Re: Audi needs more power

[tomh@metrics.com (Tom Haapanen)]

> For some reason -- my own opinion -- Audi's non-turbo'd engine is 
> helplessly inefficient in terms of power output. Even the new 5 valve V6 
> Audi has on non-American A6 is a mockery of itself (being a high-tech 5 
> valve engine, its overall performance is still mediocre).

The 30V has an extra valve per cylinder to help with the emissions, not
to increase power output over the 24V equivalent.

> So I wondered, "How does Audi's engine's performance (torque plays most 
> of the role, but the number is harder to come by) in terms of bhp per 
> liter?" So I did a quick look-up (as of current 95/96):
> [...] 
> bhp/litre	maker
> 57.7		Audi V6 2.6
> 61.6		MB V8 5.0
> 62.1		Audi V6 2.8
> 62.2		Audi V8 3.7

All right -- these are all two-valve designs, and the Audi looks OK.

> 68.0		MB V6 2.0
> 68.1		MB V8 4.2
> 68.2		MB V6 2.2
> 68.8		MB V6 3.2
> 68.9		Audi V6 2.8 5-valve
> 68.9		BMW V6 2.8
> 70.4		MB V6 2.8
> 71.2		Audi V8 4.2
> 71.5		BMW V8 4.0
> 72.6		BMW V8 3.0
> 73.9		BMW V6 2.3
> 76.8		BMW V6 2.5

All four- or five-valves here, and the Audis are right in the middle of
the pack.  So what's wrong with this?

> 86.8		Cosworth V6 2.5 (1993)

Whereas a specialized tuner engine isn't really comparable to anything 
else ...

> But Audi's 5-valve just made 
> in in par with "other two's" V6 2.8 -- totally dissapointing knowing Audi 
> used 5-valve to let its V6 2.8 engine to breathe.

See above -- the extra valve isn't there to increase the power output.  And
as for comparing it to the other V6s -- take a look at the torque curves.
The Audo 30V design has an incredibly flat and broad toque curve that is
unmatched in its class.

> Of course, bhp is not the whole picture for an engine -- torque plays most 
> of the picture. But by briefly looking at bhp/litre efficiency, why are 
> Audi's more popular engines at the bottom? Oh well.

Because they only have two valves per cylinder?

-- 
[ /tom haapanen -- tomh@metrics.com -- software metrics inc -- waterloo, ont ]
[ "everything that can be invented has been invented."                       ]
[                        -- charles h. duell, u.s. patent commissioner, 1899 ]