# TTRS: APR Stage 2 + APR Downpipe + Factory Sport Exhaust



## OldKenzo (Aug 14, 2012)

Thanks to the good folks at 034 Motorsports my ride got an upgrade this week:










I intentionally chose to keep the factory sport exhaust since, well, I paid for it and most commenters agree that it is not too restrictive. After installing the APR downpipe and flashing to stage two, we measured a peak 25% improvement in torque to 366 ft-lbs at 4500 RPM and a 10% improvement in HP to 353 at 5500pm, both to the wheels. It's interesting that on the 91 octane tune how the dyno chart looks much more like the APR Stage 1 chart than Stage 2. Can the two octane points and RSC exhaust make that much difference? 










When the boost comes on around 2800 RPM it spools *INSANELY* fast. The LCD boost meter in the gauge cluster shoots up almost comically fast as the car literally leaps and tears at the pavement. The first time I floored it through 1st->2nd I could barely get out "Oh @#$%#$" between breaths.  

In terms of sound, the APR downpipe definitely amplifies the resonance of the factory sport exhaust, but that's about it. It's a bit louder in the rear and the car makes a nice throaty sound at idle with the clutch out. On the freeway, I'd say there's a bit more drone when under gas and low in the tach (2,000-2,500 RPM) but when cruising or at around 3,000 RPM you don't hear it.


----------



## lpriley32 (Jul 28, 2012)

Thanks for the initial thoughts. I am going with this setup as well. I have the dp sitting in my living room just need to find the time to have it installed then will get the tune done around the first of the year. Keep us posted as you log more miles with the dp sounds and the tune if you dont mind. Oh and congrats on the new toys!


----------



## hightechrdn (Dec 9, 2011)

Congratulations! I have the same (initial) plan for my TT-RS also  

Can you post some videos of the exhaust sound? Most interested in hearing sport mode on from outside the car. Inside would be good also, but not as important. 

Sent from my Nexus 7 using Tapatalk 2


----------



## southpole12 (Mar 29, 2012)

I have the stage 2 APR tune. I was going to keep the sport exhaust but I decided to go with the full turbo back RSC exhaust and I am glad I did because it sounds AMAZING!!! The sound is so much better than the sport exhaust in my opinion, so I am happy! Now I have to sell the sport exhaust which will be unlikely lol


----------



## 034Motorsport (Apr 16, 2012)

Glad you're enjoying the upgrades! I must have missed you when you came to pick up your car.



OldKenzo said:


> It's interesting that on the 91 octane tune how the dyno chart looks much more like the APR Stage 1 chart than Stage 2. Can the two octane points and RSC exhaust make that much difference?


It's mostly the gas, unfortunately. The stock exhaust is surprisingly free-flowing with sport mode on. :thumbup:


----------



## OldKenzo (Aug 14, 2012)

[email protected] said:


> Glad you're enjoying the upgrades! I must have missed you when you came to pick up your car.
> 
> 
> It's mostly the gas, unfortunately. The stock exhaust is surprisingly free-flowing with sport mode on. :thumbup:


Yep damn California gas. I guess for more power I'll have to make a return visit for Stage 3


----------



## LynxFX (May 17, 2012)

[email protected] said:


> It's mostly the gas, unfortunately. The stock exhaust is surprisingly free-flowing with sport mode on. :thumbup:


 So with being limited to 91 octane in CA, is it worth going stage 2 + downpipe, or is stage 1 enough?


----------



## 034Motorsport (Apr 16, 2012)

LynxFX said:


> So with being limited to 91 octane in CA, is it worth going stage 2 + downpipe, or is stage 1 enough?


Stage 1 makes substantially less peak power that Stage 2+ on 91 octane. 

You also don't get the increased low end torque and quicker spool without the downpipe.

So yes, it is still worth it to go Stage 2+, even on 91.


----------



## LynxFX (May 17, 2012)

That's what I figured but seeing how much difference there was between 91 and 93 octane, figured I would ask.

Stage II it is!


----------



## crackkills (Mar 10, 2007)

I still think the 034 downpipe is a better design than the APR. Keeping both pipes and then hooking them up to the Borla which continues the dual piping is the way to go. 

I think the borla cat back is the best and least restrictive design.


----------



## Koa1 (Feb 21, 2012)

I like the 034 downpipe also. Would i be able to install it myself with my car up on race ramps like the cat deletes? Thanks.


----------



## 034Motorsport (Apr 16, 2012)

Koa1 said:


> I like the 034 downpipe also. Would i be able to install it myself with my car up on race ramps like the cat deletes? Thanks.


The install for the downpipe is rather involved, and I don't think it can be done without a lift. We've been meaning to make installation instructions, and I'll post them up when they are ready.


----------



## JohnLZ7W (Nov 23, 2003)

Need to drop the driveshaft so at least need to get up on stands


----------



## hightechrdn (Dec 9, 2011)

To 034: Care to comment on the pros and cons of your downpipe design vs the APR unit? I see you sell both, so you win either way, right? 

I also had given some thought to the 034 downpipe and Borla exhaust. It would seem to offer the least restrictive setup at least after the downpipe, but does that translate into better performance? 

Sent from my Nexus 7 using Tapatalk 2


----------



## 034Motorsport (Apr 16, 2012)

hightechrdn said:


> To 034: Care to comment on the pros and cons of your downpipe design vs the APR unit? I see you sell both, so you win either way, right?
> 
> I also had given some thought to the 034 downpipe and Borla exhaust. It would seem to offer the least restrictive setup at least after the downpipe, but does that translate into better performance?
> 
> Sent from my Nexus 7 using Tapatalk 2


Our downpipe is a full 3.5", while the APR one is 3" in diameter. The APR downpipe also necks down to a really awkward adapter of you plan to use it with stock exhaust/midpipes.

Our design does flow better, but we haven't had an opportunity to do back to back dyno testing to see what that translates to in power gains.

Side by side, I'd say that our welds are much cleaner.

All in all, both are quality products. Seeing them side by side, I'd choose ours.

Once I have more quantitative information between the two, I'll bump this thread.


----------



## crackkills (Mar 10, 2007)

I want to see flames coming out of the TT RS! I am sure with the 034 downpipes with not cats and the borla exhaust that does not have resonators you are talking about one angry loud car. 

Who is going to be the first to do this and post videos and reviews?


----------



## Black BeauTTy (Jun 11, 2011)

Aren't you guys concerned about running catless? What's the plan for emission testing...remove and replace with OEM DP? Is it possible to do the 034 DP but still have the secondary cats in place and monitored as if they were the primary cats? Just wondering since that would be a much easier swap than the DP.


----------



## crackkills (Mar 10, 2007)

Very possible to do that. Have the mid cats in place with the software that will ignore the code and you could pass visual inspection. You tell them primary cat is within the downpipe. Not sure if you would pass the sniffer test however. 

In florida we don't have emissions testing so we can poop on the planet! :what:


----------



## Koa1 (Feb 21, 2012)

I am concerned about that. That's why i wanted to know if i can install/remove the DP myself. That way i could go back to OEM for emissions testing. If i have to pay a shop a few hundred to switch back and forth, that would be a deal killer. Plus it's fun to do small stuff myself. I'll wait for 034's instructions before i decide.


----------



## lpriley32 (Jul 28, 2012)

I was udner the impression that with the APR downpipe you will throw a CEL but it can be cleared by using an 02 sensor spacer which would allow you to pass emmissions...anyone else have info on this?


----------



## lpriley32 (Jul 28, 2012)

[email protected] said:


> Our downpipe is a full 3.5", while the APR one is 3" in diameter. The APR downpipe also necks down to a really awkward adapter of you plan to use it with stock exhaust/midpipes.
> 
> Our design does flow better, but we haven't had an opportunity to do back to back dyno testing to see what that translates to in power gains.
> 
> ...


Just curious but does having two pipes all the way really help the flow of air when it stems from one exit from the turbo and bottlenecks back to one entrance into the muffler?


----------



## Black BeauTTy (Jun 11, 2011)

AFAIK APR stage 2 is required because it ignores the O2 sensors so you don't get a CEL. I think it'll still fail the readiness code check though. You bring up an interesting work around though. Theoretically, you could skip stage 2 and go with the O2 spacer and still pass. There are no such options for the 034 catless DP though, that's why I asked about the secondaries used in place of the primaries. No idea if that would work though.


----------



## 034Motorsport (Apr 16, 2012)

Black BeauTTy said:


> Aren't you guys concerned about running catless? What's the plan for emission testing...remove and replace with OEM DP? Is it possible to do the 034 DP but still have the secondary cats in place and monitored as if they were the primary cats? Just wondering since that would be a much easier swap than the DP.


AFAIK, in most states, new cars like the TT RS will not need emissions testing for a few years at the least.

You can always run a low profile oxygen sensor spacer to space out the rear O2, or get programming that eliminates the CEL for the downpipe and forces readiness to pass. APR's Stage 2+ does not set readiness, unfortunately.

You can pass the CA sniffer with two of our high-flow cats in the midpipes and no primary, but you'll need to make sure to get the cats nice and hot before testing.



lpriley32 said:


> Just curious but does having two pipes all the way really help the flow of air when it stems from one exit from the turbo and bottlenecks back to one entrance into the muffler?


If you're comparing two pipes to a single large diameter one, then no. 

However, the split is important to maintain if you want to run stock exhaust/midpipes or an exhaust that mates to the stock downpipe.

Our split is much smoother than the APR one, and the downpipe maintains a much larger cross-sectional area, which reduces the restriction.


----------



## lpriley32 (Jul 28, 2012)

*just an fyi*

i had the apr downpipe installed today and used an 02 sensor spacer and there is no CEL.


----------



## Optimus812 (May 5, 2012)

lpriley32 said:


> i had the apr downpipe installed today and used an 02 sensor spacer and there is no CEL.


Same here, no CEL and I've been driving with the APR DP for almost 3000 miles.


----------



## 034Motorsport (Apr 16, 2012)

Optimus812 said:


> Same here, no CEL and I've been driving with the APR DP for almost 3000 miles.


If you have the Stage 2 or Stage 2+ downpipe flash, then you won't get a CEL with or without a spacer, regardless of what downpipe you run. :thumbup:


----------



## lpriley32 (Jul 28, 2012)

that is very true but not all of us are ready to start messing with the ecu. Installing the dp is not nearly the risk of having issues that messing with the ecu is. Therefore, if you want to run the APR downpipe with a sensor spacer you will not get a CEL. Just useful information for anyone considering this option is all.


----------



## Black BeauTTy (Jun 11, 2011)

lpriley32 said:


> that is very true but not all of us are ready to start messing with the ecu. Installing the dp is not nearly the risk of having issues that messing with the ecu is. Therefore, if you want to run the APR downpipe with a sensor spacer you will not get a CEL. Just useful information for anyone considering this option is all.


Yep, that's what I was saying, this will work with stock ecu.


----------



## Black BeauTTy (Jun 11, 2011)

[email protected] said:


> AFAIK, in most states, new cars like the TT RS will not need emissions testing for a few years at the least.


Wow, not the case in PA. You need to get one upon registration and every year after that. I assumed that was pretty standard.



[email protected] said:


> You can always run a low profile oxygen sensor spacer to space out the rear O2, or get programming that eliminates the CEL for the downpipe and forces readiness to pass. APR's Stage 2+ does not set readiness, unfortunately.


Thanks for validating this, I thought that was the case. 



[email protected] said:


> You can pass the CA sniffer with two of our high-flow cats in the midpipes and no primary, but you'll need to make sure to get the cats nice and hot before testing.


So this would be a work around with your DP. That's great. Would relocating the O2 sensors to monitor those secondaries work? Seems like it would.


----------

