compression ratio, '88 5kcstq (motor)

[Ameer Antar]

The only way you can say one is better than the other is to run a 
side-by-side comparison on the same exact engine and setup. But the knock 
control is pretty good for MC's and better in dual-knock sensor MC's. They 
don't have individual cylinder knock control however like the J&S. The J&S 
is likely faster as well, since technology moves so fast. Compare a 12 year 
old pc to one designed a year ago. The J&S is probably much like Audi's 
'92+ cylinder-selective knock control. I think a J&S isn't for performance, 
it's for safety. It will probably take the timing out for you, but by 
reducing timing in the ecu map, the j&s won't have to take out so much 
timing, and there is a limit to how much it can take out. That's important 
if you get stuck and end up buying a tank of bad gas or whatever. The only 
thing about the j&s that sounds difficult is setting it up, mainly the 
sensitivity adjustment. I'm sure there's a good way to do it, but I don't 
think I'm that sensitive to knocking along w/ all the other engine noise...


Has anyone out there set one up on a 5k? That would be nice to hear about.


At 05:16 PM 9/12/00 -0700, Ken Keith wrote:
>If I run a J&S Safeguard, would I still need or want the code
>tweaked?
>
>Or rather a bigger question, is there any need or advantage to
>running a J&S Safeguard with a modified (okay, SJM) chip on an
>'88 5kcstq?  How about if I'm running 8.5:1 c/r?
>
>Is the stock knock sensing ignition any comparison to the J&S,
>which is supposed to be really fast, and cylinder-specific.
>
>Thanks,
>
>Ken
>
>Todd Phenneger <tquattroguy at yahoo.com> wrote:
> >
> > Heya,
> >
> >   I'm running 8.8:1 at 9psi with no problems.  I will run more but
> > not till I get an IC in there.  On hot days it will ping at any
> > thing over 9psi.  Pulls GREAT down low and really helps turbo
> > spool up.
> >
> >   I think you should be fine.  If you want just tell Scott and he
> > can (probably, I dont want to speak for him) tweak the code a tad
> > bit so the timing isnt quite so advanced but I think you should be
> > fine at 12psi.
> >
> > l8r
> >
> >   TOdd
> >
> >
> >
> >
> >   Ken Keith <auditude at neta.com> wrote:
> > What would the repercussions be if I were to put a 2.5 liter bottom
> > end in my MC motor, with a compression ration of 8.5:1?
> >
> > Would I have to make any other modifications to compensate for it,
> > to keep it from blowing up or something?
> >
> > The way the car would be setup, ideally, would be with a SJM chip
> > and spring, free flow exhaust (3" straight pipe after the cat?), and
> > Bosch bypass valve.
> >
> > Would I need any custom code for the chip?
> >
> > Thanks,
> >
> > Ken
> > _______________________________________________
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> > Todd Phenneger
> >     83' ur-q (awaiting a 20vt)
> >     84' 4ktq  fun but I'm sick of CIS.
> >
> >
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>
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