Re: 89 200tq question

[Igor Kessel <e6941tb@ix.netcom.com>]

Ctwskf@aol.com wrote:

> What is the Si turbo hose ?

It's a reinforced (braided) intercooler to throttle body *accordeon* hose, made 
out of silicon impregnated rubber. $115 from TAP.
If you chip your car I garantee you'll be going thru an OEM replacement hose 
($64) once a year. Let alone the inconvenience of having to tow a dead car. (If 
you don't have one of my most favorite tools in the trunk - a roll of industrial 
quality duct tape:-).
 
> And regarding the adjustable wastegate from 5000/200turbo FWD - since my audi
> is the 200TQ FWD..

I take it as a typo. 200TQ can't be FWD. Perhaps you have a 200T FWD?

> so do i still need the adj. wastegate ?? How can i tell if
> i have the adj wastegate ?

Take the top of the WG off the car (six 8mm nuts). In the centre of the WG there 
is a white metal disc (~10mm dia). Drill it thru (just the disk, it's about 1mm 
thick. Take the disk out with a screw extractor. Take a look in the hole, do you 
see a hex recess for a 6mm Allen wrench? If yes - it's adjustable from the 
outside. You can regulate the length and preload of the WG spring.

If you don't see the hex recess, look inside the WG. Do you see the said hex 
recess in the head of the bolt, that holds the cylindrical piece inside the WG?
If yes - you're out of luck, your WG is not adjustable. Get the one from an 
automatic 5000/200. Actually, just the top portion will do. I got mine from a 
junk yard, courtesy of my friend and a fellow lister Mike Z.
 
> Also how can i tell if I have the K26 turbo ?

By your VIN number: K26 were installed installed thru vin#_44_K_038262. After 
that - a smaller K24 unit.
 
> Regarding  TAP. they said that I have to pull out the car's chip (?) for them
> to program or  swap chip..I not sure.. Was that how you have yours done ?

The OEM chip, that you have in your car, is permanently soldered in the main 
board in your MAC-11 brain. They need to desolder the OEM chip and solder in a 
ZIF (Zero Insertion Force) socket for the replacement EPROM.
How handy are you with a soldering pencil and a solder wick? You_have_to_be very 
comfortable or you'll be risking the PCB tracks. If you have even a shadow of a 
doubt, DON'T do it, just UPS the whole brain to TAP. I am an EE and have state 
of the art temperature-controlled soldering/desoldering and reflow workstations 
in my lab for both thru-hole and surface mounted componentry, but even I once in 
a while screw-up and lift a track or peel a pad.
 
> Since my highest boost is now at 1.2 to 1.3 bar or 17.6 to 19.6 psi ( eg
> 1.2x14.7=17.6), your warning of 18 to 19 psi with new boost did not  make
> sense here ?  I thought with the new chip, I should get higher than 1.3 bar.

Well, not exactly. 1 bar roughly equals 1 atmosphere (1 atm = 1.01325 bar).
Your car's computer displays not the boost but absolute pressure. Therefore, at 
idle it shows 0.4 bar (less than 1 atm at sea level, i.e. partial vacuum).
Boost is a condition when a forced induction pressure exceeds that of the 
atmospheric, i.e. your max boost is only 0.3bar or ~5 psi. That's exactly what 
my analogue boost gauge showed before the mods.
After the mods the boost goes to 18psi or 1.22bar. Plus 1 bar atmospheric = 
2.22 bar total if only the computer were able to display it.
The thing is, TAP solders a Zener diod + ballast resistor in order to fool the 
computer into thinking that the boost level is not being exceeded as to avoid 
the overboost cut-out. All TAP modified cars erroneously show 1.2bar at max 
boost, that's why you_need an analogue boost gauge. Mine is from JC Whitney, was 
like 15bux, coveres from -30" Hg to +25psi of boost and is better than either of 
VDO gauges on the market (one goes from -15psi to +15psi - too narrow a range, 
the other one goes from 0 to +30psi - lacks negative scale).
 
> >From what you said, even after TAP sold me the new chip.. I have to some
> adjustment ..where do one make the adjustment ??

Racetrack ;-)
You want to limit your boost to about 17-18psi on a cold day, when running under 
full enrichment (open loop). I.e. when running in 4th or in 5th under WOT (Wide 
Open Throttle), you'll be watching the needle of your analogue boost gauge 
creeping up the boost scale. Keep backing off the adjustment screw in the WG 
until you get the boost saturation at about 17psi.
I have also built a fuel-to-air ratio meter with 10 red LED's for lean, 10 green 
LED's for normal and 10 blue LED's for rich condition. This gauge is 
indispensible under track condition. You_REALLY_ want to keep an eye on the 
mixture and avoid overleaning it under high boost. Otherwise you'll be risking 
detonation and take a chance to burn your pistons and valves.
 
> Hope I haven't ask you too many questions ? Appreciate your advice.

Never a case, ask away as much as you like, that's what the Q-list is about.
Take care.

-- 
Igor Kessel
'89 200TQ - 18psi (TAP)
'98 A4TQ - on order
Philadelphia, PA
USA