I5 thread

[stilian elnkov <elenkovs@mail.vtls.com>]

I am fairly new to the list. In fact this is my first post. I have driven
numerous VW's Audi's and BMW's both US and European versions and have to 
admit that despite the some minor drawbacks of the I5 engine it is one of
the best engines I have ever had the experience of driving and working on.
I have an 87 5ksq( NF engine), a 86 gti ( lots of mods) and my wife has a
86 5kcs 5 speed *rare*, (KZ engine with some mods). 

The KZ engine with decent exhaust and ported head easily gets about 130hp
and 135lftb torque, and while it is still less powerful than the BMW ETA
2.7 six (128hp, 170ftlb) it is smoother and has a much better sound and
with the 5 speed makes the car perform  as well as the BMW 325's (ETA) of
the same years.
Same thing can be said about the NF engine compared to the BMW 2.5 ( i
head) - 
130 vs 160 hp 150 vs 163 stock but with slight mods  the audi can perform
as well as the BMW  and again my impression is that the I5 was  smoother
than the I6 with just a bit of sluggish feel.
As I have mentioned above I have highly modified gti and cannot even think
of comparing the rough I4 to the silky smooth I5. 
Comparing any I5 (10 or 20v) to the 1.8t I found out that despite the power
advantage the 1.8 was still a rougher I4. I was considering buying an A4
1.8t/2.8 12v q a few months ago and test drove them both with 5 speed. I
was not very impressed by the power and torque of either of them although I
have to admit that the V6 was smoother than any I5 I have driven, but I
could not justify that much money just for that. I do not know about the
30v 2.8 - have not tried this one yet, but I will.  I rode in a friend of
mine's S4 (I5 20v turbo) in Europe and that the best performing car that I
have been in. Better than the old M3 with 2.3 six that I drove in Europe.
I know this is way older though.  
My point is that the I5 was a good design and when fitted with the turbo
(high boost), it can reliably deliver excellent performance. Due to its
sturdy design the engine is very rugged and tolerates pretty high boost,
and even abuse at times and retains its longevity and reliability,
something not characteristic to other engines of comparable performance.
And it is easy to work on. 
Today both Volvo and Acura use I5's (C 70 5t, TL 2.5) and both of these are
pretty darn good engines.
I drove a US Vigor with the latter engine and liked it better than the
Legend with the V6.
I want to drive the C 70 coupe 2.5t but I guess I will have to wait until
another trip to Europe.
Volvo also has some normally aspired I5's that are very good performers too. 
In conclusion despite the I5's "weirdness" they are still around and I am
really disappointed that Audi dropped them. After all they started building
them first and could have improved them ( alloy block 5valve per cylinder
head etc), rather than going after BMW's and MB's V8's.
Ah well I guess they know better. 


Stilian Elenkov