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RE: don't try this at home - FOLLOW-UP

Hi Robert,

>Thanks for the input everyone.
>Feel free to send more...

I heard of two turbocharged 4000 quattros on my quattro club Brainerd 
adventure last October. Here is what I wrote:

<start inclusiuon>

>> - I met two owners of turbcharged 4000 quattros, one performed the
>>conversion himself, the other was imported from Germany and was converted 
>>the factory

>More on these please?

On fellow has turbo charged his 84 4000 quattro. He says that the car has 
been constantly evolving since he bought it in 84. He went the turbo route 
with parts from an 81 5000 turbo. He bought the entire car for parts and 
swapped what he needed to make it work. He was using the stock CIS from the 
4000 along with the stock compression ratio. He didn't put on the turbo 
computer.( Not sure how the engine management on these early cars worked). 
He did install a popoff valve on the intake manifold to regulate boost. At 
some point he burned up a piston, due to using the high CR and running 14psi 
of boost pressure. So he went and re-engineered his design and rebuilt the 
engine. I can't remember exactly what state it is in now, but it is a real 
screamer. He is one of the fellows who organized the quattro club event at 
Portland last year. I guess he had the car there and it was pretty quick.

The other fellow says that there is one in his family and his sister drives 
it.  It is an 86 90(4000) quattro which they imported from germany. He said 
the conversion was done at the factory. This car is somewhere around Ohio or 

<end inclusion>

A few others I have heard of, in a disussion I had with Ned at Brainerd, I 
remember him mentioning that someone in  washington also had a turbocharged 
4000 quattro and I  think someone is running a turbocharged 4000 quattro in 
the SCCA rally series, right glen?

>I'm not too worried about the fit of the
>5kt engine.  According to everyone I talked
>to (including Ned) it is not a difficult
>swap.  You need to move the battery and
>to mount the intercooler.  Other than that
>most folks believe its a pretty stock job.

Mechanicaly, it should be a bolt in. The ancillaries will be the hard part.

>I'm assuming an entire 5kt engine, electronics,
>turbo, intercooler, the works...

Don't forget the engine wiring harness, including the engine control unit 
and its connector .

>My major concerns are:
>Will wiring harnesses match up??
>That could be a major drag.

Depends what you mean by match up. I don't think you can just unplug the 
4000 O2 control box and plug in the 5000 control unit. You will probably 
need to splice in the turbo engine harness right at the O2 control  box 
connector. I would be suprised if there were more than 50 wires which has to 
be integrated. It is most likely straight forward once you have the wiring 
diagrams of all the cars involved. You will also need the correct size Molex 
crimper($$) and a good supply of factory connectors($$).

Another factor is what year turbo engine will be transplanted. The earlier 
ones are much simpler, but say with the 1990 200TQ engine, you would have to 
integrate the computer controled wastegate, and dual knock sensors.

>Some have mentioned that the 4q can't
>handle that kind of power.  I'm assuming
>I would have the transmission rebuilt and
>install a high perf clutch.
>Can the differentials handle the extra
>power??  Are the ones in the 5tq's different??
>That would surprise me but then again this
>is an Audi were talking about.

I am not sure if this is the correct train of thought but... if you scale 
power outputs between models... the 4000q puts out around 115hp through 4 
wheels and the coupe GT has around 110hp through 2 wheels. If you assume(I 
could be wrong here as I have never looked into this) the coupe drivetrain 
and the 4000q drivetrain are identical and the coupe can handle 55hp per 
wheel, you can scale this so that the 4000q can handle a 220hp engine 
distributed thru all 4 wheels.  And the stock 5000t engine puts out around 
160hp. I am not sure what the weak link might be with the 4000 drivetrain. 
As for transmissions, can the 5000q gearbox  be a replacement for the 4000q 
box? Has anyone ever measured or looked at these? Do they use the same 
housing? If this could work, then you can also use a late model 5000q box 
with the Torsen center diff.

And don't forget the brakes which need to be upgraded to deal with the new 

A swap simmilar to what you are talking about has been performed by Dialynx 
in the UK. They have built a sport quattro lookalike from an 84 coupe. They 
cut a foot out of the middle and installed a turbo engine into the car. This 
car is using front wheel drive, not the quattro drivetrain. An excerpt from  
the Nov 94 VW/Audi car article on this car states,

"The engine came from a 1982 Audi 200 5000T, a 170bhp 2144 cc 5 cylinder 
turbo. The driveshafts and front struts are quattro components, fitted with 
koni sport inserts. Keith was concerned whether the drive-shafts would take 
the power in 2 wheel drive form, but he compared them with 200 turbo(2-wheel 
drive) parts and found they were the same size. The rear axle came from a 
late model 200; it had to be a non-driven type with five-bolt wheels. Rear 
suspension is Leda and fully adjustable.

Originally he fitted a Sachs clutch supplied for a 90 quattro, but found it 
slipped. So he had to modify the flywheel to take an ur-quattro 240mm 

There is also a picture of the engine bay, the battery has been moved to 
under the rear seat like an ur-q, in its place it looks like a fuel filter, 
like the way 5000s have them mounted. The coil looks to be bolted to the 
drivers side of the engine block in front of the distributor. With the sport 
quattro front end, the intercooler runs horizontally behind the upper front 
grill. The radiator has what appears as the auxillary radiator lines capped 
off. It also retains the vacuum boosted brake system, ie big disk along the 
firewall behind the brake master cylinder. There appears to be a check valve 
on the line going to the intake manifold from the vacuum brake reservoir. 
Interesting. I have wondered if a vacuum brake system might work on an ur-q. 
Seem it might.

Hope this was of interest.
Dave Lawson  dlawson@ball.com