houstonT

OK, let me state the conditions that I dyno'ed the car in stock vs. with the PTS exhaust. My plan was to use the same dyno in the same weather but it didn't quite work out the way as planned.

Stock Dyno Location: Hennessey Performance Engineering using Dynojet
PTS Dyno Location: Advanced Racing Dynamics using Dynojet

Stock Dyno Weather: 84.33 degrees, 29.77 in-Hg, 69% humidity (SAE correction factor was 1.02)
PTS Dyno Weather: 67.81 degrees, 30.16 in-Hg, 27% humidity (SAE correction factor was 0.96)

One more point to make, I accidentally left the climate control/air-conditioning on during my runs with the PTS exhaust (whoops). You can actually see the computer kill the compressor at about 3,600 rpm's, but of course, no effect on the top end.

Anyhow, on to the results, draw your own conclusions.

PTS Exhaust - Uncorrected



PTS Exhaust - SAE



PTS vs Stock - Uncorrected



PTS vs Stock - SAE



PTS vs Stock - Conditions

LexISguy

A 13whp gain I was expecting more or less 20whp. Maybe you should have set the smoothing to 5 instead of 0 for better results. Thanks for the dyno results...

caymandive

iTrader: (2)

I have a few comments.

1. There is obviously a gain in power with the exhaust esp in mid to upper rpms.
2. Exactly how much is still unknown to you since every dyno is slightly different even if they are all dynojets.
3. Smoothing should be turned on to 5. Set at 0 there is too much noise.
4. Why did you go to a different dyno shop for the PTS exhaust runs?
5. I'm jealous (love the exhaust and I love the color)

houstonT

1. There is gain everywhere, you can see where the A/C compressor flicked off at 3,600 rpm...if I turned it off to begin with, who knows what the results would have been... Maybe at TX2K9 I will redyno at Hennessey's place...
2. Yup
3. I disagree here...maybe 2-3 but not 5, smoothing set to 5 will artificially guesstimate your curve by smoothing it. Smoothing at 0 gives you a real read-out with no artificial tampering. At any rate, the net gain whether on 0 or 5 was almost identical so it's moot.
4. I wanted to go to Hennessey's place today as he was running 1/4 mile. He invited me to run 1/4 mile but when I asked about dyno'ing he said he could not guarantee a dyno run as he was busy shooting and testing for a magazine article. His ZR1 ran 11.0@138 on street tires, a Hennessey modded CTS-V went 11.8@122 and a Hennessey modded 997TT went 10.8@130! I simply didn't want to risk driving 50 miles and not being able to dyno. ARD is only 5 miles from my house...
5. Thanks!

Peter

ToothDoc

Regardless of which dyno, 371 RWP is pretty good! Do you have the intake chip or are you planning on ECU/TCU?

BigMikeISF

Thanks for getting a dyno done HoustonT Are you enjoying the exhaust now that you've had it a few days? I can't wait to get mine on this upcoming Friday

MHP

13rwhp/7rwtq SAE, not bad for an untuned OEM manifold back exhaust. Combined with v2 I bet we may see some 390-400rw SAE IS-Fs.
Our longtubes will use the factory connection points as does Joe's exhaust (IIRC) meaning they should mate up perfectly.

MHP

Peter can you email the before/after winpeps to andrew@modernhorsepower.com, or set smoothing at 5 with SAE correction and post the graph.

Thanks
Andy

ISFer

iTrader: (2)

Verification pending of course, but that's something! Very substantial......

Andy, What do you estimate the gains would be with v2 and the longtubes?

Thanks for posting, HoustonT....

C.

BLOWZILLA

Longtubes? manifold?

FPR1939

When I get my v2 tuned ECM/TCM back next week I will be running on the same dyno (ARD's) that Peter (houstonT) ran on Saturday. That will be as close of a direct comparison as you can get.

I want to publicly thank Peter for downloading the Winfiles of my ISF and my Son's Tundra from ARD's computer memory. They didn't know how to download the files to my e-mail and Peter did it for them. Thanks, Peter.

After I run my dynos with the v2 tune only I am considering getting the Joe Z exhaust system (really like the looks) and then redyno. May have to send the ECM/TCM back to Andy for further tuning once the exhaust is installed. I will let Andy decide if there is much to be gained.

Thank goodness I have two extra vehicles (my wife's 2002 Expedition that she had before she got the new BMW 335i convert and my 2004 Dodge Ram 1500 Hemi that I had before I got the ISF). Glad I kept both since there have been times during the last few weeks that both Mike's Tundra and my ISF ECM/TCMs have been with MHP.

I have already purchased BF Goodrich 275X35X18 drag radials (they are in my living room). They are on 19# wheels. With them we should be able to put the additional HP to the track.

Pat

LexISguy

Looking good I am anticipating dynoing my car as well.

Joe Z

iTrader: (10)

Nice work Peter...!!

371 Rwhp and 345 Rwtq with the A/C On are great numbers..



^^ Andy lets be smart and try not to directly compare Stock Dyno #'s to PTS Dyno #'s from two different dyno shops..


Although not exact, it makes a good tool to verify the gains..

Thank You

Joe Z

LexISguy

wonder how many more hp would have been achieved by turning the a/c off.

caymandive

iTrader: (2)

None. The a/c kicks off on WOT at around 3600rpm so peak numbers aren't affected.