Silver90Quattro

Hey all, I have been reading through previous posts but would appreciate some opinions regarding our current situation. We started taking apart stuff to do the clutch on my father's '93 S4 - 196Kmi., Hoppen/MTM Stage 1 (280hp/332lbft.) Got the exhaust and down pipes off, and uh ohh... cracked exhaust manifold! Has anyone ever experienced this before? What causes this? Also, the back side of the turbo impeller and oxygen sensor are white/have white deposits. As does the area around the crack in the EM. To us, this indicates a lean condition - from the cracked EM??? Or another problem?
Before starting this job, we jokingly said, well if we find the EM is cracked, we will have to go for the RS2 EM. First, would you guys recommened having the cracked, stock EM welded by a very experienced welder? What success would this have (don't want to tear it all apart again!)? Also, Hoppen has three chip kits available for the 20vt. Is the software the SAME in all three kits? In other words, because the car already has the Stage 1 software, would acheiving 320hp be possible simply by adding the RS2 EM and RS2 Turbo? Would you guys recommened this, given that the car has basically 200k miles? Also, how is it that the factory got 315hp out of this motor with a different MAF, injectors, etc., etc., but Hoppen claims 320hp, with just the chip, turbo, and EM? Is it simply better softeware management?
Last but not least, I know that there are a few different 3" Turbo-back Exhaust options out there. Do all of these units delete the cats? Or do they work with them?
Thanks all very much for your time, and sorry for asking any questions that have been previously addressed in the forum!

EvanUrS4

When I asked them about doing a stage one they told me I could upgrade later for 199 bucks. Not a terrible deal.

You might be able to have it rewelded, but personally I wouldn't. If your father is at all interested in performance, this sounds like a good opportunity to upgrade.

Someone (UrS4boy) correct me if I'm wrong. But I believe the reason Audi only got 315 with MAF, Injectors, and the like is liability. When you build a car from the factory you have to include a large safety factor. You can say the same thing of our cars... how come they only made 227 horsepower, when a stage 1 Ecu alone can bring them near 300. Audi doesn't want a car to come from them already nearing it's limits incase it breaks. I believe the true possible horsepower on the RS2 parts is more in the area of 370 with the right software.

Deleting cats is usually your choice. As far as I know it's illegal in every state except for racing? But I think most of the 3" systems for our car include, or have cut-outs for a cat.

Evan

UrS4boy

left a margin of safety/reliability so Audi would get all the performance cudo's but none of the warranty issues that would come if they had gone to the absolute edge of the motor's potential. Hence, all a tuner had to do was to "tap" (hate to use THAT word) into the safety margin a bit and extract more horsepower using new boost and fuel maps. AFAIK, the stock motor internals can be pushed to close to 400 hp without a problem. However, in that range and above, the weak links become the connecting rods, the head gasket and the head bolts (you need to go to studs).

Bottomline: For most of the chip sets and turbo's out there, there aren't any major reliability issues. Going to RS2 turbo and EM gets you lots of extra hp with the right chip. Upgrading the MAF and injectors can add more (with a different chip set).

Dave F.

Aaron[MA]

I installed an RS2 EM during the transplant.
Email me if interested.

BTW,
Got my RS2 piece from Blau (they had it in stock!)and was a full $200 cheaper than 2Bennett wanted.

EvanUrS4

<center><img src="http://pictureposter.audiworld.com/39395/bent_rod.jpg"></center><p>Nearing 400hp is where you start risking serious failures in the engine. Mainly rods like this one.