Valves- carboning up

[HYFR]

Your car should be the best performing B7 RS4 at the RR tomorrow.

Hope it goes well.

cheers Sims

I think I will be the ONLY B7 there

im not really doing it in the hope of getting a good number, its just good fun

car needs a service in less than 2k so I doubt its in top form, but we'll see

[Sims]

Your car should be the best performing B7 RS4 at the RR tomorrow.

Hope it goes well.

cheers Sims

I think I will be the ONLY B7 there

im not really doing it in the hope of getting a good number, its just good fun

car needs a service in less than 2k so I doubt its in top form, but we'll see

If you are the only B7, then clearly yours will the best

Your car has had all other issues sorted recently, and has been running really well (5k surge etc). So it will be good to see how a 70k engine that has been used well, but has not had any cleaning work done, performs.

I may come tomorrow, and if I do will introduce myself to you if you are around.

[SR71]

Ill be there.

After all I've been grounded the last 3 days...

[ArthurPE]

try to have them adjust the load...
peak torque is ~5500 or so, set the load low, then increase it until the engine holds (can't go beyond) 5500 or so, then gradually decrease it and apply throttle until the engine climbs to 7800, then raise it a bit, see if the engine slows, if so, you're at peak power...
that will give you a true measure of peak torque and power...

[Sims]

Unless you know anything otherwise Sims then I was led to believe by Audi people at Geneva that it is the same 4.2 FSi V8 unit with revisions as per the press specs, i.e twin air intake rather than single and dual 70mm throttle bodies rather than a single 90mm one on our cars as per the pics I posted up oin the RS5.

This comment by Chris Harris in Evo magazine throws some light on this subject. On the review, he does like the BMW & Porsche driving style

http://www.evo.co.uk/carreviews/evocarr ... w_rs5.html


What is it?

The latest RS model from Audi, the RS5 coupe, which joins the TTRS and RS6. It uses a new 4.2-litre naturally aspirated V8 with 444bhp and 317lb ft of torque. The motor isn’t a re-worked version of the old RS4’s V8, it’s actually 4/5ths of the Audi R8's 5.2-litre V10.

[ArthurPE]

http://www.caranddriver.com/news/car/10 ... s_and_info
At the Geneva auto show, we’ll meet the upcoming Audi RS5, the wildest evolution of the A5 coupe, and as direct a competitor to the BMW M3 coupe that exists. Here, Audi's 4.2-liter V-8 makes 450 hp at 8250 rpm, and maximum torque is 317 lb-ft, available between 4000 and 6000 rpm. The hand-built engine is direct-injected and closely related to the 420-hp V-8 which powers the R8 supercar.

http://www.caranddriver.com/news/car/10 ... .-car_news
Interestingly, Audi is sticking to its extremely high-revving engine, an evolution of the former RS4 and current R8 unit,

http://cars.uk.msn.com/news/photos.aspx ... =152278007
The powerful coupé has the same 4.2-litre engine as used in the Audi R8 supercar, with a 24bhp boost to bring the total power output of the RS5 up to 444bhp.

[HYFR]

that last one is wrong as the current 4.2 puts out 414bhp (supposedly, just not near a rolling road )

[ArthurPE]

http://www.automotiveaddicts.com/11028/ ... ges-update
The RS5 made its debut at the Geneva Motor Show last month sporting the upgraded 4.2-liter FSI V8 from the RS4 that delivers 450hp and 317 lb-ft of torque.

http://www.motorauthority.com/blog/1033 ... -the-works
The engine will be the same 4.2L unit found under the hood of the RS4 sedan but some tinkering of its electronics and exhaust will see output rise to around 450hp (335kW) and 332lb-ft (450Nm) of torque in the RS5.

[ArthurPE]

that last one is wrong as the current 4.2 puts out 414bhp (supposedly, just not near a rolling road )

nooooooo!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[HYFR]

LOL

only kidding only kidding

[P_G]

It appears dependent on which maagzine you read you get a different version and most appear to be inaccurate in some form or another. Example; "it is the RS4's 4.2V8 with reworked mapping and exhaust giving 450ps" If that were the case that mean dual air intkaes and twin throttle bodies have no discernable effect on performance which we all know to be untrue.

I'll ask at the factory. I wonder if the part V10 correlation comes from a differing V angle similar to that of the V10 and not our FSi V8?

[HYFR]

i think there is probably some truth in a lot of these magazine not really knowing what they are talking about...

[ArthurPE]

the displacements, V angle, Cr and bore/stroke are identical
V8 4163 cc (both RS4 and RS5)
V10 is 5204
8/10 x 5204 = 4163
all 3 engines share the basic architecture and are derived from the same engine...since the RS4 was first, the others are derived from it...
only makes economic sense...it would be bad business to retool for an entirely new engine generation for such a limited production car, especially when you already have one being produced (and probably has not paid for itself due to it's limited production volume)

btw: 5204/4163 x 414 = 517 HP the V10 rating

it's marketing: rather than telling you thast you are getting the 'same old engine', it's better to cast it in the light of 'an entirely new design'
the Chevy small block (and several BMW inline 6's, Porsche 911's, etc.) have production runs in excess of 20 years...
I'd rather have a proven quantity, an evolution of a great motor, with all the bugs worked out, rather than some untested completely new engine...

[PetrolDave]

that last one is wrong as the current 4.2 puts out 414bhp (supposedly, just not near a rolling road )

That's a journalist not understanding the difference between PS and bhp.

The RS4 engine is rated at 420PS (414bhp), and the RS5 engine is rated at 444PS - a 24PS difference.

[ArthurPE]

that last one is wrong as the current 4.2 puts out 414bhp (supposedly, just not near a rolling road )

That's a journalist not understanding the difference between PS and bhp.

The RS4 engine is rated at 420PS (414bhp), and the RS5 engine is rated at 444PS - a 24PS difference.

if that is the case, the increased power (PS) is solely due to rpm increase:
I was think is was 420 and 450 PS (or 414 and 444 HP)

8250/7800 x 420 = 444
and all the airbox does it allows it to get the air to pump at 8250