OB_WAN

I've got a 4.8l with a powerglide(1.82), atlas 3.8, 4.56 gears trying to turn 35" tires in a competition 2000ish jeep wrangler. torque converter stall is somewhere around 2k.

Here's my problem: with the high gear of the powerglide, and high powerband of the 4.8L I'm having difficulty when the wheels are bound and I'm trying to walk out of an obstacle. The tranny tries, bogs down, and no go.

I know these engines are higher RPM engines(4000 rpms peak torque) so here are the options I see so far.

1. get a higher stall converter. perhaps ~3000rpm. this will allow me to reach some halfway decent torque to pull out of obstacles. but it will also have me launching out of spots I may want to crawl out of(=brakes+gas)
2. get a torque cam that pulls higher torque @ lower rpms. I don't know what else is involved(new lifters, etc?) and I don't know if there's a cam out there that will provide the low end grunt I need.
3. replace powerglide with a built th350 for lower 1st gear - this buggy was built around a powerglide. I'm guessing this will be more $$$ and pain than I can afford.
4. replace the 4.8 with a 5.3. has a little better power band down low but I'm guessing not enough to improve things that much. and it's more $$$ if it doesn't work.

I'm on a serious budget. If I could find a sponsor to swing a deal on something I might try it out but guessing that's not an option so I'd like your opinion on options above. I'm really swinging on #1 or #2 and don't know much about either.

Kenova

iTrader: (4)

You are right about the 4.8s liking the revs. I have one in my pickup and I find it quite impressive for such a small engine.
Numbers 1 & 2 might give you the results you're looking for. Talk to the cam company of your choice and get a recommendation for a cam and converter combo, then verify it with the converter company of your choice. If both the cam and torque converter are selected to work together, you should get some favorable results. Just keep in mind that you won't get mountains of torque out of such a small engine.
Personally, I think the TH350 would be the absolute best solution (other than putting a blower on it ).

Ken

Schwanke Engines

iTrader: (1)

You might as well invest in a 6.0L if you are going to be changing the engine.
You should be able to find a junkyard 6.0L somewhere for around 600~1000.

Andy1

A 4.8L is a short stroke 5.3L. The 5.3's are very plentiful and cheap (and sure to have more torque due to the stroke increase; It's the same stroke as a 5.7 or 6.0). Can't however disagree with Schwanke, may as well do the 6.0L.

Andy1

OB_WAN

Thanks a lot for the input guys. I found some RPM/Torque comparisons between the stock 4.8L, 5.3, 5.7(LS1) and 6.0L. Was really impressed how much of an increase the 5.3 is over the 4.8. And how close the 5.3 and 5.7 are. Yeah, the 6.0 is a different animal. about as much gain over the 5.3/5.7 as the 5.3/5.7 have over the 4.8.

http://www.s10forum.com/forum/f213/l...0l-lq9-330477/