Dyno results: Audi S8 (with mods)
#12
I don't get why stg2 feels so much faster when stock to stg1 gets a much bigger gain than stg1 to stg2. Either way it definitely is much faster and feels great... Glad I got stg2
#13
Audiworld Junior Member
Thread Starter
Looks like a no-brainer when it comes to ft-lbs/$. May have to put this ahead of my anticipated exhaust enhancements.
What octane were you running during the dyno test? Just curious - the before/after intake delta tells me all I need to know. I can't help but notice how different these power and torque wheel ratings line up vs. APR's (https://www.goapr.com/products/ecu_u...40tfsi_s8.html). I understand that different dynos yield different results - just trying to normalize the data.
What octane were you running during the dyno test? Just curious - the before/after intake delta tells me all I need to know. I can't help but notice how different these power and torque wheel ratings line up vs. APR's (https://www.goapr.com/products/ecu_u...40tfsi_s8.html). I understand that different dynos yield different results - just trying to normalize the data.
#14
Audiworld Junior Member
Thread Starter
I can ask, they'd need a D4 4.0 to make them on though. Unless an S6/S7/RS7 intake fits on them, which I'm sure should fit. They sell intakes for the S6/S7/RS7 also, if you'd like to check it out on their website. Power ratings are on there also. I don't see why they wouldn't fit, it's the same motor with the same turbos I'm fairly certain.
#15
Audiworld Junior Member
Thread Starter
I drove mine for about 500mi or so after the stage 1 tune and the intakes were installed, then we put it on the dyno. The most power made was after multiple runs on the dyno already, so the ECU had more than likely adjusted at that point. Just give it a few pulls down the street into the triple digits and it'll learn.
#16
AudiWorld Member
Stage 2 over Stage 1
So when I got stg1 yesterday it didn't feel as strong as I thought with all the comments saying how awesome it was. It started to feel a little better today but then I got stg2 and wow... This is much faster.
I don't get why stg2 feels so much faster when stock to stg1 gets a much bigger gain than stg1 to stg2. Either way it definitely is much faster and feels great... Glad I got stg2
I don't get why stg2 feels so much faster when stock to stg1 gets a much bigger gain than stg1 to stg2. Either way it definitely is much faster and feels great... Glad I got stg2
Left = Variance Stage 1 vs. Stock Right = Variance Stage 2 vs. Stock
#17
Audiworld Junior Member
Thread Starter
These charts illustrate the difference. It's the area under the curve - so you're feeling the delta in HP and torque over a rev-range. These charts are NOT traditional HP and torque curves. They show the variance between Stage 1 vs Stock (left) and Stage 2 vs. Stock (right). Notice how much higher the torque difference is (white line) Stage 2 vs. Stage 1. Huge. The reason is that with Stage 1, you've created significantly more airflow under WOT and the stock exhaust isn't designed to handle that velocity of airflow. Tuning the exhaust to match the engine performance "frees" up potential power, allowing that animal to breathe (think of the stock exhaust as an exhaust restrictor plate - not dissimilar to the intake restrictor plates on carburated race cars to normalize engine outputs).
Left = Variance Stage 1 vs. Stock Right = Variance Stage 2 vs. Stock
Left = Variance Stage 1 vs. Stock Right = Variance Stage 2 vs. Stock
#18
AudiWorld Member
Are you concerned at all about the air to fuel ratio being off on the stage 2 tune since APR didn’t factor in your added air flow? Or do you think the ECU will compensate? I want those intakes!
Last edited by BTAudi; 05-12-2018 at 08:39 AM.
#19
Audiworld Junior Member
Thread Starter
Thankfully these vehicles don't use a MAF sensor as my previous vehicle did. The Subaru required a tune no matter what you did to the airflow. The reason why you need a stage 2 tune for the downpipes in this vehicle because of the O2 sensors reading the air ratios. The intake doesn't due to not having a MAF sensor. It runs off of a speed density sensor, which allows the ECU to learn and adjust parameters depending on how much airflow is entering the intakes, thus, the more air, the more fuel, and the more power it makes. In short, the ECU does compensate for the extra airflow, and will more than likely add even more power due to the extra air (exhaust) leaving the exhaust side. More air leaving = more air that the motor needs = more air that it pulls in = more power! If I'm wrong, someone correct me. Once I get this exhaust all finished I'll have it dynoed with the intakes and see how much it makes.