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Author
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Topic: Just noticed something....
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65_289
Gearhead Posts: 192
From:
Registered: Jul 2001
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posted 10-03-2001 11:46 AM
   
Look at my dyno sheet. The hp seems to level off at around 5200 rpm. Shouldn't it climb all the way to the peak and then go back down?  ------------------
1965 Coupe, Tremec 3550, Steeda Tri-Ax, Cable Clutch conversion, 3.25 gears, Ford XB3 longblock, x303 heads, B-Cam, 9:1 comp., Ford Racing high-torque starter, Pertronix Ignitor & Flamethrower coil, Accel 8.8mm wires, 650 double pumper, Edelbrock RPM intake, K&N air, Holley electric fuel pump & AFPR, dual 2-chamber Flowmasters, KYB shocks, 5-leaf springs, Chrome Export Brace, Griffen Radiator, Comp. Eng. subs. [This message has been edited by 65_289 (edited 10-03-2001).]
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n2oMike
Gearhead Posts: 341
From: Spencer, WV
Registered: Jan 2001
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posted 10-03-2001 11:56 AM
quote:
Originally posted by 65_289:
Look at my dyno sheet. The hp seems to level off at around 5200 rpm. Shouldn't it climb all the way to the peak and then go back down?
That is usually caused by a restriction somewhere... keeping the engine from breathing to its potential throughout its rev range. Your combo was levelling off around 4200-4400 rpm before, and you fixed the first "cork" with another carburetor. Guess where this one is located? UP AND AROUND THE REAR AXLE!!! 
Those pinched, kinked, p.o.s. muffler shop 2 1/4" taipipes and generic Tri-Y (why try) headers! You knew I was going to say that, didn't you?  Later...
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Mike Burch
66 mustang real street
302 4-speed 289 heads
10.63 @ 129.3
http://www.geocities.com/carbedstangs/cmml_mburch.html
http://www.fortunecity.com/silverstone/healey/367
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65_289
Gearhead Posts: 192
From:
Registered: Jul 2001
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posted 10-03-2001 12:02 PM
quote:
Originally posted by n2oMike:
That is usually caused by a restriction somewhere... keeping the engine from breathing to its potential throughout its rev range.Your combo was levelling off around 4200-4400 rpm before, and you fixed the first "cork" with another carburetor. Guess where this one is located? UP AND AROUND THE REAR AXLE!!!
Those pinched, kinked, p.o.s. muffler shop 2 1/4" taipipes and generic Tri-Y (why try) headers! You knew I was going to say that, didn't you? Later...
Somehow, when I got the e-mail saying someone had replied, and it was n2oMike, I knew exhuast was going to come up.
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1965 Coupe, Tremec 3550, Steeda Tri-Ax, Cable Clutch conversion, 3.25 gears, Ford XB3 longblock, x303 heads, B-Cam, 9:1 comp., Ford Racing high-torque starter, Pertronix Ignitor & Flamethrower coil, Accel 8.8mm wires, 650 double pumper, Edelbrock RPM intake, K&N air, Holley electric fuel pump & AFPR, dual 2-chamber Flowmasters, KYB shocks, 5-leaf springs, Chrome Export Brace, Griffen Radiator, Comp. Eng. subs.
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65_289
Gearhead Posts: 192
From:
Registered: Jul 2001
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posted 10-03-2001 12:13 PM
Could the 1" 4-hole spacer be causing a problem?
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bluestreek
Gearhead Posts: 266
From: Athens,GA
Registered: Jul 2001
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posted 10-03-2001 02:50 PM
Since your fuel curve hangs in there throughout the full rpm range and the HP doesn't really drop off , I would have to agree with Mike on the exhaust restriction.. Clutch or tire slippage can also cause this symptom on a chassis dyno but it's not likely at your torque & HP level..
Keep at it, there is more HP to gain!!
Dan
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chips67
Gearhead Posts: 272
From: louisville, ky, usa
Registered: Jul 2001
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posted 10-03-2001 06:19 PM
its weird to see a long flat hp curve and such a "peaky" torque curve. i thought that torque and hp were supposed to cross at 5200, why is his crossing so low? i am really curious about my power curves too, just havent boned up the $50 yet for the three pulls you get at the local chasis dyno here. i think its 3 pulls or 1/2 hour. dont know if i can get more than one jet change in 1/2 hour. maybe get a few timing changes though. ------------------
67 coupe, 650dp and rpm intake on 5.0 with afr 165 heads, 4 speed, 4.11's.....best so far is [email protected] in 1/8 mile with 1.79 60ft. time.
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65_289
Gearhead Posts: 192
From:
Registered: Jul 2001
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posted 10-03-2001 06:36 PM
quote:
Originally posted by chips67:
its weird to see a long flat hp curve and such a "peaky" torque curve. i thought that torque and hp were supposed to cross at 5200, why is his crossing so low? i am really curious about my power curves too, just havent boned up the $50 yet for the three pulls you get at the local chasis dyno here. i think its 3 pulls or 1/2 hour. dont know if i can get more than one jet change in 1/2 hour. maybe get a few timing changes though.
They cross low because the scales are different. Where torque is 280, the hp is oly 250. You got to mentally shift them.
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bluestreek
Gearhead Posts: 266
From: Athens,GA
Registered: Jul 2001
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posted 10-04-2001 02:49 AM
quote:
Originally posted by chips67:
its weird to see a long flat hp curve and such a "peaky" torque curve. i thought that torque and hp were supposed to cross at 5200, why is his crossing so low?
I was thinking the same thing.. The torque sure does fall off quickly!!
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unklshu
Gearhead Posts: 210
From: San Bernardino, Ca
Registered: Jul 2001
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posted 10-04-2001 09:03 AM
You now need to let that baby breath.
I think they told you before to just unhook your exaust at the collectors the next time you test and see what that does, then you can decide for yourself if you want to upgrade youre exhuast.------------------
"joe
2001 SVT Cobra
68 GT Fastback
98 F-150
90 Escort GT (smokes the tires in all 5 gears, or just smokes through all gears)"
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Moneymaker
Administrator Posts: 8870
From: Lyons, IL, USA
Registered: May 99
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posted 10-05-2001 04:12 PM
Flat is good! Spacer is not a problem. Try opening the headers and a little more jet just for kicks. ------------------
Alex Denysenko
Co-Administrator and Moderator
NHRA/IHRA/SRA member
NHRA and IHRA SS/LA National Record Holder '00 & '01
Fleet of FoMoCo products
Moneymaker Bio
US Class Nationals link
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65_289
Gearhead Posts: 192
From:
Registered: Jul 2001
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posted 10-05-2001 04:16 PM
quote:
Originally posted by Moneymaker:
Flat is good! Spacer is not a problem. Try opening the headers and a little more jet just for kicks.
I thought a flat torque curve was good, not the upper-rpm hp curve.
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