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Dyno Results "Interesting"


Guest Greg Ross
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Guest Greg Ross

Mission accomplished;<BR>Run No. 1 <BR>Max Torque 192.2 @ 2850-2950 rpm<BR>MAX Power 136.3 @ 5200 rpm<P>Run No. 2 <BR>Max Torque 189.0 @ 2900 rpm<BR>MAX Power 131.0 @ ? rpm lost signal<P>Run No. 3 <BR>Max Torque 179.8 @ 3200 rpm<BR>MAX Power 137.1 @ 5050 rpm<BR>Notes;<BR>Runs' 1 & 2 baseline<BR>Run 3 Airbox open and took a data Snap shot during this final run;<BR>ED01 4.22<BR>ED06 19.8<BR>ED 08 26 DEG.<BR>ED11 5220 RPM<BR>ED12 80 MPH<BR>ED17 271 (corrrected value)<BR>ED19 128<BR>ED20 128<BR>ED21 155.2<BR>ED22 156<BR>ED23 39 DEG.<BR>Far easier I know to view the chart and make some judgements. I'll get it scanned the first of the week.<BR>Run's 1 and 3 run bang on, line on line, the only discernable difference being peak torque/ rpm, thereafter they both converge at about 3600 rpm.<BR>What do you think of those #'s "2Seater" wink.gif" border="0<p>[ 08-18-2002: Message edited by: GM Ross ]

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Questions<BR>1) Is this engine dyno or 'tire' dyno?<BR>2) Was engine heating up or was temp constant?<BR>3) Open box with or with out air filter on runs?<BR>4) Is this the s/c engine?<BR>Comments<BR>1) I've noticed et's increase on 1/4 mile run with air filter out of the box.<BR>2) When in service mode I believe the computer goes into limp home mode. this may explain the hp drop.

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Guest Greg Ross

Don,<BR>1) Is this engine dyno or 'tire' dyno?<BR>Tire Dyno.<P>2) Was engine heating up or was temp constant?<BR>Runs were probably 10 minutes apart, no problem with overheating. Severa fans are placed at the front of the car. Run 2, he ran it up to 124 mph.<P>3) Open box with or with out air filter on runs?<BR>Air filter (K & N) was in place for the first two runs. Last run in diagnostics mode was with the airbox cover propped open.<P>4) Is this the s/c engine?<BR>This is the "Stock" 3.8/ '88 showing 213,400 miles. Motor has had 1 burned exhaust valve replaced, timing chain done 100 K ago, otherwise not rebuilt.<BR>Not sure on the "Limp Home" mode, best HP achieved on Run 3 though. Something very different occuring on this run with the open Air Box-you maybe right, bottom end wasn't there until WOT/ 3200 rpm reached and thereafter the run was identical to run 1.<BR>Chart shows runs 1 and 2 kicked off from approx. 2800 rpm making 100 hp.<BR>Run 3 at 3100 rpm was only indicating 25 hp.

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Guest Greg Ross

Carry Fwd. now the gusstimates made. Looks to me like Padgett is carrying the torch right now with 90Red a close second on the "In Numbers"<BR>Greg's numbers<BR>Going in "peak" 2400rpm 130hp/ 140ft.lbs.<BR>Coming out " 3600 " 185 "/ 195 " "<P>EDBB's <BR>His guess was;<BR>Going in "peak" 2400rpm 122hp/ 132ft.lbs.<BR>Coming out " 3800 " 192 "/ 201 " with CAI and K&N 9" cone<BR>New series I results 170 / 190 at pavement and think I am high?<P>Padgett's <BR>Guestimate going in for chassis dyno: 125hp/200 ft-lbs/3600 peak, coming out 185 hp (50% gain)/240 ft-lbs/4800 rpm.<BR> <BR>90RedReatta<BR>Going In: Stock 135hp/150tq<BR>Goint Out: SC Series I 180hp/220tq<P>2Seater<BR>My best guess as to present hp. at the wheels would be 146, no guess on the torque. Based on 182 gross horsepower less 20% drivetrain loss.

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Interesting. at 5200 rpm hp and torgue are almost equal so you have about 140 lb-ft at 5000. Am surprised that opening the airbox lowered the peak for hp. Only other thing I see is the highest yet recored MAF (155), someone was surprised I saw 141 earlier.<P>ED17 of 27 does not make sense, please check. Assume ED16 was zero ?<P>Other than that numbers are close to normal though would have expected considerably more advance at 5k rpm, need to look at the tables.<P>Only other thing is that 150 on the IAC, would have expected it to be about closed but shouldn't make much difference.

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Guest Greg Ross

Padgett,<BR>Hung in the passenger Window to capture and record the Snap Shot values, from my scribble notes it's much more likely to have been "271", not 27 deg.??? <BR>I may have been too conservative on my set-up of the MSD Magic Box, I have the rev limiter set at 5500 so perhaps the retard curve is starting to drag down ED08.<BR>Based on the Chart, torque and hp curves converged at about 5200-5250 and the torque value was actually closer to 145 ft/lbs at 5000. Did you calculate the 140?<BR>The Techie used a value of 15% for loss through the tranny that would yield a peak of about 157 hp at the crankshaft.<BR>We're a long long way from being classed as "High Performance" though, the gent who drove the test sequences told me as I was retrieving the Snap Shot values that his LT1 draws 392 gm/sec-MAF. wink.gif" border="0

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Guest Greg Ross

FTM (forgot to mention)<BR>J. Sellers will no doubt deem this to be "an-out-of-body-experience" but standing beside one's car at 124 mph, phew! awesome exhaust note off the system I have on "Betsy Blue" wink.gif" border="0

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Really just eyeballing: hp=torque*rpm/5252 so at 5200 they are real close to each other.<P>Torque must have really dropped off over 5000 on run #3, if had stayed flat, would have been over 140 hp at 5200. Even 5,000 is considerably higher than I would have expected it to peak. (K&N + no cat I suppose, wonder if any difference with stock filter)

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Well, I'm glad you posted them and frankly I'm impressed. Great torgue which has always been a Buick forte. The only reading I'm curious about is the O2 volts (ED07). I guessed high and I actually thought about forgetting to deduct for the hp. eaten by the water pump, power steering, and alternator. Oh well, no loss, we have real numbers. I am curious if the engine is running "fat", high O2? At 5200 rpm, static fuel injector pulse width would be about 23 ms. Your fuel delivery should support 196 hp. Does anyone know the rated flow of our injectors. My estimate was based on 19#/hr. The air flow is really spectacular. If there is a 170 gm/sec. limit on the ability to read air flow, you aren't too far off even with a tired engine. The timing does seem 8-10 degrees below what I would expect but I wonder if the computer is pulling timing due to knock counts, or perhaps there really is the rumored torque control GM uses to save the transaxle. It looks like you would be right at the shift point for the 2-3 shift. Thanks again for the results.

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Guest Greg Ross

Hal,<BR>The O2 reading was .72 in that Snap Shot take. <BR>My suspicion was the MSD rev limit of 5500 I had set may be a progressive retard function, or torque control as you point out.<BR>Car is working really well, the carbon blowout was a bonus!<BR>Started some work on the Series I today, got the Long Block on a stand, TP Manifold disassembled for cleaning. Suprised to find an inner divider piece (removable) that forms the runners. Pretty cruddy from the EGR! frown.gif" border="0

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That O2 volts is pretty good. Mine runs way fat, usually in the high .8 to a little over .9 so I am losing some performance. Something more to look at I guess.<P>Unfortunately all the crud inside the intake isn't from the EGR, it's from the intake valve sitting open when the engine is shut off too. The vapors cool and deposit on the walls of the intake, although I would think a plastic one would be better. No fuel through the manifold to clean the worst of it off.<P>I am still trying to find out the flow rating of our injectors. If they are small 16# injectors (big bummer), your fuel flow would be about 166.4 hp. This would be a gross number, which does not take any losses into account. The other weak link is what the BSFC (base specific fuel consumption) numbers are for our engine. I have been using a basic number of 1/2 lb per horsepower per hour, but this is just a crude fomula for figuring approximate fuel needs, and I think our engine is more efficient than that. Again, thanks for the results.

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