gear change for big HP......

[Nowwhat]

Ok....

for those running...let's say 700+ rwhp.....

shouldn't we go to a higher gear.....4.10s....?................

 

[JTS VENOM PERFORMANCE]

We need to get jack in on this, he is the shit when it comes to this calculatin stuff.

but I do think with 700+nos=different ratio say 4.10:dontknow:

 

[jrgnd]

I say if your are spraying a big shot of the line...Then yes....Blower only of the line...nope...

 

[Silverback]

You are missing the important thing here. When you shift, or in your case the transmission shifts you want the engine to drop down to the rpm range where your making the most torque. This provides you with the greatest acceleration.

So with that in mind a set of 4.10's will drop you further down the rpm range than a set of 5.13's will.

Make sense?

Another good rule of thumb is that you are at, or just below redline in high gear when you cross the finish line. The quicker you can accelerate though a gear, the faster you will be.

Needless to say the above all relates to a blast down the quarter mile.

 

[Rice Eater]

i have an 04 with 410's w/ the 150 shot and the big M&H Drag Radials i think they are about 30" tall I trap in 4th at 5,400 rpm

 

[1Fast400]

depends on the tire you run

 

[Silverback]

depends on the tire you run

Yep, that's part of the equation also.

 

[Texas Yellow Fever]

The other obvious piece of the equation is what the red line of the motor will be once the rebuild is complete. I would assume with all that's being done to some of these engines, the redline and associated max output of the engine will be much higher than the stock ones, thus you'll want to be at a much higher RPM when you cross the line. Based on that alone, if everything stayed the same (tire height etc) intuitively it would seem that instead of going to a 4:10, you should go to 4:88's or 5:13's, but what do I know.

 

[RedSrt007]

I would think too many unknowns to determine yet.

Motor Build, Rollout of the M&H's, and figuring out Torque Mulitplication for the given ratio.

 

[Silverback]

The other obvious piece of the equation is what the red line of the motor will be once the rebuild is complete. I would assume with all that's being done to some of these engines, the redline and associated max output of the engine will be much higher than the stock ones, thus you'll want to be at a much higher RPM when you cross the line. Based on that alone, if everything stayed the same (tire height etc) intuitively it would seem that instead of going to a 4:10, you should go to 4:88's or 5:13's, but what do I know.

One of the things that will limit the redline in the engines is the uneven firing. This causes additional stress on the timing chain as well as other items.

I had one of the old style Buick V-6 engines in my 70 Jeep. I rebuilt it and P&P the heads, added a cam, Paxton and a lot of other go fast goodies. Well the redline went from 5200 to right at 7000. I had to replace timing chains every couple thousand miles as they just would not last in that rpm range.

That is why when Buick bought back the rights and tooling for that engine they designed a crank with offset journals to eliminate the problems associated with uneven firing engines.

 

[Texas Yellow Fever]

One of the things that will limit the redline in the engines is the uneven firing. This causes additional stress on the timing chain as well as other items.

I had one of the old style Buick V-6 engines in my 70 Jeep. I rebuilt it and P&P the heads, added a cam, Paxton and a lot of other go fast goodies. Well the redline went from 5200 to right at 7000. I had to replace timing chains every couple thousand miles as they just would not last in that rpm range.

That is why when Buick bought back the rights and tooling for that engine they designed a crank with offset journals to eliminate the problems associated with uneven firing engines.

Maybe it's time switch these finicky engines out for one of those big Hemi crate engines...they love RPM.

 

[Silverback]

Maybe it's time switch these finicky engines out for one of those big Hemi crate engines...they love RPM.

I must admit, that if I lost the original engine to the point that it could not be rebuilt, I would give serious consideration to a 528 crate motor.

 

[mopower1958]

One other variable to enter is the 5800 lb brick that you are trying to move from a dead stop! Mike has taken off the wing which is maybe 10 lbs because it serves no purpose, how about the back seat,spare tire,jack,windshield wiper motor and transmission,radio,amp and all the speakers,a/c and all related hardware. That should be around 400 pounds which would make a BIG difference in 60 ft and 1/4 mile.

 

[Nowwhat]

my question ws more one of.....traction.....the 4.56s with let's say 800 rwhp blows the tires off....4.10's would help this...

 

[Texas Yellow Fever]

my question ws more one of.....traction.....the 4.56s with let's say 800 rwhp blows the tires off....4.10's would help this...

I still think you're going the wrong way...if you ever break the tires loose it'll be all over, you'll never catch up with them by red lining and shifting. With a lower gear you'll catch up to them sooner. Does that make any sense? I'd go with 4:56 or 4:88 and then work into the right RPM on the finish line with tire height.

 

[Silverback]

I still think you're going the wrong way...if you ever break the tires loose it'll be all over, you'll never catch up with them by red lining and shifting. With a lower gear you'll catch up to them sooner. Does that make any sense? I'd go with 4:56 or 4:88 and then work into the right RPM on the finish line with tire height.

Steve is right.:rock: You guys are approaching this wrong.

 

[zex-srt10]

I would go with 4.10's if i was you. I think that if you had 4.56's or 4.88's you will brake the tire loose to easy. Your truck will have enough power to still get out of the hole.

 

[JTS VENOM PERFORMANCE]

Everyone is correct jsut different approaches to the same problem.

I you go with 4.56 or 4.10 you can always change the final ratio with tire hieghth, Although with a stock tire and a 4.10, I would think it would be less likely to break loose than a 4.56.

But you got to also take into consideration when you do start getting extremely good traction that the quicker you get off the line and accelerate to the end the quicker the quarter time will be.

but then you must also consider each shift takes away from your 1/4 times, so that would leadto the 4.10's to being a better gear.

If we were actually building a pure race vehicle it would be very simple, you want to accelerate completly till you redline jsut after the end fo the line, or on top of the line, but that never stays consistant, it may change every run.


so for me I am going to a 4.56 it will still give me plenty of room on the track, but will be a blast on the track

 

[Silverback]

I give up.

 

[JTS VENOM PERFORMANCE]

I understand totally what youre sayin there friend, but I'm on the nyquil so my typin and mindset is on the loaf

the point I was actually tryin to make is , I'm not buildin it for the track, and on the street feel a small lack, so I want the 4.56 on the street to have more fun

does that make sense:dontknow:

I feel like my heaad is ddoing this:dancing: :dancing: :dancing: