13B>>>>Quattro

["Graydon D. Stuckey" <graydon@apollo.gmi.edu>]

On Sun, 23 Mar 1997, Joshua Hadler wrote:

> Mike mused:
> 
> > Modest proposal: Engine swap to 13B Mazda rotary.
> >
> > Pro:
> > Mazda 13B engine can make 250-275 HP without lots of wildness, more 
> > available.
> 
> If you plunk down the big bucks for the twin turbo set up. Yes, 250 or
> so is feasible from a normally aspirated 13B but it will _not_ be a very
> nice engine to drive on the street. No bottom end power at that point.

I'd take exception to that.   A properly built 13B, for this application, 
would be a fine driving motor BTDT.   I wouldn't do it without the turbos 
though.

> > Terminal flame wars from purists
> 
> [snip] lots of engine swap technical gotchas that I wouldn't call a
> "con".

That's true.   It would be alot of work.

> The big problem I see is _torque_. The Audi is a heavy car, no matter
> how you look at it. And to get a heavy car to launch off a line takes
> torque, either that or frequent clutch jobs. The 13B is a fanastic
> engine - in a light car - but in a heavy car like the Audis I think it
> would be a mistake.

Even the 13B single turbo motor with 200hp makes 80% of its max tork at 
1500rpm.   I don't think that is any worse than a stock I5 turbo.   a 
5KCSTQ with a turbo rotary in it would be a fine car indeed.   The 
reduced weight would be a huge advantage I think.   The smoothness would 
be welcome in a currently rather rough car.

> Yes, the 13B has a fantastic linear power band with
> no real redline. Yes, it can put out gobs of power for such a tiny
> engine. But I don't think that a 13B has the neccessary low end grunt to
> get a big 'ol Audi quattro moving. 

No real redline?   Hmmm, I think if you rev that little beer keg to 8500+ 
too many times, you'll find one of the rotary's few weaknesses - the 
eccentric shaft bearings tend to wander a little.   8 grand is easy 
though :-)

The trouble is that it is expensive.   A properly built N/A 13B will cost 
you in excess of 4000 dollars.  A turbo will be even more.   Then to make 
it work at elevated hp levels will require a decent aftrermarket EFI 
system which adds a couple grand.  Then you need to dyno the thing to 
make it work right, which can quickly eat up another grand.   At that 
point you might as well get a 20V engine.

The best part would be the four little triangular rings in the grill!  :-)

Later,
Graydon D. Stuckey 
'86 5KCSTQ, getting more toys every day...