Hey all,
Very new to Audi's in general, and have had a fairly hard time tracking down information so far.
I live up in North California, have snow conditions for the better part of the winter, hence the Quattro, and am looking to see if a I5 Audi turbo might be a good move to cure my frustration with a '85 Honda 2.0 Si Prelude.
So if I might be able to get any help that would be great!
What models exactly came to the US with a I5 turbo?
What are the limites for the 10v and 20v motors?
How tune-able is the stock ECM?
I need to keep things smog legal-ish, so how far can the stock intake / manifold go?
How are parts availability?
Is servicing by an Audi specialist necessary or can I wrench on it myself with plenty of time and a backup ride available?
Do they age well or require increasing levels of service?
How is the highway milage, at say 65 and 75+?

Thanks for any help that might be provided!
-Pete

 

Besides the C4 S4, what other vehicles had the I5 turbo? Maybe someone could point me in the right direction for a good FAQ on this era of Audi's . . .?

EDIT
The Quattro has the I5 turbo, does the 90 coupe ever come with it?

 

www.google.com , www.edmunds.com

 

US I5 turbos would be any turbo prior to the introduction of the 1.8 turbo (I4) in the A4 models. That was mid 90's. Audi had the 5k turbo starting in '86, continued with the same basic package up til1991 when it was called the 200. The '91 introduced the 20v turbo engine (the '91 20v turbo quattro, very rare, and one is in my garage). That engine was the engine for the later S4's and S6's through the mid '90's. There was also a turbo wagon (Avant). At this point it may be difficult to find one that is ready to go. Those that have them, tend to love them.
As to their servicing and reliability, the I5 is about bulletproof in my experience (mine were'85 4ks, '87 4kcs, '90 90s, '91 200 20vtq, and others in the family '86 4ks, '87 5k, '84 4ks, '93 90s(V6), and '88 5kt avant), they have tended to outlast the electrical system. They can be costly to keep up as they have somewhat rare parts, but they can be found, and the tuning potential is great. The I5 turbo can really put out the power, just know that will reduce the reliability, and you are generally looking at an old engine. I think that the last were made in '94 or so. but all of the I5's in the list above were all over 200k miles when they were let go.
I have seen some conversions of the 4k with a turbo, and they are quick. but it is probably tough to find one at this date.
My experience is the milage, if you are taking things easy, and it is relatively flat is that you can get between 22 and 29 mpg.
Self service, if you know your way around is doable, but can be time consuming. You might also want to consult a specialist as the engine bay can get a might tight, but that is a greater problem in newer models.

 

^ rihgt on the money sir

 

Wow, thanks for the post!
I guess I got lost in all the different models of Audi's, cars that I have heard very little of before.

How much of a performance difference is there between the 10v and 20v motors? Just getting rough estimates from Progressive.com seems to spit out fairly high insurance rates for the early S4's. Is that due to the long I5 block's lack of room in the instance of a fender bender . . . or what?
Are there any aftermarket tuning programs for the stock ECM?

It's the middle of the summer and I managed to pass up a '99 Trans Am. I like to be able to drive home in the snow that much

Thanks again!

 

The 20v engine is much more tunable, but somewhat rarer, at least in the turbo form. I do know of some that have gotten better than 400 hp from the 20v turbo in their daily driver, but that is way outside the norm. They tend to be getting serviced like an old Italian car. More time in the shop than on the road.
My guess as to why the insurance is so high is that it is an old car, and fairly difficult to find replacement body parts for, as it was also somewhat rare (unintended acceleration and all of that). Also, since the S4 was really a performance car with 4 doors, it was subject to higher rates. Remember that in the early to mid '90s, 300hp was a big deal.
The 10v turbo also could be tuned very well, but that had a much lower limit due to the restrictions that the 10 valves placed on their breathing. It is probably an easier engine to find.
The really fun one to find would be a Sport Quattro Coupe. Those were the Group B homogulation cars that were required to allow the old Group B rally racing (think Porsche 959). I once saw one chase down a new 911 turbo at Road America. But I digress. The 20v, if you can find one is one great engine, but the peripheries can really cost .