RS4 Supercharger Argument

B6/7 S4/RS4
#681

I thought it was funny when I was accused of only caring about pump gas vs. race gas recently. It was said I did so because JHM ran a great pump gas time on their RS4 and APR ran both. I think all of you B8 guys have seen the race gas vs. pump gas debates where I’ve questioned the meritts of race times over the last few years lol. Ahh well, the site is doing well and people just want to be angry at it. What can you do. This site isn’t about making friends with the entire audi world. It’s about an open place to discuss cars without moderation or advertising influencing content.

As for the 2 different 4.2 FSI High Revving engines, yes, the new one is pretty much all new. Although it has bad manifolds whereas the RS4 had some nice TriY headers stock. Basically though we’re not likely to see a huge difference engine to engine. As for what they can handle, the RS4 has handled 550-600 WHP and WTQ and I’m sure the RS5 isn’t going to push more, so even if its internals are stout that won’t change. The other problems from boost most of the companies don’t seem worried about so that won’t likely be much different on the RS5 kits either.

So we will see.

#682

Lol because you’re so special with your rare stock 7-year-old car that you’re scared to break warranty on?

Why? That’s not my Dad’s cottage. That’s my cottage.

get over yourself there Oakvilleite.

#683

As ESS uses the same S/C as the jhm unit they as well max boost at 8psi.

http://www.esstuning.com/products/E9x-M3-VT2%2d650-Intercooled-Supercharger-System.html

I wonder if it’s more of an issue with high compression motors that limits the safe PSI range to 8? I know stage 3 M3 run into the 700+hp and 11+psi with a built motors.

#684

This gtr you have listed has a “branded title”. Just saying

#685

Bear - are you going to slap that S/C on your M3?

#686

It definitely isn’t because of the blower, it will be a while before that gets maxed out.

Just think though, these high revving V8s already have crazy high compression and people are stuffing even more air into them. In the end, they were never designed for boost. Most FI motors have certain features when it comes to pistons, rings, etc so it’s interesting to see how long they will hold up. Usually people are worried about rod strength…but I think that should be later on down the line when it comes to potential problem ares.

#687

Which one? All three…

#688

I really do think the biggest issue that goes ignored is indeed the fact that these motors do have a 12.5:1 compression ratio. From what I’ve seen, M3’s start to have engine issues with power above 550whp and it’s not rod strength or pistons it’s just the fact the compression ratio is too damn high for boost.

Even 8psi is decently high, 15psi to me just sounds bizarre- I personally would never run that type of boost on a high compression motor…

Has anyone thought about running a compression dropping head gasket?

As for the RS5 v. RS4 here’s what my opinion is…

The RS5 has dual intakes, I would think that this would help when supercharged v. the RS4 but time will tell.

Also we only have one stock RS5 time right? So were basically comparing the ONLY RS5 time stock to the fastest RS4 time ever stock.

Saki you ran in negative DA correct? IIRC I believe APR ran their 12.4 in +900 DA.

I’d say the difference between a properly driven RS4 and RS5 in the same conditions will prob be between .4-.5 seconds.

Now with the blower I don’t think the difference between the two will be .5 seconds but I def think the RS5 will be around ~.3 seconds quicker than the RS5.

That’s just my hypothesis, I could be totally wrong but we’ll see…

Exciting stuff for sure

#689

I suck at the quarter mile but I will make it a point to go to the strip in spring. Kinda hard living in the Pacific North Wet. Road courses are on for sure.

#690

You don’t have to be good with the RS5 :wink:

Launch control, ESP/ASR off, full throttle and keep the steering wheel straight. Lol!

#691

When I went 12.75 @ 108.36 it was +300 I believe. April 6, 2012 at 3pm at Toronto motorsports Park.

When I went 12.82 @109.9 it was - 1050. There was a 12.6 in it that day if I had been smart enough to lower pressures. Car just spun like crazy all day. Here’s one of those runs

http://www.youtube.com/watch?v=_jwVIdAp3ZE

There are two other stock rs4s that went pretty much what I did. Jnaut went 12.84@107.9 and Richard jeans went 12.87@108

Apr went 12.43@ 110.38 and that is the rs5 record. I have seen like 5 other stock rs5 times. Magazines have it anywhere from 12.7-12.9.

Some dude at Englishtown 12.9 @ 107
http://www.youtube.com/watch?v=I8fvrb9l6Sk

Some dude in Australia 12.7 @ 109 and 12.44 @ ??? (MPH is broken but 1/8 was same as the 109 run)
http://www.youtube.com/watch?v=I8fvrb9l6Sk

Car and Driver 12.8@111
http://media.caranddriver.com/files/2013-audi-rs5audi-rs5-spec-chart.pdf

Car and Driver again (but not a track…this was pbox data from a road in Germany) 12.5@112
http://media.caranddriver.com/files/2011-audi-rs5-vs-2010-bmw-m3-2011-cadillac-cts-v-2.pdf

Motor Trend 12.8 @ 108
http://www.motortrend.com/roadtests/coupes/1009_2010_audi_rs_5_vs_2011_bmw_m3_vs_2011_cadillac_cts_v_comparison/specs.html

As I said I think dsg and that extra 35hp helps, but it’s not going to be 0.5 seconds if it’s a good drier in the rs4.

Edit: 3:43 pm. Da was +281 feet at 4pm.

http://audirevolution.net/addons/albums/images/414442169.jpg

#692

The red one with with the kit going for $51k

#693

Richard Jeans had a full milltek on his run. Edit: I spoke to Richard and only mod on that run was Michelin Pliot Cup tires which don’t seem like much of a mod when you look at the 60’.

Jnaut was about .4 seconds slower than a stock RS5.

I don’t put much credit in magazine 1/4 mile times. Every magazine had the RS4 at 13.2 and B8 S4’s in the 13.4 range.

Also Richard Jeans car is lighter since it’s non US spec. About ~100lbs.

Also some other things to remember. The 20" wheels are def heavier than the RS4 wheels, that RS5 run at E-Town was +1000 DA and 75 degrees.

The other guy ran 12.44 and APR ran 12.4 which seems pretty fair as to what a stock RS5 is capable of.

#694

Tough question… The primal desire for power in me say get the biggest baddest blower immediately! But since I’ve owed the M3 I’ve gained an appreciation for the overall balance of the M3 package. Though I do feel more power could be fun, in certain areas, I worry that it may throw-off the overall balance that I’m beginning to really enjoy… I would image the same can be said for any RS model as we’ll…

#695

It is just lulz to compare performance of any auidi, even the R8 v10 plus, to a GTR. You cant, however it is funny how the GTR was brought up when I just recently went down to the Nissan dealer two days ago to seriously check one out.

I came to the same conclusion as 81bear did, the fit and finish, rear end, and interior just was off. I just don’t like them to make it my daily driver, no matter how fast it may be and how tunable it may be. I will keep my S5, still love everything about it.

The only upgrade I would go from here would be a TT UR R8, something retarded like 1200hp on pump.

I don’t care that a stage III+ RS4 is as fast as a stock GTR or faster than the 2008 GTR (which would be a more fair comparison at 11.6 quarter mile) it is simply a much nicer car overall. If all you care about is performance then GTR is your car. It is more tunable and cost effective to bring that GTR to a level the RS4 will never touch with over 1000 hp on pump.

#696

Agreed… I believe it’s the high compression engine that will be the limiting factor! You could do a full engine rebuild but it’s very prices especially compared to other platforms i.e GTR’s

#697
  • 1000%

I’d be willing to settle for a V8 R8 S/C’ed if I can do consistent 10’s in the 1/4 mile on pump (lol… Can’t believe I’m saying I’m “settle” for an R8)

#698

Audi RS4 = $35,000 for a good one (not a great one, not a beat one)
JHM Engine build with sleeved block = $15,000 (guestimate)
JHM stage 3 supercharger kit = $14,000
JHM Exhaust and Stage 5R clutch/Flywheel = $5,000

This will be good for approximately 700 WHP, and if they introduce a bigger supercharger, even more. They are already working on this, with teh V3 Si getting pushed to its limit on stage 3.

So $64,000 .

What’s going to touch that for $64,000? Is there a GTR in North America even for sale for that money? Never mind the $10,000 or so in mods you will need to catch a stage III RS4. And nevermind the fact that you’re driving a 2 door, somewhat ugly, impractical, rickety JDM car with probably 100,000 kms on it.

#699

You’ve totally lost me… I was saying the cost to build a NA S65 engine (M3) is about $15k where as building a GTR motor is about $7-8k (half the cost).

To your point you can get a GTR in the mid $50’s (US) + $7kish in bolt-ons will have the GTR in a position where it’ll out perform the hypothetical RS4 car in your scenario. It should have about 40-60k miles on it and it probably be an 09-10 model year. Ugly is subjective. Rickety probably…

An example of the GTR in my scenario:

http://www.gtrlife.com/forums/topic/92399-soldsold%26-65281%3B2009-nissan-gt-r-black-premium-46k-miles-53k/

http://www.gtrlife.com/forums/topic/90741-sold-2009-blk-gt-r-milwaukee-wi-45000-miles-57k-price-drop/

The package I’m referring to is SBD700 kit ($5k). I’d also include ported intake manifold for $1,200 (not included on the 10.5@130.5mph below)

http://www.gtrlife.com/forums/topic/91847-new-pb-93-octane-oem-turbos-10525-13056mph/

This shows the SBD700 kit going 10.0@136mph (on E85 but is missing the ported intake manifold which should equal out)

http://speed-by-design.myshopify.com/collections/sbd-performance-packages

#700

seriously. look at this one with a 60-130 ~4 sec

http://www.youtube.com/watch?v=pqN7muvITgo