We've had numerous inquiries from supercharged tC owners asking whether or not we've tested our 3" exhaust system on a tC with a TRD S/C. We recently brought in an '05 tC with a TRD S/C running a stock 7psi pulley, for testing. We were skeptical about whether there would be any power gains, since we felt a 3" exhaust was a bit large for a S/C tC. Our intuition told us that we might gain some power up top, but possibly lose power down low and even in the midrange. Our dyno, however, proved us wrong.
We dynoed the TRD S/C tC with the following exhaust configurations all within a 4-5 hour period. The temperature was between 55-57degrees in our dyno cell during all the dyno sessions.

The car came in equipped with a stock header, stock S-pipe and TRD axle-back exhaust. This set-up provided us with the baseline information.

We then proceeded to test the following exhaust system configurations:

- PTUNING 3" full turbo-back exhaust - or in this case we'll call it a "header back".
- PTUNING 3" S-back exhaust with factory S-pipe.
- Megan Racing S-Pipe and Megan Racing 60mm drift-spec exhaust system.


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Updated: 12/20/2007
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The dyno results are in. Sorry it took so long, but it takes time to get all the graphs and crunch the numbers. Let's see who guessed the right set-up.

Baseline dyno number
-----------------------------------------------------------
RUN: 062237.004 (baseline)
-TRD S/C w/ standard 7psi pulley
-stock s-pipe
-stock mid-pipe w/cat


Below is a graph showing that we are testing a 7psi pulley



Baseline vs PTUNING 3" Turbo-back/Header-back Exhaust
-----------------------------------------------------------
RUN: 062237.004 (baseline)
-TRD S/C w/ standard 7psi pulley
-stock s-pipe
-stock mid-pipe w/cat

RUN: 062237.008
-TRD S/C w/ standard 7psi pulley
-PTUNING 3" Turbo-back Exhaust

Max Gain Over Baseline
----------------------
HP: 13.7 WHP @6300
TQ: 12.0 FT/LB @5650

Peak Gain Over Baseline
----------------------
HP: 10.4 WHP
TQ: 6.8 FT/LB




Baseline vs PTUNING 3" S-back Exhaust
-----------------------------------------------------------
RUN: 062237.004 (baseline)
-TRD S/C w/ standard 7psi pulley
-stock s-pipe
-stock mid-pipe w/cat

RUN: 062237.013
-TRD S/C w/ standard 7psi pulley
-stock s-pipe
-PTUNING 3" S-back Exhaust

Max Gain Over Baseline
----------------------
HP: 5.7 WHP @5900
TQ: 6.0 FT/LB @3550

Peak Gain Over Baseline
----------------------
HP: 3.4 WHP
TQ: 4.1 FT/LB




Baseline vs MEGAN 60mm Drift-Spec Exhaust + Megan S-pipe
-----------------------------------------------------------
RUN: 062237.004 (baseline)
-TRD S/C w/ standard 7psi pulley
-stock s-pipe
-stock mid-pipe w/cat

RUN: 062237.019
-TRD S/C w/ standard 7psi pulley
-Megan S-pipe
-MEGAN 60mm Drift-Spec Full Exhaust

Max Gain Over Baseline
----------------------
HP: 4.9 WHP @5900
TQ: 5.0 FT/LB @4150

Peak Gain Over Baseline
----------------------
HP: 2.5 WHP
TQ: 4.2 FT/LB




PTUNING 3" S-back Exhaust vs MEGAN 60mm Drift-Spec Exhaust + Megan S-pipe
---------------------------------------------------------------------------
RUN: 062237.013 (baseline)
-TRD S/C w/ standard 7psi pulley
-stock s-pipe
-PTUNING 3" S-back Exhaust

RUN: 062237.019
-TRD S/C w/ standard 7psi pulley
-Megan S-pipe
-MEGAN 60mm Drift-Spec Full Exhaust





PTUNING 3" Turbo-back Exhaust vs MEGAN 60mm Drift-Spec Exhaust + Megan S-pipe
---------------------------------------------------------------------------
RUN: 062237.013 (baseline)
-TRD S/C w/ standard 7psi pulley
-PTUNING 3" Turbo-back/Header-back Exhaust

RUN: 062237.019
-TRD S/C w/ standard 7psi pulley
-Megan S-pipe
-MEGAN 60mm Drift-Spec Full Exhaust



Baseline vs MEGAN vs PTUNING 3" S-B vs PTUNING 3" T-B
---------------------------------------------------------------------------


I hope you enjoy the info. It was a lot of work on the dyno, on the lift and on the computer.

Happy Holidays,
MrC

 

this is definitely something i will be watching... i want to know the results!

 

i hope you do a dyno of the car without the exhaust also so we can truly see the difference

 

:D

 

^Im really curious to see what numbers it put out

 

Results? You have the info, whats the point of making us all wait?

 

They have to get the Dyno Results posted. Chillax.

 

Not upset, just don't understand why some companies do things like this. Everyone knows waiting is no fun :-P

 

^ not every works at warp speed... but I can't wait to see them. I'm gonna go out on a limb here and guess about the results, we all should until they get posted. I have a feeling... the factory s-pipe with the 3 inch exhaust got the most power...

 

The dyno results are in, see the first post. Sorry it took so long.

Enjoy,
MrC

 

Nice results. Interesting to see that the S-Pipe really does appear to be one of the more restricting parts of the exhaust.

 

it's should be obviously clear that the 3 inch exhaust is the way to go. the results are great. thanks ptuning. now i got to save up some $$$ for the exhaust.

 

Thanks for using my car as the beta tester! Hopefully we can get a great idea on exhaust components now.

 

Would the cars do better with a 2.5" exhaust over the 3"???

I thought 3 inch exhaust was for high power applications or big V8's?

 

^ the megan exhaust is 2.5 all the way back... and it only made a slight gain according to the results...

 

Wow nice numbers to back up a product now all we need is an intake manifold to go with it.

 

I meant a Ptuning 2.5"

 

i don't think that the results would be that much different. maybe the guys from ptuning can chime in...

 

After seeing the result with the 3" turbo-back, we can conclude that a S/C tc likes a fully unrestricted system. I don't think a full 2.5" system is going to make more power. Since we did not see an power loss at the low to mid-range with the 3" system, but instead we actually saw a slight gain at the low-end and we actually saw a big gain on top with a full 3" system.

At this point we will say that the 3" turbo-back is the way to go for even a S/C system--it's obvious that the S/C cars does not need any back-pressure for exhaust scavenging like a N/A car. The gains on top will be even more significant for those running a 9 psi pulley with the 3" turbo-back system.

MrC

 

I have had my 3' turbo back for about a month now and love it. I gained 23 whp and 19.8 TQ

Good job guys!!