Gear ratio and Tire size

When I pull the sled with mine the best set-up so far is this.....

4 Lo
4.30 gears
37x13.50r20 tires

Start in first about 1/2 throttle till I get it moving then drop the hammer, then manually shift the auto into second and hold it till the end. If I shift into 3rd it dogs. If I stay in 2and RPMS stay high.....around 2,800 or so at the end. She pulls right up until it chokes it out.Haven't pulled with the new motor yet. Will have to see. What do you think? Thinking of maybe trying 35's.
 
Big A said:
When I pull the sled with mine the best set-up so far is this.....

4 Lo
4.30 gears
37x13.50r20 tires

Start in first about 1/2 throttle till I get it moving then drop the hammer, then manually shift the auto into second and hold it till the end. If I shift into 3rd it dogs. If I stay in 2and RPMS stay high.....around 2,800 or so at the end. She pulls right up until it chokes it out.Haven't pulled with the new motor yet. Will have to see. What do you think? Thinking of maybe trying 35's.
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When I pulled with my PSD I just put it in 4 low and drive and let the tuning for the BTS do the rest as far as shifting. If I got everything else to hold together down the track it did really well, I didn't even lock the converter up. But I always snuffed it at the end, but I don't know whether that was because it didn't down shift, or if the loss of a sh*t ton of nitrous had an effect on it. But good luck, hope you don't break anything.
 
zstroken said:
Coppess hit 3rd gear with 3.54 gears, an s400 with a large housing. Tomac and Burkhard can speak up what they hit at scheid. Scheid was a long track, not saying 40mph happens all the time, but I recall 35+ isn't uncommon for a certain DMAX from michigan.
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lets make sure everyone understands, burkhart fastest ground speed was 28or so mph. his traction has to be good to win, so 35mph might be a little stretch.
 
SEOHPowerstroke said:
When I pulled with my PSD I just put it in 4 low and drive and let the tuning for the BTS do the rest as far as shifting. If I got everything else to hold together down the track it did really well, I didn't even lock the converter up. But I always snuffed it at the end, but I don't know whether that was because it didn't down shift, or if the loss of a sh*t ton of nitrous had an effect on it. But good luck, hope you don't break anything.
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if you think your buddies CR can spin 5k down the track, i would love to hear how your PSD pulls.
 
joeservo said:
lets make sure everyone understands, burkhart fastest ground speed was 28or so mph. his traction has to be good to win, so 35mph might be a little stretch.
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I could be mistaken... But I thought I read where he was running 4:10's in the rear. So with a 35" tire, and running direct in the trans.(4th) at say 3900 RPM's, 35MPH isn't too far off, right?
 
The D-max guys that run 35" tall tires usually opt to keep it in third and maintain the rpm correct?

-Tom
 
joeservo said:
if you think your buddies CR can spin 5k down the track, i would love to hear how your PSD pulls.
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I'm sure it would pull whatever your drivin.:bigsmile:
 
SEOHPowerstroke said:
I'm sure it would pull whatever your drivin.:bigsmile:
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On a trailer for a few miles before your powerstroke blew up.........



:hehe: :hehe: :hehe:


-Tom
 
Burhart has stated that he hits 4th gear 4000 rpm with 33" tires. That comes out to about 38 mph if I am correct. Tomac is running 315 tires which are like 34.5" and he gets into 4th quite often. The Dmax guys love the long tracks!
 
zstroken said:
Burhart has stated that he hits 4th gear 4000 rpm with 33" tires. That comes out to about 38 mph if I am correct. Tomac is running 315 tires which are like 34.5" and he gets into 4th quite often. The Dmax guys love the long tracks!
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I have no doubt Burkhart hits fourth gear with 33" tires but sure don't sound like he is spinning 4k in 4th gear.

-Tom
 
I am only going by what he has said. Can't confirm either, but at Scheids when Coppess hit 3rd gear with 3.54 gears and a quite large charger I have not doubt he was 3800+ in 3rd. Do the math and he still got beat by Tomac and Burkhart(we won't go into that). The Dmax 3rd is just slightly lower than a dodge's second.
 
I would like to know what rpm Burkhart was turning in third to grab a hold of fourth AND turn 4k??? Come on......

-Tom
 
We are talking A5k chargers, and a 6.6 liter engine(probably 4k port job on the heads) with variable timing. I know my 5.9 with mechanical timing will stay on my 3.0 charger down to 3100.

Coppess runs a larger turbine section than I do, so I would suspect he can drive down to 3300 or so and when I saw him he was way over 3300 in 3rd. This was a 340'+ track. At the short tracks(less than 300) I don't think the duramax grabs 4th.
 
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Tcolesanti said:
On a trailer for a few miles before your powerstroke blew up.........



:hehe: :hehe: :hehe:


-Tom
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If your truck made power it might break something too.LOL
 
zstroken said:
We are talking A5k chargers, and a 6.6 liter engine(probably 4k port job on the heads) with variable timing. I know my 5.9 with mechanical timing will stay on my 3.0 charger down to 3100.

Coppess runs a larger turbine section than I do, so I would suspect he can drive down to 3300 or so and when I saw him he was way over 3300 in 3rd. This was a 340'+ track. At the short tracks(less than 300) I don't think the duramax grabs 4th.
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You make a valid point with the tight chargers you guys run. I just have a hard time seeing how a truck could gain rpm from a 3-4 shift that late in the game.

-Tom
 
Tcolesanti said:
You make a valid point with the tight chargers you guys run. I just have a hard time seeing how a truck could gain rpm from a 3-4 shift that late in the game.

-Tom
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Tight chargers? I never thought a 3.0 with a .9 or 1.0 was tight. LOL Just how loose is yours??
 
But it also depends on what housing I have on it, the big one is even worse.

-Tom
 
1.1 your small one and then a 1.25(maybe 1.32) or so a/r for the big one?
 
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