TOPIC: 1998 Toyota Camry 2.2L 4 Cylinder

So I cut my first groove and was able to get a feel of the groove cutting experience. I understand why so many people said to not try to make the groove look pretty, it's really tempting and I may have even done it in a small spot before stopping myself.

While the throttle body is off the car it's a good time to replace the 4 screws that hold the IAC on.

These two links have information on removing the throttle body and IAC.

DIY removal & cleaning of IAC | Toyota Nation Forum
5sfe IAC Removal (lots of pictures) | Toyota Nation Forum

Idle Air Passage:
I cleaned up the jb weld a bit but didn't take a picture.






The Groove:
In a couple places I tried moving the bit to the left to join the cuts together but I didn't feel confident with my groove cutting work area and I thought that I might ruin the shape. I can always recut it and I figured I would see how this cut performs.






I made some changes to increase manifold vacuum as much as possible.

So far I have noticed some improvments in MPG, drivability and increased vacuum but the car probably needs a new front o2 sensor.

I have been making a lot of changes so it may be some time before I get some solid results. I have probably reset the ecu 3-4 times this week.

Congratulations on getting results. Please keep us posted on the MPG gains.
I am guilty of making mine look "pretty" and in doing so didnt have a tight wedge with the bit in the groove. That is the test to see if you did a good groove. Did you try the wedge test? Mine was a pretty groove for sure because of the grinding off of the rougher looking spots to polish it but when it came to the results of the wedge test, I failed big time. Too much taken off trying to make it smooth and "pretty". Too much detail in looks and not enough detail in following Rons instructions.
Also from what I can see in the pics, it looks like the groove cuts are not connected. Did you connect the channels of each cut so you have a even groove? Which size bit did you use? Dan and Tracy say they do many grooves with the medium bit with good results and of course less holes in the TB that JB Weld has to fill
Karl

Nope they are not connected, maybe one or two are sorta connected. Once I started cutting I realized that how I had my work space setup wasn't going to allow me to connect the grooves without messing up the shape (creating bit wobble). With the cuts now, the bit does get stuck, it wobbles but I'm pretty sure it's in the acceptable range. I'm thinking maybe I made the cuts to far apart but maybe some of you can offer some feedback about the cut/technique etc.

Tracy suggested I use the medium bit and recut with the large later but I went with the large bit.

I'm interested in the learning experience and the worst case scenario is getting another throttle body (which I will probably do anyways). This cut was just a trial run to get a feel for things and to experience a more primitive cut. If I do get another throttle body I will most likely use the medium bit.

I did break some "scan gauge records" even with all the messing around I was doing but I didn't verify anything at the gas pump.

Closed throttle TPS reading on the scan gauge is 10. At 19 there is a sweet spot where the car starts accelerating and the vacuum appears to be doing something different. 19 may also be the middle of the "groove zone".

Hey Nate you're doing good on your first Groove!

Yes it does take practice to get used to doing Grooves. what I noticed in Ron's training vid's (and in person) is- Start on far left end, when you see/feel/hear the tool speed drop a bit its a sign the bit is full depth and the angled part of the bit shaft right behind the head is starting to drag on the bore wall. Now move 1/2 of the width of bit to the right and repeat. By overlapping the cuts this way it helps to eliminate scalloped cuts. Notice that Ron will often (me too) hold the tool steady and make a slight left cut once the bit is full depth- this connects the cuts together. Continue on this way to the right end avoiding the throttle shaft. Once the full Groove has been cut you can make one pass from right to left as a cleanup. But Ron emphasized to do only ONE cleanup pass. It is tempting to keep at it- but the more you do the more wallowed-out the Groove gets.

Now that it seems like you are seeing some gains, we will all wait for more results. If after some tanks of gas and calculating at the pump you Do see gains, this will prove the point that it's results that count and not looks of the Groove!

Nate did you roughen the aluminum surface in the IAC channel before applying epoxy? I always do to help ensure better bonding. I just did a TB for Karl, and did a big epoxy dam in the IAC "spillway" into the TB bore. IF it's Ok w/ Karl, I can post a few pics of this to give a clue of a technique. Took w/ a camera new to me just gotta get pics loaded to be able to share.

I went and bought a Panavice 2 yrs ago, mounted on a heavy piece of iron u-channel, to give a stable holding fixture that I could move around on the bench. I relly like it. Using some kind of vice is a real good idea for Grooving. I like to use both hands to steady the Dremel whenever I can.

Thanks for sharing those nice clear pics w/ us Nate, you're gonna do great!

Tracy G

I did break some "scan gauge records" even with all the messing around I was doing but I didn't verify anything at the gas pump.

Closed throttle TPS reading on the scan gauge is 10. At 19 there is a sweet spot where the car starts accelerating and the vacuum appears to be doing something different. 19 may also be the middle of the "groove zone".
Nate,

Its good to have a SG for reasons like that. My TPS reading on closed supposedly is 16 which is good if I were to use the throttle plate as a guide to cutting the groove which Ron says works best between 15-20 degrees if I remember correctly. One can even use the throttle screw to open the plate to 15-20 and use it as a support for a groove cut instead of guessing where the right angle is freestyle.
What are your readings on the MPG now on the CG? Curious to what SG is telling you. But also remember that SG can give you the yipees on the current MPG readout but reality at the pump at fill-up can deflate that balloon real quick.

Tracy
Yes Tracy you can post any pics you want of the double groove TB. Am anxious to see it myself and test it out. Your promise of doubling my gas mileage with the double groove you did is very exciting to hear.

Only kidding. Am anxious to see if there is any difference in the performance with the second cut.
Makes me uneasy though to hear the $$$ you spent on the special bits. With all that extra $$$, you could have instead bought another Subie to bang your head against.
Karl

The pics show my 2nd attempt at building up the IAC passage. I wasn't happy with the first attempt.
I did rough up the aluminum the 2nd try. The little JB wall that restricts the IAC passage is connected to JB that is building up the bottom of the throttle body. I wanted to be sure the little JB wall couldn't break off and get sucked into the intake manifold.

I wasn't too sure on how I wanted to do the IAC passage so I decided to do something that seemed on the mild side. I figured I wasn't sure what I wanted to do I would do something simple. I also planned to mess with other idle related adjustments on the throttle body and didn't want to do too much at once incase of a problem.

I am interested in seeing more techniques

Karl411 wrote: <em>I did break some "scan gauge records" even with all the messing around I was doing but I didn't verify anything at the gas pump.

Closed throttle TPS reading on the scan gauge is 10. At 19 there is a sweet spot where the car starts accelerating and the vacuum appears to be doing something different. 19 may also be the middle of the "groove zone". </em>
Nate,

Its good to have a SG for reasons like that. My TPS reading on closed supposedly is 16 which is good if I were to use the throttle plate as a guide to cutting the groove which Ron says works best between 15-20 degrees if I remember correctly. One can even use the throttle screw to open the plate to 15-20 and use it as a support for a groove cut instead of guessing where the right angle is freestyle.
What are your readings on the MPG now on the CG? Curious to what SG is telling you. But also remember that SG can give you the yipees on the current MPG readout but reality at the pump at fill-up can deflate that balloon real quick.

On a side note: I put about 4gallons of winter fuel that was at least 4 months old in the tank before i cut the groove. It was in a gas can and needed to be used.

In one area I drive in has a speed limit 50mph with many stop lights. Before the groove I used to see 18-22mpg AVG and 24mpg with light traffic. After the groove the average has been 24-28 and 30 on a good day. My last trip in that area was 36.7mpg. I think the spike may have been from the ecu's adaptive learning. I reset the ecu (at least twice) since then but I know what I did before that mpg spike happened so I'll see if I can replicate it.

I haven't done any post groove highway tests yet but pre groove I was able to get 29-30mpg avg on the SG. The car was able to get 30mpg highway (pump test) pre groove. I think 32 was my best with only gapped plugs and stock pcv connections.

My best SG highway avg was 33mpg (gapped plugs, lcv reroute). It may have been before the winter fuel.

Nate and Karl- you guys keep at it, I think you are both going to show us things in the time to come!

Yes Karl the double groove will certainly double your mileage, as long as you calculate in half-mile increments...and it always does this on the fifth Tuesday of every month, guar-un-tee'd... That's not all, if you make the trip cross-country, I'll even show ya my secret method of rotating all 4 of your tires simultaneously, no need to go to the tire store...

Ok the guy with the long hook just jerked me off the stage...

Actually Karl ya got me slapping my forehead here...of course...it IS possible to move the Groove slightly downstream from the normal idle position with help of the idle set screw, dunno why I never thought of that...can't remember if Ron ever had much to say on that. Some analogy to Grooving the GM Vortec DBW TB's here, where if you get the Groove at too low of throttle angle it has, shall we say, Interesting results. Like a truck that won't idle at under 18 MPH- where the Owner lives next to/in a 15MPH Park speed zone!! (ask me why I know)

Nate I'll see If I can get the pic's of Karl's TB uploaded tomorrow, I'm too tired to do much right now. And Karl right you are about the Certified bits/program heck I could buy a Subaru I know of right now and still have 2 grand left... but it's all in the name of Progress and Adventure and Curiosity, right? But hey- I'm a guy who has fun w/ a Dremel and discovered tin snips a few years back...

One other thing- Karl in speaking of throttle angles and bit Groove cutting angles together, we may be confusing the issue possibly. Throttle angle is how many degrees of arc from fully closed (or maybe theoretically from a tangent position relative to bore centerline)a throttle is at. When Ron spoke of the 15-20 deg angle I think he referred to how far up from parallell to the bore wall the tool shaft is as it is held while cutting. Now- you could use an idle set screw to move a throttle plate to a certain angle, but in so doing you would be moving the Groove downstream if you were placing the flat end of bit against the plate as a backstop...I usually just look at the shaft taper just below the bit head, and try to get that taper about parallell to the bore wall. For those fastidious enough, get a cheap protractor from the school supply isle, and measure out the desired angle to some flat card stock and cut a template of the angle you wish. You can do this to a size to fit most any- or even to a certain TB in question. Then you have a guide to stick into the bore to give a visual of that angle as reference when cutting that Groove. Probably would work better for those with better vision than mine!

Ok that's enuf crazy detail for one evening...keep Grooving, make more aluminum dust!!

Tracy G

Ok so you guys got me thinking here..

I decided to pull off the intake tube to have a look at the groove. I think at the very back the groove is connected but the connection between grooves lessens with the shape of the bit.

It's tricky to get clear pictures of the groove but I'm figuring it out!

Here is a picture at the 19 TPS. Driving an 19TPS isn't the best for MPG (according to the SG) but the car is really happy.



Here is a picture with the throttle plate wide open.

Tracy,

Since my TPS tells me that its 16, Im figuring 16 degrees from perpendicular to the TB shaft.
Mine supposedly is closed at 16 since when I took it off the plate is closed and the SG reads 16 when running on idle.
Guessing my cut would be easier using the plate at 16 degrees as a backstop and going straight down to the wall to cut. Thats the way my mind processed it.

Nate,
Supposedly those ridges between cuts are supposed to be gone and have one smooth groove to each side.
I overdid it by making multiple passes back and forth to clean it up and that is where I overdid it.
Tracy or Dan can tell you the best way to remove the extra ridges there without taking too much off like I did. Like only making one pass to knock off the excess.
Karl

Karl what I've learned to do from Ron and others- is I often use a Sharpie pen to put a mark on throttle blade at where each end of the Groove will be to avoid the shaft. Then w/ Dremel off I will position the bit/Dremel to practice the bit angle, to see how to hold to keep bit square in relation to plane of throttle blade. I'll check the position in the Panavice of the TB so it's as comfortable as can be. Only then will I dip bit in light oil, then turn Dremel on. First cut at left end, holding Dremel steady using enough press. to keep it steady but not too hard either. When I think the bit has bottomed out (listen watch feel, the sound can change as the bit shaft begins to drag on bore wall,) I pull out then so to avoid making a divot w/ the shaft. I re-dip bit in oil, then often turn dremel off, to check the work, brush out alum. dust, and re-check positioning. Next cut is half a bit-width to right of initial cut, takes concentration to get the bit repositioned in control. I like to use both hands if I can on Dremel, when bit bottoms THEN I aim to put leftward pressure in it to clean it up to begin making an actual groove. Trick is- as always don't cut too much, just cut down any scalloped ridge between cuts. this is reason to make a series of "half-bit-width" cuts, to avoid sharp scalloped cuts that aren't well joined. I nitice that often things want to go awry about halfway through at the critical mid point. This is of course the center of the Groove the area that is exposed to airflow first as throttle is opened. I try to re-double concentration from here to end always visually re-checking tool/bit angles all the way. Some
TB's have harder aluminum than others. It's tempting to get rushed along by how the bit wants to cut, must try to maintain control. And I often remove bit at end of a cut and re-dip it in oil these bits need care to last. And-if I'm cutting into JB weld w/ the bit I sometimes avoid oiling bit to avoid interference w/ the epoxy.

IT's also easy to use the blade as a backstop sliding flat back face of bit down against bore wall and maintaining your angles as you go. All this does take practice. Some do better looking work than others. But I've seen rather rough looking Grooves work. We want a full-depth Groove cut as deep as bit will allow, yet as tight to the bit shape as we can. Heck we aren't CNC machines we're humans! Upper Groove for Karl's Mazda was a doozy to cut. TB was so deep- it swallowed the whole long legnth Certified reverse bit and part of Dremel too. Could hardly see what was going on. The Upper Groove is an Experiment on top of an Experimental Mod! Probably a good Thing I'm just cutting Grooves here, not building Moon rockets. "Hey, who wants to bring us some nice Green cheese?"
Anyhow another way to think of Grooving is to visualize a series of close chop cuts, where you are moving left-right, but at end of a cut you also do a slight left back-cut to connect the cuts but without digging around. Remember what Ron taught about avoiding "Penciling" w/ the bit... Then at end of the Groove, you can make one left hand pass from right end to clean things up, but use restraint.

Tracy G

So when the time comes and I'm ready to recut this groove, How would you guys go about it?