[s-cars] More dyno results

[Elijahallen92 at aol.com]

Dave,
 Very nice #'s and intersting info. What RPM are you getting full  boost? 
Also, what resonators are you using? Are they straight through?  Can't wait to 
see what that thing will do in the 1/4 mile. Looking forward to  seeing the 
results with the 928 MAF as well. As for the cam, any chance you can  do a before 
and after using the 7A exhaust and intake cams? Alot of guys use  both 7A cams 
on there S2's in the UK over the RS2 exhaust cam. I have the  7A exhaust cam 
and am thinking about doing the intake cam as well but am curious  to its 
gains over extra lag.

Elijah
 
 
 
In a message dated 7/5/2005 8:52:04 PM Eastern Standard Time,  
Djdawson2 at aol.com writes:

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
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