I just picked up a 1998 Ram 1500, 5.2L, and the truck has had some nice upgrades, but it feels sluggish off the line... I really need to give it a lot of gas to get it going.

The specs of the truck are as follows:

- 35" tires
- 4.10 Gears
- Headers
- Full Magnaflow exhaust system
- Cold Air Intake
- Rebuilt trans with 2500 rpm stall converter (w/shift kit)

I have been reading on the intake plenum issue that these engines had issues with, but I don't seem to be going through excessive amount of oil, just low end performance.

I need to replace the water pump, so thought about pulling the intake at the same time and swapping out the gaskets for the intake at the same time.

I have heard that 4.56 gears with the 35" tires and the 5.2L would have been a better choice, but I figured the 4.10 would feel snappier than they do.

So, I am left with assuming the sluggish off-line performance is a result of either the Plenum issue, running a 2500 rpm stall, or ???

I will be doing a full tune-up while I am swapping the water pump (plugs, wires, cap, rotor, PCV, etc.), to see if any of that helps as well.

Any advice would be greatly appreciated.

 

The stall isn't hurting off the line but the plenum certainly will. But 4.10's are a little on the high side for the 5.2 with 35's. Also pick up an sct tuner. You won't find one complaint on them and they're only 265.

 

why did they bump stall?

the stall is rated by the RPM's the truck would need to generate for the engine to overcome the brakes.. you could see why racers would want that- but why in the world would someone put a higher stall on a truck pushing 35's and pretty much no mods?

you would see a nice little bump by dropping to a TC made for towing- around 1600-1800RPM or so.. that would help your immediate engagement 'off the line' and in low end situations..

that said- dude, fix your plenum.. you may find enough 'off the line' with that to disregard that goofy TC.

 

My question exactly drew.... the previous owner said that he did it to help with towing, which seemed totally backwards to me.

I don't know for sure if the plenum is giving me problems, I just know that it has 150K on it, and am not sure if its been done. I am not using oil, but definitely feel like I have to give it a bunch of gas to get going, and any highway inclines really require a good press on the gas to keep the speed constant. If I mash it from a get go, it gets going ok.

I am going to do the plenum this weekend, along with all of the tune up stuff and the water pump, so either way we will find out how it does on Monday.

I have a line on a Superchips tuner for $75, so thinking of running that for now, just to see if it has a positive effect... it should.

 

You answered your own question in the first two lines of you specs....35" tires and 4.56 gears equal factory power minus the additional weight of the tires...35" tires and 4.10 gears will be sluggish but will net better mpg if you drive like and old man in no hurry....
btw I have everything you have with mine....except I have a 5.9L with 4.56 gears and dont have the converter....and mine is no performance car either...(nor was it designed to be) it does remind me how foolish I am everytime i look and the fuel gauge and head to the gas pump that much more... which is why a rarely drive it these days..

 

Hmm... I wondered if that wasn't the whole issue there. I am willing to do the plenum job, but not sure if that is the source of the sluggishness.

As for the gears, I had thought about swapping to 4.56, but based on your post, not sure if its worth the extra $$.

 

I don't think a 4.10 to a 4.56 is worth the money. Maybe a 4.88 cause then you've got power for more tire lol.

 

With 35's, would the highway rpms be pretty crazy if I went with the 4.88's? I'm sure it would improve the low end, and probably help with mileage during towing as well....

 

4.10 to 4.46 makes quit a difference in power...I did in on my jeep because after adding 32" tires 5th gear was useless and I was getting horrible mpg always downshifting with my 2.5l 4 banger...after swapping to 4.56 my gas mileage improved a lot and I could use 5th gear and hold speeds again..(it will also correct your speedometer which is off now) .. its the same as going from 3.55 stock to 4.10 and I'm sure there are others here who have done that who could chime in.... and if you search "gears youll find a thread on here with a chart breaking down ratios and rpms and effects on mileage and power...

 

Stock stall is 1800. 5.2 needs help with 35's. 4.88's.