[Supras] Thanks for all the valuable "Awesome" info_information

[berniek at technicaldevelop.com]

Good evening from a Supra owner with smiles from ear to ear.  I'd like 
to thank all of the many individuals who contributed to understanding of 
newness, suggestions and elements of danger to watch out for. 

A number of items were learned in rapid order, hopefully of use to 
others on the list, or hopefully useful to me if anyone has had the same 
experience. 


1.  The car runs wonderfully, up to just short of 6K RPM, just like the 
stocker did but with a LOT more push back in the seat.  No point in 
using full throttle in first gear unless I want to spend $$$ on 
275-40-17 tires every six months.  Wheels are late MKIV items with 17X9 
rears.  Only 275-40-17 tires will fit with any reasonable height in the 
rear. 


2.  Summary of mods are as follows:  550cc Greddy injectors, modified 
stock FPR presently set to 38 PSI (reading with no vacuum on spring 
side), 57 trim turbo, Walbro pump, drilled out J tube, free flowing AEM 
air filter (more about that later).  Lex AFM, Dawes ball and spring 
boost controller (little overshoot, more about that later), 57 trim 
turbo, Random Technology 3" downpipe and cat, Lipp elbow, HKS 80 MM 
exhaust (LET-T-16).  Lex stock screw set about 75% in.  Car is not a 
Targa, so is about 150 lb lighter than my '90 is.  Engine is a refreshed 
JDM with light honing, new rings, Cometic 2.2 mm gasket (head was decked 
twice due to a stupid mishap), ARP studs torqued to 85-90 lb-ft.


3.  Boost is set to 15 PSI, checked with a decent gauge piped into the 
cabin instead of the electronic transducer.  I also hastily built a 
resistive voltage divider to make the stock gauge read about 14 PSI at 
full scale (limit of the stock transducer).  Just got a Sensym el-cheapo 
pressure transducer from Digi-Key with 30 PSIG maximum calibration.  
Need to build a perf-board in-box transducer from it, and map out the 
stock gauge voltage vs. reading.


4.  I did read that the Dawes ball-spring boost controller does not 
spike, understandable in view of the damping of the stock dash gauge.  
However, some spiking to about 17 - 18 PSI is evident with a real 
pressure gauge if the nominal setting is 15 PSI.  This appears 
acceptable if it is never any more than that. 


5.  Still need to check Vf to see correction from O2 sensor trim, but I 
think I'm well within the acceptable range.  Car runs very evenly like 
stock until you press the loud pedal about 3000 RPM.  Pulls beautifully 
to near 6000, but starts to slack off at about 5700, probably due to use 
of stock cams, or possibly transient leanness or richness.  Am presently 
installing a Dawes rich-end LED indicator operated from the stock O2 
sensor to make sure I'm rich enough.  Just installed and pulled wiring 
tonight but need to do final connection.  Also have water injection to 
install using a RV potable water pump.  Someone had listed a McMaster 
Carr spray nozzle for that application.  Making that information 
available again would be appreciated. 


6.  By luck, my local Advance store had an AEM 21-203D dry filter 
element which fit the 3" round (slippery) rubber adapter on front of the 
Lex AFM with almost no length to clear Adapter was meant for stock AFM, 
but was ported and intake bored out for Lex AFM).  AEM says the filter 
will flow 820 CFM with only 5"  water column pressure drop, negligible.  
Has a nice radiused inlet to the AFM adapter.  It replaced an HKS foam 
filter which looked like it sucked in everything.  The stock bracket 
which also holds the canister purge hose works well to hold the AFM 
(rotated to get to the bypass screw) if the bracket end is bent about 90 
degrees.  I wound up cutting off the thin section of the accordian hose, 
and carefully thinning the rubber in the thick section with a Dremel 
wheel to fit the Lex AFM and move it back about 1/2".  Regarding flow:  
If you run 15 PSI boost, it is equivalent to 2 atmospheres, or a 6 liter 
normally aspirated engine.  The big question is:  What is the volumetric 
efficiency?  If we assume 0.9 at something below 5500 RPM, it works out 
to about 530 CFM at that speed (because of stock cam characteristics, VF 
is probably less than 0.9).  So, the filter stated should serve as a 
conservative choice without the hassle and Karman dangers of oiling, and 
without the millimeter size foam openings in the HKS filter. 


8.  Oil pickup was moved about 3-1/2 back in pan.  I can send pix of how 
this was done if interested.  Also have lightweight chrome-moly flywheel 
with new conventional Exedy clutch. 


9.  As the car now is, there is little point to full throttle use in 
first gear.  Nonetheless I'd be interested in what will likely break 
first in suspension arms and such if I get to rambunctious. 


10:  Lastly, almost every stock 89-93 motor mount I've seen is broken, 
with only the steel stop preventing the engine from coming through the 
hood.  '98 MKIV mounts are the same size, need one bottom lug ground 
off, and are very stiff.  The vibration isolation is poor below 1500 
RPM, but who cares? 


Looking for suggestions, as always.  Hope these point help those who can 
benefit.


          BernieK