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Swapped out some 50hp injectors for some 100's today


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1 hour ago, Threadzy said:

Meant to post that question on another thread.

Yes, it seems this thread morphed into a sidebar of the other thread. And I was confused, not you! It's 5AKman with the EZ. Caleb Hardy has an Adrenaline.  Sheesh!

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19 hours ago, 5akman said:

MoparMan, so by keeping my same tire size that I have now but re-gearing to 3.73's, I'll raise my cruise rpm by 200 or so. Are you thinking that even with considering the rpm increase, that I will see better fuel mileage or would that just be if I drop a tire size and keep the 3.55's? I'll soon have the quad installed and will be wanting to buy some tunes from you. 

 

Well you have to consider the rotational mass, that will still pull the MPG down. For every 1 pound of rotational mass you get rid of that is equal to removing 8 pounds off the frame. So small and lighter tires provide better results over trying to keep oversized tires which adds to that rotational mass. Back several years I compared 235/85 R16 to a 265/75 R16 which are both 31 inch tires but ditching the width of the tire I was ditching the steel belt and was almost 25 pounds lighter on the 235's. Now I dropped to the 245/75 R16 which adds 10mm of steel belt back but being its a 30 inch tire I gained more torque to the ground. I could swap to 215/85 R16 which is still a 30 inch tire but it would a bit too skinny for off road use up here in the snow. 

 

3.69 final ratio It will produce 2,000 RPM at 66 MPH. This is excellent being you dead middle of the torque curve and the engine isn't lugging. Anything below about 1,600 to 1,800 is going to be to low in RPMs and the timing will retarded to long so the MPG's a lower. I'm running 21 degrees at 2,000 RPM's and hitting 28 MPG

 

Consider looking at racing tires and how light they are. This is because the rational mass. Anyone racing wants the power to the ground. Wide offroad tires are not efficient at all. Way too heavy.

 

Personal note. My last truck was a 1972 Dodge Power Wagon that I destroyed the front axle trying to do lift kits and big wide tires and started snapping wheel joints, bearings weren't lasting long, and it was nearly every month I was fixing the front axle from the tires I put on and traded the truck in for the Cummins. I never did any oversized tires or lifts and never had any of the issues everyone talks about. Ball joints last forever, tie rods lasted very long time, no death wobble ever. 

Edited by Mopar1973Man
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  • 2 weeks later...

First off I have never driven a manual ram so can't comment on gear ratios 

That said I don't get the regear or smaller tyres on an auto. 

My truck tows most of the time, maybe 8 to 9k lb not really heavy but enough sometimes more but not too often 

I have a 32 to 33" ish tyre either 305 or 315, can't remember,  just on the limit of rubbing anything. Truck looks about right. 

OD off I'm over 2k at 60 and it is just right for our speed limits.

EGT's are low usually between 500 and 1000f, mpg I don't check as I'm paid for travel at £1.40 per mile and I know it needs injectors but it is OK, I could no doubt get more mpg if I spent some time messing with the quad. 

Best thing is with OD off converter stays locked to below our urban speed limits off 30mph. 

Also I'm never tempted to tow in od so that's another bonus. 

All the above said.  35" tyres would NOT work for me as they would be too much and mess up what for me is perfect 👌 

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