turbo sizes - was "kkk vs. garrett'

[Mihnea Cotet]

Javad,

That's not totally false, a very bad chip as the ones
being sold on Ebay provide with a very quick overboost
"spike" to 1.9 Bar relative pressure but as the
pressure drops very quickly afterwards to 0.8 Barg,
this makes the turbo accelerate and decelerate very
quickly and this deceleration kills its thrust
bearings, BTBrokeThat on my own previous K24. Now if
the chip is properly done and there is an appropriate
MAP sensor in the ECU, it's possible to have an
overboost to pretty high pressures but to have boost
pressure drop slower, thus not putting so much strain
on the turbo as with the "crappy" chips.

I've tested this in a friend's UrS4 who wanted to use
a WG spring that you could barely compress 5mm with
both your hands (I mean it was stiff as a suspension
spring :-) ) just for the fun of it, so I did him a
chipset with which he could reach almost any pressure
if the spring was stiff enough during overboost, then
pressure would drop to programmed values. The result?
1.9 Bar relative (2.9 absolute) at 2000 RPM, same
pressure for 10 seconds in 4th through 6th gears, then
it would drop to approximately 1.6 Bar until 5000 RPM
and then 1.25 Bar at 6000 and 1 Bar at 7000. We don't
have any actual figures but the engine response was
instantaneous (and I used to think a K24 with a stock
spring didn't have lag, yeah right, it has!) and
torque was massive to the point that the clutch would
slip even in 2nd and 3rd gears if we floored the car
around 3000 RPM.

I know such experiences are stupid with a K24 because
they reduce reliability of the turbo but my friend
tested this for 5 days and the turbo is still fine
now, 3 months after whereas the ebay chips destroyed
the turbo in my friend's 3B-ed 90q20v and mine (3B as
well) in 1 day and about 5 hard accelerations.
Anyway, don't try this at home unless you know how to
reprogram a boost chip for such springs (I do) because
otherwise kaboom might be the final word (and I don't
even speak about fuel and ignition settings here).

Just my 0.02,

Mihnea

--- JShadzi at aol.com wrote:
> --
> [ Picked text/plain from multipart/alternative ]
> Hmm, maybe I should keep my mouth shut...but... that
> last bit below sounds
> like a BS at worst, marketing hype at best...
>
> Javad
>
> In a message dated 3/5/2003 7:59:40 PM Pacific
> Standard Time,
> conner at cfm.Ohio-State.edu writes:
>
> > >Oh! and one other thing regarding how tough the
> turbos are:
> > >I can supply a pair of chips that will blow up
> your stock turbo in 3
> > seconds
> > >or less.  You'll have way over 300 hp for those
> seconds though.
> > >
> > >Ned
> > >http://www.IntendedAcceleration.com
> >
>
>
>
>


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