Dyno results, before/after Aero-Turbine Exhaust install

[RockyMtnTitan]

Dyno'd my truck today to test results of Aero-Turbine muffler, reso and new Y-pipe.

The "baseline" run (red) was with K&N drop-in, and stock airbox mod, stock exhaust. The today's comparison run (blue) is with new exhaust.

Notice the nice gains (especially torque) in the 3700 to about 4300rpm range. I'm very pleased with the results. I'll do one more dyno after the Volant install, maybe next week.

Before (corrected): 253.7 hp/ 304.6 tq
After (corrected): 260.5 hp/ 331.1 tq

Here's the graphs, both corrected and actual:

[the head]

Cool. I've been looking for more Volant dyno runs before I get one. So thanks!

[RockyMtnTitan]

Originally Posted by the head

Cool. I've been looking for more Volant dyno runs before I get one. So thanks!

Yeah.....bet you'll have NO problems getting those 13's consistently after installing the Volant. Joe at Volant emailed me results of their dyno on the Titan. Came back at 9.7hp, but, sadly, provided no torque numbers. From what I've seen, hp/tq gains have been as much as 16/20 when running modified exhaust........hopefully more in your case w/ nos.

Steve

[TOTitan]

How much louder is it than the stock system ?

[GETSOMZ28]

Man, that is one wierd looking graph,what is up with that spike at 4K?! Realistically, it looks like you gained a solid 10hp/tq under the curve.

[Tony]

WOW! At 2700 RPM the torque increased by 90LB-FT and the HP by 45? The graph implies the new muffler set-up caused the curves to shift to the left providing whopping torque gains at the low end. (kidding)
Were these runs made in different gears so nothing below 3250 RPM can be compared?
I’ve read posts claiming low RPM power measurements could not be determined on dynos. Guess those were generalizations and inaccurate.

[Bob]

The high torque spike at 2700 RPM was possibly coming from the torque convertor when the gear changed and should be probably be ignored.

[GETSOMZ28]

Actually, it looks as if the dyno operator just recoded the truck getting up to speed and then flooring it, that is why you see that spike at 2700, which is like Bob said, the TC. If you know anything about about autos, is that thing called shift extension, which is the rpms it drops to when the gears upshift. For that reason, you wont get good low rpm data, except for 1st gear, but then there is the gearing that throws off the data even more.

Actually, all these dynos that are posted on here have been in 3rd gear and our Titans 1:1 gear is actually 4th gear (while a 4-speed auto like GM, Ford, and Dodge is 3rd gear - yes, even the less acurate titling of the 5-speed in the Hemi, it only has 4 forward gears and is not a true 5-speed tranny). So in saying that, none of these dyno are a "true" depiction of what the actual hp/tq numbers are.

Why are they not done in 4th gear?? Because the speed limiter of the truck doesnt allow it to go through the entire rpm band (since you would probably be going 140mph on the dyno).

[RockyMtnTitan]

Originally Posted by GETSOMZ28

Actually, it looks as if the dyno operator just recoded the truck getting up to speed and then flooring it, that is why you see that spike at 2700, which is like Bob said, the TC. If you know anything about about autos, is that thing called shift extension, which is the rpms it drops to when the gears upshift. For that reason, you wont get good low rpm data, except for 1st gear, but then there is the gearing that throws off the data even more.

Actually, all these dynos that are posted on here have been in 3rd gear and our Titans 1:1 gear is actually 4th gear (while a 4-speed auto like GM, Ford, and Dodge is 3rd gear - yes, even the less acurate titling of the 5-speed in the Hemi, it only has 4 forward gears and is not a true 5-speed tranny). So in saying that, none of these dyno are a "true" depiction of what the actual hp/tq numbers are.

Why are they not done in 4th gear?? Because the speed limiter of the truck doesnt allow it to go through the entire rpm band (since you would probably be going 140mph on the dyno).

Yeah, what he said! Ideally, a 1:1 is preferred, but like GETSOMZ28 said, the speed limiter would kick you out at, I believe, 114mph in 4th. I'm not sure how inaccurate the numbers are when not using a 1:1 gear, but I don't think it matters if your just dynoing to test gains from adding mods like I am, as long as you try to do it the same way each time. Dynoing w/ an AT seems tricky cause you have get thru the lower gear changes and then roll into the throttle gently once in 3rd so you don't cause a downshift. The graph will always show the shift changes (hence the spikes) up to the gear you're dynoing in, unless of course, you have a manual tranny where you could just start out in your 1:1 gear and stay in it throughout the entire run. Once your beyond that point where it won't downshift to a lower gear, you can nail it at start making horsepower.

These were my first two visits to a dyno shop, and what a blast. Just to see and hear your truck doin over 110mph while sittin right in front of you.....wow! Note to self, though: "Don't stand behind vehicle while truck is rappin out at almost 6000rpm". Like an idiot, (cause I had to hear them pipes, don't ya know) I'm standing behind my truck when the tire tread decides to spit a small rock out at me, hittin me in the upper high.......Youch.....thought I'd been shot!

Steve

[Tony]

Thanks for the explanation guys.

[QShip]

Nice, informative thread!

[RockyMtnTitan]

Originally Posted by TOTitan

How much louder is it than the stock system ?

Quite a bit louder than stock.
Here's my sound clips (post#26)

AeroTurbine Exhaust?????

[NailsInOurbacks]

Originally Posted by RockyMtnTitan

Yeah, what he said! Ideally, a 1:1 is preferred, but like GETSOMZ28 said, the speed limiter would kick you out at, I believe, 114mph in 4th. I'm not sure how inaccurate the numbers are when not using a 1:1 gear, but I don't think it matters if your just dynoing to test gains from adding mods like I am, as long as you try to do it the same way each time. Dynoing w/ an AT seems tricky cause you have get thru the lower gear changes and then roll into the throttle gently once in 3rd so you don't cause a downshift. The graph will always show the shift changes (hence the spikes) up to the gear you're dynoing in, unless of course, you have a manual tranny where you could just start out in your 1:1 gear and stay in it throughout the entire run. Once your beyond that point where it won't downshift to a lower gear, you can nail it at start making horsepower.

These were my first two visits to a dyno shop, and what a blast. Just to see and hear your truck doin over 110mph while sittin right in front of you.....wow! Note to self, though: "Don't stand behind vehicle while truck is rappin out at almost 6000rpm". Like an idiot, (cause I had to hear them pipes, don't ya know) I'm standing behind my truck when the tire tread decides to spit a small rock out at me, hittin me in the upper high.......Youch.....thought I'd been shot!

Steve

I'm not laughing at you... I just learned something from every part of your post... thank you for educating before i myself up!
---Colin-