Hi just after some tuning experince

[A WithE]

Hi all I just bought a nice mint condition 1998 Audi 80 Cabriolet... the 2.8 V6 and just like to know what are the best mods for improving performance i.e enlarged TB, remap etc and if thge engine handles any modifications well?

[adamss24]

You wont get much from it unless you supercharge the engine, look for a PES suspercharger...

[scotty33]

To get the best from this engine without a supercharger, the heads and intake are something of a bottleneck, and would probably hold back anything else you did? having said that the head design on the later AFC engine you have is a slight improvement with lighter valvetrain and 6mm stem valves, vs 7mm on the older AAH engine.
Some owners report improvements by modding throttlebodies and modding the MAF sensor housing, Though there are a number of different MAF sensor/housings used through the years, I guess less to be gained if yours is the larger type to begin with?
Schrick used to offer cams and Kent can reprofile the original ones I think. In fact the older AAH engine had slightly 'wilder cams' but not certain they can be fitted to the AFC heads. Only the earliest (c1992) ECU's with the mms200 processor can be chipped. Some later cars can be retrofitted with this ECU, not sure if yours could , being so late?
Basically there are a few things you can dabble with, but serious mods needed for a decent bump in hp.

Plenty of threads here:

http://forums.audiworld.com/search.php?searchid=4832551

User name VAP or Mance Etheridge is probably best poster to look out for

There is a PES supercharger kit for the 30v engine but not the 12v (as far as I know). Motodyne marketed a 12v supercharger kit back in the day, but not sure it ever actually existed, a lot of people paid but never received their kit.
As fitting forced induction involves a least a piggy back ECU to deal with the increase in fuelling, if you are considering it, you might as well go for a 30v engine transplant or another option is the 1.8t, or even 2.2 20v turbo from the S2/earlyS4?

[95cabrio]

check that you have a MAF first, i am pretty sure you dont :)

[scotty33]

check that you have a MAF first, i am pretty sure you dont :)

Correct, 2.6 does not use one, guess I got carried away..

[95cabrio]

to keep this post going

after a bit more research i can only find that (for these engines) only doing nominal upgrades like air filter, ECU chip and a de-cat, maybe an exhaust are the only worthwhile and financially viable solutions. Any more than this and it makes sense to put the money towards a transplant for a newer engine w/better fuel and power. Thinking about how you could save yourself £20-40 a week fuel makes the long term ownership of a newer engine much more sense.

[scotty33]

Last thing, forgot to mention before, I am of the opinion that the difference in power between the 2.6 150hp and 2.8 174hp is disproportionate, the big difference betwwen the two engines, apart from the cc and the MAF, is that the 2.8 uses a dual path intake manifold. At low rpm's the air enters the engine through a long smaller bore intake (good for low down torque), at a predetermined rpm point, a rotary valve is operated, which shuts off this air path and opens up a shorter bigger bore air path which is more suited to top end power. I believe if this manifold were fitted to a 2.6 you would get a reasonable boost in power, the hard part is that the 2.6 ECU is not equipped to operate the rotary valve.
Some sort of piggyback power valve controller e.g ignitech or zeeltronic would probably be able to do the job? Not sure if you could find something that reads the tach signal and could switch a solenoid valve at the rpm's of your choice? Or just bolt one on and manually operate it in both positions, see whether it is worth pursuing?

see what I mean re the power curves

http://www.12v.org/engine/index.php?section=fe

http://www.12v.org/engine/index.php?section=hw&sm=im