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Am I OVER-GEARED
#1028447
07/08/11 05:34 PM
07/08/11 05:34 PM
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Joined: Oct 2004
Posts: 513
HOUSTON,TEXAS
FIREGUY12
OP
mopar
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OP
mopar
Joined: Oct 2004
Posts: 513
HOUSTON,TEXAS
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Here is the scoop trying to decide which way to go on the next gear. Here is the current combo 3000 lbs. 71 duster 454 ci small block mopar powerglide 1.80 first gear 8 inch converter 5300 stall 4.56 Rear gear 14x32 tire with a 105 roll out 1050 dominator crosses at 6500 Rpm H.P. according to dyno sheet 633 h.p. at a low 5700 rpm 650 ft. lbs torque @ 4600 rpm Shift ay 6500 rpm Ran 1.41 60 ft 4.11 330ft 6.41 1/8 th 8.40 1000ft 10.11 1/4 131.43 mph Since I broke the case on the glide thinking about changing the 1.80 gear set to a 2.08 or 2.11 while its down in hopes of picking up the 60 ft. This engine is difficult to run due to its unusual power band. Any suggestion moparts. Is this a good move or should I go up on the rear end gear? http://www.youtube.com/watch?v=QQZQsoXCpvA
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Re: Am I OVER-GEARED
[Re: FIREGUY12]
#1028451
07/08/11 05:57 PM
07/08/11 05:57 PM
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Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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Your a couple hundred RPM over what max should be... as a rule of thumb you want to cross the line 10% over peak HP RPM... which in your case would be 6300 or so... big torque engines can use less than 10% so it can pull harder 
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Re: Am I OVER-GEARED
[Re: MR_P_BODY]
#1028453
07/08/11 06:00 PM
07/08/11 06:00 PM
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Joined: Apr 2005
Posts: 2,128
Salt Lake City
camastomcat
top fuel
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top fuel
Joined: Apr 2005
Posts: 2,128
Salt Lake City
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Quote:
Your a couple hundred RPM over what max should be...
as a rule of thumb you want to cross the line 10%
over peak HP RPM... which in your case would be 6300
or so... big torque engines can use less than 10% so
it can pull harder
It seems wrong that it makes more tourqe than HP?
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Re: Am I OVER-GEARED
[Re: camastomcat]
#1028454
07/08/11 06:02 PM
07/08/11 06:02 PM
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Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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Quote:
Quote:
Your a couple hundred RPM over what max should be...
as a rule of thumb you want to cross the line 10%
over peak HP RPM... which in your case would be 6300
or so... big torque engines can use less than 10% so
it can pull harder
It seems wrong that it makes more tourqe than HP?
Not really
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Re: Am I OVER-GEARED
[Re: FIREGUY12]
#1028456
07/08/11 06:07 PM
07/08/11 06:07 PM
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Joined: Apr 2005
Posts: 2,128
Salt Lake City
camastomcat
top fuel
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top fuel
Joined: Apr 2005
Posts: 2,128
Salt Lake City
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Quote:
What about the 2.08 first gear versus the current 1.80. do you think that will help the 60 ft.
It might, but I think they are weaker in strength. Are they going to be straight cuts?
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Re: Am I OVER-GEARED
[Re: FIREGUY12]
#1028457
07/08/11 06:10 PM
07/08/11 06:10 PM
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Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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A 2.08 would help in the 60' IF you dont loose traction... you would gain more torque with them.... are you sure your chassis is working the best it can EDIT I think you have a bit too much stall on the conv... your well past peak torque and its falling at higher revs
Last edited by MR_P_BODY; 07/08/11 06:12 PM.
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Re: Am I OVER-GEARED
[Re: earthmover]
#1028462
07/08/11 10:09 PM
07/08/11 10:09 PM
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Joined: Dec 2009
Posts: 20,640
in a cattle trailer down by th...
Guitar Jones
Paddle faster! I hear banjo music!
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Paddle faster! I hear banjo music!
Joined: Dec 2009
Posts: 20,640
in a cattle trailer down by th...
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Quote:
you know what mr.p said makes alot of since to me ...about the verta to big....i had a 340 with a small solid cam and ported heads and i changed everything i could think of to make the car 60' even the verta but i went to a smaller verta(8") from a 9.5 5000 the 8" was a 5600 car didnt lose any but didnt gain a thing....now that i think about it if i would have put maybe a 4000/4500 or even a 3800 car may have been alot better then it was...something to think on...sorry for the hi jack just had to share my ex. mike 
Wow, 650 at 4600? You have way too much converter. I'd use about a 4400 with a 1.76/1.80 glide. You don't need more 1st gear, you have the torque to pull that 1.80 gear, you just need to get the engine in that powerband.
You could probably use less gear in the rear as well. With that torque I wouldn't be surprised if it ran the same shifting at 6000.
I should add that I use a 4200 converter. Before with the 340 I was using a 4600 but I have a low gear 904 so I'm sure that helps make up for any lack of stall speed.
Last edited by Guitar Jones; 07/08/11 10:17 PM.
"Follow me the wise man said, but he walked behind"
'92 D250 Club Cab CTD, 47RH conversion, pump tweaks, injectors, rear disc and hydroboost conversion.
'74 W200 Crew Cab 360, NV4500, D44, D60 and NP205 divorced transfer case. Rear disc and hydroboost coming soon!
2019 1500 Long Horn Crew Cab 4WD, 5.7 Hemi.
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Re: Am I OVER-GEARED
[Re: Guitar Jones]
#1028463
07/08/11 10:44 PM
07/08/11 10:44 PM
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Joined: Feb 2005
Posts: 20,173
PA.
pittsburghracer
"Little"John
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"Little"John
Joined: Feb 2005
Posts: 20,173
PA.
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Why did the tranny case break. I've gone 8.50's with stock powerglide cases and others have gone a lot faster than that. How's the pinion angle.
1970 Duster
Edelbrock headed 408
5.984@112.52
422 Indy headed small block
5.982@112.56 mph
9.42@138.27
Livin and lovin life one day at a time
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Re: Am I OVER-GEARED
[Re: FIREGUY12]
#1028465
07/09/11 12:23 AM
07/09/11 12:23 AM
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Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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Quote:
In a back half car the cars tend to twist even thou you may not see it. I run a front engine plate and a mid plate. The tranny is bolted down to the trans crossmember. So when the chaasis flexes the weakess point break. On a poweglide the stock cases are weak. I have the JW bell housing and tail shaft. Glides tend to crack right above the shifter arm as mine did. I should have not bolted the tail housing down and the tranny could have move with the chassis and not broke. I will upgrade to an aftermarket case to fix this problem.
Are you using a solid trans mount with a front and
mid plate.... use a stock rubber trans mount
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Re: Am I OVER-GEARED
[Re: pittsburghracer]
#1028467
07/09/11 03:06 AM
07/09/11 03:06 AM
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Joined: Jan 2003
Posts: 4,448
Phoenix, AZ
MoparBilly
master
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master
Joined: Jan 2003
Posts: 4,448
Phoenix, AZ
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The car will respond favorably to less gar ratio, as it will sit on the convertor longer. I'd try 4.10's.
"Livin' in a powder keg and givin' off sparks"
4 Street cars, 5 Race engines
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Re: Am I OVER-GEARED
[Re: MoparBilly]
#1028468
07/09/11 10:29 AM
07/09/11 10:29 AM
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Joined: Jan 2003
Posts: 9,996
Frostbitefalls MN (Rocky&Bullw...
gregsdart
master
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master
Joined: Jan 2003
Posts: 9,996
Frostbitefalls MN (Rocky&Bullw...
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 I believe in LOOSE converters, and I don't think yours is too loose. Epecially with a glide. If the motor is still pulling good hp at 6500 rpm, leave the gear. The place I would start would be less tire weight, same roll out, or less roll out with 4.30 or 4.10 gears. You haven't said if your 60 fts are consistant. Are you able to run several within .01? Until you get there, it is going to be tuff to improve the combo. The current 1.41 60 ft isn't far off the mark if at all, depending on rollout. What is the class that you run?
8..603 156 mph best, 2905 lbs 549, indy 572-13, alky
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Re: Am I OVER-GEARED
[Re: FIREGUY12]
#1028469
07/09/11 10:50 AM
07/09/11 10:50 AM
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Joined: Jan 2003
Posts: 9,996
Frostbitefalls MN (Rocky&Bullw...
gregsdart
master
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master
Joined: Jan 2003
Posts: 9,996
Frostbitefalls MN (Rocky&Bullw...
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Quote:
In a back half car the cars tend to twist even thou you may not see it. I run a front engine plate and a mid plate. The tranny is bolted down to the trans crossmember. So when the chaasis flexes the weakess point break. On a poweglide the stock cases are weak. I have the JW bell housing and tail shaft. Glides tend to crack right above the shifter arm as mine did. I should have not bolted the tail housing down and the tranny could have move with the chassis and not broke. I will upgrade to an aftermarket case to fix this problem.
If you have solid motor plates, do not mount the glide solid. The stock cases live behind much more power than you are currently putting out.
You have to provide room for the chassis flex. If you choose to support it, use some form of mount that has some give in it. Old shock biscuits work well. I put one on either side of the tailshaft mounting point so it can move a little up or down. You may want to go two on each side, with only a back half car. I have an extremely stiff chassis, don't need much. I use a total of four biscuits, with two mounting bolts in my custom mount. You might want to double that, to give the extra flex room and still give the tranny some support.
Looks like there is some room for improvement with some rear shock adjustments. Try hitting the tire a little harder before adding ballast. How loose is the front? Best place to start is as loose as you can get it, with as much front travel as is available, then reduce both a little at a time till you are happy with it.
8..603 156 mph best, 2905 lbs 549, indy 572-13, alky
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Re: Am I OVER-GEARED
[Re: gregsdart]
#1028470
07/09/11 12:29 PM
07/09/11 12:29 PM
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Joined: Dec 2009
Posts: 20,640
in a cattle trailer down by th...
Guitar Jones
Paddle faster! I hear banjo music!
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Paddle faster! I hear banjo music!
Joined: Dec 2009
Posts: 20,640
in a cattle trailer down by th...
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Quote:
I believe in LOOSE converters, and I don't think yours is too loose. Epecially with a glide.
To me a loose converter in his case seems counter productive. Why would you want to launch the car on the downward part of the torque curve? Seems to me you would want to take advantage of that torque on the launch to get the car moving then use the horsepower on the top end.
"Follow me the wise man said, but he walked behind"
'92 D250 Club Cab CTD, 47RH conversion, pump tweaks, injectors, rear disc and hydroboost conversion.
'74 W200 Crew Cab 360, NV4500, D44, D60 and NP205 divorced transfer case. Rear disc and hydroboost coming soon!
2019 1500 Long Horn Crew Cab 4WD, 5.7 Hemi.
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Re: Am I OVER-GEARED
[Re: Guitar Jones]
#1028472
07/09/11 01:10 PM
07/09/11 01:10 PM
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Joined: Jan 2003
Posts: 684
St. Charles, MO.
Slingshot383
mopar
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mopar
Joined: Jan 2003
Posts: 684
St. Charles, MO.
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It's time to update your cam, and get one matched to your combination. Get some 12" X 33" slicks and leave everything else alone. Too much tire to drag around.
1994 Undercover Chassis 125" altered
stack injected big block, soon blown and injected
Member of The Torque and Recoil Club
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