audiluvr

Hi Sam,

I am picking up my RS4 on Thursday....can't wait!!!

sakimano

^^^colour?

EXRS4

I just got rid of my Phantom black 08 RS4, loved the car, great wow factor and turned lots of heads

1. These cars run 12.5:1 compression and I had a lot of carbon build up myself. I found the fuel was one of the biggest problems and started avoiding gas stations that had 91 octane containing ethanol, Shell sells no ethanol 91, some PetroCan's sell 94 with Ethonal and that works fine. First symptoms of carbon buildup for me was noticeable ping and low rpm missfires, Audi does sell carbon cleaner that is an inexpensive alternative an actually works quite well. After a tank of gas I noticed improvement and the ping went away, performance came back. I found running a tank every 3,000 kms worked best at keeping my engine clean.

2. I never ran into heat problems with the car but did replace the exhaust with a stainless Miltec which I liked very much. Exhaust choices are personal taste but the Miltec gave the car a very menacing roar and improved mid-range performance. I never gave an inch to a couple of M3's that I came across and usually pulled a good hoodlength

3. I never changed the tune in the car and also never had an issue with throttle response, keep the car above 3,200 rpm and response was immediate. If I had kept the car chances are I would have sooner or later modified it. This car was a blast to drive. On the tuning side I am speaking from experience, I had a 98 Firebird WS6, 415 CID LS1, T88 single turbo that laid down 850 RWHP, now that was a monster LOL.

Enjoy the car

Axel

You don't notice it until you get the JHM tune. Took me a month to properly adjust to the sensitivity and responsiveness of the JHM tune's throttle.

EXRS4

Ain't tuning fun LOL, it can and usually does make a big difference. That said I've gone through the aggravation of tuning high performance cars in the past there's always a give and take somewhere and a few gotcha's thrown in for good measure. I know tuning has certainly improved but there's a limit to the variables that can be changed by custom programming. My old Firebird was set on kill and starting, driveability, mileage and even engine life suffered along the way. It was in no way a daily driver any longer after that.

I'm all for people modding their cars but as a I say "eyes wide open" there's lots that can go wrong. My RS4 was a daily driver and even then on hot days in the city it pinged like a can of coins in traffic (before and after carbon cleaning). To get better performance with tuning only, you need to change fuel delivery, timing and curves which usually leans out the AF ratio at least at certain parameters. I wouldn't tune my car unless I understood what combination truly worked. I would likely change injectors and air delivery first. As a an example stock injectors as a whole are usually maxed out from the factory; My stock firebird injectors were 24 lb/hr and to get a working tune on the car I eventually had to go all the way up to 51 lb/hr injectors (added cost). Generally you can't just tune and go, you usually have adjust the whole package eventually.

This of course is only my humble opinion

Axel

I agree with all of your points. That said, a JHM tuned B7 S4 with full catless exhaust (DP+CB) and a light weight crank pulley can shave a full second off the 1/4 mile and enter RS4 territory. With negligible impact on drivability.

EXRS4

Axel, I see your car is already quite modified and looks sweet . To be honest the RS4 is no point and shoot drag queen, its high HP and low TQ are a disadvantage out of the hole. Where it shines and where mine was truly fast was cruising speed acceleration, and twisties, then it was a bullet. I commend the performance you're getting out of the car. You said catless, thats a pretty major mod, I ran my car catless and got pulled off the road by our fine OPP constabulatory (just gutted them and re-installed them after that). My personal take now on modding a car is stealty power these days, just to suprise the odd unwitting victim

It's good to see driveability is not an issue, its no fun when you can't just hop in and turn the key when you feel like it. Just remember (and I'm sure you do) that you're trying to max out your car without investing the money that could have bought an RS4 to begin with . IF you can pull that off, great job

Maybe I'll see you at the track this coming season?

Axel

Yeah, I currently have more low end torque but about equal high end hp right about now (I'm on a conservative tune for the time being).
On a low 3rd gear to mid 4th gear run, I was able to get 2 car lengths on a stock RS4. However, on a high 2nd gear to a high 3rd gear run, I was neck and neck with the same stock RS4. Once I switch to a more aggressive tune, that should change a bit. Unfortunately, the S4's 4.2 isn't as sturdy as the RS4's 4.2 so I have a ceiling in terms of how much power I can add before I need to start changing internals which is costly.

Wow, they actually pulled you over eh? How did it play out? What was their justification? How did they get that feeling you were catless? I guess they just felt it was modded, pulled you over and then started inspecting and noticed the catless? I read somewhere that technically, a police officer is not qualified to assess the mechanics of a vehicle and that they need to call over a proper police mechanic for an authoritative diagnosis. Not sure how accurate that is. Lots of bad info to weed through on the net. I guess it also helps that I drive a wagon Looks pretty mundane.

In all honesty, I would have purchased an RS4 from the get go IF Audi had brought the RS4 Avant over. Stupid North American market shuns wagons though. What can you do. They didn't even bring the B8 S4 Avant and now they're considering not even bringing the B9 A4 Avant at all (just the AllRoad). Sigh...
I don't know what the price difference is between a used S4 and a used RS4 but I think I spent the same amount of money getting slightly more power (once the aggressive tune is in) than an RS4 for the price of an RS4 (if both were sedans).
However, I would have spent the same extra money to bump the RS4's power up had it been an RS4 Avant. If Audi ever brings the new RS4 Avant to Canada, I'll be among the first to line up and put a deposit down on it but sadly, that's not going to happen. So I'm "stuck" with my supercharged S4 Avant. Depending on cost. I might do the forged pistons and rods in order to be able to increase power but I doubt it. Only time will tell.

Hopefully I'm personally more interested in road tracks than drag strips (not sure which kind of track you were referring to) but I'll do a few 1/4 mile runs to see what the car does.

sakimano

the fuel used has been shown to not change anything. The fact is FSI (direct injection) means no fuel to wash the valves as injection occurs in the cylinder bypassing the valves, and as a result, you end up with carbon build up on intake valves. Shell 91, Petro 94...none of it matters. Audi used to recommend Petro 94, then changed to Shell 91, then changed to 'doesn't matter, just use top tier.'


No offsense, but I don't think the parameters that a calibrator can adjust on a 20+ year old domestic vs. an RS4 are exactly comparable. A cammed out domestic vs. an RS4 are certainly not a good comparison when talking about drivability. My 2007 S4 had downpipes, catback, LW crank pulley, JHM tune, all of which increased the power and torque the car was making by about 10-15%. Other than a bit more noise from the exhaust, and as Axel noted, a throttle that was replicating a drive by cable car (thus was tough to get used to the first week) the car was pretty boring and entirely driveable. I daily drove it 35,000 kms in this form.

A friend and I went to the dragstrip with Axel and a few others. My friend has an RS4 with full exhaust, tune, stage IV clutch and lightweight flywheel. His car feels just about like stock, with the exception of perhaps 20% louder exhaust volume. I ran 13.1 @ 106, and he ran 12.2 @ 112. His car lost no 'driveability' or civility with his modlist. Again, this is not a mid 80s cammed out domestic.

Further, old vs. new...throttle alone is an area that has changed DRAMATICALLY with modern drive by wire systems (some say for the bad)...and the adjustments that one can make here within a tune can make or break a car's performance. The RS4 needs two ECUs to cope with the engine speeds and complexity. That gives you an idea of the insanity within.

this is not common...just for the record. You may have had a problem that you weren't aware of.

again...the injectors on your old firebird should not be used as a proxy for the suitability of the injectors on an RS4. One of the reasons these cars (especially the RS variants) are so ridiculously priced is the over-engineering that goes into the build and design. While the RS4 makes about 300 whp, it isn't until the car gets into forced induction well beyond 400+ whp that you need to change the injectors, and even then, it's not until you get a very serious blower upgrade, as the RS4 injectors can move a serious amount of fuel. I know you just used this as an example, but it's also proving to be an example of what you may not know about your former car.

As for changing parameters leaning out AF is not a dangerous practice if the stock AFR is excessively rich (it is). There's an optimal AFR for an all motor NA car to make power and remain safe, and JHM hits it right on the head.

The calibrator for JHM makes over 100 adjustments to the RS4 tune. If you don't believe that, I understand, as most 'old firebird tuners' or even modern Audi tuners don't change much more than half a dozen parameters on NA Audi tunes, but that's just an example of the poor selection of NA tunes available to Audi owners. The JHM tuner works in the performance division of a major automaker and writes tunes and designs performance system for their performance variants. He is not a closet tuner pretending, like many of the 'tuners' at the major Audi performance companies, and the 'I read the Bosch manual' people who tune their own cars on these forums. JHM is lucky to have his services frankly.