'88 5kcstq mods

Ken Keith auditude@neta.com
Mon, 19 Mar 2001 12:28:10 -0700

Fun stuff.  This weekend, I replaced my pass. window regulator, 
installed a boost gauge, strapped my IC, replaced my ecu with a 
TAP chipped one, and replaced the WG spring with a TAP one.

The car is now much quicker under boost.  The gauge seems to 
read around 12 psi, usually overshooting it by one psi when it 

I think when I first drove it, I was getting more like 14 psi.  I don't 
know why it is different now.  Maybe I have a leak now somewhere, 
or it took a while to settle in(?).  Am I seeing the boost I should be. 
 When it kicks in, it kicks in pretty good.  It's requires a bit of a 
different driving style.  Are there any resources describing 
techniques for driving a turbo car (clutch slippage, rev range, part-
throttle shifting w/o a bypass valve, etc)?

I wonder how much more quickly the boost would build if I put in a 
pressure valve/manual boost controller, that would keep any boost 
pressure from reaching the WG controller until it reached a specific 
pressure.  This is like one of the two valves used in the 
autospeed.com MBC they put on an ur-S4.  This is not a bleeder, 
nor does the specific valve I'm talking about affect how much boost 
is produced, only how quickly.

I want to put in the stock bypass valve that I bought.  I got a plastic 
fitting and some cement from the hardware store.  It idea is to glue 
it through a hole in the right IC end cap from the inside like Peter (I 
think it was) did.  The plastic fitting I bought was the gray plastic 
type.  "80" was the type or series of plastic, as opposed to "40" or 
something which was used to describe the white pvc.  Does 
anyone know if I've got the best plastic for this type of application?  
I didn't find any of the black plastic in the right diameter.  Would 
this be better to use?

I think for the return for the bypass valve, I'd like to just take out the 
metal intake pipe, and find some radiator shop or someplace to 
weld a 1" metal fitting onto it.  I'll have to do some trial fitting to 
mark the spot for the hole/fitting.

I mounted my boost gauge in the center of the dash where the 
switches are ('88 5kcstq), on the left of the switches.  This required 
removing metal, which justified the purchase of a Dremel.  I was 
quite surprised to find that the exposed dashboard area was metal!  
I thought it was plastic.  I got it to fit there very nicely.

The gauge is an autometer, the silver style.  It looks really good 
with the red bulb sock to make it match the rest of the dash 
lighting, somewhat.

I'll get some pics up later, after I get some pc things squared away.

Thanks for all the help with where to tap into the pressure signal for 
the gauge, and the carbon canister valve thing...

Oh yeah, my carbon canister valve is currently not really 
connected.  I plugged the intake boot hole, and am awaiting the 
arrival of the used replacement valve.  No noticeable difference w/o 
it, and it's nice to be able to drive.

Hey, btw, does a free flow exhaust help spool up?  I'm thinking the 
turbo can spin freely until the intake pressure gets to a certain 
point, then the impeller has to stop or slow down until the pressure 
can go somewhere?  I'm trying to ask if a free flow exhaust 
specifically helps spool up as opposed to max boost or power 
output.  Thanks.



'88 5kcstq, eurolights, TAP stage I, strapped IC, mechanical boost 
gauge, bypass valve soon

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