Bore out TB?

[Dark Knight GT]

I guess people dont look at the TB..its FREEGIN smooth. "smoothing" it up wont do anything...in reality the groves you make in it wath sand paper will probably reduces flow. And like said, you cant make it any bigger because the blade will not sill, and if you make the rest of it bigger, it will hit the lip where it has to seal the blade and will also reduce flow......buy a BBK 75MM TB like I did. I was going to do the same thing until I was told about the blade sealing thing....and buy a TF plenum for $140...all cheaper and better castings.

I wish I had taken a picture of the stock throttle body, before and after I polished it. Well, actually, I did but the picture was lost with the thread in the crash. I didn't leave any lines or grooves from the sandpaper. These are pretty easy to get out. Thats why you use medium grit, then go down to fine grit. By fine grit, I'm talking 320 grit man, not something harsh. You are also suppost to polish in the direction of the airflow, not against it, like some people do. I should of taken pictures of the FRPP 70mm throttle body I just worked on. I got it even smoother than the CNC finished surface of my brothers 75mm BBK throttle body.

 

[Orions98GT]

I did my plenum last night, took a good 4-5 hours with sanding and everything, the way it was it had all this buildup in it, was really nasty. Then I looked at the TB and it did not seem worth it, wasnt much to be removed and it wouldn't if any increase the flow.

 

[Dark Knight GT]

The plenum had an oily build up I take it ? That tends to happen thanks to PCV blow by. This can be avoided in the future by installing a PCV filtration system. They're pretty easy to make and doesn't cost but around 20 dollars in parts and the time needed to install it. Did it on my car just recently.

 

[Orions98GT]

parts list plz?

 

[hotmustang331]

My stock GT TB was darn smooth, really about like my BBK TB. IMHO 320 is WAY to rough...I used about 800-1000 grit in the final prep when I P&Pd my TF plenum.

But in reality the gains you would see by polishing the already SUPER smooth TB wouldnt even be measurable. P&P the really rough plenums...either stock or aftermarket...WILL gain a little but even then only a few. Heck a 75MM TB will only give 2-3RWHP over the stock TB. And the stock TB will ALMOST fit inside the 75MM one...so thats a BIG flow difference. So what makes you thing smoothing up an already smooth surface on the stocker will gain a measureble amount of power?

 

[hotmustang331]

The plenum had an oily build up I take it ? That tends to happen thanks to PCV blow by. This can be avoided in the future by installing a PCV filtration system. They're pretty easy to make and doesn't cost but around 20 dollars in parts and the time needed to install it. Did it on my car just recently.

Same here...few months ago I think. Make sure your route BOTH PCV lines into the filer with a T fitting. I ran around for a few months with just 1 hooked into the filter LOL...the one that enters the intake tube...didnt realize it had one on the plenum...and that was sucking up all the oil.

 

[Orions98GT]

Same here...few months ago I think. Make sure your route BOTH PCV lines into the filer with a T fitting. I ran around for a few months with just 1 hooked into the filter LOL...the one that enters the intake tube...didnt realize it had one on the plenum...and that was sucking up all the oil.

that sounds like a mess lol.

 

[Dark Knight GT]

parts list plz?

Sure. Go to Wal-mart, check in their power tools section, and look for a water/air filter with one inlet, and one outlet. I believe the one they carry around here is perfect for the application. Its a Campbell and Hausfeld water/air seperator. It can be purchased for about 12 dollars. Also, while in that section, find a pack of adjustable steel hose clamps for around 2 dollars. Then, go to Home Depot or Lowes and match up a couple small barb fittings to the water/air filter. Then, just cut the stock PCV tubing(rubber hosing near where it attaches to the intake tubing) and use the hose clamps to clamp it all in place. It's pretty straight forward.

My stock GT TB was darn smooth, really about like my BBK TB. IMHO 320 is WAY to rough...I used about 800-1000 grit in the final prep when I P&Pd my TF plenum.

Two things. One, you and I must of had different throttle bodies. Two, where the hell do you get 800 grit and finer grit ? The sanding block I used was a 320 sanding block and it makes metal pefectly smooth, like as smooth as the lip of the factory Bullit wheels or as smooth as your stock tail pipes. It could be cause its a sanding block and not paper.

But in reality the gains you would see by polishing the already SUPER smooth TB wouldnt even be measurable. P&P the really rough plenums...either stock or aftermarket...WILL gain a little but even then only a few. Heck a 75MM TB will only give 2-3RWHP over the stock TB. And the stock TB will ALMOST fit inside the 75MM one...so thats a BIG flow difference. So what makes you thing smoothing up an already smooth surface on the stocker will gain a measureble amount of power?

In itself, it probably does very little. Its just something else to do to help increase flow while porting and polishing the stock plenum. Every little bit helps right ? If anything, it will at least make the throttle body attractive on the inside if you wish to sell it.

 

[Orions98GT]

cool thanks.

 

[hotmustang331]

They sell 2000 grit sandpaper . Mine was pretty fine...I also had some emory(sp) cloth. Its been a while but I could have used that...its about 400. I know I used it at one of the stages lol.

yea I hear you, nothing else to do....and hey it WONT hurt if done correctly. (like you said, sand in direction of flow)
I just didnt want people actually going through alot of pain going out to their car and sanding it, thinking they will feel a difference lol. Like a "free mod" or something. IMO I guess if you already have the TB off then go for it...I wouldnt take it off JUST to do it unless your board as heck lol....alls cool.

 

[forpit2000gt]

:


In itself, it probably does very little. Its just something else to do to help increase flow while porting and polishing the stock plenum. Every little bit helps right ? If anything, it will at least make the throttle body attractive on the inside if you wish to sell it. [/QUOTE]

It does do very little, I polished my TB and it made no difference that I could tell. sure didn't affect track time. It also didn't hurt anything. I used 800 and 1200 sandpaper and wetsanded , then used polishing wheel with polishing paste. It was almost mirrorlike. Looking back, I wish I had put that time into something else. I also did some porting and polished the plenum. I did feel a difference with this mod. I then bought a 75mm BBK TB and C&L plenum. I don't know how much that gave me because I installed a timing adjuster at the same time. I did pick up time at the track and I felt a difference.
IMHO polishing the inside of the stock TB was a waste of my time. If you do it or did it and it doesn't hurt performance I would consider yourself lucky.
There are proven mods to bolt on. Most of the free stuff looks good but doesn't help. Ford gave us less restrictions than the 5.0s had to begin with. Even the plastic intake is better flowing than the aluminum intakes on the pushrod engines. (I wish it were aluminum though) happy polishing

 

[Skidzz]

Well I think you guys have convinced me to just buy an aftermarket TB and plenum. At least that way I know I can't go wrong.

 

[Joel's98GT]

i have ported and sold many plenums, my latest is on e-bay now.

the link is for picture purposes, not intended for advertising

http://cgi.ebay.com/ebaymotors/ws/e...=7995202648&rd=1&sspagename=STRK:MESE:IT&rd=1

the view you can't see in the inner radius, which is where most of the metal is removed.

 

[white-04]

I know I'm bringing this back from the grave, but I didn't see anyone mention the screws that stick out of the tb shaft. The two screws that hold the blade to the shaft on mine were way out into the airflow probably causing turbulence too. I cut those down and put them back in and also took some material off the shaft area and smoothed it with emery paper. I think my car is running better cause of it.

Removing restrictions surely doesn't hurt. A decent free mod that will show up more when you put an aftermarket plenum on. That seems to be the bigger restriction.

 

['01 Steed]

God, I hope you used thread locker when you put the screws back in!! If you noticed, the stockers are hollow at the tips and are squeezed flat (or close to it). This keeps them from backing out.

BTW, your t/b blade doesn't open to 90* (or flat). It opens to approx. 88*. The shaft doesn't impede air flow.

All, it's best not to mess with the stock t/b. Just buy a larger one that is made that way.

 

[twogts4us]

God, I hope you used thread locker when you put the screws back in!! If you noticed, the stockers are hollow at the tips and are squeezed flat (or close to it). This keeps them from backing out.

BTW, your t/b blade doesn't open to 90* (or flat). It opens to approx. 88*. The shaft doesn't impede air flow.

All, it's best not to mess with the stock t/b. Just buy a larger one that is made that way.

Agreed, Agreed, Agreed - jesus, if you're gonna screw with your car, why do folks always wanna play with the TB (or the MAF) - a couple of the most sensitive parts...? Lord help him if one of those screws vibes loose and gets sucked down into the motor...

 

[white-04]

Thanks for the vote of confidence guys. Of course I noticed the thread locker. Its not like I'm playing with a Ford GT, GT500 with a whole lot at stake.

01Steed, I call bull****. Just because the blade is at an angle doesn't mean the shaft doesn't impede airflow unless the angle is creating a vacuum. It just means that one side of the shaft may be more important than the other. The shaft is THE narrowest point in the TB and is on both sides of the blade. Removing the excess screws from that point and removing material from the shaft increases volume and should thus increase flow. It does the same as going to a larger size TB.

So you are saying if I did the opposite and doubled the size of the shaft (on both sides of the blade) I would not restrict airflow. I'm not buying it.

 

['01 Steed]

We're just cautioning against potential catastrophic consequences.

Whether you chose to believe the facts or not is your prerogative. That doesn't change the fact that it is what it is.

Oh, and making the shaft bigger is not a fair argument. Of course it will impede flow is it's larger. Now, if you increase the diameter of the blade by twice, you'll be roughly back where you started from....no significant impedement.

You need to study up on your aerodynamics and thermo-dynamics. The only thing you may have done is reduced the speed at which the air flows through that particular point in the system. You haven't increased the volume of air in terms of #'s per minute.

BTW, you "noticed" the threadlocker. Did you reapply new threadlocker???

 

[white-04]

Yes I did reapply threadlock.

Unfortunately I didn't take aerodynamics or thermodynamics in college. If you know the theory I'd like to know, cause to me its not making logical sense.

You agreed that if you make the shaft larger, it will impede airflow, but you say by reducing its size (making a larger opening), you will not increase flow? Even if you have Forced Induction? Not totally making sense to me.

Honestly, I don't expect much until I put an Accufab plenum on it.

 

['01 Steed]

Basically, in stock form, the cross-sectional area of the shaft is "shadowed" by the blade because the blade is at an angle of approx. 2* to the flow. If it were perfectly parallel, we'd be having a totally different conversation where I'd be agreeing with you 100%. However, that blade can only open to that point.

Obviously, if you only increase the shaft size, it will start to emerge from this shadow, thus creating more restriction. Now, if you increase the blade diameter in equal ratios to the shaft, you're not changing the fact that it is still shadowed.

I think I've explained it pretty well.

No flame intended (anywhere in this thread for that matter), but I hope this isn't a case of "I spent alot of time and effort on this, and I'm not going to admit that it was all for nothing" type of thing.
We're all here to learn and share our knowledge. What we as individuals do with the information shared here is beyond anyone's control.

Like you state at the end of your last post, we're pretty much splitting frog hairs here, but the principles are valid.