Miata Mailing List: November 1997, Message #1233
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From: 	Chris King <clking@mindspring.com>

Subject: Turbo First Impressions

Date: 	Mon, 10 Nov 1997 14:40:18 +0000



I posted this to the Miatapower list late last week, and meant to post

it here as well, but I spaced it - sorry if if the bulk of this is a

repeat for some of you.



++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Bill Cardell put my used Cartech (Warner-Ishi-based turbo kit, very

similar to BEGI System III w/big IC), his ECU, injectors, and kevlar

clutch into my 93.  Beacause the clutch is still breaking in, it's set

at only 7 PSI of boost.  Once I get a few miles on it, I'll dial it up

to 12 PSI or so.  I drove it to Bill's in Palisade, CO (nice country,

BTW), and flew home for the week.  Picked it up last weekend and drove

back to SF.



Impressions after a week:



Sweet.  It doesn't have the on/off switch boost response that a

supercharger does, but @7 PSI, this setup makes a lot more power than my

Sebring did (duh) top-end pull is MUCH stronger - the 80-120mph thing

takes no time at all, and the ECU adds some low-end to make up for it. 

The boost is very smooth, sort of swells up behind you and pushes.  Then

you look down at the speedo, and realize that while speed limits in the

large square states are generous, you are WELL beyond them.  I'm

expecting a 5 PSI boost bump to make this more of a...uhh, problem.  I

will do the large downpipe (the only piece I'm missing from the FM

ensemble) at the end of the year, which should make the turbo spool up

even faster.



Noises:  I think I like the supercharger soundtrack better, but the

giant sucking sound the turbo makes is pretty cool.  My bypass valve is

the smaller variety Corky shipped with the Cartech, and makes a

'chuckle' instead of the 'whoosh' that takes some getting used to (might

change that out later).



ECU - VERY COOL.  You can tune without getting your hands dirty -

including lock out a big chunk of RPMs so valet types can't do burnouts

in your ride.  Still have a bit of fine tuning to do on the cold idle to

make it perfect, but it now passes the wife test (wife can borrow the

car for a day without incident).  With the ECU, off-boost response and

torque are excellent (much stronger than the FPR arrangement that my 92

w/Sebring had).



The whole feel of the car is changed - it has become unbalanced - it's a

blast in a straight line, but there's too much power for the stock

suspension and brakes (my Sebring car didn't have this problem.....hmmm

;-).  Time for more upgrades...I'm considering starting a 12 step for

Miata upgrade addiction, but I'm having trouble getting beyond admitting

that I have a problem ;-)



Bill has done a great job on the install and support, and was very

accomodating when it came to the logistics of getting out there and

back.  Plus, I got a ride in his car....surely a candidate for the

ultimate Miata.



Question for BEGI/Cartech owners - do your heat shields rattle at

certain rpms?  Mine does at high (6k-7k) revs and occaisionally after

lifting the throttle.  Is there anything I can do about it?



All in all, very happy with the setup.



+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Addendum:  Corky Bell made a suggestion to fix the resonance/rattle with

the heatshield (put a bolt through the lower wing of the shield to

change it's mass) that I'll be trying shortly.



I adjusted the wastegate on Saturday.  Went too high (14 PSI), then too

low (10-11 PSI).  Still trying to get it perfect (12 PSI).  Testing has

been difficult due to the high speeds/rate of acceleration involved!



Balancing the car - got some swaybars coming.  The need was even more

apparent this weekend on the guardrail-free twisties of Marin County.



Chris King

Black 93 C+

San Francisco