4low strong enough for racing?

[michael hurd]

From someone that has a brother that won a lot of money racing with a big block powered 4x4: if you are not driving it on the street at all then lighten it up as much as possible within the class rules.

A moderate tire with plenty of wheel speed will do better most times than a large tire turning slower... as long as you have the power to get and keep the wheels spinning fast enough to self clean.

That does not however apply to a bog where the tallest ground clearance wins every time.

Too low a gear is not beneficial as is too high a gear ratio. If you can keep the total vehicle weight down consider using a TH350 with extra clutches and better parts as it takes less power to turn.

 

[michael hurd]

Spraying the tires with WD_40 or a similar product just befire a run can help the tire clean before it gets up to full speed.

 

[highperf4x4]

Spraying the tires with WD_40 or a similar product just befire a run can help the tire clean before it gets up to full speed.

Aha! Tricks! I need all of those I can get. I wonder how much a gallon of WD40 is anyway? lol

I see what you're saying about the gears and the weight. They have so many rules to determine classes that I'm about to get myself bumped up into the open class where I can't even tell what I'm smelling from their exhaust. I have been thinking about lightening the truck I'm just trying to figure out how to do it and still meet the requirements for my class. I do plan on getting up to a 35" tire at some point and the truck is a little heavy so I figured the 4.56 would be the best choice. It's so expensive to gear swap that I hate to come up short and be stuck with the 33" tire. I'm not sure the 4.10 will be low enough for the 35" unless I can pull the weight out of the truck.

 

[highperf4x4]

If it's race only, you need a torque converter that stalls up higher. That'll help your launch RPM.

As for the $8/gal fuel, I know a lot of drag racers are switching over to e-85 because it resists knock as well as (or better than) most race gasses and is like $3/gal. You'll have to jet up a bit on a carburetor because it takes a little more of the e-85 to reach stoich than gas, but it's not really that much and I think there are calculators online for determining jet size.

I've already got a B&M Holeshot stall for the th400. It's a 2000rpm. I probably could have gone a little higher but it's a lot cheaper to change the stall if this one isn't enough and I have another truck with a big block and a th400 as well that I can use it in.

I'll read up on the E85. I wouldn't mine being able to cruise this thing around a little bit. I can get some clamps to bolt mufflers onto it I suppose. I sure do like to toy with the rice burners LOL

 

[highperf4x4]

Wrong the most important part of a mud truck is tires

I can see your point if you're speaking about performance and monetary point of view. You can get by just as well with the $1000 RCX 6" lift as you can the $2000 BDS 6" lift. When it comes to tires, if you want better performance you're going to pay bigger bucks to get it. However, I was referring to my order of operation. You can't put the bigger tires on until you install the lift kit right?




Btw, these are my current tires.

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[SCOTTYINWV]

If your going to 35s, I would run 4.88 or lower,

 

[highperf4x4]

If your going to 35s, I would run 4.88 or lower,

Wow that's pretty low


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[michael hurd]

I would not advise going to that low a gear... How many cubic inches is your engine and what is the weight and camshaft duration? Wheel speed is where its at.

 

[highperf4x4]

Engine is 383, flat top pistons, Vortec heads with Z28 springs, cam is 268/280 duration and 475/490 lift, dual plane air gap, Holley 670 street avenger. Truck weighs roughly 5000 right now with the new 6" lift.

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[michael hurd]

That seems like a pretty mild camshaft for the compression, and the dual plane intake will be fine for low end torque production. I would suggest 4:10 with a 34-35 inch tire, 4.56 at the lowest.

If you can drop some weight it would be very beneficial. If you feel comfortable with a ratchet shifter use a manual valve body in the transmission. Reducing weight will also help out in drive line longevity. A couple boxside skins held in place with some light angle and tubing will shed a few hundred pounds. Relocate the battery and fuel tank or cell to offset the weight bias on the front if allowed.