Hi everyone. I just came across this forum. I am an owner of a 1990 100 quattro with the 10v engine and 158K miles. I have maintained it very well and even though I recently purchased a 2001 A8L, I very much want to keep the 100. I always loved the ride, its incredible build quality and looks. I have 2 major problems at the moment, and everything else is fine. Problem 1 is with the AC and the 2nd and worst problem is the leaking transmission seals ( 5 speed manual ).

What I wanted to know is what is the best mod to the engine that can make more power ( already have K&N airfilter ) or where can I purchase a used engine with a Turbo that can be easily dropped in. Are there any other mods I should consider?

Thanks for your help.

Well...

Most engine swaps are not easy. Most will say to just get a 200 if you want a turbo version of your car. If you want to swap something in, you can get a 1990-1991 10v turbo or a 1991 20v turbo from the 200 series. Could also stick a 3.6L 32v or early 4.2L 32v engine in it using bits from the 1990-1994 V8 quattro.

As far as getting more power out of the current 2.3L, cam, minor head work, new exhaust (stock exhaust is 55mm, turbo cars got 60mm, I have a good used TQ exhaust that I am going to fit to my non-turbo car). Can also get rid of the CIS system in favor of a good EFI system. Cheap systems like MegaSquirt require the retention of the factory ignition stuff. Nicer systems like the 034EFI units can handle fuel or both fuel and ignition duty. They were originally designed for the 10v/10vt engines.

What problem(s) is the AC system encountering? The CC head unit can output error codes to the display. I think SJMAutotechnic.com has the proceedure, as well as 20v.org.

Trans seals can be replaced once the trans is dropped from the car.

I had a 90 100 which I used as my "daily driver" for years and years. Great looking car and comfortable ride.

Unfortunately, serious power increases will probably have a cost exceeding the value of the car. Without a turbo, it is difficult/expensive to exceed 155hp. The turbo engine conversion, while doable is a substantial project. The N/A and turbo cars have more diffrences than are readily apparent.

The usual advice, and not without wisdom, is to buy a turbo car.

I think I would enjoy the car for what it is, what it is isn't so bad.

As stated, the CC head can provide useful info. The only caution is that it provides results, not causes. For example, it will diagram the position of the flaps and doors in the unit. If one door is not closing, you tend to assume the problem is with the door. Not the case, the problem is in the vacuum system someplace. Bentley dedicates about 15% of the manual to the A/C system. A troubleshooting guide is essential. It is in the manual, but is probably available on the net somewhere. Most likely the problem is a standard one and relief can be obtained.

It is a shame that there wasnt something "easy" to give this car more power and your right that the cost of adding a turbo engine just arent worth the expense. I will just have to suck it up and enjoy the cars other great attributes. I really want to keep it going since it is in such great shape and dont want to add alot of miles to my A8. I will most likely skip fixing the AC and try to get the leaky trans fixed.

Manny

You didn't describe your problems with the A/C too clearly. Although you do see a lot of Type 44's with their windows open in the summer, it is not necessarily the case that the cure is exotic and expensive. I had some troubles with mine, but was able to keep it going for a number of years without ridiculous expense.

Fixing the transmission leaks should be doable without extraordinary expense.

These questions might receive beter answers in the 5K, 100 Forum, or the Quattro List.

I was told the cost to repair the seals would be around $1000 with the clutch getting replaced at the same time. The seals are cheap, but I was told that the transmission would need to be removed to get to all the seals and that adds $$$ to the labor.

As far as the AC, I need to have it diagnosed as I did find a vacuum hose came loose.

To do the seals AND clutch, that's not a bad price for a shop....

I once had a 100 Audi auto tranny rebuilt for $750.00, including R&R. They claimed a "labor saving" method of removal. They wouldn't let me watch, perhaps just as well. Anyway, it worked.

A lot of the price may be in the "clutch kit". I am not sure that "more" means "better". On the other hand, I am not sure that it doesn't. You might ask yourself how you drive and how long you want it to last. For "normal" driving, "only the best will do" is not necessarily the appropriate criteria.

Most kits in the aftermarket are $250-$450 depending on brand (Sachs or Luk factory items, or some "aftermarket" brands are less).

Luk items were stock on my CQ, and could easily have done another 50k. The 5kq's on the other hand feels pretty weak, and I've had it slip on the 2-3 gear change. I'd like to swap it over to a 240mm setup (just need the 240 disc and PP, the FW can take a 240), which will out last the car for sure.