a new tbi mod
 

i was searching things out online and ran across this. it is very interesting. i have an extra tbi that i am going to try this on soon. thought more would like to read about it. go to the page and go to the rerouting gm tbi groove and download. very interesting reading. when i do mine i will show doing it and the results.

http://www.gadgetmangroove.com/index...nts&Itemid=429

Re: a new tbi mod
 

:bs::idiot:

Re: a new tbi mod
 

that's awesome

please be sure to post before and after dyno graphs

Re: a new tbi mod
 

My first XMas present. THANK YOU !

Re: a new tbi mod
 

dyno graphs wont help any. it is not a power mod. this is an idle, runability, and fuel mileage mod at best. but right now i can drive between 70 and 75 and get 22 mpg. my idle is not the smoothest but is pretty darn good.

when i do this i will show it all step by step and report back. i have a digital timing light that shows rpm's. ill hook it up before on this tb i have now with ultimate tbi mods and then the modified tbi. then if it works i will do the ultimate tbi m ods to this one and see where we go from here.

Re: a new tbi mod
 

Really interested to see how this all comes out! Please keep us all posted. Ill be waiting to see the results!

Thanks for doing this!

Re: a new tbi mod
 

Woof.

Do I understand this correctly? The big plan is to mostly plug the IAC air passage, and then compensate by opening the throttle more via the idle speed screw? Yeah, that'll make for 40% better fuel economy.

Got news for y'all. The engine needs a certain amount of air to idle. The engine does not know where the air comes from. So you can get the air through the throttle plates, or through the IAC passage. Actually, the air comes in through BOTH. The only thing you're doing with this mod is reducing the air at the IAC passage, and increasing the air at the throttle plate.

In the process, you're screwing up the ability of the IAC to control the idle speed; and you're screwing up the TPS voltage that the computer is expecting to see at idle. Neither of these side effects is going to improve fuel economy or driveability.

Then, of course, not all TBIs have the divided passageway:
http://hbassociates.us/5.7_TBI_original_sm.jpg

Compare to:
http://hbassociates.us/5.7_TBI_newer_sm.jpg


Overall, I'd say the author of that article is nuts.

Re: a new tbi mod
 

they reshapeed the passage tho i still don't know how it helps

Re: a new tbi mod
 

Yes, it's reshaped along with being made smaller.

Fixed it for you.

I have no ambivalence. This is a waste of time, money, effort, and enthusiasm; if it does ANYTHING, it is more likely to create a problem than increase fuel economy or improve idle quality.

Re: a new tbi mod
 

it should still read how as well. because I see they reshaped how it enters the throttle blade area but I don't see any explanation as to why this reshaping is beneficial. I am still supportive of you guys trying it out if you got the time and spare parts. I would just like to know IF it helps, why does it help.

Re: a new tbi mod
 

i believe the end result is to lower the amount of control in which the iac has over idle. since the iac is a metered vacuum leak i believe that is what they are after to try to eliminate although not completely.
as for the tps mine is grooved as most others that have modded their tbi's.
the iac will still be in play somewhat just not as much as before. so their idea to limit the iac vacuum leak to a minimal is all they are trying to do as the iac in 80% of the tbi's out there never really closes off completely. between me and a buddy we have a couple extra tb's to try it on.

ill try the one i have first and see how it goes. heck if all i get out of it is a really steady idle i will be happy.

Re: a new tbi mod
 

And I might add, that those of us with EBL Flash probably won't have as much of a problem due to tunability. Since it's not being cut off completely I don't see why it wouldn't work and lead to some improvement. Can't wait to see how it turns out for you. Perfect timing too, since I'm re-working my fuel injection at the moment

Re: a new tbi mod
 

let us know how it works out

Re: a new tbi mod
 

just remember it is not being cut off completely. only reduced considerably. tuning is not an assure towards it except maybe injector pulse width. i will definitely let all know how it turns out.:nod:

Re: a new tbi mod
 

interested to see if this works. my car is running like hell, idle is terrible, when i start the car it sounds lke i have a big cam in it then it levels out. when i unplug the MAP sensor it dosent do it. I cleaned the IAC and it was running alot better for like a week, now its running the worst it ever has...

Re: a new tbi mod
 

and what happens if u where to make that channel deeper than what he had done? hmm interesting

Re: a new tbi mod
 

Doesn't much matter- he said to take it down as far as possible. The idea is to seal up most of the space by the throttle bores, just leaving a little bit for the IAC to work

Re: a new tbi mod
 

Well, I'm not going to comment on whether or not it might improve idle quality, but I can virtually guarantee that you will not see a 40% improvement in fuel economy. Since that is what he states, and mentions nothing at all about idle quality, it appears to be snake oil. I would venture to guess that the end result will be no change whatsoever on a properly tuned engine.

Re: a new tbi mod
 

I don't see how this would help fuel economy. All you are doing is lessening the effect of the IAC on idle. I could see it helping idle by atomizing the fuel a little more since you are sucking air through the butterflys.

Re: a new tbi mod
 

i think their belief is that the iac never completely seals. i have not done this yet.

Re: a new tbi mod
 

*sigh* Would you guys like me to play guinea pig? Hopefully I'll be taking my TBI unit off this weekend for some grinding and I'll be able to attempt this

Re: a new tbi mod
 

It doesn't need to totally seal.

Re: a new tbi mod
 

i understand it doesnt NEED to totally seal. im sure it gets close to it.

im sure all will have their own opinions. hopefully ron will do it. i might do it now for real since i will now have an extra tb for sure. they are trying to limit the air that the iac leaks. which in turn by them is veiwed as extra air.

Re: a new tbi mod
 

Reality check!!!
:lmao: :lmao: :lmao: :lmao: :lmao: :lmao:

You guys aren't really going to put epoxy in you IAC ports are you? :idiot:

Your going to follow instructions from a guy who got 40% increase in fuel mileage? OK let's see, GM hasn't been able to increase fuel mileage buy 40% in 40 years... When the epoxy cracks and sends chunks through your engine let me know how that 40% increase in fuel mileage worked out for you....

How is this going to help idle? He never said anything about that? If the passage was smaller it does not matter the IAC is only letting in a little air anyway...

Now if there was any truth to increased fuel mileage by forcing more air through throttle blades to atomize fuel better instead of air coming through IAC port. Then just wire up a switch to close your IAC on a highway drive and see if fuel mileage increases! Better yet, close IAC by crossing A and B of ALDL port, unplug IAC. Remove jumper from ALDL port and go for a drive to check mileage. If your min air was set correctly it's only going to idle 100 RPM lower. Or open the throttle blades up a little and adjust your TPS.

But don't put epoxy in your IAC ports please? Did you read the other one? He mixes aluminum shavings in epoxy to give it more strength. More strength? Just what you need more strength in the hunks flying through your motor...

OK I'm going to go to bed now and have nightmares of blown motors around the world because people belive what they read from Gadgeman on the internet...

Re: a new tbi mod
 

This seems to be a weird discussion to me, but I am subscribing to see if anyone actually does it and what, if anything, really happens.

Curiosity is a real bit@h sometimes hahahhaha!

Subscribed!

Re: a new tbi mod
 

What if we used solder instead of epoxy? It would be harder to work with but we wouldn't have to worry about cracking or decaying

Re: a new tbi mod
 

Yoo would have to use that aluma weld stuff that it basically solder for aluminum. You need a lot hotter flame for it. If I was going to fool with something like that I would just get some 1/8 inch or 1/16th copper tubing lay it in the passageways then incase it in epoxy but lightly coat the aluminum with grease. You would be less likely to have the epoxy break up and the epoxy would be easy to remove when you decided it wasn't worth fooling with.

Re: a new tbi mod
 

Filling it with a weld then dremling, then maching the bottom flat would be safe. It's still just a stupid idea, but to put something in there that could crack a pice loose to fly through the engine is just dumb! :idiot:

But I still think it's a waste of time.

When I do a next highway trip I am going to close IAC and record MPG to see if there is any difference just for kicks!

But 40%? :lmao:

Re: a new tbi mod
 

Or...
1. Push clay into the IAC channel
2. Pull clay out and bake it
3. Very carefully grind a portion of the plug to open up the channel
4. Press the modified plug into a piece of clay
5. Bake the plug and mold together
6. Drip solder into the newly hardened mold
7. Secure into IAC somehow

Just something off the top of my head- thoughts?

Re: a new tbi mod
 

I have to agree with Mark on this, even IF you were to do this, and it did limit the amount of air the IAC lets through, opening the throttle blades more to compensate for this will do just that, compensate. Even if by some miracle you did manage to offset the Air/Fuel ratio and get better mileage, it will only be temporary, until the BLM in the ECM adjusts the whole thing back to oscillating back and forth across stoich, might take a tank of gas or three.

And again that is ignoring the loss of Idle quality that is built into these. Especially the later PCMs.

If you have a later PCM running your system, then there are a lot of options for adjusting IAC control, and tuning AFR. I would go that route. It would much easier to get better mileage by tuning the ECM/PCM, and not risk "dropping a deuce" down the TBI.:lmao:

Re: a new tbi mod
 

I to have seen every fricking vid that has been done on this mod and reviewed a few other forums where this mod was done! not real hard data but a heck of alot of seat of the pance happy customer. this groove creating this low pressure wave is past me I'm looking at the flow pattern to determ how he is getting the low smog number on his testing equipment? I'm not sure we see all he is doing. Thanks

Re: a new tbi mod
 

I never saw this thread. im going to call BS on it. But I am interested in see'ing results.

Re: a new tbi mod
 

Hey Guys, I met with the inventor today and have a moded tbi in hand! Also I watch the process done on a saturn driven before and after! Just A FYI on the groove its not what you would think the name implys. I also have a post started which I'm using for testing and reporting.

Re: a new tbi mod
 

Did he invent that carburetor that got 100 MPG too? Cause if he did this must be true...

Closed my IAC today and did a 64 mile trip, filled up before I left, filled up when I got back at same gas pump. Got a HUGE increase in MPG.... 17.6 mpg... same trip with IAC hooked up was 17.5 I'm guessing if I had keep better numbers it may have been less then .1

So now it's up to someone to make little groves cause closing IAC does nothing...

Re: a new tbi mod
 

this is one of the dumbest effin things i've read.