Is the RS5 4.2 even worth buying?

[txb7sline]

So I am/was looking at a RS5 with the 4.2. But on google I can't seem to find supercharger or turbo kits. McChip-dkr in Germany does but they seem to want you to buy them an RS5 for the price of their kits. So what's the deal. And is this the same 4.2 that is used in the R8?

Sent from my SM-N975U using Audizine mobile app

[namvar]

it all depends on what you are looking for. plenty of threads here on how to get a little more power but also plenty of threads showing how an S5 can be tuned and upgraded to gave more power and torque. do some digging.

[brilliant_black]

The engine bay layout is similar to the V8 S5 and other older Audi V8s where the motor is just crammed in there. If anything breaks you will pay a lot of labor since there’s no room to do anything unless you take off the front end.

It’s a special car that you can only really take advantage of if you live in an area with long twisty roads where you have ample room to play with the 8200 rpm redline.





Sent from my iPhone using Tapatalk

[txb7sline]

Thank you for the input. I just know that some 4.2 V8 Audi made are scrap material if you boost them,but fine if left alone and given a mild tune.

So I been thinking my best bet is to go with the little less prestigious S5 under the RS5. But, it is what it is. I have read that the the 3.0T can hit 500+hp and about 500fpt. So I can live with that, hitting tuned RS5 numbers and be a little lighter.

Sent from my SM-N975U using Audizine mobile app

[JamesRS5]

So I am/was looking at a RS5 with the 4.2. But on google I can't seem to find supercharger or turbo kits. McChip-dkr in Germany does but they seem to want you to buy them an RS5 for the price of their kits. So what's the deal. And is this the same 4.2 that is used in the R8?

Sent from my SM-N975U using Audizine mobile app

If you're still looking at the B8.5 RS5 then take a look at JHM for an ECU tune and also follow them as they are currently working on a supercharger. Also look at Red Mist Racing for necessary bolt on goodies to ensure you get the best out of the car.

It is not the same motor used in the V8 R8, that one is similar to the RS4, the B8.5 RS5 has more in common with the R8 V10, it's basically the same motor but short 2 cylinders.

[Don Arco]

There was literally a thread on this several threads down... here’s some key points made by Ape:

I'm a die hard manual guy. I love the S-Tronic/CFSA combination (that's the RS5's engine code btw...) The two of those mechanical devices together is really what makes the car. I honestly haven't longed for a manual in the RS5 at all and the car would be a good deal slower with a manual transmission. Anything slower, yeah, a manual would be the way to go just to keep that engagement.

Even though the S5 3.0T can be made faster (for now) for relatively little money, the rest of the RS is tuned to a different level. It's such a capable point A to point B car and just sounds out of this world. And yes, stage 2 is a MUST. Should have come from the factory with that tuning. It would have crushed all it's competitors at the time and seriously upped its status in the future. But lucky us, we can have it now and purchase the car at half of what Audi sold it for.

The RS5 has a wider stance, different hubs, different drivetrain tuning (rear and center diff, transmission), different gearing, brakes, etc...yes there's a difference. The RS also has room to run wider wheels and there are some differences in the bracing as indicated by the FSM.

Ultimately it depends on what you’re looking for. If you want a quick V6 then get the 3.0T, but if you’re looking for more beyond that then get the RS5 V8. If you’re close to Houston, then I’m more than willing to take you on a ride in my RS5 Stage 2.

[Ape Factory]

So I am/was looking at a RS5 with the 4.2. But on google I can't seem to find supercharger or turbo kits. McChip-dkr in Germany does but they seem to want you to buy them an RS5 for the price of their kits. So what's the deal. And is this the same 4.2 that is used in the R8?

Sent from my SM-N975U using Audizine mobile app

Ok...a few misconceptions here...the RS5's motor is NOT the B7 RS4 (same as the V8 R8) or B8 S5 V8. Yes, all of them are 4.2L but the RS5 has a clean slate design so to speak. It's actually the R8 V10 motor with two cylinders lopped off. If you look up many of the part numbers for both engines, they're exactly the same. Same rods, pistons, rings, valves, etc..obviously the parts needed to incorporate two more cylinders, like the crank and cylinder heads, are different. But the intake/exhaust ports are the same as is the combustion chamber.

We all know how how well the V10 motor takes boost. It's pretty much good for 900 wheel hp before needing internal upgrades. So the RS5 should be good, with proper fueling, should be good for 70-80hp per cylinder at the wheels.

We now have two RS5's running JHM stage2 tuning, which have run sub 12 second 1/4 miles. Theoretically, that's possible with just the tune, K&N drop-in filters and an exhaust. I should be in the 11's but I just can't catch a break with weather and track conditions.

JHM will have a supercharger kit out soon. What was formerly PES also has a supercharger kit, can't remember what the new company is named... No room for turbos although there's one person who is doing a turbo RS5 but it'll be a hot mess. Wouldn't touch it with a 10ft. poll and the builder is a truly pathological liar.

The McChip kit is the PES kit slightly reworked with their tuning.

If you find yourself in Austin, Houston or San Antonio, I'm sure someone would be willing to give you a ride in a JHM stage 2 tuned RS5. It'll be an eye opener. The RS5 is totally worth it.

[JamesRS5]

The McChip kit is the PES kit slightly reworked with their tuning.

Such an elegant solution.

I just can't see how the JHM can match this for clean looks unless they feed the charge air up behind the grille and retain stock filter position so effectively filter after the supercharger.
I guess you could then run a combined air filter/charge cooler in the OE air filter position.

[txb7sline]

Thank you that was very informative. It gives me a lot to think on. I just heard some nightmare stories about the 4.2. Thank you for clearing that up for me.

Ok...a few misconceptions here...the RS5's motor is NOT the B7 RS4 (same as the V8 R8) or B8 S5 V8. Yes, all of them are 4.2L but the RS5 has a clean slate design so to speak. It's actually the R8 V10 motor with two cylinders lopped off. If you look up many of the part numbers for both engines, they're exactly the same. Same rods, pistons, rings, valves, etc..obviously the parts needed to incorporate two more cylinders, like the crank and cylinder heads, are different. But the intake/exhaust ports are the same as is the combustion chamber.

We all know how how well the V10 motor takes boost. It's pretty much good for 900 wheel hp before needing internal upgrades. So the RS5 should be good, with proper fueling, should be good for 70-80hp per cylinder at the wheels.

We now have two RS5's running JHM stage2 tuning, which have run sub 12 second 1/4 miles. Theoretically, that's possible with just the tune, K&N drop-in filters and an exhaust. I should be in the 11's but I just can't catch a break with weather and track conditions.

JHM will have a supercharger kit out soon. What was formerly PES also has a supercharger kit, can't remember what the new company is named... No room for turbos although there's one person who is doing a turbo RS5 but it'll be a hot mess. Wouldn't touch it with a 10ft. poll and the builder is a truly pathological liar.

The McChip kit is the PES kit slightly reworked with their tuning.

If you find yourself in Austin, Houston or San Antonio, I'm sure someone would be willing to give you a ride in a JHM stage 2 tuned RS5. It'll be an eye opener. The RS5 is totally worth it.

Sent from my SM-N975U using Audizine mobile app

[Ape Factory]

Thank you that was very informative. It gives me a lot to think on. I just heard some nightmare stories about the 4.2. Thank you for clearing that up for me.

Sent from my SM-N975U using Audizine mobile app

Most welcome!

[Ape Factory]

Such an elegant solution.

I just can't see how the JHM can match this for clean looks unless they feed the charge air up behind the grille and retain stock filter position so effectively filter after the supercharger.
I guess you could then run a combined air filter/charge cooler in the OE air filter position.

I agree, the roots type/screw really is a clean installation. Something like a TVS-R 2300 would be great on the RS5. But we'll see what they come up with. It looks like there's a ton of room in the grille area but there really isn't. It's surprisingly tight due to the OEM crash bar, oil cooler and Homelink transmitter.

The air pumps on either side take up a lot of space as do the auxiliary radiators. Then there's the adaptive cruise control radar (if so equipped) on the passenger's side. I'm super curious to see where it'll go.