This is the story of a Groove job on a '05 Ford Ranger STX 4.0 L V-6. My first pastic TB, it got the double Groove, and complete epoxy fill in the IAC integral port, w/ a hole drilled thru the fill for IAC air. Mike, the owner, has given me glowing reports on the results this Groove job has given. He's an astute owner/enthusiast, with above average abilities, and quite car-savvy. Mike has followed all my recommendations, like doing the ECU re-program, and is treating the 4.0 V6 with RVS.
Mike did a minor enlargement of the IAC hole, and slightly flared the inlet opening. Here is some of what he's told me:
Cold engine idle was slow by 200 rpm so where it normally ran 1150, it was at 950. Engine warmed up, idle was perfect at 950. This with the first hole size. I did re-drill the hole at 17/64 and from there flared it a little to ? See pictures. Like I had mentioned before, you weren't that far off with the first estimate. Tap plastics makes a carbon fiber hollow tube that I think might work. I believe I still have some and would be willing to send you a piece if you'd like. I did run the truck and I can say it pulls so well down low, RPMs between 1500 and 3000 that I can drive it in a gear higher. (manual trans.) The fuel savings will be gained by virtue of the fact that I barely have to depress the accelerator to get off the line from a stop light. Believe you me, this a blessing here in SJ where everybody drives a 300hp+ zippy car with an automatic transmission. Nobody drives a stick anymore so when I shift to second gear they're on my bumper flip'n me off. Ya they think I am mess,n with 'em until I shift again. I always thought that the '05 was geared a little too tall with 3.55s and the space between the gears felt a little gappy. Was thinking 3.83's out of an Explorer were in order, Not now! I can appreciate the stretch between gears as the motor now has a linear pull that bridges the gap. Gone is the lazy throttle off idle, when you rap it you get music through the headers like it has high compression heads. It zing's up to and drops off back to idle in an instant. I am stoked to have a new machine, although I will have to learn to drive it with a lighter foot.
I will post favorably on the forum with more of the details. It goes without say'n, Good job T...
and today here's what he said:
Feel free to post previous e-mails. Just got back from Stonyford / Medicino National Forest which was a good test or road trip. And this time I just drove the truck the way I wanted to, meaning I wasn't overly concerned about the mileage. But much to my surprise the mileage wasn't to far off the mark, that is to say it was still a little better than stock. The 'Groove' just as a stand alone performance mod, not with expectations as a gas miser modification greatly enhanced the lower RPM range out on the mountain. For those who don't know what Ford's STX model Ranger is or how I have set it up. It is more like a GT or Grand Touring car. And this mod just flat out works on serpentine, twisty sections of the mountain. Read more bottom end off of the corners. Out on to the 505 by-pass no one was out in front of me for as far as I could see and there is no where for Jonny law to hide. So I took the opportunity to let this motor stretch its legs and then proceeded to bury the tack, the GPS was track'n me at 155 mph with a little more to go. This throttle body mod just gave it a nice pull from the bottom to just before midrange and from there with the butterfly open all the way you could hear a nice growl in the manifold as the engine pulled all the way to the top, I am still grin'n . Will check out the suggested links and reading on GMG.
A (couple) little grooves make a Big Difference! ( and some epoxy too!) Ok heres the pics:
I used a lot of epoxy on this one. Plastic TB is thin walled, so back filled both Groove areas. Back fill inside the IAC port to back up the critical Groove middle part. Then- complete fill of the IAC port required several stages as port has a dog leg sort of shape. Used clear box tape over inlet end, filled from downstream end. Carefully kept epoxy away from gray rubber O ring gasket, gently cleaned under O ring w/ small driver bit when it was wet.
After full cure overnight, pulled clear tape off then painstakingly removed excess epoxy from bore wall around IAC port, and shaped the fill area to match wall contour. Filled in 2 delta-shaped voids in plastic extending to behind main Groove. Had to judge just where to use epoxy, and where to begin and end both Grooves. I used large bit for main Groove, from now on will use Med, large just wanted to break thru too much. Kept it under control w/ generous epoxy use but Med might have saved some work. Certified reverse bit for upper Groove. This one was several times more work than a normal Groove, but judge the results!
Gadgetman Reno, NV
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Here's another report from Mike on his Grooved Ranger.
As many will know, an un-scientific yet telling test of Groove results is to actually smell the exhaust stream from a fully-warmed engine. If you get clean smelling hot air, you know the vehicle is in the Groove...At Ron's in Phoenix 2 yrs. ago, a car he'd Grooved was giving zero's on the 5 gas analyzer, so I tried sniffing the exhaust, it was hot moist air, I was amazed. That really "set the hook" for me...
Tracy, (Feb. 19th)
Did a long warm-up in the driveway while I was sidetracked in the garage machining a part.(ten min.?) Dropped what I was doing and jumped in and slow rev'd the engine, let it settle for a bit. Then rap'd it fairly hard to hear on de-cell how clean it drops to idle; That tells me it is warm enough to drive hard out of the gate. Then I let it idle for about two minutes, jumped out and gave it the whiff test. If ? maybe If at all was there a trace of something I couldn't identify as exhaust. Alright, I needed another opinion so I grabbed by brother who has a very sensitive nose to see what he thought. This guy can smell solvents on my hand even after washing them in the garage sink before entering the house. Same thing! Nary a trace of what one might normally think of as an exhaust smell.
That's what I've got for now, let me know how I can help you out in the future.
A little Groove can do a lot...
Gadgetman Reno, NV
quick note to Gadgetmen: be on the lookout for these Ford V-6 F-150's Some brief research revealed some cool Ford engineering re: the intake manifold design on these Ford v-6 engines, 4.2 L. Look at this pic from Ebay:
length short/long runners to each cylinder to boost torque band. I don't see any pesky runner control valve on this manifold either. Notice how IAC is separate from TB, so filling in upper air inlet slot in TB to smooth boundary flow adding small hole in fill as restriction is effective. Very good Groove candidate IMHO Tracy G
Gadgetman Reno, NV