4.30 verse 3.23 gears

4.30 verse 3.23 gears - 10/02/14 08:00 PM

A few weeks ago I blew up a set of 4.30 gears that were in my car. All I had was a set of 3.23s so I threw them in just so I could continue racing the rest of the season. I had 30" tall drag radials on it. So I figured with the 3.23s I would need all the help I could get so I threw on a set of 26" drag radials. Now the 4.30s with 30" tires comes out to be roughly 4.01 ratio and the 3.23s with the 26" tall tires come out to be 3.46 ratio. Much to my surprise the car had the same 60 ft of a 1.53 and the same 96 mph and same ets 7.08 in the 1/8. So now im thinking what to do for next year and wondering why nothing changed.
I had jetted the carb up and down before and it didn't change anything either.
Im starting to wonder if the head flow is where the loss/no change is.
What everybody think?
Combo
72 dart
440/499
comp 540/555 lift solid
otb stealth heads
fenderwell headers
2800 -3200 stall
850 demon on a rpm intake

Posted By: GTX MATT

Re: 4.30 verse 3.23 gears - 10/02/14 08:02 PM

Which cam are you running?

Posted By: challengermike

Re: 4.30 verse 3.23 gears - 10/02/14 08:36 PM

comp xe290s-10
which is.540/558 lift 110 sep, duration @ 50 is 252/260

Posted By: sshemi

Re: 4.30 verse 3.23 gears - 10/02/14 08:40 PM

A long time ago i went from 3.55s to 4.10s in a Dart and didnt see any difference

Posted By: GTX MATT

Re: 4.30 verse 3.23 gears - 10/02/14 08:48 PM

Quote:

comp xe290s-10
which is.540/558 lift 110 sep, duration @ 50 is 252/260

I have that in my 440, with OOTB Stealths also.
I'd say you're not seeing much difference because in a 500 cubic inch engine that is not really a lot of cam. It probably has a pretty flat torque curve and doesn't need the extra gear.

I had 2.94s in my car when it went together and drove it a bit (4 speed). I put 4.56s in it. (29.5 inch tall tires). The car was a handful with 2.94s, but I can hardly keep up with it with 4.56s, it spins the 9 inch slicks from a roll in 3rd.

Out of curiousity, what valve springs are you running?

Posted By: dannysbee

Re: 4.30 verse 3.23 gears - 10/02/14 08:49 PM

The smaller ports with the big cubic inch engine has such a wide power range and torque range. So long as you have a torque converter that will jump the engine in power range it will pull that gear no problem and probably be more consistant.

Posted By: challengermike

Re: 4.30 verse 3.23 gears - 10/02/14 09:00 PM

Quote:

Quote:

comp xe290s-10
which is.540/558 lift 110 sep, duration @ 50 is 252/260

I have that in my 440, with OOTB Stealths also.
I'd say you're not seeing much difference because in a 500 cubic inch engine that is not really a lot of cam. It probably has a pretty flat torque curve and doesn't need the extra gear.

I had 2.94s in my car when it went together and drove it a bit (4 speed). I put 4.56s in it. (29.5 inch tall tires). The car was a handful with 2.94s, but I can hardly keep up with it with 4.56s, it spins the 9 inch slicks from a roll in 3rd.

Out of curiousity, what valve springs are you running?

When I built the engine it was for a street car so I didn't want a huge cam. It was 9.8 compression with ported 906S. I sold the car and put the engine in the current car with the otb stealths which lowered comp a little ,ROUGHLY 9.5 comp.The valve springs (I think)are still the factory stealths.I cant remember if I swaped springs from the 906s or not. I have no valve float issues, its been to 7,200 rpm but doesn't pick up any et or mph doing so. I shift at roughly 6,000.

Posted By: Pacnorthcuda

Re: 4.30 verse 3.23 gears - 10/02/14 09:09 PM

Maybe you coincindentally hit the same two performance points on a parabolic curve??? Meaning every ratio BETWEEN the two would be faster (or I suppose slower). Kinda like sighting a scoped gun, if you know what I mean.

Posted By: challengermike

Re: 4.30 verse 3.23 gears - 10/02/14 09:18 PM

Quote:

Maybe you coincindentally hit the same two performance points on a parabolic curve??? Meaning every ratio BETWEEN the two would be faster (or I suppose slower). Kinda like sighting a scoped gun, if you know what I mean.

When I had the 4.30s though I did try putting the 26' tires on to see what it would do. I couldn't get it to hook but the mph was the same if that means anything.

Posted By: GTX MATT

Re: 4.30 verse 3.23 gears - 10/02/14 09:28 PM

Quote:

When I built the engine it was for a street car so I didn't want a huge cam. It was 9.8 compression with ported 906S. I sold the car and put the engine in the current car with the otb stealths which lowered comp a little ,ROUGHLY 9.5 comp.The valve springs (I think)are still the factory stealths.I cant remember if I swaped springs from the 906s or not. I have no valve float issues, its been to 7,200 rpm but doesn't pick up any et or mph doing so. I shift at roughly 6,000.

And thats what you got, a street motor. Broad torque curve, nice response everywhere, deep gears not required.

Posted By: BMChrysler68

Re: 4.30 verse 3.23 gears - 10/02/14 09:35 PM

Quote:

...otb stealths which lowered comp a little ,ROUGHLY 9.5 comp...

Excuse my ignorance, but how did you lose compression going to an 80cc closed chamber head? Were the 906s milled a bunch?

Posted By: OUTLAWD

Re: 4.30 verse 3.23 gears - 10/02/14 09:39 PM

Same experience with my 493. Running 3.55s and 4.10s, margnial difference between the two, also no difference shifting between 5500 and 6500, 530 cam 260/266 @ 0.050.

So I run the 3.55s and shift early...it's a blast on the street.

Posted By: challengermike

Re: 4.30 verse 3.23 gears - 10/02/14 09:48 PM

Quote:

Quote:

...otb stealths which lowered comp a little ,ROUGHLY 9.5 comp...

Excuse my ignorance, but how did you lose compression going to an 80cc closed chamber head? Were the 906s milled a bunch?

I guess I was wrong. the 906s were shaved to 82 cc and the stealths are I think 80 cc. I thought my 906s were shaved to 78 cc. my mistake.

Posted By: challengermike

Re: 4.30 verse 3.23 gears - 10/02/14 09:51 PM

Quote:

Same experience with my 493. Running 3.55s and 4.10s, margnial difference between the two, also no difference shifting between 5500 and 6500, 530 cam 260/266 @ 0.050.

So I run the 3.55s and shift early...it's a blast on the street.

Thats what I found, street driving is a huge difference, Although I don't drive it much due to the spool. And once you to get the tires to spin they don't want to stop , lol

Posted By: 383man

Re: 4.30 verse 3.23 gears - 10/02/14 10:30 PM

I am running 4.30's with 30" tires and I have been thinking of going to 3.91's as I was hoping with my 493 it wont slow me down any. But my 63 goes just over 3700 lbs so I assume it weighs more then your Dart. I cruise at 60 mph turning about 3200 rpm and the eng actually seems to love cruising at that rpm. So I may drop gear a little one day myself to see what happens. Ron

Posted By: Paul_Fancsali

Re: 4.30 verse 3.23 gears - 10/02/14 10:37 PM

Big engines and high torque do not need the gear . Heavy car with smaller engine do need itI have run all the above gears and now holding onto the 3.91s. Car was faster with 4.30s and about the same with 4.56s

Posted By: Twostick

Re: 4.30 verse 3.23 gears - 10/02/14 11:18 PM

I think you just found out your converter is optimized for your engine combo.

Kevin

Posted By: D-50

Re: 4.30 verse 3.23 gears - 10/03/14 02:02 AM

A couple of years ago I was running 5.14's in my D50. At the time my best ET was 1.35 60 ft., 6.35 @ 108 in the 1/8. I broke those gears and put some 3.50's with a mini spool out of a Ford truck in it so I could race. I had a 1.40 60 ft., 6.39 @ 109 crossing the finish line in 2nd gear. Pump gas small block at 2950 lbs. with 315/60 MT Drag Radials 30 in tall. I am running 4.56's at the moment that are not low enough because I shift at 6800 and cross the finish line at 6000.

Posted By: Cab_Burge

Re: 4.30 verse 3.23 gears - 10/03/14 06:02 AM

Quote:

I had jetted the carb up and down before and it didn't change anything either.
Im starting to wonder if the head flow is where the loss/no change is.
What everybody think?
Combo
72 dart
440/499
comp 540/555 lift solid
otb stealth heads
fenderwell headers
2800 -3200 stall
850 demon on a rpm intake

If you couldn't jet it up rich enough to slow the MPH down in the 1/4 you don't have enough fuel supply

I've seen this many, many times in race cars, every body usually under builds the fuel system and never fix it

They have enough fuel to as fast as there going until they change the fuel system, there're many gremlins in the fuel system

All the way from the fuel filters to the needles and seat sizes and every other part in between the tank and carb. or injection

Let us know what you find

BTW, my old pump gas Duster, 518 C.I. pump gas Duster, didn't care if it had 3;73 to 4;30

It ended up running high nines through the muffs with the air cleaner on, motor only

Posted By: GY3

Re: 4.30 verse 3.23 gears - 10/03/14 01:18 PM

I went from 3.23 to 4.56 in a street car.

At the track it ran almost identical #s.

Posted By: challengermike

Re: 4.30 verse 3.23 gears - 10/03/14 11:42 PM

Quote:

Quote:

I had jetted the carb up and down before and it didn't change anything either.
Im starting to wonder if the head flow is where the loss/no change is.
What everybody think?
Combo
72 dart
440/499
comp 540/555 lift solid
otb stealth heads
fenderwell headers
2800 -3200 stall
850 demon on a rpm intake

If you couldn't jet it up rich enough to slow the MPH down in the 1/4 you don't have enough fuel supply I've seen this many, many times in race cars, every body usually under builds the fuel system and never fix it They have enough fuel to as fast as there going until they change the fuel system, there're many gremlins in the fuel system All the way from the fuel filters to the needles and seat sizes and every other part in between the tank and carb. or injection Let us know what you find BTW, my old pump gas Duster, 518 C.I. pump gas Duster, didn't care if it had 3;73 to 4;30 It ended up running high nines through the muffs with the air cleaner on, motor only

That's something I never though of. I only went up a few maybe 4 jet sizes and it didn't change the mph so I went back to where it was. I figured I was in the ball park when nothing happened. It does have a summit electric fuel pump(same as the holley blue pump) and an older style fram big fuel filter that has a paper element inside and the line is I think 1/2 or bigger. The season is over for me so I wont have any good info till next spring. So over winter im going to pull the 3.23s out and I need to figure out what ratio to put back in it. Thinking maybe 3.91s, but not sure though.