Dyno Results assistance
Thread Starter
Pro
Joined: Sep 2004
Posts: 500
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From: Philadelphia PA
Dyno Results assistance
Here are some dyno results of my 388 stroker built this year.
I am asking for your 2cents/comments, as I wasnt impressed with the HP. And while torque is high, it starts off at 2750 and goes down from there (and I have a 3500 stall).
Thanks
I am asking for your 2cents/comments, as I wasnt impressed with the HP. And while torque is high, it starts off at 2750 and goes down from there (and I have a 3500 stall).
Thanks
Last edited by Highhat; Dec 11, 2005 at 01:51 AM.
Thread Starter
Pro
Joined: Sep 2004
Posts: 500
Likes: 1
From: Philadelphia PA
Yes, Mustang Chassis Dyno
Motor specs:
388 stroker 10.25cr
Sportsman II heads, 2.055/1.625 valves; ported
Victor Jr, intake tall, plus 1in supersucker spacer
Holley HP 750
Comp Cam XS290 solid tappet (252/260 @ .050; 290/298 gross)
Hooker comp headers
3.7 rear; TH400 3500 stall
Motor specs:
388 stroker 10.25cr
Sportsman II heads, 2.055/1.625 valves; ported
Victor Jr, intake tall, plus 1in supersucker spacer
Holley HP 750
Comp Cam XS290 solid tappet (252/260 @ .050; 290/298 gross)
Hooker comp headers
3.7 rear; TH400 3500 stall
Last edited by Highhat; Dec 11, 2005 at 02:05 AM.
Racer
Joined: Oct 2005
Posts: 343
Likes: 0
From: Rye TX
Doesn't look like you are getting any use of your torque past your launch, though your 60' time is excellent. Looks like it is hooking up good. Your HP curve is a liitle flat. Are you shifting at 5750? The 1/8th and 1/4 times seems a little out of sync. Other than that, good numbers.
Le Mans Master
Joined: Sep 2000
Posts: 9,078
Likes: 7
From: DFW TX
Cruise-In VII Veteran
St. Jude Donor '07
Need engine specs. First thing I see is it ran out of cam.
I would ingore the timeslip. The car would have to weight 2500 to run a 11 second quarter with less than 300 rwhp.
I would ingore the timeslip. The car would have to weight 2500 to run a 11 second quarter with less than 300 rwhp.
Thread Starter
Pro
Joined: Sep 2004
Posts: 500
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From: Philadelphia PA
Quirky thing is, as far as ET's are concerned, I've run an 11.7 at 119. That's why the HPs here dont add up.
Originally Posted by Budman78
Need engine specs. First thing I see is it ran out of cam.
I would ingore the timeslip. The car would have to weight 2500 to run a 11 second quarter with less than 300 rwhp.
I would ingore the timeslip. The car would have to weight 2500 to run a 11 second quarter with less than 300 rwhp.
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Thread Starter
Pro
Joined: Sep 2004
Posts: 500
Likes: 1
From: Philadelphia PA
I shifted at 6700
Originally Posted by AlCherry
Doesn't look like you are getting any use of your torque past your launch, though your 60' time is excellent. Looks like it is hooking up good. Your HP curve is a liitle flat. Are you shifting at 5750? The 1/8th and 1/4 times seems a little out of sync. Other than that, good numbers.
Advanced
Joined: May 2005
Posts: 82
Likes: 0
From: London Ontario
I read a post somewhere about how the dyno tends to understate the HP and torque ratings when there is a big stall converter, because the dyno doesnt provide enough resistance for it to work properly. Does anyone know anything about that? I dont know if its true or not.
Race Director
Joined: Jan 2003
Posts: 15,176
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From: State of Confusion
Originally Posted by Highhat
..... I've run an 11.7 at 119.....
I bet you surprise those C5/C6-guys!!!!!
I'd think with more converter, gear, and rear-tire, the stated 11-forty E.T. might be possible, based-on your 119-MPH trap-speed.
Race Director
Joined: Apr 2000
Posts: 17,676
Likes: 201
From: Who says "Nothing is impossible" ? I've been doing nothing for years.
Originally Posted by Highhat
Yes, Mustang Chassis Dyno
Motor specs:
388 stroker 10.25cr
Sportsman II heads, 2.055/1.625 valves; ported
Victor Jr, intake tall, plus 1in supersucker spacer
Holley HP 750
Comp Cam XS290 solid tappet (252/260 @ .050; 290/298 gross)
Hooker comp headers
3.7 rear; TH400 3500 stall
Motor specs:
388 stroker 10.25cr
Sportsman II heads, 2.055/1.625 valves; ported
Victor Jr, intake tall, plus 1in supersucker spacer
Holley HP 750
Comp Cam XS290 solid tappet (252/260 @ .050; 290/298 gross)
Hooker comp headers
3.7 rear; TH400 3500 stall
That does not mean the HP would be higher than the 451, the torque would come down alot and the HP should come up.
Somthing is wrong here, plugging up that motor, what mufflers do you have ?
Thread Starter
Pro
Joined: Sep 2004
Posts: 500
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From: Philadelphia PA
1 3/4 Hooker SuperComp headers, 2.5 exhaust thru 2 chamber Flowmasters
Originally Posted by MotorHead
With that cam I would expect the HP to be slightly higher than the torque,
That does not mean the HP would be higher than the 451, the torque would come down alot and the HP should come up.
Somthing is wrong here, plugging up that motor, what mufflers do you have ?
That does not mean the HP would be higher than the 451, the torque would come down alot and the HP should come up.
Somthing is wrong here, plugging up that motor, what mufflers do you have ?
Safety Car
Joined: Oct 2004
Posts: 3,926
Likes: 739
From: Youngstown Ohio
Highhat, your dyno info may seem off because of your 3500 rpm converter.....torque converters multiply launch TQ by approx. 2.5 times or so (depending on converter) and this happens at stall speed or flash stall on the dyno. Then it gradually drops as RPM increases. Though these are true TQ readings, this is not necessarily what your engine numbers would be on an engine dyno as far as correct RPM for max TQ....(it would be at a higher RPM, perhaps 4200 or so). This phenomenon happened to me when I changed from a 2200 rpm to a 3000 rpm (4000 flash stall) converter. This changed my peak rpm readings from 4600 rpm to 3200 rpm (same motor, same rear gear). The dyno loads your car differently than actual road driving (though I heard Mustang dynos come close). It's like going slightly uphill, adding even more stall to the converter! Take note of your car in "real world" driving, and compare differences you make in components or tuning. I use the dyno as a tuning aid to measuring small changes (new carb or intake evaluation, etc.).......also, use the same dyno each time, for accurate comparisons. All are not calibrated the same. 
Team Owner
Joined: Apr 1999
Posts: 21,953
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
I'd say the dyno operator didn't understand a few things. Like why if you shift a 6700 did he shut down the test at 5700?
Your cam is really pretty radical. I would think that 7500 rpm wouldn't be a problem.
Your cam is really pretty radical. I would think that 7500 rpm wouldn't be a problem.
Thread Starter
Pro
Joined: Sep 2004
Posts: 500
Likes: 1
From: Philadelphia PA
While I could shift into 2nd and 3rd at 6700, it leveled off at 5700 in 3rd.
Originally Posted by gkull
I'd say the dyno operator didn't understand a few things. Like why if you shift a 6700 did he shut down the test at 5700?
Your cam is really pretty radical. I would think that 7500 rpm wouldn't be a problem.
Your cam is really pretty radical. I would think that 7500 rpm wouldn't be a problem.
Race Director
Joined: Dec 1999
Posts: 11,096
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From: Sierra Foothills CA
Originally Posted by Highhat
While I could shift into 2nd and 3rd at 6700, it leveled off at 5700 in 3rd.
Pro
Joined: Aug 2005
Posts: 704
Likes: 2
From: Cincinnati OH
I hate Mustang dyno's. #1 if you are execting what your friends got or others tell you they got on a Dynojet you'll be disappointed: 15% lower on Mustang just due to the type it is. #2 the way Mustang works, using torque not rotational inertia, may have an impact on numbers in conjuncction with your high stall. Someone chime in on #2 that knows what they're tlaking about. I just write this $hit 
Safety Car
Joined: Oct 2004
Posts: 3,926
Likes: 739
From: Youngstown Ohio
Originally Posted by TheMongoose
I hate Mustang dyno's. #1 if you are execting what your friends got or others tell you they got on a Dynojet you'll be disappointed: 15% lower on Mustang just due to the type it is. #2 the way Mustang works, using torque not rotational inertia, may have an impact on numbers in conjuncction with your high stall. Someone chime in on #2 that knows what they're tlaking about. I just write this $hit
.....I don't like Mustang dynos.......
