How To: Modify a 4.0L OHV Throttle Body..

*Spdrcer34* · 04-22-2007, 05:26 PM

I needed some money, so I sold the BBK Throttle Body off of my Daily Driver...not REALLY wanting to go back to a stock TB...I was reminded of the ThrottleBody mod that 'aldive' had done to the Ford Motorsports TB on his SOHC ( http://www.explorerforum.com/forums/...ottle+body+mod )...I wanted to do the same thing...well 1/2 of what he had done at the least...

So this is how I did it:

Start with a TOTALLY STOCK Throttle body (note: this mod has to be done with the TB off the vehicle) Like this one:

When you open the throttle/butterfly, you'll see the issues with this particular design:

The VERY FIRST thing you need to do, in order to disassemble the TB, is to grind off these little screw ends. The best tool here to use, as shown, is a rotary tool. Often called a Dremel. I have a flex shaft installed on the end of mine, making it easier to get into small spaces. The factory used a hollowed out screw tip so it could be crushed during final assembly. They did this to prevent a screw from coming loose and entering the motor.

After you get those pieces cut off, you can start taking it all apart.

Start with the Butterfly Screws

And slide the Butterfly out of the throttle shaft

Remove the plastic link from the 2 cams on the side of the TB, and remove the 8mm bolt.

Now everything just slides out easily. DO NOT let the springs gets bent, lost, or otherwise damaged!

Okay...once you cross this line, you are at the point of no return. Let's start cutting! Take a look at the throttle shaft that holds the butterfly. You are going to cut part of it off the shaft. You are going to cut the side that DOES NOT.....I repeat...you are going to cut the side that DOES NOT have the threads tapped in it.

This is exactly what you have come this far to remove

Now comes the tricky part. If you'll notice in the pic of the section removed from the shaft, I didn't make the cut flush with the slot in the shaft. I left a LITTLE meat in there. I started to dry fit everything together....and trimmed a little more from the meat I left of the shaft.

Once you get the shaft trimmed to match the bore of the TB, it's time to trime the screws again to make up for the length lost in this modification.

Get it the shaft and butterfly all cleaned up again, and start the assembly.

Start with your now clean Throttle Body

Put the Larger of the 2 springs in place, the way the 'hook' is oriented in the pictures is correct

Insert the Throttle Shaft in the Throttle Body. Wind the spring around 1x. Do not load the spring any more than that.

Now attach the Butterfly on the Throttle Shaft, in the Throttle Body.

Only a couple more things to do, and you're done. Attach the other Throttle Linkage Cam with the 8mm bolt. Make sure you wind the spring only 1x. And after the shaft is bolted down, attach the plastic link to both Linkage Parts

And that's it...You're DONE!

Ryan

*Spdrcer34* · 04-22-2007, 06:06 PM

Here is a decent Side By Side Comparison of the Before & After..

And with the Throttle Closed

I wish I would have gotten a better before pic, of the shaft in the body, and how much area I gained by removing that part of the shaft.

Ryan

bikeboarder · 04-22-2007, 06:08 PM

any noticeable gain in power from doing this? or is it like the "tornato"? sounds like a good idiea. but i dont want to tear into my perfictly good TB for little power if it could cause trouble down the road.

*Spdrcer34* · 04-22-2007, 06:14 PM

This is definitly worth while...I just removed the BBK Throttle Body, Installed my newly modified Stock one and took the car around the block. I noticed NO difference in the way it left the line, and no driveability problems in the short drive I took....

I think the BEST thing to do, would be to do this to a BBK ThrottleBody...it took me very little time to do, and I had never done anything like this before.

With this write-up, and pictures....surely you guys could do this too now!?!?

Ryan

bikeboarder · 04-22-2007, 06:20 PM

i'm doing it. I just want to go to the junk yard and buy a replacement shaft just incase i cut the wrong side or some stupid thing like that. Because i have been known to stupid stupid stuff like that.

*Spdrcer34* · 04-22-2007, 07:53 PM

..wife just came home....

I showed her this thread, and now she wants me to do this to her Explorer too..

So I'll have to do this to her X on Wed, or Thurs.

Ryan

aldive · 04-22-2007, 08:53 PM

Did you consider increasing the diameter of the TB also?

bikeboarder · 04-22-2007, 09:35 PM

So i did this. I cant tell a differance at WOT but i can when i give it 3/4 or so throttle.

Quote:

Originally Posted by aldive

Did you consider increasing the diameter of the TB also?

how would you do that? would you have to hone out the TB then use a bigger throttle plate?

trucku · 04-22-2007, 09:54 PM

Nice Writeup!

*Spdrcer34* · 04-23-2007, 01:34 AM

Al...Yeah...I will do that at a later time...after all...the WHOLE reason I had to go back to the stock unit from the BBK, is I have medical bills to pay....

Thanks for the kind words guys....I appreciate it, ALOT

Ryan

*Spdrcer34* · 04-23-2007, 12:12 PM

Quote:

Originally Posted by bikeboarder

how would you do that? would you have to hone out the TB then use a bigger throttle plate?

Exactly. They would cut the inner diameter, the exact same way they would cut a bore into a block, for larger pistons.

Then once they are done with that, they would measure the inside diameter, and have a throttle blade cut to fit.

Ryan

*Spdrcer34* · 04-24-2007, 09:47 PM

..okay...

After a couple days of driving the X, there are NO driveability issuses at all. Just no loss of power when I swapped from the BBK TB to the Modded Stock one.

The only way to REALLY know, is to do back to back to back comparisons. 3 pulls for Stock, then average them. 3 more from Modded Stock then average them, and 3 more for the BBK, then average them.

That would be the only REAL way to test it's effectiveness...then if you had time/money left over..you could modify a BBK casting.

Ryan

bikeboarder · 04-25-2007, 11:32 PM

after doing mine the Idle went up to 1100rpm. then after a day of driving it dropped back down to normal. now that the idle is normal it really increased the power. now if i am stopped at a red light and i floor it to beat a cocky ricer i get a chirp then a couple axel hops.

*Spdrcer34* · 05-24-2007, 12:57 PM

...been away for a while....

Family emergencies, medical issues, and yet another trip to the ER has kept me away...

But after 1 month on the road, I can HONESTLY say that this is BY FAR the best FREE mod you can do!...I notice NO DIFFERENCE in mileage, OR power from the BBK ThrottleBody I had!

In the begining I was contemplating re-purchasing the BBK again, but now all I am going to do is have the TB bored out...

Thanks,
Ryan

UKExploder · 05-25-2007, 07:24 AM

What did you gain from this 'lit'l modification', if anything?

Seems like you were just sorta rebuilding a TB 2 me........

93explorer4life · 05-25-2007, 09:54 AM

did it to my truck, but i cant tell a diferance, not cause of the mod, but because i had an auto in it for a year, blew it and am not driving my first 5speed exploder, so it has a dramatick power gain from the tranny, im sure it gave me a power gain just not noticing it yet! and hopefully a lill bit better milage.

~TJ~

*Spdrcer34* · 05-26-2007, 08:08 PM

I don't have a lot of money right now, so I didn't have time to dyno the Explorer...but MAYBE...just MAYBE I'll be able to do that when I do it to my Green X...

Who knows...

Ryan

robmurt04 · 11-23-2008, 09:42 AM

I just did this on my explorer, and i must say

This baby moves! I noticed a huge difference over the stock TB, and it wasn't hard at all. Anyone with some time & common sense could do this. It made such a difference I managed to get a ticket for accelerating to fast with it! haha I did trip my check engine light though, but I'm positive thats my own fault though. I think I got the TB cleaner on the sensor and it shorted something, b/c im getting a low voltage code. Oh well

Why isn't this a sticky?

I'm doing the 5.0 EX MAF swap today to replace my stock 4.0 MAF w/ Cone Adapter, I'll let you know how that works.

boggs1227 · 11-23-2008, 01:24 PM

all right.....after reading this ...some do see a difference some don't

....so what i'm asking is does this work or not ? if it does then i'll go buy a tb off a junked explorer and give it a try, but i'm not going to waste the money if it's a big waste time to just rebuild a tb to just see the butterfly on the outside .

of course i thought this way about the gas peddle mod and thought it was kinda dumb but to my surprise it made a difference so i'm trying to keep a open mind about all this ......

robmurt04 · 11-23-2008, 01:29 PM

Quote:

Originally Posted by boggs1227

all right.....after reading this ...some do see a difference some don't

....so what i'm asking is does this work or not ? if it does then i'll go buy a tb off a junked explorer and give it a try, but i'm not going to waste the money if it's a big waste time to just rebuild a tb to just see the butterfly on the outside .

of course i thought this way about the gas peddle mod and thought it was kinda dumb but to my surprise it made a difference so i'm trying to keep a open mind about all this ......

Honestly, on my explorer that has exhaust and intake, I feel like it made a huge difference.

04-22-2007, 05:26 PM	#1
Spdrcer34 Speed Bremerton, WA 1992 Explorer XL Join Date: Mar 2002 Posts: 3,884 Vehicle Specs (Original Poster)	How To: Modify a 4.0L OHV Throttle Body.. I needed some money, so I sold the BBK Throttle Body off of my Daily Driver...not REALLY wanting to go back to a stock TB...I was reminded of the ThrottleBody mod that 'aldive' had done to the Ford Motorsports TB on his SOHC ( http://www.explorerforum.com/forums/...ottle+body+mod )...I wanted to do the same thing...well 1/2 of what he had done at the least... So this is how I did it: Start with a TOTALLY STOCK Throttle body (note: this mod has to be done with the TB off the vehicle) Like this one: When you open the throttle/butterfly, you'll see the issues with this particular design: The VERY FIRST thing you need to do, in order to disassemble the TB, is to grind off these little screw ends. The best tool here to use, as shown, is a rotary tool. Often called a Dremel. I have a flex shaft installed on the end of mine, making it easier to get into small spaces. The factory used a hollowed out screw tip so it could be crushed during final assembly. They did this to prevent a screw from coming loose and entering the motor. After you get those pieces cut off, you can start taking it all apart. Start with the Butterfly Screws And slide the Butterfly out of the throttle shaft Remove the plastic link from the 2 cams on the side of the TB, and remove the 8mm bolt. Now everything just slides out easily. DO NOT let the springs gets bent, lost, or otherwise damaged! Okay...once you cross this line, you are at the point of no return. Let's start cutting! Take a look at the throttle shaft that holds the butterfly. You are going to cut part of it off the shaft. You are going to cut the side that DOES NOT.....I repeat...you are going to cut the side that DOES NOT have the threads tapped in it. This is exactly what you have come this far to remove Now comes the tricky part. If you'll notice in the pic of the section removed from the shaft, I didn't make the cut flush with the slot in the shaft. I left a LITTLE meat in there. I started to dry fit everything together....and trimmed a little more from the meat I left of the shaft. Once you get the shaft trimmed to match the bore of the TB, it's time to trime the screws again to make up for the length lost in this modification. Get it the shaft and butterfly all cleaned up again, and start the assembly. Start with your now clean Throttle Body Put the Larger of the 2 springs in place, the way the 'hook' is oriented in the pictures is correct Insert the Throttle Shaft in the Throttle Body. Wind the spring around 1x. Do not load the spring any more than that. Now attach the Butterfly on the Throttle Shaft, in the Throttle Body. Only a couple more things to do, and you're done. Attach the other Throttle Linkage Cam with the 8mm bolt. Make sure you wind the spring only 1x. And after the shaft is bolted down, attach the plastic link to both Linkage Parts And that's it...You're DONE! Ryan __________________ 1992 Ford Explorer XL - with a few bolt ons... Last edited by Spdrcer34; 04-22-2007 at 06:11 PM.

04-22-2007, 06:06 PM	#2
Spdrcer34 Speed Bremerton, WA 1992 Explorer XL Join Date: Mar 2002 Posts: 3,884 Vehicle Specs (Original Poster)	Here is a decent Side By Side Comparison of the Before & After.. And with the Throttle Closed I wish I would have gotten a better before pic, of the shaft in the body, and how much area I gained by removing that part of the shaft. Ryan __________________ 1992 Ford Explorer XL - with a few bolt ons...

04-22-2007, 06:08 PM	#3
bikeboarder Wannabe Elite Explorer Spokane,WA '91 Eddie Bauer, 92 XLT Join Date: Aug 2006 Posts: 440 Vehicle Specs	any noticeable gain in power from doing this? or is it like the "tornato"? sounds like a good idiea. but i dont want to tear into my perfictly good TB for little power if it could cause trouble down the road. __________________ Shackels, F150 coil spacers, 31 inch Chaparral A/Ps, Eddlebrock IAS shocks, extended breathers, 2.25 inch exhaust, Borla Headers, No cats, 2.5 inch FlowPro, True cold air intake, and a 5.0 liter MAF. 116 HP and 156 TQ to the wheels with 200,000+ miles.

04-22-2007, 06:14 PM	#4
Spdrcer34 Speed Bremerton, WA 1992 Explorer XL Join Date: Mar 2002 Posts: 3,884 Vehicle Specs (Original Poster)	This is definitly worth while...I just removed the BBK Throttle Body, Installed my newly modified Stock one and took the car around the block. I noticed NO difference in the way it left the line, and no driveability problems in the short drive I took.... I think the BEST thing to do, would be to do this to a BBK ThrottleBody...it took me very little time to do, and I had never done anything like this before. With this write-up, and pictures....surely you guys could do this too now!?!? Ryan __________________ 1992 Ford Explorer XL - with a few bolt ons...

04-22-2007, 06:20 PM	#5
bikeboarder Wannabe Elite Explorer Spokane,WA '91 Eddie Bauer, 92 XLT Join Date: Aug 2006 Posts: 440 Vehicle Specs	i'm doing it. I just want to go to the junk yard and buy a replacement shaft just incase i cut the wrong side or some stupid thing like that. Because i have been known to stupid stupid stuff like that. __________________ Shackels, F150 coil spacers, 31 inch Chaparral A/Ps, Eddlebrock IAS shocks, extended breathers, 2.25 inch exhaust, Borla Headers, No cats, 2.5 inch FlowPro, True cold air intake, and a 5.0 liter MAF. 116 HP and 156 TQ to the wheels with 200,000+ miles.

04-22-2007, 07:53 PM	#6
Spdrcer34 Speed Bremerton, WA 1992 Explorer XL Join Date: Mar 2002 Posts: 3,884 Vehicle Specs (Original Poster)	..wife just came home.... I showed her this thread, and now she wants me to do this to her Explorer too.. So I'll have to do this to her X on Wed, or Thurs. Ryan __________________ 1992 Ford Explorer XL - with a few bolt ons...

04-22-2007, 08:53 PM	#7
aldive Elite In Memoriam 1999 XLT Join Date: Jan 2001 Posts: 25,270 Vehicle Specs	Did you consider increasing the diameter of the TB also? __________________ Al Franklin My truck My Quest for 30 RIP Al Franklin! 1947-2010. Gone but not forgotten! :(

04-22-2007, 09:54 PM	#9
trucku Wannabe Elite Explorer Queens, New York and living in Budd Lake, NJ now. 2002 Explorer XLS 4.0 4x4 Join Date: Jan 2005 Posts: 2,054 Vehicle Specs	Nice Writeup! __________________ 2002 XLS 4.0 SOHC 4x4. Frantz Bypass filter, Mobil 1 5W30.Perma-cool dual remote (2 full flow PureOne PL30001). Perma-cool remote transmission filter (Pure One PL30001). Scanguage II, Sunpro Oil Pressure Guage Gen 4 mirrors "The More Complex The Mind, The Greater The Need For The Simplicity Of Play"

04-23-2007, 01:34 AM	#10
Spdrcer34 Speed Bremerton, WA 1992 Explorer XL Join Date: Mar 2002 Posts: 3,884 Vehicle Specs (Original Poster)	Al...Yeah...I will do that at a later time...after all...the WHOLE reason I had to go back to the stock unit from the BBK, is I have medical bills to pay.... Thanks for the kind words guys....I appreciate it, ALOT Ryan __________________ 1992 Ford Explorer XL - with a few bolt ons...

04-24-2007, 09:47 PM	#12
Spdrcer34 Speed Bremerton, WA 1992 Explorer XL Join Date: Mar 2002 Posts: 3,884 Vehicle Specs (Original Poster)	..okay... After a couple days of driving the X, there are NO driveability issuses at all. Just no loss of power when I swapped from the BBK TB to the Modded Stock one. The only way to REALLY know, is to do back to back to back comparisons. 3 pulls for Stock, then average them. 3 more from Modded Stock then average them, and 3 more for the BBK, then average them. That would be the only REAL way to test it's effectiveness...then if you had time/money left over..you could modify a BBK casting. Ryan __________________ 1992 Ford Explorer XL - with a few bolt ons...

04-25-2007, 11:32 PM	#13
bikeboarder Wannabe Elite Explorer Spokane,WA '91 Eddie Bauer, 92 XLT Join Date: Aug 2006 Posts: 440 Vehicle Specs	after doing mine the Idle went up to 1100rpm. then after a day of driving it dropped back down to normal. now that the idle is normal it really increased the power. now if i am stopped at a red light and i floor it to beat a cocky ricer i get a chirp then a couple axel hops. __________________ Shackels, F150 coil spacers, 31 inch Chaparral A/Ps, Eddlebrock IAS shocks, extended breathers, 2.25 inch exhaust, Borla Headers, No cats, 2.5 inch FlowPro, True cold air intake, and a 5.0 liter MAF. 116 HP and 156 TQ to the wheels with 200,000+ miles.

05-24-2007, 12:57 PM	#14
Spdrcer34 Speed Bremerton, WA 1992 Explorer XL Join Date: Mar 2002 Posts: 3,884 Vehicle Specs (Original Poster)	...been away for a while.... Family emergencies, medical issues, and yet another trip to the ER has kept me away... But after 1 month on the road, I can HONESTLY say that this is BY FAR the best FREE mod you can do!...I notice NO DIFFERENCE in mileage, OR power from the BBK ThrottleBody I had! In the begining I was contemplating re-purchasing the BBK again, but now all I am going to do is have the TB bored out... Thanks, Ryan __________________ 1992 Ford Explorer XL - with a few bolt ons...

05-25-2007, 07:24 AM	#15
UKExploder Wannabe Elite Explorer near Liverpool,in the Wirral {England} 1994 Limited, US spec. Join Date: Mar 2007 Posts: 863 Vehicle Specs	How to: modify throttle body; 4.0L OHV What did you gain from this 'lit'l modification', if anything? Seems like you were just sorta rebuilding a TB 2 me........ __________________ 1994 Limited 4x4,(full sized)US spec., 4.0L, automatic, dual side exit exhaust w/glasspacks Life is what you make it, so make it good for yourself.

05-25-2007, 09:54 AM	#16
93explorer4life Wannabe Elite Explorer Bloomfield, Indiana no curent Join Date: Apr 2006 Posts: 520 Vehicle Specs	did it to my truck, but i cant tell a diferance, not cause of the mod, but because i had an auto in it for a year, blew it and am not driving my first 5speed exploder, so it has a dramatick power gain from the tranny, im sure it gave me a power gain just not noticing it yet! and hopefully a lill bit better milage. ~TJ~

05-26-2007, 08:08 PM	#17
Spdrcer34 Speed Bremerton, WA 1992 Explorer XL Join Date: Mar 2002 Posts: 3,884 Vehicle Specs (Original Poster)	I don't have a lot of money right now, so I didn't have time to dyno the Explorer...but MAYBE...just MAYBE I'll be able to do that when I do it to my Green X... Who knows... Ryan __________________ 1992 Ford Explorer XL - with a few bolt ons...

11-23-2008, 09:42 AM	#18
robmurt04 Wannabe Elite Explorer Pennsylvania '94 4WD Join Date: Dec 2006 Posts: 381 Vehicle Specs	I just did this on my explorer, and i must say This baby moves! I noticed a huge difference over the stock TB, and it wasn't hard at all. Anyone with some time & common sense could do this. It made such a difference I managed to get a ticket for accelerating to fast with it! haha I did trip my check engine light though, but I'm positive thats my own fault though. I think I got the TB cleaner on the sensor and it shorted something, b/c im getting a low voltage code. Oh well Why isn't this a sticky? I'm doing the 5.0 EX MAF swap today to replace my stock 4.0 MAF w/ Cone Adapter, I'll let you know how that works.

11-23-2008, 01:24 PM	#19
boggs1227 Wannabe Elite Explorer Flowery Branch , Georgia, 1994 sport 2wd auto 2005 colorado 2wd 5spd Join Date: Feb 2008 Posts: 1,521 Vehicle Specs	all right.....after reading this ...some do see a difference some don't ....so what i'm asking is does this work or not ? if it does then i'll go buy a tb off a junked explorer and give it a try, but i'm not going to waste the money if it's a big waste time to just rebuild a tb to just see the butterfly on the outside . of course i thought this way about the gas peddle mod and thought it was kinda dumb but to my surprise it made a difference so i'm trying to keep a open mind about all this ...... __________________ Scott .