[s-cars] More dyno results

[Djdawson2 at aol.com]

For those who aren't sick of seeing my dyno posts  ;-)...
 
This past Saturday, I was able to do a little more time at the dyno.   As of 
my last dyno post, the car was making 418/445 at the wheels, (like it or  not) 
SAE corrected.
 
Since that post, a few things have been done.
 
First, the turbine housing on the GT30R was changed from a .82 to a .63 A/R  
unit.  This was aimed at providing a quicker "hit" (which it does), but  
should result in a lower peak hp.
 
Second, an additional resonator was added to the exhaust system to  eliminate 
the drone... again, should result in a reduced peak number.
 
Third, I decided to try a very cheap FMIC.  I purchased a bar and  plate IC 
on ebay that cost $229.  It has a 22" x 8" x 3.5" core, and has  cast aluminum 
end tanks with 2.5" inlet and outlet already built in, and in the  correct 
location.  I also bought a box of 6 2.5" polished aluminum 90  degree elbows that 
each had one long leg.  This was $79.99.  Other  than that, the "kit" 
required 2 2.5" silicon 45 degree elbows, a 2 - 2.5"  silicon transition, and one 4" 
section of straight 2.5" silicon hose... about  $60 for that stuff.
 
The FMIC was surprisingly easy to put together... took about 6 hours of  
work.  I did the welding myself, but that could have been eliminated by  simply 
using silicon connectors.  The whole thing cost under $400, but the  labor was 
"free."
 
Off to the dyno...
I did 3 pulls, and all were remarkably similar, indicating that the IC was  
performing very well.  Previously, I would see large losses between pulls  with 
the stock IC.
 
The numbers were 442/430, and only varied by 1 hp, or 1 ft/lb between  runs.  
In fact, the third one was the highest reading.
 
Other interesting notes... The hp figures no longer looked like  peaks.  In 
fact, the curve would cross the 420hp line, and remain there  until 7500rpm, 
where I would end the run.  The "area under the curve" was a  huge improvement 
compared to prior runs.  These things all seemed to  indicate that el cheapo 
FMIC was performing great.
 
Bad news... I lost 15 ft/lbs of torque, even though the curve as a whole  
looks better.  Lastly, don't ask me for a copy of the dyno chart, as I  don't 
have any yet.  The guys at MAC Autosport lost the files, and all I  have are the 
printouts, which I'll try and make available soon to those who may  want them.
 
3 last things to try include a 928 MAF, and RS2 exhaust cam, and a return  to 
the .82 A/R turbine housing.  The .63 does hit a little earlier, but  
compressor surge is a problem in higher gears/low rpm.
 
I'm thinking that I should be able to get this engine into the 470-480  range 
when all is said and done.  After that, I'll drag it out to sea level  for 
some dyno runs, as well as some real quarter mile runs to provide data  that 
some feel is more valid than the SAE corrected data.
 
That's it for now.
Take care,
Dave