APS remap, Milltek exhaust and GruppeM fitted today

[ArthurPE]

here's a dragtime ~12.6/110 http://www.dragtimes.com/Audi-RS-4-Timeslip-16110.html
only mods were an exhaust...
dyno'ed at 316...
can a car that weighs ~4100 lbs loaded run like that with 360 crank HP?

a list http://www.dragtimes.com/Audi--RS-4-Drag-Racing.html
avg 12.9/107.8 (pretty much in line with the magazine stuff I've seen)
low 12.57
low 102.1
hi 13.2
hi 112.5

plugging 13.2/102.1 and 4100 lbs into a rwhp calculator ~340...

dynos are for bragging rights, drag times, for reality check...
dynos are only useful for back to back comparisons on the same car, same day, etc.

[sonny]

It seems I have opened a can of warms here, some very interesting reading above! OK so I don't have 414bhp, but I will tell you what, I am very happy with the drivability of my car after the mods, I have just come back from a 4 hour driving session at Bruntingthorpe (made the most of the down poor) and I am blown away with how the car performed, again big thanks to APS.

One small thing, I'm not 100% keen on the deepness of the exhaust at very low speeds (around town, feel like a Von Chav) even though I knew this would be the case, I'm going to give it 6 months to bed in and see how it goes!...the induction system noise is just out standing

[sonny]

Repost

[SR71]

but to accuse Audi (and the SAE, DIN, TUV, etc.) of criminal activity and conspiracy seems a bit over the top...

You obviously don't remember Toyota's antics in the WRC during the early 90's...a discipline Audi used to do well in...



Still I haven't accused Audi of squat...merely presented you some of the observations of European owners.

All you're doing is quoting stats that back up your conclusions.

What you ought to be doing is telling us what everyone on this side of the Pond is doing wrong...

Personally, I'm quite happy with my car although I want that manifold ported and polished...

It 1/4's sub 13 which is fine by me for a 3900lb car...

[ArthurPE]

but to accuse Audi (and the SAE, DIN, TUV, etc.) of criminal activity and conspiracy seems a bit over the top...

You obviously don't remember Toyota's antics in the WRC during the early 90's...a discipline Audi used to do well in...



Still I haven't accused Audi of squat...merely presented you some of the observations of European owners.

All you're doing is quoting stats that back up your conclusions.

What you ought to be doing is telling us what everyone on this side of the Pond is doing wrong...

Personally, I'm quite happy with my car although I want that manifold ported and polished...

It 1/4's sub 13 which is fine by me for a 3900lb car...

antics? nope, falsifying data used to make a purchase is a crime...

yes, I'm quoting 'facts' to back up my assertions...
funny how those pesky facts get in the way of a good debate
a sub 13 sec 3900 lb (curb wt) car...takes good HP to crack that
although the trap speed is more telling of HP, the awd skews the ET results...

honestly, I DON'T believe porting/polishing will enhance the HP more than a few ponies...the engine is already extemely volumetric efficient...

not sure if you have this in the UK, but it is a very good method...
http://www.extrudehone.com/auto/auto-performance.php

basically polishing/enlarging with a viscous, abrasive slurry being pump through the object of desire...lol

http://www.extrudehone.com/about.html they're about 30 miles from where I live...

nice graphic of operation: http://www.gethoned.com/parts.php?get_p ... automotive

looks like ~$500 US to polish and port to gasket size...
this get to places std machining can't

[SR71]

I give up...

honestly, I DON'T believe porting/polishing will enhance the HP more than a few ponies...the engine is already extemely volumetric efficient...

Check a couple of threads down and you'll find it netted 32hp for one of our respected Italian owners who has provided more real B7 data than probably anybody else on the board.

http://www.rs246.com/index.php?name=PNp ... ic&t=73889

There is another American owner seeking to duplicate his results as we speak. I'll leave you to find his thread.

Bowing out....

PS: The curb weight of the Euro spec B7's is, according to my B7 tech specs, 1650kg = 3630lbs.

[ArthurPE]

I give up...

honestly, I DON'T believe porting/polishing will enhance the HP more than a few ponies...the engine is already extemely volumetric efficient...

Check a couple of threads down and you'll find it netted 32hp for one of our respected Italian owners who has provided more real B7 data than probably anybody else on the board.

http://www.rs246.com/index.php?name=PNp ... ic&t=73889

There is another American owner seeking to duplicate his results as we speak. I'll leave you to find his thread.

Bowing out....

PS: The curb weight of the Euro spec B7's is, according to my B7 tech specs, 1650kg = 3630lbs.

I've read the thread...
notice the dyno says 'corrected' power?
what if each run used a different factor?
show us the raw numbers and the correction factors...
HP can vary by 8% based of temp/humid/atm press alone...
not even factoring in altitude...

regardless, an 8%+ increase with porting/polishing?
I don't buy it...why?

the engine is efficient to begin with...the gains are basically pumping loss reduction...the HP lost due to overcoming intake track pressure drop...
although it's argueable there may be better mixing (or the contrary, turbulence increases mixing)

to realize that increase due to airflow increase alone is ~ like adding ~1.5 psi or so of boost...
especially with no ECU mods to optimize it, or exhaust track mods to compliment it...

at +32 HP it should be measurable...
run five 1/4 mile runs with, then without, same car, same conditions...do some data analysis...

the actual weighed numbers for US cars are ~3800-3900 depending on options...add 150-200 for fuel, driver, etc.

[silverRS4]

Geez, is it no wonder I haven't posted anything on the USA Audi forums about the intake work. That would only start endless pages of pointless debate. The folks on east side of the ocean look at it as I do - a fun project with interesting potential, which is encouraging. I am hardly expecting 30 some HP. I would be happy with 5. I am not posting any credentials, but I know a fair amount about engines. I see where PE's coming from, but I'm doing it anyway because its INTERESTING and FUN...And BTW, the Extrude Hone process (while an exceptional method) does not lend itself well to the RS4 intake due to the way the manifold is split- the trumpets may get damaged. Why do I know? Because I got of my armchair, took one apart and looked at it.

[silverRS4]

Edit, sorry - I meant "off" my armchair. PE's obviously crunched numbers, so how about he calculates the velocity of the air traveling through each port using a mass flow of 325 g/s. I could tell him what the average area of the port is, but I'm sure he could make an educated guess. The velocity is substantial, is it not? If anyone's spent a fair amount of time with a flowbench, and measuring airflows of cylinder heads and intakes at various stages of gas flowing (porting), it becomes quickly obvious how sensitive the path is to minor changes. There is always room for improvement, right? The RS4 manifold is a stellar piece and at first glance doesn't appear to need alot of work. But there are several improvements that can be made. I have the time and the tools, so I'm going to give it a shot. I agree that HP gains are difficult to quantify on a wheel dyno, but I am loooking more for volumetric flow improvement (mass flow modified using intake air temp and barometric pressure). That is easily quantified with VAGCOM. Think of all the chaps that told Ron Dennis not to bother with something because is wasn't "worth the time or effort". I'd guess they are all in the States now trying to start a F1 team.

[PetrolDave]

How many people who own an RS4 and think that it doesn't generate 420PS at the flywheel used to own a turbo-charged car before?

The power delivery of a large normally aspirated engine (linearly increasing) is completely different to a small highly turbo-charged engine (nothing, then lots slowly tailing off) - which makes the "feel" completely different. There is no kick in the back, so it can appear that you have less power - but you don't you just have the power delivered in a totally different way.

[pippyrips]

How many people who own an RS4 and think that it doesn't generate 420PS at the flywheel used to own a turbo-charged car before?

The power delivery of a large normally aspirated engine (linearly increasing) is completely different to a small highly turbo-charged engine (nothing, then lots slowly tailing off) - which makes the "feel" completely different. There is no kick in the back, so it can appear that you have less power - but you don't you just have the power delivered in a totally different way.

Good point, well made PD. I was so underwhelmed on the ride home from buying the RS i almost took it back! it was only when i looked down at the speedo and saw *** I started to understand the different delivery. I was driving a 400bhp turbo the day before....

That said, i do think there is something in them not getting the figures quoted.