MEVI Dyno--Where O' Where Has My Peak Torque Gone?
10-19-2002, 01:42 PM
#1
MEVI Dyno--Where O' Where Has My Peak Torque Gone?
Dyno'd the MEVI today. I made 4 runs, 2 runs with an automatic ECU, and 2 with my 5spd ECU. Difference was about 2hp between the two, with the 5spd ECU being the higher of the two.
Of all my runs, 182.7 hp @ 6000RPM and 172.4TQ @ 4700 and 4800RPM. This was MEVI, JWT POP, Cattman Ypipe, and WSP test pipe.
For comparison, with just JWT POP and Cattman Y, I dynod 181.9HP @ 5500RPM and 189.4TQ @ 4800RPM. I lost 17TQ at peak.
Keep in mind these were actually done on different DynoJets, but the conditions were similar, and both sets of numbers are corrected anyhow. CF on this new set is .98. Baro was 29.38 (low) and vapor pressure was .21 inHg. Temp was 54.6F.
Basically it appears the VI has lopped off the two resonance humps that you see with the stock manifold. My MEVI tq curve is flat as a board from where the dyno started at 1800RPM to 6300RPM.
I will post the dyno files, graphs, and spread sheets later tonight or tomorrow, plus more discussion later tonight when I get home, but for now I have to go.
Of all my runs, 182.7 hp @ 6000RPM and 172.4TQ @ 4700 and 4800RPM. This was MEVI, JWT POP, Cattman Ypipe, and WSP test pipe.
For comparison, with just JWT POP and Cattman Y, I dynod 181.9HP @ 5500RPM and 189.4TQ @ 4800RPM. I lost 17TQ at peak.
Keep in mind these were actually done on different DynoJets, but the conditions were similar, and both sets of numbers are corrected anyhow. CF on this new set is .98. Baro was 29.38 (low) and vapor pressure was .21 inHg. Temp was 54.6F.
Basically it appears the VI has lopped off the two resonance humps that you see with the stock manifold. My MEVI tq curve is flat as a board from where the dyno started at 1800RPM to 6300RPM.
I will post the dyno files, graphs, and spread sheets later tonight or tomorrow, plus more discussion later tonight when I get home, but for now I have to go.
10-19-2002, 03:14 PM
#2
Dyno plot says I have the most area under the Administrator curve
Join Date: Jul 2001
Posts: 7,060
Hmm...looks like a standard engineering trade-off to me.
The OE manifold has higher resonance (more torque), but doesn't have the dynamic range to cover the entire operating range of the engine, and so it falls flat on its face after 5000rpm. But it gets the job done, and gives you LOTS of torque where most people will need it (below 5000rpm)
The MEVI on the otherhand is most likely designed differently (duh). It doesn't seem to have the peak resonance (torque) that the OE manifold has, but what it offers you is more dynamic range. You tradeoff a little of the peak torque in exchange for greater operating range/coverage. Now it will keep working beyond 5000rpm and cover the whole range, but you give up some of the torquieness.
In theory, of course...
Can't wait to see the dyno's
The OE manifold has higher resonance (more torque), but doesn't have the dynamic range to cover the entire operating range of the engine, and so it falls flat on its face after 5000rpm. But it gets the job done, and gives you LOTS of torque where most people will need it (below 5000rpm)
The MEVI on the otherhand is most likely designed differently (duh). It doesn't seem to have the peak resonance (torque) that the OE manifold has, but what it offers you is more dynamic range. You tradeoff a little of the peak torque in exchange for greater operating range/coverage. Now it will keep working beyond 5000rpm and cover the whole range, but you give up some of the torquieness.
In theory, of course...
Can't wait to see the dyno's
10-19-2002, 03:56 PM
#3
Donating Maxima.org Member
Join Date: Apr 2001
Posts: 1,085
Re: MEVI Dyno--Where O' Where Has My Peak Torque Gone?
Originally posted by Nealoc187
Dyno'd the MEVI today. I made 4 runs, 2 runs with an automatic ECU, and 2 with my 5spd ECU. Difference was about 2hp between the two, with the 5spd ECU being the higher of the two.
Of all my runs, 182.7 hp @ 6000RPM and 172.4TQ @ 4700 and 4800RPM. This was MEVI, JWT POP, Cattman Ypipe, and WSP test pipe.
For comparison, with just JWT POP and Cattman Y, I dynod 181.9HP @ 5500RPM and 189.4TQ @ 4800RPM. I lost 17TQ at peak.
Keep in mind these were actually done on different DynoJets, but the conditions were similar, and both sets of numbers are corrected anyhow. CF on this new set is .98. Baro was 29.38 (low) and vapor pressure was .21 inHg. Temp was 54.6F.
Basically it appears the VI has lopped off the two resonance humps that you see with the stock manifold. My MEVI tq curve is flat as a board from where the dyno started at 1800RPM to 6300RPM.
I will post the dyno files, graphs, and spread sheets later tonight or tomorrow, plus more discussion later tonight when I get home, but for now I have to go.
Dyno'd the MEVI today. I made 4 runs, 2 runs with an automatic ECU, and 2 with my 5spd ECU. Difference was about 2hp between the two, with the 5spd ECU being the higher of the two.
Of all my runs, 182.7 hp @ 6000RPM and 172.4TQ @ 4700 and 4800RPM. This was MEVI, JWT POP, Cattman Ypipe, and WSP test pipe.
For comparison, with just JWT POP and Cattman Y, I dynod 181.9HP @ 5500RPM and 189.4TQ @ 4800RPM. I lost 17TQ at peak.
Keep in mind these were actually done on different DynoJets, but the conditions were similar, and both sets of numbers are corrected anyhow. CF on this new set is .98. Baro was 29.38 (low) and vapor pressure was .21 inHg. Temp was 54.6F.
Basically it appears the VI has lopped off the two resonance humps that you see with the stock manifold. My MEVI tq curve is flat as a board from where the dyno started at 1800RPM to 6300RPM.
I will post the dyno files, graphs, and spread sheets later tonight or tomorrow, plus more discussion later tonight when I get home, but for now I have to go.
10-19-2002, 04:37 PM
#4
Not DAVEB the parts guy
Join Date: Aug 2000
Posts: 8,555
I lost my humps too 
I lost about 7fwtq (193fwtq down to 186fwtq). I'd imagine your torque curve is REALLY flat now. I know mine is. Did your power pretty much continue straight to 6500rpms. I peaked at 6000rpms (189fwhp) and only dropped to 183fwhp at 6500rpms.
I'll tell ya what though, I reinstalled my Poorman's CAI for fun last night and I swear my car feels more torquey at all rpms. I'm going to run both the hybrid and the Poorman's CAI at the track next week.
Dave
I lost about 7fwtq (193fwtq down to 186fwtq). I'd imagine your torque curve is REALLY flat now. I know mine is. Did your power pretty much continue straight to 6500rpms. I peaked at 6000rpms (189fwhp) and only dropped to 183fwhp at 6500rpms. I'll tell ya what though, I reinstalled my Poorman's CAI for fun last night and I swear my car feels more torquey at all rpms. I'm going to run both the hybrid and the Poorman's CAI at the track next week.
Dave
10-19-2002, 11:56 PM
#5
Senior Member
Join Date: Aug 2000
Posts: 2,807
This almost proves it. MEVI reduces the torque of the VQ. I'm going to say that a MEVI'd VQ will have the same shape torque curve of a VE with the same mods till 5800rpm+. However I bet if Neal gets a B-pipe he'd probably gain around 5-8wtq back in the midrange.
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