Who is running APR Stage 2 with stock downpipes?

[pez81]

I have been contemplating stage 2 for a little while now. I currently have APR stage 1 and it's fantastic but there's always a want for more power i guess. Probably never ends.
My only concern is the fumes from running downpipes with race cats. I have a little one on the way and it is still our primary family car so I don't want to risk the health of my child because I wanted more power.
After reading thread after thread and I know it's something old VOL4.0T used to go over endlessly but I have seen others on here who said they are running stage 2 software with stock downpipes. So my question is for those who are running stage 2 software on stock hardware are there any gains to be had? Have you run it on the dyno to see gains or can you just feel the difference?
It's not really about cost but sure that helps a bit so any feedback from those running any companies tune stage 2 with the factory pipes your comments would be most welcomed.

Thanks in advance.

£120 for stage 2 software flash, even if it gains nothing its no loss but 10-20hp and TQ would be a bargain of the year.

[Rez90]

from what i understand the stage 2 and the downpipes go hand and hand....

[pez81]

I thought so too but I have heard it can be done without safely. Just wondered if anyone else had done it

[Dre325]

My only concern is the fumes from running downpipes with race cats. I have a little one on the way and it is still our primary family car so I don't want to risk the health of my child because I wanted more power.

I have APR downpipes with the high flow cats and stage 2 software. I'm not really understanding this concern. Are you worried about fumes coming inside the car when driving or something? Otherwise, you'll be strapping the kid into the carseat, closing the doors, and then starting the car so shouldn't be a concern. I have 2 little girls--not something I've even thought about.

[carx7]

There is another post on here of a stage two owner running with stock downpipes. Either LimeyPride or RSLRS7 I think.

RE fumes: I had more fumes in my car with the APR DPs than I did with my Miltek catless system. There are high flow cat options as well (APR, AMS, Mike's) that can fulfill both the performance and piece of mind concerns you are identifying.

[Chris@EPL]

I think he wants to go Stage 2 without doing any downpipes. You may get worse performance doing that. Most of the Stage 2 gains are from the hardware and the tune takes advantage of it to maximize it.

[pez81]

Thanks everyone for the replies so far. I thought the race catted downpipes might still give off a lot of fuel smell which I didn't want. But if you're saying that's not the case then that's encouraging I may try it and dyno and log to see if it yields any positive gains.

Sent from my SM-G920F using Audizine mobile app

[Ze_Nardo6]

Tom, depending on which DPs you're looking at, if they are catted, the fumes are negligible. I can't speak for the APR DPs since I never installed them but the AMS catted pipes do not emit any more fumes over stock that I can physically smell. Others may be more sensitive to the smell than me, but not sure.

Given your concerns, I would be wary of non catted options, but if you stay catted, you should be perfectly fine

[pez81]

Thanks Mickey that helps massively. For some reason I thought catted DPs might still give off a load of fumes. Ledge thanks bro

Sent from my SM-G920F using Audizine mobile app

[Ze_Nardo6]

Thanks Mickey that helps massively. For some reason I thought catted DPs might still give off a load of fumes. Ledge thanks bro

Sent from my SM-G920F using Audizine mobile app

Happy to help. I will let others chime in as sensitivity to exhaust fumes will vary by person. The cats on aftermarket DPs like AMS and APR are going to emit more fumes than stock, but it's minimal in my experience. I have been in a few C7s with noncatted DPs and its VERY obvious to me, especially at idle.

[Hofahome]

Just put on the AMS downpipes and smelled fumes. Got concerned because I have a 1.5 y/o. However the smell was gone after a few days of driving like others on here told me it would.


Sent from my iPhone using Tapatalk

[S4Per]

I've never experienced fumes with cats in place, even race cats on several different types of DP's. I lived with no cats on my RS4 for a year, and that was fume city...never again.

[JGood]

I'm pretty sure LimeyPride was running stage 2 without downpipes on his RS7

[pez81]

This is really good to hear. Thanks everyone. I'm a lot more confident in going stage 2 now you've put my mind at ease. I'm getting the tune this Saturday all being well.

Sent from my SM-G920F using Audizine mobile app

[digdah]

I have been mulling doing this myself. Let me know how it goes without the DPs particularly if you run into any issues.

Best of luck man!

[hmuller]

Thanks everyone for the replies so far. I thought the race catted downpipes might still give off a lot of fuel smell which I didn't want. But if you're saying that's not the case then that's encouraging I may try it and dyno and log to see if it yields any positive gains.

I had my APR DPs installed last summer. While driving I don't smell anything but when standing (at red lights, intersections, driveway, etc.) I get the fuel smell.

[pez81]

Flashed to stage 2 today with the stock downpipes. I am going to get downpipes but was just curious to see if the flash alone would make any difference. Haven't had much driving time probably an hour but to me it feels more responsive and stronger esp lower down. Again without a dyno run this is all subjective. I'll try find time to dyno it next week and report back. If for no other reason to get downpipes I'm in it for the sound. My guess is it's making another quite a bit more torque.

Sent from my SM-G920F using Audizine mobile app

[pez81]

Also got the APR dongle which is great for switching but there is no logging available for some reason

Sent from my SM-G920F using Audizine mobile app

[digdah]

Flashed to stage 2 today with the stock downpipes. I am going to get downpipes but was just curious to see if the flash alone would make any difference. Haven't had much driving time probably an hour but to me it feels more responsive and stronger esp lower down. Again without a dyno run this is all subjective. I'll try find time to dyno it next week and report back. If for no other reason to get downpipes I'm in it for the sound. My guess is it's making another quite a bit more torque.

Sent from my SM-G920F using Audizine mobile app

Let us know if you run into any issues. How long do you plan on going without DPs?

Sent from my SM-G955U using Tapatalk

[pez81]

Let us know if you run into any issues. How long do you plan on going without DPs?

Sent from my SM-G955U using Tapatalk

1 day so far. No fault codes no issues or misfired all good. Gonna dyno this week before ordering custom downpipes. Might me in my head but it feels real strong. Wasn't sure about going stage 2 so will be interesting to get dyno figures without hardware upgrades and after.

Sent from my SM-G920F using Audizine mobile app

[digdah]

1 day so far. No fault codes no issues or misfired all good. Gonna dyno this week before ordering custom downpipes. Might me in my head but it feels real strong. Wasn't sure about going stage 2 so will be interesting to get dyno figures without hardware upgrades and after.

Sent from my SM-G920F using Audizine mobile app

Keep an eye on your temps as well. Interested to see your dyno results.

Sent from my SM-G955U using Tapatalk

[pez81]

Keep an eye on your temps as well. Interested to see your dyno results.

Sent from my SM-G955U using Tapatalk

Definitely. I haven't seen them show any higher yet.

Sent from my SM-G920F using Audizine mobile app

[pez81]

So a couple of days seat time and I'm going to get the hardware to run the stage 2 set up. No issues but I want more noise and the reassurance that it has the necessary hardware to run it. Using my only reference tool at this point 'torque pro boost seems about the same maybe a little more like. 3 psi bit the torque delivery is really strong. Getting it on the dyno this week and will do the same once I have the downpipes. I switched over to the 91 map and it feels as strong if not stronger than 93 stage 1. Hopefully I will be able to present data that puts the downpipes vs no downpipes discussion to an end once and for all. If I pick up no .ore but have a sweeter sounding car I'm happy with that as it needs more grunt at this level of power. I'm really interested to see what it does on the dyno but torque pro is showing 30whp peak gains on 91 vs 93. Not tested the 93 maps out in torque pro yet. Torque is over 650ft lbs on 91 and 700 on 93. Again all subjective but from what it has been reading of 440whp and 600ftlbs that's substantial.

Sent from my SM-G920F using Audizine mobile app

[SleekS7]

Good to see I'm not the only one wondering why downpipes are required for the current stage 2 tuning on S6/7 cars. As Vol did mention a while back... the factory cats and downpipes are the exact same part #s for all years of the 4.0TT engine in S6, S7, S8, and RS7, so we know they are at least capable of supporting RS7 stage 1 power.

Even for a 605hp 2017 RS7 Performance model, the part #s 1, 2, 15, 16 that aftermarket downpipes replace are the same as my 2013 S7.
2017 RS7 Performance https://parts.audiusa.com/a/Audi_201...S/1331429.html

2013 S7 https://parts.audiusa.com/a/Audi_201...S/1330309.html


Quoting APR's own dyno numbers, specifically C7.5 S6/7 and RS7 cars with 93 octane only to keep it simple:

C7.5 S6/7 https://www.goapr.com/products/ecu_u...i_c75s6s7.html
Stock As Measured by APR 93 489 HP 447 FT-LBS
APR Stage I 93 574 HP 639 FT-LBS
APR Stage II 93 588 HP 685 FT-LBS

C7.5 RS7 https://www.goapr.com/products/ecu_u...c75rs6rs7.html
Stock As Measured by APR 93 558 HP 559 FT-LBS
APR Stage I 93 667 HP 746 FT-LBS
APR Stage II 93 709 HP 797 FT-LBS


Now, I understand higher flow downpipes are required for RS7/S8 stage 2 or higher octane files since they make much more power, but if stage 2 93oct S6/7 is making less power than a stage 1 RS7, why are higher flow downpipes needed when the RS7 stage 1 doesn't?

[pez81]

Not sure either but I wanted to be thorough. It's probably a safety thing and you must get a little more from the hardware. That's my guess. I'm doing it for the sound really now. I just got a 2.9 0-60 on torque pro. I know I'm gonna get bashed for saying that but it's been pretty accurate so far. According to my track runs. Just measured 470whp and 650wtq on 93 file. Dyno coming soon. Could have egg on my face after this but it feels really strong

Sent from my SM-G920F using Audizine mobile app

[limeypride]

Flashed to stage 2 today with the stock downpipes. I am going to get downpipes but was just curious to see if the flash alone would make any difference. Haven't had much driving time probably an hour but to me it feels more responsive and stronger esp lower down. Again without a dyno run this is all subjective. I'll try find time to dyno it next week and report back. If for no other reason to get downpipes I'm in it for the sound. My guess is it's making another quite a bit more torque.

Sent from my SM-G920F using Audizine mobile app

I ran that setup for a while. It felt more powerful to me, too, so I stuck with it.

I will add that the guy that gave me a custom tune just before I sold the car said the engine was knocking like crazy--he showed me and it sounded like dry rice in a centrifuge. I've no more data to determine whether that was attributable to the stage 2 or APR in general or just my car or ...


Sent from my iPhone using Audizine

[pez81]

I ran that setup for a while. It felt more powerful to me, too, so I stuck with it.

I will add that the guy that gave me a custom tune just before I sold the car said the engine was knocking like crazy--he showed me and it sounded like dry rice in a centrifuge. I've no more data to determine whether that was attributable to the stage 2 or APR in general or just my car or ...


Sent from my iPhone using Audizine

How odd. I've not seen any knock but that could be heat could it Not?

Sent from my SM-G920F using Audizine mobile app

[limeypride]

How odd. I've not seen any knock but that could be heat could it Not?

Sent from my SM-G920F using Audizine mobile app

I'm naive when it comes to the mechanics so I won't comment. My point, though, was about a specific set of conditions (RS7+APR stage II w/o downpipes) that a (credible to my mind) tuner observed and demonstrated to me that might cause problems for other pursuing the same setup. I wish I could offer a scientific opinion but I'm soooooo not qualified

[MikeDwerks]

Been running stage 2 software and stock down pipes for about 10k miles. funny part is that i have had APR downpipes sitting in my garage uninstalled for about a year

[pez81]

Been running stage 2 software and stock down pipes for about 10k miles. funny part is that i have had APR downpipes sitting in my garage uninstalled for about a year

And no issues either? I was most surprised how the 91 map feels. That's really strong. If anyone can't access 93+ go stage 2 and I think you'll be surprised. Mike have you dynod yours? How does it feel for You?

Sent from my SM-G920F using Audizine mobile app

[MikeDwerks]

And no issues either? I was most surprised how the 91 map feels. That's really strong. If anyone can't access 93+ go stage 2 and I think you'll be surprised. Mike have you dynod yours? How does it feel for You?

Sent from my SM-G920F using Audizine mobile app

No issues. I did some logs for boost, knock, timing, intake temps, etc on stg 1 and also for stg 2 w/o downpipes and no red flags.

Don't have any dyno's between the two. Nor could I "feel" a significant difference, but I am not one that believes you can feel 20hp on a 500ph car

I run a 93 map, using E85 blend with 91. 4.5 gallons E85 and the rest 91

One thing I would note, which I don't know how much it is tied to this topic or not, is that I also have a raised rev limiter. Based on some runs at the 1/4 mile, appears that the car is slower down the track letting it shift at the higher redline that manually shift at about the stock redline. My guess is that with the small stock turbo's and stock downpipes that revving that extra 500 rpm's actually takes you out of the max power band. I can feel the car sort of fall on it's face power wise that last 500 rpm's. *Maybe* if I had better flowing downpipes power would not drop off as bad and actually make the extended redline useful.. but all that is just a guess.

[JWebb_C7_Comp]

I have APR downpipes with the high flow cats and stage 2 software. I'm not really understanding this concern. Are you worried about fumes coming inside the car when driving or something? Otherwise, you'll be strapping the kid into the carseat, closing the doors, and then starting the car so shouldn't be a concern. I have 2 little girls--not something I've even thought about.

I had catted "hi-flow" DPs on my tuned BMW. No problems, no change in emissions (that I could tell), no nothing. Doesn't seem to be an issue from where I sit.

[pez81]

I had catted "hi-flow" DPs on my tuned BMW. No problems, no change in emissions (that I could tell), no nothing. Doesn't seem to be an issue from where I sit.

Thanks buddy

Sent from my SM-G920F using Tapatalk

[pez81]

Results are in. Had the car dynod today. Similar conditions and the same Dyno. Midrange 30-35ftlbs gain and more torque through the the powerband. 30-35hp max gains. Again a lot in the midrange but after 5400rpm it picks up 30hp.
The curve is even smoother than before. So that settles it. Software on its own is good for 30hp but makes no more than the peak hp as stage 1 did. I'm guessing when I get the downpipes fitted I might get another 20-30 in torque on the 98ron(93oct) file. APR claims what 80ftlbs more over stage 1? Hmmm I'll be happily surprised if it does but that would mean the hardware is responsible for the majority of the gains. Still software cost me £130 and I got 35hp (ish). That's way more than the £450intake did so I'll take that. Anyone had their cars dynod stage 1 to stage 2?

Summary: stage 2 stock downpipes give a much smoother powerband than stage 1 but downpipes are probably needed to see the full potential. Car has run faultlessly and I'm not disappointed at all with those results. Car is making almost 200ftlbs over stock and 80whp (ish) over stock. The powerband has changed though for the better making headline power earlier on. Which is why it feels much stronger.

Sorry not got the Dyno print out as I asked them to email me it. This Maha Dyno always reads low for me but it showed 425whp 792nm. Revo tune showed 390whp 717nm. And about 345whp stock and 552nm from memory.

Sent from my Pixel 2 XL using Tapatalk

[Chris Morales]

Fascinating. Next up is a stage 2 dyno with the downpipes, right?

[pez81]

Fascinating. Next up is a stage 2 dyno with the downpipes, right?

Well i find it fascinating (total geek) Yes Chris next up, install custom downpipes and run the bitch again. I'm happy at this power level, numbers aside it drives really well but if it could get to 630ftlbs i'd be even happier. They're getting done early may fingers crossed.

[SleekS7]

Well i find it fascinating (total geek) Yes Chris next up, install custom downpipes and run the bitch again. I'm happy at this power level, numbers aside it drives really well but if it could get to 630ftlbs i'd be even happier. They're getting done early may fingers crossed.

Looking forward to your update as well, but I'm betting you won't see much more of an increase with the custom downpipes unless they are catless and/or larger diameter.

[pez81]

You reckon? Interesting. Custom 3" high flow with 200gesi cats. Shop said these are as close to non restricted as possible.

Sent from my Pixel 2 XL using Tapatalk

[SleekS7]

You reckon? Interesting. Custom 3" high flow with 200gesi cats. Shop said these are as close to non restricted as possible.

Sent from my Pixel 2 XL using Tapatalk

Don't get me wrong, I hope you do see gains with the lower restriction custom downpipe.
But as previously mentioned, the factory cats and downpipes are the same for all 4.0T motors even on the higher output RS7. APR's own published dyno results show their APR stage 2 S cars are still well under APR stage 1 RS7 #s.

[digdah]

How did you get the S2 flash without DPs? Nobody around here is willing to do mine.