. Maybe I’ll end up doing a Diablo tune, maybe a low 13 second time….

KARNUT · April 17, 2022

13 minutes ago, SILVER SLED said:

I noticed it first when swapped transmissions in my 69 Dart in my dads garage. I had to cut the exhaust in front of the muffler. It sounded terrible after that and felt like it was making a lot of noise just to get down the road and seemed slower. My dad said once you get the exhaust fixed it will be fine, and it was. This truck exhaust was louder than I wanted originally. Same sensation as in my Dart for me. I’m now getting used to exhaust-replaced muffler and flapper valve with straight through muffler, kept resonators-and honestly kinda like it. Maybe just me.

I use to do lots of amateur drag racing. I ran cut outs. Opening cut outs produced better times. These modern vehicles who knows. The first thing I always did from my first vehicle was twice pipes and glass packs. Then measure tire marks. at 60 years old it all changed. Quiet please.

TNTSierra · April 17, 2022

23 minutes ago, SILVER SLED said:

I still have my S&B intake to install yet. Maybe I’ll end up doing a Diablo tune, maybe a low 13 second time….

I also am thinking of the Diablo tune or flash paq/Superchips. The Diablo is $662 right now on website. Not to bad of a deal. Just went over my warranty. Have 37k in it now.

CamGTP · April 17, 2022

Being .1 or even .2 faster can be down to no wheel spin and your 60 foot. The 60 foot is really critical when it comes to E.T.

A better comparison would be to measure time between two different speeds. Like going from 30-80mph or 50-70mph.

SILVER SLED · April 18, 2022

3 hours ago, CamGTP said:

Being .1 or even .2 faster can be down to no wheel spin and your 60 foot. The 60 foot is really critical when it comes to E.T.

A better comparison would be to measure time between two different speeds. Like going from 30-80mph or 50-70mph.

I agree. I launch the truck in 4wd hi and don’t get any wheels pin.

TNTSierra · April 18, 2022

3 minutes ago, SILVER SLED said:

I agree. I launch the truck in 4wd hi and don’t get any wheels pin.

I use 4 auto. Sport mode and mash the gas. That’s had my best results.

SILVER SLED · April 18, 2022

1 minute ago, TNTSilverado said:

I use 4 auto. Sport mode and mash the gas. That’s had my best results.

I use sport mode also. One day I’ll try tow/haul mode. It seems like a more aggressive mode in “ normal ish” driving. Maybe I’ll try 4wd auto one day also.