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> Tale of the dyno, It's SuperTrapp over Magna Flow
drew365
post Jul 25 2003, 03:58 PM
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I dyno'd my car today. We did three pulls and the end results are SuperTrapps with 15 disks gave the most h.p., Magna Flow's were second and SuperTrapps with no disks was the weakest combo. Here's the numbers:

SuperTrapps w/ 15 disks: 196.5 h.p. @ 6600rpm
Torque 165.4 @ 5200rpm

Magna Flows: 188.6 h.p. @ 6450 rpm
Torque 165.8 @ 5200 rpm

SuperTrapps w/ no disks: 186.8 h.p. @ 6600 rpm
Torque 162.7 @ 5250 rpm

Air fuel ratio was about 14.7:1 with the SuperTrapps. Is this too lean? I screwed up and forgot to put some racing gas in the tank before I left the house so all the results are using 91 pump fuel.
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seanery
post Jul 25 2003, 04:07 PM
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you have a 2.7, right? any mods? headers?
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Brad Roberts
post Jul 25 2003, 04:09 PM
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Why did the MagnaFlow pulls stop at 6450 instead of 6600 like the other two pulls ??


B
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drew365
post Jul 25 2003, 04:30 PM
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The engine is a twin plug, electromotive crankfire ignition, 11.5:1 Mahle pistons, S cam, stainless steel headers w/o heater crap.
We ran all the dyno's to 7k. The rpm that I posted is where the h.p. peaked. It stayed pretty level from peak to 7k.
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garyh
post Jul 25 2003, 04:47 PM
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QUOTE(drew365 @ Jul 25 2003, 01:58 PM)
Air fuel ratio was about 14.7:1 with the SuperTrapps. Is this too lean?

14.7 is minimum emissions.
13.2 is maximum power
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Jeroen
post Jul 25 2003, 05:21 PM
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The max torque is pretty high up in the rpm range. How's the torque curve?
Can you post the graphs from the dyno?

cheers,

Jeroen
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drew365
post Jul 25 2003, 05:47 PM
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I'll try to scan the graphs and post them over the weekend. I'll have to request time on my wifes scanner. The torque bottoms at about 139 @ 4600 rpm and climbs to 165 @ 5250 rpm and then starts to slowly drop off.
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TimT
post Jul 25 2003, 07:13 PM
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flat torque curve is cool.... you would prefer a rising torque curve, but you dont want a torque curve that peaks then falls to zero.... (IMG:style_emoticons/default/beer.gif)
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ChrisReale
post Jul 25 2003, 10:08 PM
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QUOTE(drew365 @ Jul 25 2003, 04:47 PM)
. The torque bottoms at about 139 @ 4600 rpm

Poor you! (IMG:style_emoticons/default/laugh.gif)

Just kidding. How loud is the Supertrapp with fifteen disks?
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Qarl
post Jul 25 2003, 10:10 PM
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Schweet dude... and that's rear wheel horsepower too.... (IMG:style_emoticons/default/boldblue.gif)

Wonder what the power is at the flywheel? Woohoo!
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Joe Bob
post Jul 25 2003, 10:37 PM
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Interesting,,,,,I always thought I had less oomph all around with no discs....thought I was going or getting MORE bonkers.... (IMG:style_emoticons/default/blink.gif)
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Jeroen
post Jul 26 2003, 04:42 AM
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QUOTE(mikez @ Jul 26 2003, 06:37 AM)
Interesting,,,,,I always thought I had less oomph all around with no discs....thought I was going or getting MORE bonkers.... (IMG:style_emoticons/default/blink.gif)

Mikey, that does make sense... compared to a stock setup
Lack of backpressure will cause a drop in torque in the lower rpm range (which is where you experience the "oomph")

cheers,

Jeroen
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drew365
post Jul 26 2003, 08:47 AM
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I recounted the SuperTrapp disks now that they are off the car and there are 18. The sound in the upper rpm range is nice but it is much quieter than the Magna Flows are. On the street the Magna Flows set off alarms constantly, good cheap thrill.
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Joe Bob
post Jul 26 2003, 09:38 AM
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The guy that built my 3.6 conversion claimed an extra 8 hp w/o discs on the dyno. Iwas unable to feel any diff when running un corked. That's why I made that comment.

There is LOUD and too fucking loud......I would rather hear my shifts than have to wear earplugs on the track and watch the tach ALL the time.... (IMG:style_emoticons/default/unsure.gif)
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drew365
post Jul 26 2003, 05:15 PM
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I'll see if I scanned the graphs right so they can be posted. The first is SuperTrapps with the recounted 18 disks. The guy printed a test run and the first run together so that's why there's double lines. The air / fuel ratio didn't pickup on this one through the disks.


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drew365
post Jul 26 2003, 05:17 PM
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What do you know, it worked. The second is SuperTrapps with no disks.


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drew365
post Jul 26 2003, 05:18 PM
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Third pull was with the Magna Flow mufflers.


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drew365
post Jul 28 2003, 06:05 PM
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Can someone tell me by looking at the second and third graphs what my air / fuel ratio is? I don't know if it's the peak which appears to be about 14.7:1 or an average. Just trying to figure out if my carbs could be dialed in better. Thanks.
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TimT
post Jul 28 2003, 06:47 PM
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Those graphs look pretty good.

what rpm and gear were you doing the pulls from?

looks like things get rich around 4000rpm then hover around stoi from 400+

too rich at 4000 then safe at 5000+

you could use a touch smaller main jet, and a different emulsion tube.

This is a case were I wouldnt use a 125 instead of a 130 main jet, I would ream a 125 till i got the power that is available.

(dont know if your using 130's its just an example)
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drew365
post Jul 28 2003, 07:14 PM
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Thanks for the advice Tim; all the pulls were done in 3rd gear except the original test run was in 2nd. A weber guru set up the carbs so I could run the Virginia City Hillclimb last year and they haven't been changed since. I believe he set them pretty lean since the hillclimb is at 8,000ft. I'm not sure what size main's he put in but I seem to remember 150's being mentioned.
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