Will a gear change help a redlighting problem in my bracket car?

Everett Vassar · 06-01-2009, 02:22 PM

Dont know WTF whats so different about my car.3K lb Duster mild 440/727/456 Runs low 7,s 1/8 1.53-1.55 60ft
Yesterday dropping my launch RPM down to 1800,staging as shallow as possible.Making sure I see the bottom yellow.Still .018 red.Getting frustrating.(I was dead on with a 6 after the redlight) I cant stare at the bottom yellow all day.Thats just way to inconsistent. So heres my choces I have come up with so far to slow the little Dusters R/T,s The cheapest and most suggested fix Simply leave in 2nd gear! I dont really like this cause it will slow the cars E.T. down .
Put a taller tire on the front.I have 25" hoosiers thats the tallest that will clear the Hooker fenderwells.
Go to a powerglide to get rid of that 727 2.45 1st gear ratio.Would love to,But too expensive right now.
And my latest thought Swap the 4.56 for a 3.91 I know I am probably doing ths the wrong way but heres some simple math of adding trans first gear ratios and rear gears ratios to come up with a final number.
1. Leaving in first with 4.56 = 7.01
2. Leaving in 2nd with 4.56 = 6.01
3. Powerglide with 1.76 low gear and 4.56 = 6.32 (I think this is where I want to be)
4. Leaving in first with 727 (2.45 low gear) and 3.91 rearend = 6.36
5. Same as above with 4.30 rearend = 6.75

Notice how close #3 and #4 are. A R&P set only about 200 bucks.I might lose a little E.T but should pick up a little MPH.

So am I on the right track here?

KingReptile · 06-01-2009, 03:47 PM

Taller front tire will put you right there

Everett Vassar · 06-01-2009, 05:03 PM

Man I wished I could.This winter I bought a new set of Hooker fenderwells because I was told they could be re-done to fit a 26" tire.After I paid the guy still could only fit a 25" without beating up a couple of tubes which he refused to do.Think I would have to go to a 28" to help.They just aint gonna fit on this car

magnumv8 · 06-01-2009, 05:35 PM

A couple suggestions.....not knowing all the details.....a couple lbs. out of the front tires could give you all you need if you have the pressure up pretty high....if the front still has the stock control arms and you still have the upper rubber bump stops in place you can trim them down,this will give you more travel (more time) before the front tires pull the beams.....you can also lower your torsion bars a little(gives you a little more travel) before the tires pull the beams, this will probably require an alignment to put the front end back in spec, but these are all cheaper than replacing gears, I have used all these individually or in combination to dial a reaction time in depending on the track conditions.....

Mark Yacavone · 06-01-2009, 05:49 PM

Have you tried " blocking", or a 5 tenths pro tree to see where you're really at?

Everett Vassar · 06-01-2009, 06:25 PM

I have trimmed maybe half of the rubber stoppers off.Think I will just take them out.Sat I had 27lbs air in front.Can I safely go down to 20? Mark What if i cant get a light on a .5 pro tree Does that tell me I'm anticipating and leaving with the bottom yellow? Sure doesnt seem like it.Am going to T&T Wed to try a couple things.-----But still--will going from 4:56 to 3:91 slow down the cars R/T? with everything else being the same? I have a new converter here I just got (BTE) Havent had time to swap it out.Will a looser converter slow down R/T?

Mark Yacavone · 06-01-2009, 06:36 PM

Quote:

Originally Posted by Everett Vassar

I have trimmed maybe half of the rubber stoppers off.Think I will just take them out.Sat I had 27lbs air in front.Can I safely go down to 20? Mark What if i cant get a light on a .5 pro tree Does that tell me I'm anticipating and leaving with the bottom yellow? Sure doesnt seem like it.Am going to T&T Wed to try a couple things.-----But still--will going from 4:56 to 3:91 slow down the cars R/T? with everything else being the same? I have a new converter here I just got (BTE) Havent had time to swap it out.Will a looser converter slow down R/T?

Yes, to the question directed to me. Some of the guys over on the .90 side (Super Street ) are coming out WFO at 5-6000 to get a light on the .5 tree.

The gear change effect would be miniscule, the way I see it.
Yes, it is possible to tailor a converter flash loose and then hit hard, but I don't think that's your problem.
Won't the car idle at 1500?

Everett Vassar · 06-01-2009, 06:43 PM

Won't the car idle at 1500?

Maybe. Was having a hard time keeping it at 1800 Soon as you do anything it wants to go to 2000 Before Wed T&T I think I will pick up a stiffer throttle return spring and drop the air to 22 or 20 lbs

HawkBrosMav · 06-01-2009, 08:48 PM

I just went from a 4.56 to a 4.33 in my bracket car has about the same 60's and runs 6.90's in the 1/8th. Mind you i have a glide in mine but even this small change moved my spot on the bulb a noticeable amount. I went from having to hang on the bulb just a bit to being able to just let go like it was the top bulb. car weighs 2850 with driver. this is with a small block leaving at 3000 Rpm. with 32lbs of pressure in the fronts. 26" tall fronts. car wont yank the tire out of the beam so if yours is already picking it up out of the beams i dont know whether the gears will help.

doorslammer · 06-02-2009, 12:49 AM

I know this is big motor , what the intake center line, whats the duration , Tying down the front end .Try slowing down the carburator . Can you post your et and mph in the quarter . Does this car wheel stand .

Doorslammer

06-01-2009, 02:22 PM	#1
Everett Vassar Member Join Date: Jun 2004 Location: Kennedale,Tx Posts: 227 Likes: 0 Liked 2 Times in 2 Posts	Will a gear change help a redlighting problem in my bracket car? Dont know WTF whats so different about my car.3K lb Duster mild 440/727/456 Runs low 7,s 1/8 1.53-1.55 60ft Yesterday dropping my launch RPM down to 1800,staging as shallow as possible.Making sure I see the bottom yellow.Still .018 red.Getting frustrating.(I was dead on with a 6 after the redlight) I cant stare at the bottom yellow all day.Thats just way to inconsistent. So heres my choces I have come up with so far to slow the little Dusters R/T,s The cheapest and most suggested fix Simply leave in 2nd gear! I dont really like this cause it will slow the cars E.T. down . Put a taller tire on the front.I have 25" hoosiers thats the tallest that will clear the Hooker fenderwells. Go to a powerglide to get rid of that 727 2.45 1st gear ratio.Would love to,But too expensive right now. And my latest thought Swap the 4.56 for a 3.91 I know I am probably doing ths the wrong way but heres some simple math of adding trans first gear ratios and rear gears ratios to come up with a final number. 1. Leaving in first with 4.56 = 7.01 2. Leaving in 2nd with 4.56 = 6.01 3. Powerglide with 1.76 low gear and 4.56 = 6.32 (I think this is where I want to be) 4. Leaving in first with 727 (2.45 low gear) and 3.91 rearend = 6.36 5. Same as above with 4.30 rearend = 6.75 Notice how close #3 and #4 are. A R&P set only about 200 bucks.I might lose a little E.T but should pick up a little MPH. So am I on the right track here?

06-01-2009, 03:47 PM	#2
KingReptile Member Join Date: Mar 2008 Posts: 257 Likes: 0 Liked 0 Times in 0 Posts	Re: Will a gear change help a redlighting problem in my bracket car? Taller front tire will put you right there

06-01-2009, 05:49 PM	#5
Mark Yacavone Veteran Member Join Date: Mar 2002 Location: Miles From Nowhere Posts: 7,742 Likes: 2,844 Liked 5,002 Times in 1,902 Posts	Re: Will a gear change help a redlighting problem in my bracket car? Have you tried " blocking", or a 5 tenths pro tree to see where you're really at? __________________ "We are lucky we don't get as much Government as we pay for." Will Rogers

06-01-2009, 06:25 PM	#6
Everett Vassar Member Join Date: Jun 2004 Location: Kennedale,Tx Posts: 227 Likes: 0 Liked 2 Times in 2 Posts	Re: Will a gear change help a redlighting problem in my bracket car? I have trimmed maybe half of the rubber stoppers off.Think I will just take them out.Sat I had 27lbs air in front.Can I safely go down to 20? Mark What if i cant get a light on a .5 pro tree Does that tell me I'm anticipating and leaving with the bottom yellow? Sure doesnt seem like it.Am going to T&T Wed to try a couple things.-----But still--will going from 4:56 to 3:91 slow down the cars R/T? with everything else being the same? I have a new converter here I just got (BTE) Havent had time to swap it out.Will a looser converter slow down R/T?

06-01-2009, 06:43 PM	#8
Everett Vassar Member Join Date: Jun 2004 Location: Kennedale,Tx Posts: 227 Likes: 0 Liked 2 Times in 2 Posts	Re: Will a gear change help a redlighting problem in my bracket car? Won't the car idle at 1500? Maybe. Was having a hard time keeping it at 1800 Soon as you do anything it wants to go to 2000 Before Wed T&T I think I will pick up a stiffer throttle return spring and drop the air to 22 or 20 lbs

06-01-2009, 05:03 PM	#3
Everett Vassar Member Join Date: Jun 2004 Location: Kennedale,Tx Posts: 227 Likes: 0 Liked 2 Times in 2 Posts	Re: Will a gear change help a redlighting problem in my bracket car? Man I wished I could.This winter I bought a new set of Hooker fenderwells because I was told they could be re-done to fit a 26" tire.After I paid the guy still could only fit a 25" without beating up a couple of tubes which he refused to do.Think I would have to go to a 28" to help.They just aint gonna fit on this car

06-01-2009, 05:35 PM	#4
magnumv8 Member Join Date: Feb 2009 Location: Coraopolis, Pa. Posts: 172 Likes: 0 Liked 0 Times in 0 Posts	Re: Will a gear change help a redlighting problem in my bracket car? A couple suggestions.....not knowing all the details.....a couple lbs. out of the front tires could give you all you need if you have the pressure up pretty high....if the front still has the stock control arms and you still have the upper rubber bump stops in place you can trim them down,this will give you more travel (more time) before the front tires pull the beams.....you can also lower your torsion bars a little(gives you a little more travel) before the tires pull the beams, this will probably require an alignment to put the front end back in spec, but these are all cheaper than replacing gears, I have used all these individually or in combination to dial a reaction time in depending on the track conditions.....

06-01-2009, 08:48 PM	#9
HawkBrosMav Member Join Date: Apr 2009 Posts: 362 Likes: 6 Liked 302 Times in 73 Posts	Re: Will a gear change help a redlighting problem in my bracket car? I just went from a 4.56 to a 4.33 in my bracket car has about the same 60's and runs 6.90's in the 1/8th. Mind you i have a glide in mine but even this small change moved my spot on the bulb a noticeable amount. I went from having to hang on the bulb just a bit to being able to just let go like it was the top bulb. car weighs 2850 with driver. this is with a small block leaving at 3000 Rpm. with 32lbs of pressure in the fronts. 26" tall fronts. car wont yank the tire out of the beam so if yours is already picking it up out of the beams i dont know whether the gears will help.

06-02-2009, 12:49 AM	#10
doorslammer Junior Member Join Date: Mar 2005 Posts: 13 Likes: 0 Liked 0 Times in 0 Posts	Re: Will a gear change help a redlighting problem in my bracket car? I know this is big motor , what the intake center line, whats the duration , Tying down the front end .Try slowing down the carburator . Can you post your et and mph in the quarter . Does this car wheel stand . Doorslammer