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RE: Turbo questions - K24, WG Spring etc.
Try this first. I've done many mods to my turbos over the years using
imagination and generic hardware store type parts. The only thing you'll
lose by shimming the mc spring and not liking it is your time. If you
don't like it, try the k24 (although, the boost curve wil be very
different). Try all your inexpensive options first. If you don't like the
results than the expensive one is the one to go with.
****************************************************************************
*Steve Sachelle Babbar
*'87 5000CS Turbo 5spd 1.3-2.0 bar <SBABBAR@IRIS.NYIT.EDU>
*Cockpit adjustable wastegate, AudiSport badge
*
*Disclaimer:"Any information contained herein is based purely on my own
*personal experience and may not necessarily reflect yours. Use caution as
*your results may vary from mine."
********************************************************************************
On Mon, 22 Nov 1999, Swann, Benjamin R. (BSWANN) wrote:
> So I could get boost to occur at lower RPM by shimming the existing wastgate
> spring?
>
> This sounds like an inexpensive mod. worth doing. Any caveats,
> BTDT/procedures from the list. Parts specifics from Home Depot or other?
> If I could get boost to come on at a lower RPM - great!
>
> Why get the K24 turbo then ?
>
> Thanks for the replies.
>
> Ben
> correction - '85 4KQ - (not turbo) $1200 or will donate soon for tax
> writeoff.
> '86 5KCSQT
> '87 5KCSQT Wagon
>
>
> -----Original Message-----
> From: Sachelle Babbar [mailto:sbabbar@iris.nyit.edu]
> Sent: Monday, November 22, 1999 3:21 PM
> To: Swann, Benjamin R. (BSWANN)
> Cc: 'quattro@audifans.com'
> Subject: Re: Turbo questions - K24, WG Spring etc.
>
>
> I have just used a kh spring in my mc. Not compatable, but I made the
> necessary parts swaps for it.
>
> The wg spring is what gives you the boost. The wastegate valve opens
> gradually as boost rises, not at it's limit. Consequently, you will have
> turbine (hot side) bypass fairly early. Not necessarily good for turbo
> lag. A stiffer spring ie: progressive may be light in the intial travel,
> allowing for the wg valve to open early, but a limited distance. Further
> boost (as rpm rises) will develop as the spring goes into its
> progressively higher rate.
>
> Power is not necessarily how much there is, it's how you get it; it's
> speed of onset and location. Maybe that's why you see so many cars with
> less power accelerating faster than more powerful cars. Flat torque curves
> in 3B and 20v turbo 1.8's help quite a bit.
>
> The power and toque curve is altered.
>
> I have a valve tee'd off from the lower line of the wg to the upper to
> raise boost. This effectively gives a stiffer spring asnd will change the
> curve of boost.
>
> The kh spring that I've installed has a more linear action than the mc.
> The mc is very soft in the beginning, reducing low end boost due to early
> exhaust bypass of the turbocharger turbine. With my wg controller, it just
> stayed closed a really bad power curve;shot up too damn fast. Was unusable
> and could not develop more than 1.4 bar in first gear because the engine
> rpm shot up so fast. The Kh spring allows for more torque and a
> m=noticably more usable, flat power curve. I'll correct myself and say
> that the engine doesn't develop more torque (as I've seen), but is more
> torquey and feels much faster. The power is more controllable while
> driving at high boost levels (where they may vary).
>
> On the highway, I no longer need to drop a gear to get around turbo lag or
> open the wg controller for 2.0 bar. The low end is dramatically improved
> and midrange is excellent.
>
> Believe it or not, the traction during acceleration (hard) is much
> improved. This is from rest and at speed.
>
> I would suggest for mc owners who don't like this characteristic to simply
> shim the wg spring and post the results. I'd do it myself, but am too lazy
> and busy to go back to the old spring and back to the new one.
>
> On the larger dia kh spring, I used this bronze colored split rings from
> home depot. They're like snap rings that you need the special needlenose
> tool for. The inside circumference is perfectly round as the extra
> material for the holes are around the outer circumference. They have a
> loose fit in the perch and are maybe .25 mm in thickness. On my old kh, To
> go from 1.48 bar-1.68, I needed seven. 3 bottom, 4 top. Find the
> appropriate size for the mc spring.
>
>
> ****************************************************************************
> *Steve Sachelle Babbar
> *'87 5000CS Turbo 5spd 1.3-2.0 bar <SBABBAR@IRIS.NYIT.EDU>
> *Cockpit adjustable wastegate, AudiSport badge
> *
> *Disclaimer:"Any information contained herein is based purely on my own
> *personal experience and may not necessarily reflect yours. Use caution as
> *your results may vary from mine."
> ****************************************************************************
> ****
>
>
>
>
>
> On Mon, 22 Nov 1999, Swann, Benjamin R. (BSWANN) wrote:
>
> >
> > I guess I still have much to learn about forced air induction.
> >
> > With regard to the comments in previous posts about K24 turbo and various
> > wastegate spring, I could probably use some re-education to straighten out
> > my understanding.
> >
> > I can understand how the K24 turbo can create more boost at low end. It
> is
> > one of the upgrades I would consider for my '87 5KQT wagon, to help get
> more
> > low end torque. Currently, the boost doesn't kick in until higher revs,
> and
> > then it is almost too much, 'cause I'm shifting by the time it kicks in.
> > Car is great on the highway though - will hit triple digits easily.
> >
> > BTW I have the car set to get about 1.9 bar through a pressure regulator.
> I
> > almost never drive the car that way , however, some test runs got over
> > 2.0(22 PSI) until I backed off because I was blowing the end caps of my
> IC,
> > and I didn't think it would be good to do more than this on a stock
> engine.
> >
> > How then does the wastgate spring contribute to low end boost. I thought
> > the wastegate was strictly to control overboost conditions, and has no
> > bearing as to when boost starts to kick in. But comments in the posts
> > indicate one can change a spring and get more boost at low rpms.
> >
> > What am I missing here. Is there a low cost way to get my current turbo
> > (stock = K26?) to spool up faster?
> >
> > Appreciate comments/dissertation to further my understanding to make
> > enlightened decisions on how to obtain better performance, esp. on the low
> > end. Hope I'm not starting any turbo wars here.
> >
> > I eventually would like to be able to use the wagon for towing a moderate
> > load compfortably. I feel right now it would be aggravating to get stuck
> in
> > stop and go traffic at the Bay bridge towing a camper or boat. I doubt
> I'll
> > be hitting over 100 MPH frequently, but just curious, how is top end
> > affected by K24, etc?
> >
> > Comments below prompted my curiosity. I assume the KH is the KH engine?
> >
> > Regards,
> >
> > Ben Swann
> >
> > '85 4KQT - For sale $1200
> > '86 5KCSQT
> > '87 5KCSQT Wagon
> >
> > >The spring allows for poor bottom end.<
> >
> > >KH spring + MC engine. Wonderful match. There is more down low torque and
> > >the power is useable. Stock, a mild in crease in boost, maybe .1-.2.
> Power
> > >arrives earlier, but more progressive and incredibly controllable (I have
> > >a fwd 5 speed). It's overall a torquier feeling engine and I actually
> have
> > .what feels like power in the wg controller closed position. I've restored
> > >the adjustability in the boost increase; I haven't seen 1.7 bar since my
> > >old kh. Just goes straight from 1.5-1.9. I can execute many maneuvers
> that
> > >I haven't been able to since my kh.
> >
> > >Conversely, I feel that the lighter mc spring in the kh + the wastegate
> > >controller would be a wonderful combination due to the engine's better
> off
> > .Idle torque.
> >
> >
>
>