The truth about APR coils?

A6 All/ S6 All
#1

Hi, this is my first post on here. I’m probably gonna start a log since I’ve got some interesting stuff on my newfound S6. However, I need your opinion this…

My OEM coils were fine, but I decided to swap to APR coils for the 10% of power gain they promise.

I thought it would be interesting to try to measure any results. I used the dyno app PerfExpert which has received good reviews and is supposed to be pretty accurate. It measures acceleration on a certain gear using the GPS and phone acceleration sensors, and calculates the power and torque based on all the car specs, gear ratios, the weather, fuel and driver weight etc.

Did some pulls before swapping the coils and it showed a pretty consistent 415 hp, and the next day with the APR coils only 395. Again, did several pulls which were all pretty close together. The car also felt subjectively slower.

Of course, it could just be an inconsistency with the app, different day, placebo etc, but I’m still pretty disappointed. I expected it to do nothing at worst, but to get an almost 5% reduction in horsepower is pretty dismal.

So what I’m asking is if you can think of any reason why these coils would perform worse than OEM, or do you think it’s just coincidence or unreliability with the measurements? Do you have experiences with the APR coils ?

#2

I see claims of increased spark energy output.

Where are you seeing claims of increased engine power output?

#3

So great post with a nice approach to trying to find more about the coils.

I’ve never been a fan of the hype about the APR coils as they’re basically just rebranded from the holley group. At best maybe the coil winding has more coil wind than others. But the one time I installed APR coils I never saw a measured difference in the actual coil Vs the OEM coil it was replacing. Your coil might have been different the one I saw looked no different than OEM.

I think the claim I remember was that they put out 10% electric energy or Spark out put. But now all Audi cars are coil over plug and this isn’t a 1980 distributer cap and rotor system. When I took apart the OEM NKG coil packs (after a replacement of 80K) They looked very robust. While I can’t say with no doubt that the OEM coil packs are bettered by the APR ones. I will say there are plenty of 2000whp R8s running on OEM coil packs. And TONS of 1000whp RS3/TTRS cars on OEM coil packs. So I don’t know if this something that’s needed more so something that’s offered.

I will say a dyno app on the phone isn’t going to be a bench mark that’s going to be very accurate. But 20hp seems like a decent difference. I’d say for me dyno phone app isn’t going to convince me one way or the other. But it’s still an interesting comment none the less.

#4

Good point about the claim being increased energy output, not engine power. I did see a video where some guys dynoed the coils making gains: https://www.youtube.com/watch?v=jw9ZI_uaka8 (skip to 8 minutes for the results).

I would easily blame the app if the measurements weren’t so consistent on each run. Too bad I didn’t take more measurements on different days before the swap to see how much variance there is based on the day. And alas I can’t do more measurements on the same setup with the APR coils either since I’m having a custom catback installed as we speak.

Is it possible for the ECU to limit power with the new coils for some reason? Don’t know enough about these things yet to fully understand how they work together.

#5

I don’t see any reason why the ECU would pull power due to the coil packs. I think in general they just are not worth much if any extra money.

In theory you’d think that if the coil packs were putting out more of anything. You’d get a cleaner burn a more complete combustion. Then the result would lend itself to more power.

If I was to make any argument against the coil packs trying to use general logic. It would be that perhaps the APR coils have more winding. If they have more winding that can take more charge. Perhaps the electrical system isn’t able to fully charge the larger (but I’ve not seen them be larger ) coil packs.

#6

I need to take more measurements, then swap the coils back to OEM and measure again to see if I get the same result.

#7

Yeah if the OEM ones were not too bad. I’d measure the APR ones Vs the OEM ones. Snap a few pics and post them. That should help get a size idea