Looking for insight. 13 rs5 engine build.

[PRJCTRS5]

Purchase a set of heads complete from a 14 RS5 out of GA. The intentions are to port and polish the heads and find some upgraded internals. Does anyone know of upgraded cams, springs, retainers ect. Also any suggestions on the intake manifold on this car? can i use one off a v8 r8? do the intake ports and heads match? any information would be greatly appreciated.

[Ape Factory]

Ok...first I would find an Audi engine specialist builder who's worked with various Audi engines including the R8 V10. It's essentially an RS5 engine with two more cylinders. The OEM ports aren't terrible by a long shot and I'd think you could get by with a port match and a smidge of cleanup. Valves are sodium filled and about as good as they get until you get into titanium. The only cams available are regrinds. I don't think there are upgraded springs or retainers although, I suspect, the R8 V10 valves/springs might be identical. I've not looked up part numbers. There's one shop in Germany who does the cam regrinds. I'll see if I can find the name for you. You have to call them too, not listed on the website.

Intake manifold...the RS5 intake manifold is superior to the R8's intake manifold. I'm guessing that it'll probably line up but not sure if all the bolts are in the right place.

Ultimately are you looking at forced induction or sticking with a naturally aspirated setup?

[PRJCTRS5]

Im going to stay N/A. Let me know what you find out this will be my project for 2019.

[Ape Factory]

https://dbilas-shop.com/en/engine-va...di/3-6-4-2-v8/

I would contact them and see if they'll do something for the RS5. Those may be for the B7 RS4 or B8 S5 V8. Not sure what the OEM lift/duration is on the RS5 off hand.

Also, I talked to someone else and you can see good gains from porting the RS5 and R8 heads. Take a look at the exhaust valves. Again, I don't know the size off hand but the 2nd gen exhaust valves out of the R8 V10 may fit. They're 1mm thinner and flow better than the first gen. R8 V10 exhaust valves.

Velocity is going to be critical so I'd find someone who's experienced with high revving n/a setups to port the heads. If you were going forced induction, you could mostly just hog them out.

Also, check with Shrick for complete camshaft kits. They may not sell directly to the public, might have to go to a vendor.
http://www.schrick.com/index.php?article_id=50&clang=1

All of this would, of course, require custom ECU work.

[Ape Factory]

Valves are the same between the 2015 R8 V10 and the RS5 with one minor difference...the stem diameter is a few hundredths difference (just use the proper valve guide).

Intake Valves
Intake valve face diameter=33.85mm
Intake valve length=103.97
Valve seat ange=45 degrees

Stem diameter RS5=5.95mm
Stem diameter R8=5.965

Exhaust valves
Exhaust valve face diamter=28mm
Exhaust valve length=101.9
Valve seat angle=45 degrees

Stem Diameter RS5=5.96mm
Stem Diameter R8=5.955

So there may be some benefit going to the 2nd get (2016+) exhaust valves if they are indeed one mm thinner in stem diameter. The third gen (2019+) uses titanium exhaust valves if I remember correctly.

One place you may be able to check is someone like Underground Racing. They may be going with aftermarket valves, springs, retainers and other bits. Not all of that will be useful as they're building super high hp forced induction engines. If you do not go with cams, there's probably no need to go with aftermarket springs. I could see going with titanium retainers for weight but that'd be making such a small difference. But...if it's an off the shelf item, already in existence, you're probably looking at $500 for all 32 valves. Personally, if you're not racing the car, I'd stick with as much OEM in the valve train as possible for reliability. JHM has been running their RS5 to 9,000 rpm and hasn't broken anything yet.

[PRJCTRS5]

That is some really excellent insight. 9000 RPMS? How do you like their tune? I am running the burble from VAP now.

[Ape Factory]

Really liking it. I’d almost say it’s a requirement. Had a good chance to flog the car yesterday through the countryside after a big Audi meet. Ran into a modified Focus RS and handled him pretty easily.

Check with the S6/Rs7 guys as they may have someone who’s built up the 4.0L and is familiar with The Audi V8.