So I am sort of a poor weather poster, meaning I tend to only get on when I have issues I need help solving. Everyone on this forum and others have always been extremely helpful and I really appreciate it. After owning my D2 S8 for 3 years and 80,000 miles I think it’s time I give back where I can. I have noticed there is almost no information on the only tune available for our cars. Stage 1 and stage 1+ Unitronic. Well at the rip age of 13 with 206000 miles, I went ahead and got it done (only stage 1 was available for my VIN I'm not going to complain about 5 HP). Call me crazy but I have had this engine open after the Pistons hit the valves. And well I'll just say i understand why they call it bullet proof.

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THE SHORT EXPLANATION (because I know I can be long winded) is that it is exactly how it is described on the Unitronic website. More power, smooth delivery, MUCH better throttle response. The Throttle response alone I feel is worth the price. I have not done any dyno runs but on a hot day (90 when I tuned it) it felt like the quoted power, and it only got better as it cooled off.

Closing words: For and NA engine, the difference is comparable to a turbo tune (not quite as night and day but you definitely notice). Again if you are looking for extra performance out of your S8, I recommend this.

If anyone has any questions, please feel free to post and ill try to answer.

Special shout out to Nate at Rabe MotorSport in Wallingford CT for installing the tune. He's a good guy and gave me great info on Unitronic as a company and the tune, highly recommend him if your in the area for any work.

 

Good to hear, I'm thinking about getting that tune on mine at some point.

 

Installed?

 

Nice to hear! I have been thinking about doing this as well... By chance do you know the cut off dates for the Stage 1+? I'm curious to see if I can get it it or not.
(perhaps I am being lazy and should just call them )

 

Cost was $550 plus tax, its not right in front of me but in total it was about $580.

 

I don't know if their is a cut off by VIN, When I asked Nate (Tuner) he said (and I honestly forget so don't quote me) something like a code in the ECU had to match up with a specific code in the tune otherwise the ECU would not take the tune. I know that's probably not a good answer and he definitely said something more intelligent when explaining it, but what I'm trying to say is it seemed more like an ECU match rather than a VIN cut off. He had to type my VIN in to see what was available.

That being said, I only run 93 (except in AZ where that did not exist -__-). I asked if it would effect the tune negatively and I was told 93 will still get you more power even with the 91 program (like the stock program adjusts to the octane you run) The program is just set to get the most out of 91. Basically saying when developing "Stage 1" the car was run with 91 octane and when developing the Stage 1+, it was run on 93. (I am not a tuner but that's what I understood from what I was being told)

Just to clarify because I know I am terrible at sentence structure/ The "Stage 1" does not turn into "Stage 1+" just because you put 93 in.

The tune is adaptive meaning if you get an exhaust or intake it will adjust to get the most out of those, I sometimes run a month on 93/100 mix to get 96ish, and again Nate said' like your stock program, it will adjust the timing to try to make the most of it. (the gains from mixing 100 may be in my head but I justify it by considering 93 is probably "regular gas" in Europe.)

As I said before If your looking to give the old girl a little extra kick I highly recommend it. Having driven on it for some time now, I would say it just feels that much quicker. (Low end especially)

If I can ramble more, Played with a 2011 S5 4.2l
headers and full exhaust and intake ~60K miles engine rated at 356 hp only driver.
/ my car 210,000K miles Tune rated 382hp bad Axles, stock exhaust (-muffler) stock intake (Zip ties to connect the manifold actuators -not proud of that-) with MANN filter. Beautiful Passenger and 8 gallons of water (coolant leak ) 50- redlining 4th and into 5th before letting off, something like 14mph (my eyes were on the road not the dash) and he didnt pull at all, dead even and in 5th i may have been creeping up but I couldn't confirm. Great engine even after all these miles.

alright Im done, if you cant tell I fell in love with the car all over again.

 

Nice post! Everything here is great food for thought. As you stated in your first post, better throttle response would be worth the price of admission. The closest dealer/installer to me is Minneapolis or Omaha.

Thanks for taking the time to post on this modification.

 

Any transmission worries? I mean, 22hp shouldn't make a huge deal regardless, and a 13YO S8 probably didn't start with the original 360 anyways. For $580, it's on my to do list.

Edit: I see you did the Stage 1 only due to VIN. $100/hp is high, but as you said, the throttle response might make the power just icing on the cake.

Edit#2: So stage 1 is 22hp and stage 1+ is 27 hp. Where did the 5 come from?

 

The PFL ECU includes the TCU in a single big box, all contained in an enclosure befitting a flagship. That's one serious looking box. The 2000 facelift is a Bosch Motronic ME7.1, the 2001 - 2003s are Motronic ME7.1.1 Same box but enough of a software change to be a separate designation. The FL enclosure is crap and if you mention the word water near it, it will make drowning noises. I believe 2001 onward used CAN BUS whereas 2000 did not.

1) PFL
2) FL ME 7.1
3) FL ME 7.1.1

I guess that explains the availability for upgrades to varying stages based on VIN.

 

To be honest Im not sure where the 5 HP comes from. That is beyond my understanding. Because my car doesnt have that option, Im not really missing them lol.

As far as transmission, I tend to be nicer to it off the line because I have read about the issues they have. My car has not shown more than an occasional concerning clunk going into reverse, which I think is pretty good given the millage, but it did that before the tune and I have not noticed anything worse after. If anything when I keep my food steady on the power I think it shifts smoother. I have had the fluid changed because it was making a supercharger sound when I launched from a low speed (almost like a belt slipping. I did some reading and thought maybe the filter (the pump can scream I guess when the filter is clogged), but it still does it occasionally so IDK.

dont have alot of time right now but hope that gives you some of the info you were looking for.