Jim C 2.8 dyno results (repost from Z3 message board)

["Michael J. Greto" <mjgreto@xxxxxxxxxxxx>]

Someone with a Z3 2.8 posted the following to the Z3 message board after
upgrading to Jim C. software.  I think the Dinan intake is hurting and not
helping as I know people are getting much better results than this with
stock intake and exhaust. Also based on these tests it seems he has gotten
~30HP from the intake and exhaust, I know that is pure BS.  Any other
comments?


>Well, I just returned from the dyno. My car is a 98 2.8 manual with the
>Dinan intake, Supersprint exhaust without the crimp and now with the new
>Jim C ECU. The run was made on a 248C dynojet using 92 octane fuel and a
>temp of app 20 degrees F. Here are my best numbers pre and post.
>PRE - 188.1hp at 5250rpms and 197 ft lbs at 4350 rpms.
>POST - 190.2 hp at 5250rpms and 200.6 ft lbs at 4000 rpms.
 A total gain of only 2.1 hp and 3.6 ftlbs of torque.
Assuming 15% drivetrain losses 223.8 hp and 236 ftlbs. I don't understand
the poor showing post ECU other than the fact that modifications are never
cumilative and that I was able to gain most of the easy hp with the exhaust
and intake. I have never trusted hp numbers with ECU upgrades in non turbo
cars, and this only strengthens my doubts. How much more hp can you get by
maximizing for 3-5 octane points anyways? If anyone can post some personal
dyno numbers pre and post ECU, maybe then I'll be a believer. I also expect
that the other ECU's (Autothority, Dinan, etc) will fair just as well on the
dyno.
Would I do it again, maybe... but I'm a hp freak anyways. My butt dyno did
notice a slight improvement.

To add to the discussion here are the numbers of my best pre and post runs.

TORQUE HP
RPM pre post gain pre post gain
1600 152.3 156.7 +4.4 47.0 48.4 +1.4
1700 152.3 159.5 +5.2 50.9 52.4 +1.5
1800 160.9 162.4 +1.5 56.1 56.6 +0.5
1900 167.4 168.9 +2.5 61.4 62.1 +0.7
2000 167.4 172.4 +5.0 64.7 66.7 +2.0
2100 168.1 174.6 +6.5 68.3 71.0 +1.7
2200 171.7 178.3 +6.5 73.0 75.8 +2.8
2300 172.5 179.0 +6.5 76.8 79.7 +2.9
2400 168.1 175.3 +7.2 78.0 81.4 +3.4
2500 168.1 175.3 +7.2 81.4 84.8 +3.4
2600 171.7 177.5 +5.8 86.3 89.2 +2.9
2700 171.0 176.8 +5.8 89.4 92.3 +2.9
2800 171.0 176.8 +5.8 92.6 95.6 +3.0
2900 173.9 177.5 +3.6 97.7 99.8 +2.1
3000 176.8 180.4 +3.6 102.8 104.6 +1.8
3100 180.4 183.3 +2.9 108.0 110.0 +2.0
3200 183.3 186.9 +3.6 113.3 115.6 +2.3
3300 188.3 192.7 +4.4 120.3 122.8 +2.5
3400 189.8 194.1 +4.3 125.1 127.8 +2.7
3500 189.8 194.1 +4.3 128.4 131.4 +3.0
3600 189.1 194.1 +5.0 131.6 135.3 +3.7
3700 190.5 195.5 +5.0 136.5 140.2 +3.7
3800 193.4 198.4 +5.0 142.4 145.7 +3.3
3900 194.8 199.9 +5.1 147.1 150.7 +3.6
4000 195.6 200.6 +5.0 151.5 155.2 +3.7
4100 194.1 199.2 +5.1 154.1 157.8 +3.7
4200 191.9 197.8 +5.9 156.0 161.0 +5.0
4300 196.3 199.9 +3.6 163.1 166.4 +3.3
4400 195.6 199.9 +4.3 166.4 170.0 +3.6
4500 194.9 197.8 +2.9 169.7 172.1 +2.4
4600 194.2 196.2 +2.0 172.6 174.5 +1.9
4700 192.7 194.8 +1.5 175.2 177.3 +2.1
4800 192.7 193.4 +0.7 178.7 179.8 +1.1
4900 190.5 192.7 +2.2 180.3 182.7 +2.4
5000 189.8 191.3 +1.5 183.4 185.4 +2.0
5100 189.1 190.5 +1.4 186.9 187.9 +1.0
5200 186.2 187.6 +1.4 187.4 189.1 +1.7
5300 182.6 184.7 +2.1 187.4 189.7 +2.3
5400 178.2 180.4 +2.2 186.4 188.5 +2.1
5500 173.2 174.6 +1.4 184.2 185.9 +1.7
5600 164.5 169.6 +5.1 178.6 184.1 +5.5
5700 160.9 163.1 +2.2 177.3 180.2 +2.9
5800 154.4 157.3 +2.9 173.5 176.2 +2.7
5900 147.2 152.3 +5.1 167.7 173.7 +6.0
6000 145.7 150.1 +4.4 169.6 173.9 +4.3

As you see, at no point did the post curve dip under the pre curve and also
that the most notable gains were up to about 4400 rpms. ( also the worthless
gains above 5500 rpms ).

>Waiting for the comments.

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