tn fall gtg 460 build off date oct 1st

[srcarr52]

If you're running a pretty good tune you'll pick up power with the airdog.

I'm hoping to save the new injectors I just put in, pick up a little throttle response and get rid of the stock filter head housing with check-ball that is failing. A little power will be an added bonus.

 

[Simonizer]

At the crank. I'd love to see 400 at the rear wheels. My big tires might nullify that though. I built the engine from scratch, starting with a 6.0 LQ4. It has ported LS6heads, milled for 11:1 compression. Custom ground cam.......

Your big tires might eat your HP? I don't understand. So if you take the tires off and just put a few wraps of electrical tape on the rims you will get all that power back? Confused:msp_confused:

 

[srcarr52]

Your big tires might eat your HP? I don't understand. So if you take the tires off and just put a few wraps of electrical tape on the rims you will get all that power back? Confused:msp_confused:

It takes energy to flex the rubber and larger tires flex more then smaller ones so the larger side walled tires absorb (convert to heat) more power. So when you are measuring hp at the wheels using a chassis dyno the tires have already taken their bite out.

 

[Simonizer]

It takes energy to flex the rubber and larger tires flex more then smaller ones so the larger side walled tires absorb (convert to heat) more power. So when you are measuring hp at the wheels using a chassis dyno the tires have already taken their bite out.

So give me an estimation of how much power is lost here. 10 HP per tire? That would be 7456 watts or 5 electric kettles each. I predict the difference between 33 vs 30 inch tires to be of relatively little consequence. Also, once the initial torque had been transferred to the rollers on the dyno, they would already have the sidewall flex established. I have seen many tires smoke but never from the sidewalls.

 

[little possum]

Would you not relate bigger tires to a longer bar and chain? More rotational mass you have to get to point A to point B. More drag

 

[srcarr52]

So give me an estimation of how much power is lost here. 10 HP per tire? That would be 7456 watts or 5 electric kettles each. I predict the difference between 33 vs 30 inch tires to be of relatively little consequence. Also, once the initial torque had been transferred to the rollers on the dyno, they would already have the sidewall flex established. I have seen many tires smoke but never from the sidewalls.

It equates back to the difference in rolling resistance of the tire. Every time the tire rotates slightly a new piece of the sidewall is flexed converting work into heat. The difference from a 30->33" tire on the same rim can be a fair amount since the 33" tire will probably be a wider contact patch as well which causes more drag due to the deformation of the tread. Just like a open shoulder or a deeper/wider grooved tire will scrub more power.

I would say that you're probably on the right order with around 10 HP/tire, it's probably like 14 HP for 33's vs. 10 HP for 30's vs. 7 HP for the stock highway tires (don't quote me... they are a pure engineering guess). I know the rolling resistance of a tire is usually between 0.001-0.007 * the normal force which with 30" tire, 2000lb load at 0.005 would be 150 ft-lbs, rolling around at 455 rpm (1700 engine rpm with 3.73 rear gear) would be 13 HP/tire.

So we'll say a max difference of 7HP/tire from stock, multiply by the drivetrain efficiency of around 18-20%, and you get a needed 34 HP at the crank to make the difference or 3 OHV Briggs.

Interesting tidbit: Tires that are low on air pressure usually fail where the sidewall meets the tread. This spot on the tire see the most flex but doesn't contact the road so the heat is not dissipated as quickly and usually the inside of the tire blisters until the entire tread about rips off the sidewalls. This is also how run-flats usually meet their demise (only with people who don't pay attention to their tire monitoring systems).

PS. I like your reference to electric kettles, pretty funny. 75 incandescent light bulbs, or 220 compact fluorescence.

 

[Simonizer]

Would you not relate bigger tires to a longer bar and chain? More rotational mass you have to get to point A to point B. More drag

A dyno measures power once everything is up to speed so rotational mass, (Actually "angular momentum") is irrelevant. I was talking to a friend several years ago who thought if you put a big enough flywheel on a 3.5 HP Briggs and Stratton, that you could power a cruise ship. Doesn't really work that way lol.

 

[srcarr52]

A dyno measures power once everything is up to speed so rotational mass, (Actually "angular momentum") is irrelevant. I was talking to a friend several years ago who thought if you put a big enough flywheel on a 3.5 HP Briggs and Stratton, that you could power a cruise ship. Doesn't really work that way lol.

Chains are different because they are not moving in a perfect circle.

 

[parrisw]

At the crank. I'd love to see 400 at the rear wheels. My big tires might nullify that though. I built the engine from scratch, starting with a 6.0 LQ4. It has ported LS6heads, milled for 11:1 compression. Custom ground cam.......

Sounds good!!

Same here. My chipped 02 dMax (500hp, 700ft-lbs) gets 20mpg when I drive the speed limit. It goes down to about 18mpg when I'm driving 85mph, I average about 16mpg with mostly city driving. I also have 33" on it so that hurting it a little.

I'm going to put an AirDog unit on it soon because I'm having troubles with it loosing prime occasionally. I can't believe they didn't put a lift pump on these years and rely on vacuum to pull the fuel to the injection pump (10 in_mg). Anyway AirDog claims 1-2mpg but most people say 0.5mpg increase but less air to the injectors = longer life.

I have an earlier 7.3l PSD, it suffers from smaller injectors. So I'm limited on what I can get
in power right now.

 

[Mastermind]

Taller tires change the gear ratio. Taller gears transmit less torque to the ground. Simple stuff.

 

[blsnelling]

Hi Randy. Got a 346 ordered yet?

 

[WoodChuck'r]

My 4.0L V6 Ranger gets about 14mph. They're geared rather low.

Rangers have TERRIBLE gas mileage but they have a **** ton of power for being so small.

Dynamite come in small packages.

 

[BloodOnTheIce]

My 4.0L V6 Ranger gets about 14mph. They're geared rather low.

Rangers have TERRIBLE gas mileage but they have a **** ton of power for being so small.

Dynamite come in small packages.

Really that bad? My GMC Sonoma 4.3 V6 AT gets just about 20 mpg with a leak in the down
pipe of the exhaust.

 

[WoodChuck'r]

Rangers are horrible when it comes to gas mileage - that's why they sell for so little.

My '02 3.0L V6 2wd gets 18 at best.

The mileage sucks but even the 3.0L 2wd has a ton of towing power and what not. I've put that truck through hell and it still runs like a friggin' tank. My '08 4.0L 4wd is literally built like a small F-150 underneath - for their size they are really heavy duty. I'm amazed at how tough these things are built.

They're tough little trucks but you pay for it at the pump....

 

[Mastermind]

Hi Randy. Got a 346 ordered yet?

Well being the cheapo that I am I've got a deal in the works for a NE346XP with a fried top end. I"ll be head hunting after it's built. :msp_wink:

 

[blsnelling]

Well being the cheapo that I am I've got a deal in the works for a NE346XP with a fried top end. I"ll be head hunting after it's built. :msp_wink:

Cheap is good

 

[wendell]

Dynamite come in small packages.

So your wife still buys that story?!?

 

[Mastermind]

I've been building a 064 today. Pop-up, woods port....... Oh boy.

 

[Stumpys Customs]

I've been building a 064 today. Pop-up, woods port....... Oh boy.

I finnished a 036 today. Didn't go to far with this one!!!
Bout got this stuff fingered out:msp_thumbsup:

 

[Mastermind]

I finnished a 036 today. Didn't go to far with this one!!!
Bout got this stuff fingered out:msp_thumbsup:

The next saw I build for myself will be a two piece head build. I've found that I can only go so far with the stock combustion chamber. I want to build a screaming cant cutter just for fun.