RE: K24 finally installed in 1986 5000cstq

[Eric_R_Kissell@email.whirlpool.com]

On 11-18-99  "Kaklikian, Gary" Gary.Kaklikian@Compaq.com wrote: >
>We just put the K24 from my 4000 on my '86 5000, which is stock except for 
>TAP chip, wg spring, and bypass valve. I agree - what a great improvement in 
>low-end, midrange, smoothness, throttle response, etc! Seems like a new car! 
>Conversely, the K26 works MUCH better on my 4000 (dual knock sensor 
>high-compression motor) than the K24 did.

My engineering nature wants to understand why there is a difference in 
bahavior for the k24 vs. k26 turbos with the MC-1 vs. MC-2 engines.

The lower compression ratio, single knock sensor (MC-1) benefits from 
quicker spool up using the k24 in place of the k26. I have not 
experienced any downside from using a k24 in my 5000cstq (MC-1) at 1.8 
bar maximum boost.

What performance characteristics improve when using the k26 in place of the 
k24 in the dual knock sensor, high-compression motor (MC-2)?

Does the higher compression ratio of the MC-2 produce hotter exhaust gasses 
that possess more energy to spool up the k26 sooner than the MC-1 can?

What does the boost vs. rpm data look like for the various engine/turbo 
combinations?

I do not yet have an aftermarket boost gauge, so all of my boost readings 
are from the dash readout. I still need more/better data, but as a first 
pass my MC-1/k24 gives the following:

1.3 bar 1800 rpm
1.5 bar 2000 rpm
1.8 bar shy of 3000 rpm

What is the heat soak issue I heard about with the k24? Is this only a problem 
when racing? Is it only a problem when running really high boost (>2 bar)? Why 
does it affect the k24 but not the k26? Should I expect to experience any 
problems during spririted street driving using a k24 at 1.8 bar max. with my 
5000cstq?

Anyway, the k24 appears to work nicely in my 5000cstq.

Eric R. Kissell
1986 5000cstq, 1.8 bar, k24