Who of you, other than Axel, have had a problem with the stock (SAC) on an S4, and if you had, what are your motor mods?
We all have in some way/shape or form from the rivets popping out or the SAC system moving
I haven’t seen too many s4 guys but there has been some. The rs4 pp is good but jhm got away from it for reliability reasons. It sees if you have a good one your all set it will last till the ware surface is gone. If you get a bad one usually you will know right away.
My stage 4’s SAC ratcheted itself all the way down after a nasty drag strip launch. The car also tried to pull the pinion gear out of the rear diff at the same time and almost succeeded. Tons of other launches and normal driving too.
Here are my experiences, mods are in my sig…
The factory clutch/flywheel in my B7 worked perfectly up until 74k miles when it started slipping on hard 1-2 and 2-3 shifts. I had a ton of launches and drove on it spiritedly with no issues from 44k when I bought the car. I replaced it with the JHM LW flywheel and stage IV kit. Kit worked perfectly for 14k miles until I was cruising on the highway and the crank position ring separated from the flywheel and disintegrated in the bell housing. I’ve done a little research and haven’t heard of this happening to anyone else. Info on that fiasco is here…
http://audirevolution.net/forum/index.php?topic=2272.0
JHM warrantied the flywheel and I inspected the clutch disk and RS4 pressure plate. Besides for some minor cosmetic nicks on the PP everything LOOKED fine and it went back together without a hitch. Drove the car for about 4k miles without a problem then started having issues. The engagement point on the clutch got progressively lower and lower, but would periodically be normal. It then got to the point where I would have to pump the clutch two or three times to get it in and out of gear. Looking back I probably should have asked for a whole new set-up from JHM. I still don’t really know what caused this issue. The pressure plate could have been damaged from the broken crank position ring or could have just been the SAC failing on its own, who knows. In the end I went with a 5r clutch and am currently problem free.
Wow good update Jim it was interesting to read that. Something seems to go wrong with the rs4 pp at times. It’s an OEM part so it’s hard to say what the issue is as its hit or miss.
It’s interesting to me that this only seems to occur with RS4’s and modded S4’s. If the RS4 and B7 S4 share the same PP why don’t we see similar issues on stock S4’s? Does the added power, or extra RPM in the RS4 cause these failures?
I forgot to mention I was also having similar issues to Axel before the engagement point dropped to the floor. Under hard acceleration in upper RPM’s the pedal would not return fully on shifts. I would have to put my foot under the pedal and pull to get it to return.
I think it is RPMs
there’s a crazy difference between 6800 and 8000
look what they do to the engines to handle that 1200 RPMs on the RS4 vs. the S5/Q7 or a B67. Same can be said for S6/S8 5.2 (6800) vs. R8/Gallardo 5.2 (8500)
If it’s RPM, how do you explain the S4 issues with the RS4 PP? I mean yes, the higher the RPM, the bigger the issue once the issue begins to pop up. I drove with this issue for 18 months and I was perfectly fine under 4500 rpms but when I entered the 5k-7k range, it was a problem.
That said, the problem started 2-3 months after I got my sc and I don’t have the same redline as an RS4 obviously.
Not sure what you’re asking? Your experience wasn’t typical of the S4 world. Hardly any S4 owners have this problem, supercharged or otherwise.
Whereas almost 100% of RS4s have this problem, and only a small handful of S4 owners out of the few hundred JHM sold stage 3/4 setups to for the B67.
Some might say it’s power, but to be honest, stock RS4 = JHM tune/full 2.5 exhaust S4, so that doesn’t fly.
The fact remains that S4s can’t go to 8k rpms so I’m not so sure it’s primarily an RPM thing. Some S4s have experienced this problem (not just me). The S4s that have experienced this problem, however few out there, all have performance parts (to the level of stock RS4 power as you put it) and none go to 8k rpms.
That’s why I’m leaning to power rather than rpm as the culprit.
there are tons of B67 S4s making the same power as stock Rs4s. Almost nobody has ever had a problem
You’re basically dismissing RPMs because your 1 car had this problem and maybe 1 or 2 others. That’s bad science.
Almost every single bone stock, non-carbon cleaned RS4, which is making B67 tune/exhaust power, has this problem. Explain that when almost nobody with tune/exhaust B67 S4s have had this problem.
I think you’re focusing on your own situation too much.
My JHM stage 4 clutch adjusted all the way too. The events leading up to it included me doing a quick rolling launch that wasn’t even that violent. I then parked the car on a pretty big incline and left it in 1st. I can’t remember if I pulled the parking brake or not but when I came back to the car in the morning I couldn’t get the car into gear while it was running.
Axel, any idea what your RS4 PP looked like when it came out?
On mine the teeth appeared to be bent after separating the transmission. Before taking it out my mechanic made sure everything was installed and torqued correctly and it was. When it came out and wasn’t under pressure all the teeth lined up and looked normal. 5r went in without a problem and has been great.
Not at all. I’m basing it on the fact that not a single S4 can reach 8k rpms yet some have experienced the same problem. Also, not a single stock power S4 has experienced this problem from what I can tell, only performance modded ones. By those two statements, I’m leaning toward performance over RPM. That’s all.
I think it looked fine. Heck, I think I may still have it in my storage locker.