2016 RS7 Engine Differences

[Vol 4.0T]

s6

[Chris Morales]

Once people start swapping turbos on RS7s, maybe the lower compression ratio in the c7.5s will be an advantage.

Want to track down why RS7s appear capable of brake boosting to 2800 rpm whereas S8s (like mine) seem only able to reach 2300 or so? May be most of the reason why RS7s can run 1.6 60fts while S8s only get into the mid 1.7s.

[Chris Morales]

Thanks for the info. I've not had luck flashing it, but I could experiment. The process is always floor it and release quickly, so I have to stage wisely. Best so far is 1.74. This is not something I am going to throw parts at; just sucks to have that launch disadvantage from the RS7 and DSG cars. It's a big deal in the ET.

[OOOO SSSS]

I just wanted to start a thread to help answer a question that several members had about the 2016 RS7 engine last summer, specifically why it wasn't making as much power as the 2014-2015 RS7s when both were flashed with APR's software. As some of you may recall, APR wasn't sure why the 2016 wasn't putting down as impressive numbers as the 2014-2015 when coupled with their software. They did note that there must be something different with the C7.5 engine since Audi had given the 2016 RS7 engine a different internal engine code of CWUB compared to the 14-15 models engine code of CRDB. A little while later APR came out with updated software for the C7.5 RS7 and it offered a substantial improvement over their original C7.5 calibration. What's interesting is with lower octane, such as 91, the APR tuned C7.5 makes considerably more power over stock than the C7 does over stock on 91. However, as the octane increases the C7 actually starts to make considerably more power than the C7.5.

My initial hunch when first reading these threads was that the C7.5 started using the same 9.3:1 compression ratio as the S8 instead of the C7 RS7's 10.1:1. That would certainly explain why the C7.5 saw much bigger gains on 91 octane than the C7 while on 100 octane it was the opposite: the C7 made considerably more power than the C7.5. But all of the sources I could find online for the 2016 RS7 listed it as still having the same 10.1:1 compression ratio as the 2014-2015 models. Well now I can finally confirm that all of those websites, including Audi's own 2016 RS7 Media Kit are flat out wrong. The 2016 RS7 with the CWUB engine code does in fact now share the same 9.3:1 compression ratio as the S8. I was able to confirm this by comparing piston part numbers on the 2013-15 S8, 2013-15 RS6/7, 2016 S8 and 2016 RS7. This is true not just for the USA but ROW (rest of world) too. BTW, while the North American websites show the incorrect compression ratio (10.1:1) most UK and German websites have it right for the 2016 RS6/7 (9.3:1).

So now we finally know why the C7.5 2016 RS7 has a different engine code than the C7 2014-2015 RS7. But how does this affect you? Well, if you're living in California and have a 2016 RS7 with an aftermarket tune like APR's, you will have a considerably faster car on California 91 octane than a tuned C7 2014-2015 RS7 with all else equal. However, if you're a drag queen and run your car at the dragstrip often, you're going to be a disadvantage when using race fuel compared to the C7 2014-2015 RS7. Those going for 1/4 mile records like sciblades will not be happy because on a strong tune running at or near max. boost and MBT timing, the C7 will always make considerably more power than the C7.5 due to its higher compression ratio. Again, that's with all else being equal. This would help explain why sciblades saw only marginal gains going from his 93 octane tune to his race gas tune on MS109 whereas those with C7s typically see far bigger gains going from pump to race.

Hope this information can help someone someday. I will continue to try to figure out what else may be different between the two engines.

Thanks for this.

[JoeCaMotto]

Thanks for this.

+1 lots of good info

[pmarin]

Excellent info, thank you. Seems like 2014-15's will run a 10.6 range quarter on APR tune pump gas 93, what are the times on the 2016 with same fuel? Any side by side races to see how much difference? Interesting the performance model is back to 10.1:1.

[OOOO SSSS]

I ran my '16 RS 6 with APR 100 file. I ran 10.9 @ 130.6. The biggest issue was traction for me. I was just wheel spinning. My 60ft was 1.8sec. I had to wait more than 60 min between runs. The tyres were cold. This was on an unprepped track. I couldn't get a clean get away.


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[tonymission]

I ran my '16 RS 6 with APR 100 file. I ran 10.9 @ 130.6. The biggest issue was traction for me. I was just wheel spinning. My 60ft was 1.8sec. I had to wait more than 60 min between runs. The tyres were cold. This was on an unprepped track. I couldn't get a clean get away.


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Did you turn off traction control? I literally just did two separate launches behind my office (closed surface, no other cars) and I burned a lot of rubber with traction control off and seemed to launch straight ahead with it back on. I have no data to backup which was faster but spinning tires seems counter productive. Was actually wondering how others are launching this car.

[Superdad]

let me know if you get separate times with traction control on and off. I am heading to the track in a few weeks for the first time in my 2016 rs7 and am curious which will be better

[OOOO SSSS]

Did you turn off traction control? I literally just did two separate launches behind my office (closed surface, no other cars) and I burned a lot of rubber with traction control off and seemed to launch straight ahead with it back on. I have no data to backup which was faster but spinning tires seems counter productive. Was actually wondering how others are launching this car.

3 runs traction control off
1 run traction control on - slowest run of the day with an 11.2

[tonymission]

3 runs launch control off
1 run launch control on - slowest run of the day with an 11.2

I assume you mean traction control right? I don't think we have LC just double checking.
So I'm also assuming no tire spin with it on and spin without it... Still faster? That's interesting. Thanks for sharing


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[OOOO SSSS]

Sorry my bad .... I meant traction control !!!

I edited post above


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[Shawn_K]

What about C7 stock vs C7.5 stock? Is the C7 still faster?

[marty was here]

I just wanted to start a thread to help answer a question that several members had about the 2016 RS7 engine last summer, specifically why it wasn't making as much power as the 2014-2015 RS7s when both were flashed with APR's software. As some of you may recall, APR wasn't sure why the 2016 wasn't putting down as impressive numbers as the 2014-2015 when coupled with their software. They did note that there must be something different with the C7.5 engine since Audi had given the 2016 RS7 engine a different internal engine code of CWUB compared to the 14-15 models engine code of CRDB. A little while later APR came out with updated software for the C7.5 RS7 and it offered a substantial improvement over their original C7.5 calibration. What's interesting is with lower octane, such as 91, the APR tuned C7.5 makes considerably more power over stock than the C7 does over stock on 91. However, as the octane increases the C7 actually starts to make considerably more power than the C7.5.

My initial hunch when first reading these threads was that the C7.5 started using the same 9.3:1 compression ratio as the S8 instead of the C7 RS7's 10.1:1. That would certainly explain why the C7.5 saw much bigger gains on 91 octane than the C7 while on 100 octane it was the opposite: the C7 made considerably more power than the C7.5. But all of the sources I could find online for the 2016 RS7 listed it as still having the same 10.1:1 compression ratio as the 2014-2015 models. Well now I can finally confirm that all of those websites, including Audi's own 2016 RS7 Media Kit are flat out wrong. The 2016 RS7 with the CWUB engine code does in fact now share the same 9.3:1 compression ratio as the S8. I was able to confirm this by comparing piston part numbers on the 2013-15 S8, 2013-15 RS6/7, 2016 S8 and 2016 RS7. This is true not just for the USA but ROW (rest of world) too. BTW, while the North American websites show the incorrect compression ratio (10.1:1) most UK and German websites have it right for the 2016 RS6/7 (9.3:1).

So now we finally know why the C7.5 2016 RS7 has a different engine code than the C7 2014-2015 RS7. But how does this affect you? Well, if you're living in California and have a 2016 RS7 with an aftermarket tune like APR's, you will have a considerably faster car on California 91 octane than a tuned C7 2014-2015 RS7 with all else equal. However, if you're a drag queen and run your car at the dragstrip often, you're going to be a disadvantage when using race fuel compared to the C7 2014-2015 RS7. Those going for 1/4 mile records like sciblades will not be happy because on a strong tune running at or near max. boost and MBT timing, the C7 will always make considerably more power than the C7.5 due to its higher compression ratio. Again, that's with all else being equal. This would help explain why sciblades saw only marginal gains going from his 93 octane tune to his race gas tune on MS109 whereas those with C7s typically see far bigger gains going from pump to race.

Hope this information can help someone someday. I will continue to try to figure out what else may be different between the two engines.

is there a difference in motors between the RS7 and the RS7 performance package? trying to justify the $19,100 difference in price

[cNEGOTIATOR]

It's also is back to using the 9.3:1 compression ratio that the 2014-2015s ran.

Do you mean to say 10.1.1 ?

[cNEGOTIATOR]

So Vol, which would be the more desirable engine for you?

I wish we could get proper 104 oct dyno figures for the C7.