jamienoel

Well I finally got around to doing something I've been wanting to do for a long time - GRIND DOWN THE DANG THROTTLE BODY!!!

Here is my experience for the first time using a high speed (up to 30,000 RPM) Dremel type tool and I don't recommend this for everyone!

I didn't get any pictures of the bottom of the throttle plates after I finished, but I did grind them down a bit.

I decided to simply round out the tops of the screws rather than grind them all the way down. That way there would still be some "bite room" for the torx driver, which is good because while I was grinding, the stone bit grabbed one and unscrewed it after I had ground the other side of the shaft. I had to mess the threads up a little so it would screw in tight and not have to worry about it coming loose on it's own. I'm going to check it frequently. I wonder if Loctite works at high temps?

This is the original throttle body, but the injectors are from a 350 truck as is the engine.

99.999% of you already know what comes off on top, but here is a little illustration of what needs ground off to get things started!

Note: Time stamps may not be inline. I also need to check the camera settings because I don't like it showing the day before the month.



And of course this side needs ground as well!



This is not for the faint of heart! Here is a pic with the cutting wheel halfway through one of the ridges.



Halfway through. Look at where I started on the other side. (circled)



Did I mention this isn't for the average tinkerer? And when they say patience is a virtue....

Here's a top pic of being halfway done.



Getting things evened out.





SHINY!!! I actually polished it a bit so I could better see inperfections.

jamienoel

Continued....


Note the screws how I rounded them a little. Sorry I didn't snap anything of the other side, but take my word that it's ground down a good bit.



Front shot with pod sitting in place before cleaning.



Side shot with the pod sitting on top before using carb cleaner.




Note that I used a lot of different things to even out the ridges. I actually found that using cutting wheels (dang those things are brittle) to kind of take the ridge off in layers at an angle worked best. You really need a steady hand though!

And here it is all ready to put back on the car!

I swear this thing looked better before I sprayed it! LOL!

bigreed91

looks good, i wana get a spare tb to grind on. have you put it back on yet to see if you can feel any difference?

KurtAKX

The cutting wheels are brittle, but if you do something like this again, do yourself a favor, and get the reinforced cutting wheels. They are about a dollar apiece, but they don't fly apart as soon as they touch metal.

jamienoel

I'll be sticking it back on today. Hope it's at least a little more responsive than before.

I think I will take your advice because it took me several tries before I got it down pat to where I wasn't breaking them. Luckily I had quite a few.

thomas1976

Nice, you sure did one of the nicer ultimate TBI jobs posted on here over the years.

I myself was lucky and could buy one like this http://www.chevyhiperformance.com/te.../photo_05.html from Tom Miller of Turbo City.

Nicer than jewelry

jamienoel

Thanks for the compliment! I am somewhat of a perfectionist!

I guess if you have the right machinery, it would be easy! Mine was done with sweat and fear... And of course a Dremel! LOL!

I noticed I don't have to give it as much pedal and when I take off from a stop, I am finding myself having to give it less or I chirp the tires!!!

Today my gas gauge didn't move quite as much for the same distance. Going up a big hill was effortless and I find myself using less pedal on the freeway in general.

How can a little ridge make that much difference?

I am going to the junkyard in a month or so and get a set of Vortec heads. I also want to convert it to a roller system and my block being a 93-94 has the holes tapped for a spider!

Here's a pic of it back on the car and running...

92firebird 305

very nice can you do that to my tbi im to scared to do it

jamienoel

I was scared poop-less when I did it!

I just took my time and hoped for the best. I knew that if I screwed it up, I could get another one at the junkyard, but I guess it's not bad for a first try.

Seems to work quite well, too! Amazing in fact!!!

Wonder what a bolt-on TBI supercharger would do? Probably blow the engine apart.

jamienoel

Could you just see me doing that regularly? "Yeah, $25 and cost of materials!"

I would probably have a heart attack from the fear that would accumulate each time I picked one up.

How much are the professionally ground ones going for these days?

92firebird 305

well rv morse machine wants 200 bucks for a new one bored out to 46 mmm new shafts http://www.rvmorsemachine.com/product.htm

jamienoel

Those are NICE!

badjuju342

Standard Abrasives makes a really nice kit that does a great job of porting and polishing. you can just about get it to look like chrome . I did the BBK throttle body on my LS1 with that kit .

jamienoel

I actually had this one polished like chrome so I could look for imperfections and high spots, but I unpolished it with high grit sandpaper before finishing because I heard you don't want the intake super smooth.

jamienoel

I just looked at the differences in the intake bolt patterns and such for the Vortec. Yikes! I wonder if there are any low cost intakes out there for it?

Schurkey

First guess: It doesn't.

I have a very hard time believing you've accomplished anything useful at less than 90% throttle.




I hope you cleaned out the idle air passage and IAC when you finished. If not, your engine inhaled a lot of grinding dust.

If you ground down too much of the throttle plate screws where they're staked to prevent loosening, I hope the engine doesn't inhale those as well. Yes, the screws should be Loctited if they're not staked. Yes, Loctite releases when heated. NO, the throttle plate doesn't get hot enough to weaken the Loctite.

The secret is to buy aftermarket Vortec-style heads that have the old-style 6-bolt intake bolt flange. Then use an "ordinary" performance manifold that has a Q-Jet carb flange and an EGR passage, with a 454-style TBI-to-Quadrajet adapter. (assuming you have hood clearance!) You may have to modify the EGR system as with any Vortec head, the Vortecs don't have an exhaust crossover.
http://www.chevelles.com/forums/showthread.php?t=385005

jamienoel

I wondered how long it would be until a guy had to shoot down something a girl said even when she's experiencing it.

I don't have to give it as much gas when I'm on the freeway, mileage has picked up a little and my normal takeoffs are crisper so-to-speak.

This is a 93-94 5.7L flat tappet truck engine with an RV cam, so perhaps things are different than what you're thinking?

Eventually I plan on opening things up, but right now money is scarce.

Extremely well.

Thanks for the advice!

I also failed to mention that I doubled the gaskets on the pod to give it a little extra height.

jamienoel

One more thing... I also made the fuel pressure regulator adjustable and I think I have it turned up a little higher than I should, but I don't have a gauge for it yet.

This doesn't explain the increase in mileage though since it is likely getting more gas, but if it's sucking slightly more air at less throttle, I guess it could make sense?

Shaving the throttle shaft and rounding the screws off have to count for something.

midias

You can get just about about vortec carb intake and use an adapter plate.