Step by step . . .

[JShadzi at aol.com]

--
[ Picked text/plain from multipart/alternative ]
<<ime for me to jump in...

Javad, I had no idea you were an NA man as well!!>>


Well, you gotta start somewhere =)

> <<"since I got my start massaging NA VW and Audi motors, I'm happy to pass
> on
> some info"
>
> I've been toying around with the idea of doing up an Audi 20V (7A) motor
> for my
> 90q.  I'm well aware that $/HP will be higher then if I do a turbo
> swap...but
> I've just never liked the feel of a turbo.  Working at Vibrant I've been
> able
> to drive more then my fair share of them too ;-)
>
> What do you think of the 20V platform?  Better to go with a 10v or the 20v?
>  I
> already have the NG in my '89 90q...so I could play with that...but thought
> a
> 20V might be interesting.  Not to mention allow a little more tuning with
> adjustable cam gears etc.>>

Well, for what its worth, there is no comparison between turbo and NA tuning
for the I5, 10 or 20valve, that said, and if you want a reasonable (IOW
pretty slow car), you can stretch the NA envelope to reasonable hp levels
without a huge budget.

As in VW I4 watercooled tuning, a stroked and tuned 2v motor is a formidable
even for the 4v motor to compare too.  The amount of torque in the 2v motor,
and when its available, almost always means that the 2v motor will pull
harder and be more driveable than the less torquey 4v motor.

IME, the I5 is similar, a ported, cammed and free flowing 10v is a really
nice, torquey motor capale of getting very close to the 20v output but with
more useable torque below 4krpm.  Other problem with the 7A is the management
system which is very difficult to tune and doesn't like big increases in air
flow or fueling demands, unlike the CIS systems which don't even mind quite
aggressive turbocharging when it comes to fueling...but of course, speed
density, programmable EFI makes both motors much better anyway.

> <<My thoughts would be to buy a 20v, strip it and do a 'stage 4' upgrade on
> it
> before dropping it in the car.
>
> Basic plans would be to do the following...regardless of 10V or 20V:
>
> Intake - Filter, full port and polish.  Might as well polish the TB while
> I'm
> there...not that I expect it to do anything.
>
> Valves - Should I play with size, or just do a proper valve seat?>>

No need to play with 20v valve sizes, but definitley do the 40mm intake  in
the 10v.  Also, machining 1.5mm out of the ID of each valve seat will do
wonders for the flow here too.

> <<Bore/Stroke - I have no ideas here...still need to read up on the effects
> of
> changing it...any thoughts?>>

NO need to change unless displacement considerations are being persued.

> <<Pistons - Wiesco...just because I think I have a contact there.  What
> about
> rods?>>


Both stock rods and pistons are fine, no need to change unless you want
bigger.

> <<Cams - 272 on the 10v, not sure about the 20v at this point.  Might go
> with
> something even more extreme...and ignore the 'lumpy' or 'eight-stroking'
> idle.>>

In both cases 272 or so is about as high as you can go with hyd. lifters,
Shrick makes a cam set for the 20v ($1k or so, yikes!), but increases are
relatively small.

> <<Adjustable cam gears, just to see if I can 'tweak' the powerband a little
> bit.
>
> Exhaust - Custom exhaust header (I think I can handle that ;-) as well as
> full
> cat back exhaust (already done I might add).>>

The 1990 has a beautiful equal length header stock

> <<My thoughts are to start with the above and see what sort of gains are
> pulled.
> The goal being to increase the power and torque but on a much more linear
> curve
> vs. a turbo application.  I'd probably move (after ensuring the darned
> thing
> runs) over to a 034efi or Megasquirt set-up...just to have a little bit
> more
> room to play with.>>

Yes, this will open up some possibilities, IOW an airfilter on your TB, no
MAF or intake plumbing.

> HTH,
> Javad