Well I'm off work this week and decided to play a bit. I've installed a 4.0L ASP Underdrive crank pulley and then data logged the power results. See the following graphs showing before and after power improvements.

I'll post up pics and more info later in the week when I get a chance. But here a few quick notes..

1) Right at 5050rpms I gained 12hp
2) Basicly the whole torque curve moved up & I gained some TQ up top.
3) You can definately feel the power increase. Everywhere & no matter what throttle or speed your traveling at.


Graph BEFORE the pulley:





And here is a graph AFTER installing the pulley:

 

Great info. Thanks for sharing the results.

 

according to your dyno sheet, it says you added the Underdrive pulley, Efan, and CAI


so with JUST the underdrive pulley, what type of gains are we looking at?

 

 

it had no mechanical fan on that first pull too, so i would imagine that he had the K&N on it then too.

 

it says NO- Mechanical Fan, doesnt mean is has no Mechanical fan, it could me, NO mods, and has a mechanical fan, also it doesnt say it had a CAI on the first one either. Unless he did the dyno sheet himself, they usually say what mods are on them for the dyno



we'll just have to wait till he says whats what

 

nm.....my truck has 238 ft/# torque stock........

your graph show you made around 230 ft/# torque.....that is a drop over your stock 238 ft/# torque........

your truck also comes stock with 207 HP....you show a max of 200 HP.....something is wrong with your testing procedures or wrong with your truck...

my rating source...
http://www.therangerstation.com/tech...e_Ratings.html

 

You're quoting advertised flywheel torque and his instrumentation is inferring engine torque from vehicle acceleration. Torque inferred from acceleration at the rear wheels is always lower due to drivetrain losses.

 

^^^^ahhhhhh i though the advertised #'s from a company was the rear wheel #'s.......

so if that is the case, then that is pretty good #'s after loses in the tranny, rear end, and tires....

 

yea so a stock 4.0 is pushin what 180-185hp to the rear wheels?

 

Advertised horsepower and torque is done on a production representative engine that has a complete accessory drive and intake filtration/silencing. The test is done on an engine dyno and WOT backpressure of the exhaust may simulated by a restrictor orifice instead of the bulky cats and muffler. The results are then corrected to standard temperature and pressure.

This has been the standardized test procedure since the early 70's (SAE J1349).

Before that, manufacturers usually ran a stripped engine with no FEAD, intake silencing or mufflers. Obviously, this made the the advertised numbers artificially high.

 

im really suprised on how flat the over all torque curve on these engines are. to bad u couldnt have compared both runs on the same sheet.

 

The first graph had the following mods: CAI & no fan.
The second graph was identical except for the addition of the ASP underdrives. I did put the e-fan on.. but it was not wired. So from a power consumption standpoint the ONLY difference was the underdrives. I had only driven 12 miles between the two pulls and the DA (density altitude) was nearly identical at -860ft. Oh and just for the record all these pulls were made on the exact same stretch of freeway to help eliminate any varyable from hills and wind.

The torque curve appears to be flat because up until about 3200 rpms there is a period of non-lock up in the torque convertor. *IF* I could lock the convertor all the way from a very low rpm then you'd see the normal torque curve associated with most graphs. You can clearly see the actual lock up in the dip of the HP line. To be fair a guy would have to ignore the data below about 3600rpms. Numbers could be effected just by how quickly the convertor is locking up.

Whilest I am measuring TQ numbers that are low as compaired to advertised by ford... This method is known to be very accurate when measured on at least 4 other ford products. (autotap with ford enhanced package) My numbers are also consistant with a friends 04 FX4. I believe these measurements to be correct and accurate. Even if they are somehow not accurate as a base line.. the change in power measured I think to be right on the money. This has held true on other fords I've measured as well.

I did not loose torque. I gained torque accross the board. Autotap only captures 20 points per second. And since this is time based capture.. its very hard to make a accurate graph overlay. The limited amount of points also make for a choppy graph IMO.

My summary.. this mod is worth the money. The e-fan though would really depend on how you use the truck. I happen to have one laying around.. and I'm a paved road daily driver w/a lite right foot. So for me I hope to gain milage more than anything.

My measurements here are not conclusive in of themselves. These posts from me are nothing more than a reality check for the ranger community. IMO anytime I can see some actual measurements it's worth more than popular perception.

When I do the exhaust and maybe a programmer.. I'll report the same measurements.

Regards,
Rich

 

Makes sense why u cant overlay. it'd be neat to see a chart of various rpm and mods with the torque and hp on it...food for thought LOL.

with the pulley, the alt would spin slower than? is there a way to speed up the pulley if it does indeed spin slower?

 

I am running the underdrive pulleys on the crank, alternator, and water pump on my 3.0 and I could tell a noticeable difference when they were put on. I havent had it dynoed ever so I dont know what my base line is and I already have a cold air intake and exhause so it will be interesting what I lay down when I get it dyno tuned eventually. Hopefully after regearing.

By replacing the alternator and water pump pulleys with underdrive pulleys it will speed them back up because the smaller diameter pulleys will spin faster. they are just a PITA to put on.

Devin

 

so you didnt go to an actual dyno? what equipment did you use?

how exact is it?

 

ooo i wanna see more info on this what pulleys just the main one? or anyother ones? i think this may be a good mod..

 

nology sells software and cable so u can measure hp and tq as well as 1/4 mile and stuff like that with a palm pilot through the OBD2 diagnostic port. i think the car has to have abs cuz thats how it reads all the parameters. the only downside is no abs while testing ang u have to buy a palm pilot

 

Scott, in my post I note that this uses a AUTOTAP LINK It's a program on my laptop that interfaces with the cars computer through the OBD2 port.

Other than two issues I feel this method is more accurate than a dynojet dyno. However a mustang dyno would be able to go beyond the ability of this autotap.

The two issues are 1) data collection limit of 20 points per second 2) Time based data vs rpm based data.

Oh btw.. here is a pic of the tool I used to hold the crank still while wrenching on it. (it's a thick wall pipe with a lawnmower blade on the end and holes placed where needed)

Rich

 

so would you recommend doing just the 1 pulley or all three being water pump,crank and overdrive alt to get the amperage back up? or just the crank? cause ID love the extra ponnies!!

 

Rich, you are the genious with these custom tools. You're definately thinking your way threw problems.

 

Truth be told.. I'm an engineer... and cheap to boot. So between my junk pile of scrap steel... and my mind. Making shadetree tools are half the fun!

Bryce, I'd have to look to others with 4.0L rangers to answer that question. From what I've seen people post on this forum there is no issues with just the crank pulley. I've run mine about 200 miles so far with zero problems (4.10 gears and stock tires)

I reckon that if you put higher than stock demands on the electrical system or cooling system.. you may want to stick with only the underdrive crank pulley. If your truck is stock.. and tires not too tall? Then maybe give all the pullies a try. You can always take them off if it's not working. Another little trick if it fits your situation.. is through your tuner raise the idle 100-150 rpms. That makes a fair difference in the length of time it takes to over heat.

It would also seem that if a guy did mostly stop and go, low speed , hot weather driving? It might become an issue? Personally I drive 35 miles one way to work, in michigan weather, and seldom sit still in traffic. So I'm very confident that my truck will adequately charge and cool.

Oh one quick note: I test drove differing rangers before buying this one. And IMO they all took longer than what I'd call "normal" to warm up. Seems to just be a nature of the beast. Since I did the pullies and fan it now warms up quicker. (been in the 30s here) Did'nt measure any warm up times.. but it seems about 30%-40% quicker to me. (usually let it idle for 30 seconds, then hit the road with easy throttle until the motor is fully warmed)

Rich

 

ha yes he is, that fan tool is simply amazing for 4.0l

 

ahhh ok..im runnin 33's soon to be 35's so im thinken just the crank..weather up here runs from -40F to above 100F gets DAMN cold then DAMN hot in the summer most the time the other 3/4 is the normal..i guess its a buy and try and if it doesnt work to just sell it on here ! Thanks alot i also have a 130AMP upgraded ALT for my stereo just look at my cardomain!

 

I did the pulley & EFan @ the same time on mine and saw an improvement on Gas mileage & a bit more throttle response. Actually, with all the mods I've done the get up & go is better than stock by far even with the heavy wheels & tires. I have 1 particular on ramp I use for comparison, its uphill but not sure how long of a run it is. The truck when I bought it would do right @ 80MPH @ the top, my Eclipse would do 75MPH, now with all the mods the Ranger will do 86MPH.

Rick