Re: "Smooth" VR6

[tomh@metrics.com (Tom Haapanen)]

STEADIRIC@aol.com wrote:
> The VR6 Sucks, It's Torque curve is awful.

Really?  Here are some torque curve snippets:

			-------- % of peak torque at --------
Engine			2000	3000	4000	5000	6000
-------------------------------------------------------------
VW   VR6 12V 2.8L	 85	 92	 99	 97	 88
Audi L4  20V 1.8L	 85	 91	 99	 91	 85
Audi V6  12V 2.8L	 87	100	 99	 98	 81
Audi V8  32V 3.6L	 80	 93	100	 93	 80

The numbers are approximated from actual curves, so they aren't highly
precise.  Sorry, I don't have the curves for the 4.2L V8.

In any case, the VR6 isn't significantly worse than the Audi V6 (despite
a conventional manifold), and it's definitely better than the Audi V8.

> IT's NVH is Awful (Noise, 
> Virbration, Harshness) It's V- angle is inefficient, ask the VW engineers 
> they argree!  They admit that they only did it cause it was the only way 
> to make a V-6 fit in the engine bay and their target was Mazda with it's 
> 2.0 V-6 (A MUCH better engine BTW).

The Mazda 2.0L is much better?  Have you looked at *their* torque
curves?  And in global terms, I don't think VW is at all concerned about
Mazda -- and especially not about the 2.0L V6, which is not a VR6
competitor at all.

> I would have to agree on the lowley part, But I really can't fault VW for 
> adding more sound insulation on the firewall.  The Block casting is so 
> resonate in the VR6 that it gets painful and unacceptable above 4200rpm.

My Passat isn't significantly more painful above 4200 rpm than an Audi 90
of similar vintage ('93 in my case).  And that's without having engine
mounts so soft that the while drivetrain moves an inch when you shift
quickly.

> The engines are better, the BMW kicked the VR6's butt, It's 
> smoother, quieter, and has more HP and Torque and to top it off it got 
> better gas mileage!!

I disagree with you about the engines -- based on driving both, I prefer
the VR6.  Not to mention that the BMW costs 30% more than that Passat,
and is a far smaller car.

>>> The VR6 has ABSOLUTELY NO TORQUE.

>> as in 0 foot pounds?  :)

> Not quite but close, I think it has only 130/lbs ft

Oh yes, now we see how well informed you really are.  Here are some
comparative figures:

Car		Engine		hp @ rpm	torque @ rpm
---------------------------------------------------------------
Audi A4		2.8L 12V V6	172 @ 5500	184 @ 3000
Chrysler Cirrus	2.5L 24V V6	164 @ 5900	163 @ 4350
Ford Contour	2.5L 24V V6	170 @ 6250	165 @ 4250
Honda Accord	2.7L 24V V6	170 @ 5600	165 @ 4500
Mazda 626	2.5L 24V V6	170 @ 6250	165 @ 4250
Toyota Camry	3.0L 24V V6	188 @ 5200	203 @ 4400
VW Passat	2.8L 12V VR6	172 @ 5800	177 @ 4200

The VR6 certainly has nothing to be ashamed of, not even in the company
of all these 24V sixes.  The variable manifold in the Audi engine helps
a lot -- but that's available aftermarket for the VR6 as well, and is
in no way inherent to the engine design.

>> and comparing the 318 to passat is totally dumb.  what kind of weight
>> differences are we talking about here?  

> 0 lbs..................

The 318i weighs over 3000 lbs?  Talk about bloat...

>>> But give me a 2.226 I5 for the Passat, the A4.  Heck, you 
>>> (eliot, I think) talk about wanting the VR6 for any car under 3000lb.  
>>> Get a clue - that's perfect territory for the ole I5. 

The I5?  In its 20V guise, it was not a bad engine, but it was certainly
lacking in comparison to either the Audi V6 or the VW VR6.  When I was
shopping for the Passat, I extensively test drove several 90 quattros
with this engine -- and going from that car to the Passat was like night
and day in terms of drivetrain.  A lack of low end torque in the 20V,
combined with excessively soft engine mounts (to reduce NVH) made it
poorly suited for sprited driving in my opinion.

In its original 10V form, it was certainly nothing to write home about
by modern standards.  It'll lose out in horsepower and torque to the
upcoming VR5 as well -- don't know yet how the VR5 NVH will be.

Now, the 20V turbo is a whole different ballgame ...

> I dunno with hyd engine mounts the I5 does pretty good.... The one thing 
> that your not taking into account though is that the power potential of 
> the Audi I5 is Outragious.....  400hp from 2.2L, that's 181hp/liter in a 
> dailly driver no less, try that in that fragile thin walled VR6 and your 
> going to get meltdown.

Sheesh -- I have to love your grammar and coherence.  Not to mention your
logic of discussing racing engines in the same breath as those dreaded
hydraulic engine mounts.

> BTW It is a "Double Single Overhead Cam" There is One cam Per Cylinder
> Head, making it a SOHC.

There are two cams on that single VR6 cylinder head.  And who cares about
what it says on the cam cover anyway?  VW doesn't attempt to sell is as
a "DOHC" engine in any case.

> All of this information is from a Informed opinion, One that is Informed 
> enough that auto makers Hire me to help them figure out how to present 
> their cars to the public while minimizing it's drawbacks.  

Sure, sure.  Should we all get on our hands and knees and praise your
superior intellect now?


Tom Haapanen,

1995 VW Golf GTI 2.0L		Founder, info-vw mailing list, 1986
1993 VW Passat VR6		Founder, quattro mailing list, 1990
1974 Porsche 914 2.0L		Moderator, rec.autos.sport.info, 1994-

-- 
[ /tom haapanen -- tomh@metrics.com -- software metrics inc -- waterloo, ont ]
[ "but it does move!"                                     -- galileo galilei ]