View Full Version : With a 3 bar MTM, an RS2 header, what are you guys


Maynard
10-31-2001, 09:28 AM
running for a Turbo. I am looking at the recomendations for KKK on their RS2/RS2comp/K26 and I see that the RS2 and K26 aren't supposed to run at 3 bar. Also, anyone running the RS2 cams as well? I've read up on urs4.com etc but would like any specific examples or feedback. I also had my VIN searched for recalls that weren't fixed. They came up with a code KY but wouldn't tell me what that was until a mechanic looked at it. Any idea what that code is? (at least dealer is using KY this time...) Thanks.

TimeForAnewCar
10-31-2001, 10:10 AM
Was the fuel line recall I believe....

Jimmy Pribble
10-31-2001, 10:11 AM
MTM 3 bar is too generic. There is more than one program depending on your hardware. So, I was using an MTM 3 bar program with my stock K24 turbo. That program gave me 23-24 psi boost. Once I add my RS2 turbo, I will need to change my software to match the turbo. If I go full RS2 spec (which I plan to do), I will need different software to account for the different MAF and injectors. Yet, it will always be called an MTM 3 bar program. See what I mean?

3 bar refers to the pressure sensor in the ECU. The S4/S6 comes with a 2.5 bar sensor from the factory. For aggresive chips, this sensor (hardware) is upgraded within the ECU to acurately read a MAXIMUM absolute pressure of atmospheric + boost pressure. So, the maximum boost pressure that a 3 bar sensor can READ is about 29 psi. That doesn't mean that is how much boost the chip puts out (see my example above).

The link below will show you a huge photo of an open ECU. The big black plastic thingy in the middle is the pressure sensor.

Not many people are running the RS2 cam ($1000 a pop, yikes!), so it's hard to get a good sampling of opinions. In general, it is supposed to help the low end power, which is lost to the bigger turbo.

The KY recall has to with your fuel line. This is very important, so make sure they do it. More info at this link: http://www.urs4.com/technical/UrS4_fuel_leak.html

HTH,<ul><li><a href="http://www.urs4.com/images/ECU/DSCN0158.JPG">Motronic ECU Pressure Sensor Photo (Big)</a></li></ul>

Maynard
10-31-2001, 10:18 AM

Jim
10-31-2001, 11:14 AM
Just because it shows as not being done, doesn't mean it wasn't. Mine shows as not being done at the dealer, however I had it fixed on Audi's dime BEFORE the official recall (at an Audi dealer). So I figure if it goes bad again, I can take the letter in and get it done again (?). It is easy to tell if it has not been done yet. In the engine compartment, passenger side, near the strut tower is a fuel line that runs from the firewall and connects to a different fuel line. If this fatter hose (closer to the front of the car) is braided stainless steel, then it will eventually fail at the connector and possibly spray fuel onto a hot turbo (not good). I hope my explanation makes sense. See UrS4.com for more info.
Jim K
93S4

Jason C
10-31-2001, 02:14 PM
or, go bald and convert a coupe to and S2/RS2 ???

SDPaulS8
11-05-2001, 07:11 PM
A few thoughts.
When they say "3 bar" I believe they are including atmospheric. I've got Lehmann software with a "3 bar" sensor. It peaks at 26psi with great gas on a cold day which is right around 1.8 bar which is the generally seems to be considered the max PR for a RS2.
I would be wary of using MTM software which was designed for the old K24 with an RS2/K26. I had some much less than satisfactory experieinces with this combo and recently switched to Lehmann with great results.
Think if you are contemplating RS2 your best options are Intended Acceleration or Lehmann software available thru any of Hoppen's distubutors.
I have the RS2 "comp" turbo/cam/manifold/turbo back exhaust with the stock MAF and 'near stock' RC 310 CC injectors. Has low end (1900-2600) that is at least as good (if not slightly better) as stock/chipped K24 and kicks in in a big away at 2800-3000rpm. Without the cam and exhaust the car still rocks pretty well above 3000-3200 RPM but is pretty doggy in most of the 2000-3000 range due to lag/boost threshold with a somewhat choked bigger turbo.

I would strongly suggest you find someone with the mods you are thinking of and beg a test ride. (S-car Nationals were a great place to do this)
Be forwarned: the cost of finding RS2 Nirvana is not cheap (compared to chipping a K24): $5K to ??? to do it right. Once you start down this path....you will be hooked. Then you must budget for brakes, suspension, wheels, tires, gauges, and cosmetics........
However I must say I really enjoyed on the looks on faces of 2 neigborhood mid-90s Corvette owners who could not catch an innocent little ol' wagon ...
Paul
95.5 S6 Avant mit RS2