I know this subject has been brought up since the 4.0 was first released but on that I am looking to push some more power out of mine and I have a plan and wanted to see if it would be worth it money wise and cool factor wise. I’ve always wanted to play with boosting something that wasn’t factory boosted and I found an Eaton m90 already set up for a 4.0 for 800 bucks ready to go and then another complete 4.0 with an upgraded throttle body and headers on it for 700 and then I was wondering what internal things I could do to make it stronger for little bit of boost being added and make a little extra power I was thinking something along the lines of a cam, head work, over bore, things like that
If you can find an m90 already adapted to work on a 4.0 it would be worth buying even if you weren't planning on using it.
The larger BBK throttle bodies don't really seem to do much for power, I have one that was installed on my engine before I supercharged it, didn't really do much for me power wise, I'm running a 5.0 explorer throttle body on mine currently which is actually slightly smaller than the BBK unit, I did this to make packaging simpler as the IAC is mounted directly to it.
The JBA headers I installed increased my fuel economy slightly and also seem to have the effect of lowering coolant temps slightly as well. I noticed very little if any power gain from both the pace setter headers and these JBAs (I replaced them simply because the mild steel pace setters rotted out and fell apart).
I haven't dabbled in the internals of these yet, the SOHC engines use the oil pan as a main bearing cap support and could be adapted over to the OHV engine without much effort. The main issue with that route is it will not clear the crossmember on a TTB/TIB truck. I've got one of the performance cams and push rods sitting in storage should I ever choose to go that route but I'm not expecting miracles. The stock 4.0 hits a wall at around 5k rpm, whether it has headers, a bigger throttle body, or even a supercharger.
@That_4.0_ranger
You have a "bolt on" blower, headers and T/B; why not bolt it together and see how you feel about it. I can see +50hp from the blower up to +20hp from the headers.
My concerns for these changes are:
1) fuel management.
2) your suspension
I can see around 50 ish hp being the total power gain from the whole shooting match all together, the big thing is the torque, at that power level you may be between 90 and 100 ft/lb up on stock, I can confirm that the extra 80 ish ft/lb I gained turned the truck into a tractor off road. I can lug it down to 400 rpm without much issue, but with the m62 I'm running, full boost is attainable at 1500 rpm.
I'm running a larger than stock fuel pump, at stock pressure, with stock injectors, fuel pressure regulator and tune. I keep a close eye on AFR and under full throttle and heavy load the AFR stays between 13.2 and 13.5. I'm running copper spark plugs two heat ranges colder than stock with 91 octane. Occasionally the stock timing curve gets a little spicy and it pings a bit but this is rare and mostly happens at higher ambient temps with me being stupid, haha.
It would be possible to run a boost reference fuel pressure regulator to help this a bit, maybe someday I'll try it. The OBD1 and early OBD2 pcms are not tuneable and will require a J3 piggyback chip to run a different tune (tweecer, tweecerRT, moates quarterhorse, moates is defunct but there's stuff still out there).
As for suspension, James duff used to (may still) make traction bars for the stock ranger suspension and they work well, one of my friends uses them on both of his 5.0 swapped trucks without much issue. I'm running 63 inch chevy springs and used a DIY traction bar kit from Ruffstuff specialties, it also works well but requires a bunch of fab work.
I’m trying to decide on buying those parts or not but there not very expensive so I just might but for fuel management I was going to try and get some better injectors and if I needed more fuel pressure I was thinking on doing something similar to FASS for a diesel but on a smaller scale or just add a higher pressure tank pump or in line pump and as for suspension my biggest concern about adding more power is rear axle wrap and the two piece drive shaft so I was thinking of building some custom track bars and do a one piece drive shaft
Just a higher flow fuel pump is all you need, i was running out of fuel with the stock in tank pump, swapped it with a larger Walbro and that solved the issue. Swapping to larger injectors without a tune will lead to driveability concerns because the pcm doesn't know what to do with them.
driveshaft swapping to a single piece shaft is worth it whether or not you have more power, the aftermarket carrier bearings coming out now are marginal at best.
Can’t speak to the fuel side of things…
There are aftermarket traction bars available for the Ranger. I actually have the Explorer factory traction bars on my one Ranger.
One piece driveshaft is a worthy thing.
Well said.
Yeah I’m not all that worried about beefing up the suspension my biggest concern is building the engine correctly so i can actually drive it and have fun with it one thing that I know is covered in here somewhere is fixing the lubrication issue in the top end of the ohv 4.0 which I read at some points I think it was something like need to machine the head and make the hole the oil comes through bigger for more flow
Install a supercharger and have fun, its custom stuff, you'll have bugs to work out no matter what, it's the nature of the game. The biggest issue with the 4.0 top end oiling is galling in the pushrod sockets, some engines are affected, some aren't, it's the luck of the draw. Hardened rockers and free floating rockers are both things to be done to improve this issue. I have heard nothing of enlarging oil ports to solve this, I would consult with reputable engine builders and do lots of research before going nuts with a drill.
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