Throttle body size clarification

[WY.Ram]

So Im a little confused by the current throttle body sizes being listed and sold and even my stocker. And I just bought a new ported TB and for f if it isn't the same S my stock unit.

Here's the skinny - I mic'd the inside diameter of my stock throttle body, 81.3mm. So I bought a ported 87mm TB. Upon its arrival, I mic'd it, could hardly wait to see how well it matched up to my new ported intake manifold that I bought from same shop and was specd to be hogged out to 85mm.

To my extreme disappointment, the ID on ported 87mm TB was almost exactly the same as my stock unit, 82.5mm. The additional 1.2mm is the amount mllled out.

I mic'd the OD - 87mm on both. (This dimension does t really mean squat tho. Correct)

So my stock TB on a 6.4 is 87mm? I write to my tuner guy and say I got a ported 87mm and it matches my stock TB, should I move up to the 92mm hellcat?

He says actually that's an 81mm TB for stock. And I should get an 84mm ported.

I trust my tuner guy to the end of the earth. Shop that sells them are several all list same or similar product.

They could have sent me the wrong one.

Any info to clarify the maelstrom in my brain is much appreciated.

'16 Wagon Greene tune feed'n & fire'n 6.4L with 6spd • 5.13 AAM, 37" KM3, -12mm Fuels • Thuren Overland, DOR, Purple Cranium • CAI, ARH, Solo Mach44 • z36, EBC • Custom vinyl AVS, 4% tint • Morimoto, Rigid, Diode Dynamics • AlfaOBD, Diablo, Nanny Kill, Locker bypass •.................

 

[Wild one]

So Im a little confused by the current throttle body sizes being listed and sold and even my stocker. And I just bought a new ported TB and for f if it isn't the same S my stock unit.

Here's the skinny - I mic'd the inside diameter of my stock throttle body, 81.3mm. So I bought a ported 87mm TB. Upon its arrival, I mic'd it, could hardly wait to see how well it matched up to my new ported intake manifold that I bought from same shop and was specd to be hogged out to 85mm.

To my extreme disappointment, the ID on ported 87mm TB was almost exactly the same as my stock unit, 82.5mm. The additional 1.2mm is the amount mllled out.

I mic'd the OD - 87mm on both. (This dimension does t really mean squat tho. Correct)

So my stock TB on a 6.4 is 87mm? I write to my tuner guy and say I got a ported 87mm and it matches my stock TB, should I move up to the 92mm hellcat?

He says actually that's an 81mm TB for stock. And I should get an 84mm ported.

I trust my tuner guy to the end of the earth. Shop that sells them are several all list same or similar product.

They could have sent me the wrong one.

Any info to clarify the maelstrom in my brain is much appreciated.

'16 Wagon Greene tune feed'n & fire'n 6.4L with 6spd • 5.13 AAM, 37" KM3, -12mm Fuels • Thuren Overland, DOR, Purple Cranium • CAI, ARH, Solo Mach44 • z36, EBC • Custom vinyl AVS, 4% tint • Morimoto, Rigid, Diode Dynamics • AlfaOBD, Diablo, Nanny Kill, Locker bypass •.................

I run a true bore 84 mm Fastman throttle body,it's pretty decent.BBK also has true bore throttle bodies .There's a few other outfits with true bore throttle bodies to.The 5.7 and 6.4's both use the same 251 throttle body,so anything for a 5.7 car/truck or 6.4 car/truck will interchange.

BBK Performance NHRA Approved Gen-III HEMI Throttle Body

Throttle Bodies (bbkperformance.com)

 

[WY.Ram]

I run a true bore 84 mm Fastman throttle body,it's pretty decent.BBK also has true bore throttle bodies .There's a few other outfits with true bore throttle bodies to.The 5.7 and 6.4's both use the same 251 throttle body,so anything for a 5.7 car/truck or 6.4 car/truck will interchange.

BBK Performance NHRA Approved Gen-III HEMI Throttle Body

Throttle Bodies (bbkperformance.com)

Thats exactly what JG said to get, fastmann 84mm. That BBK 85MM looks like it could swallow an F150 lol.

I'm not sure MMX stocks either but whatever, if not I'm going have to go to another. First tho I've gotta get straight with MMX and this new one sitting on my counter. So do you know the official size of the stock 6.4L TB? I'm saying its 81mm to 82mm, but I don t know , and Im pretty damn sure you know.lol
OD wouldn't mean anything useful, so they wouldn't size it OD, would they?
Thanks man.

'16 Wagon Greene tune feed'n & fire'n 6.4L with 6spd • 5.13 AAM, 37" KM3, -12mm Fuels • Thuren Overland, DOR, Purple Cranium • CAI, ARH, Solo Mach44 • z36, EBC • Custom vinyl AVS, 4% tint • Morimoto, Rigid, Diode Dynamics • AlfaOBD, Diablo, Nanny Kill, Locker bypass •.................

 

[Ramm5.7]

Thats exactly what JG said to get, fastmann 84mm. That BBK 85MM looks like it could swallow an F150 lol.

I'm not sure MMX stocks either but whatever, if not I'm going have to go to another. First tho I've gotta get straight with MMX and this new one sitting on my counter. So do you know the official size of the stock 6.4L TB? I'm saying its 81mm to 82mm, but I don t know , and Im pretty damn sure you know.lol
OD wouldn't mean anything useful, so they wouldn't size it OD, would they?
Thanks man.

'16 Wagon Greene tune feed'n & fire'n 6.4L with 6spd • 5.13 AAM, 37" KM3, -12mm Fuels • Thuren Overland, DOR, Purple Cranium • CAI, ARH, Solo Mach44 • z36, EBC • Custom vinyl AVS, 4% tint • Morimoto, Rigid, Diode Dynamics • AlfaOBD, Diablo, Nanny Kill, Locker bypass •.................

Same with me, fastman 84mm tru bore.
Cant say where to get one, I bought mine from a member here.
Good luck!!

 

[crackerjack1957]

So Im a little confused by the current throttle body sizes being listed and sold and even my stocker. And I just bought a new ported TB and for f if it isn't the same S my stock unit.

Here's the skinny - I mic'd the inside diameter of my stock throttle body, 81.3mm. So I bought a ported 87mm TB. Upon its arrival, I mic'd it, could hardly wait to see how well it matched up to my new ported intake manifold that I bought from same shop and was specd to be hogged out to 85mm.

To my extreme disappointment, the ID on ported 87mm TB was almost exactly the same as my stock unit, 82.5mm. The additional 1.2mm is the amount mllled out.

I mic'd the OD - 87mm on both. (This dimension does t really mean squat tho. Correct)

So my stock TB on a 6.4 is 87mm? I write to my tuner guy and say I got a ported 87mm and it matches my stock TB, should I move up to the 92mm hellcat?

He says actually that's an 81mm TB for stock. And I should get an 84mm ported.

I trust my tuner guy to the end of the earth. Shop that sells them are several all list same or similar product.

They could have sent me the wrong one.

Any info to clarify the maelstrom in my brain is much appreciated.

'16 Wagon Greene tune feed'n & fire'n 6.4L with 6spd • 5.13 AAM, 37" KM3, -12mm Fuels • Thuren Overland, DOR, Purple Cranium • CAI, ARH, Solo Mach44 • z36, EBC • Custom vinyl AVS, 4% tint • Morimoto, Rigid, Diode Dynamics • AlfaOBD, Diablo, Nanny Kill, Locker bypass •.................

Ported means its larger on the air side....opposite of intake
True/straight bore is larger on both sides.
The machined part where the butterfly valve is 80mm, the tapered casting on TB is 81mm + on the factory TB.

The stock 80mm throttle body has shown on many applications to be a restriction on these engines but with Modern Muscles new venturi-like design, airflow through the stock throttle body has been increased without sacrificing air speed (like straight bore 85mm and 90mm throttle bodies) allowing even more power while being a direct bolt-on part.

http://www.modernmusclextreme.com/p-457-2013-57-64l-srt-cnc-ported-throttle-body-85mm.aspx

 

[Wild one]

Thats exactly what JG said to get, fastmann 84mm. That BBK 85MM looks like it could swallow an F150 lol.

I'm not sure MMX stocks either but whatever, if not I'm going have to go to another. First tho I've gotta get straight with MMX and this new one sitting on my counter. So do you know the official size of the stock 6.4L TB? I'm saying its 81mm to 82mm, but I don t know , and Im pretty damn sure you know.lol
OD wouldn't mean anything useful, so they wouldn't size it OD, would they?
Thanks man.

'16 Wagon Greene tune feed'n & fire'n 6.4L with 6spd • 5.13 AAM, 37" KM3, -12mm Fuels • Thuren Overland, DOR, Purple Cranium • CAI, ARH, Solo Mach44 • z36, EBC • Custom vinyl AVS, 4% tint • Morimoto, Rigid, Diode Dynamics • AlfaOBD, Diablo, Nanny Kill, Locker bypass •.................

Generally the butterfly is 80mm,and the bore is slightly larger at 81 as Crackjack stated above.The blade is squared off and is actually wider then most guys think,so it's needs enough clearance to be able to close.If you decide to port or polish one "do not" open up the airgap between the throttle blade and the bore where the blade sits when it's in the closed position.If you do,you'll never get it to idle right,and you'll be buying a new throttle body to start all over experimenting on.BTW up here a new throttle body runs right around 300 Canuck at the dealer if you get a little bit carried away polishing the bore and knife edging the blade,lol

 

[BrBlack]

I run a true bore 84 mm Fastman throttle body,it's pretty decent.

Have you always had this TB or did you only add it once the cam went in? Planning a cam install as you know and am currently running the Fastman standard mod TB. Curious if the difference is noticeable when jumping to the 84mm over the standard?

I've still got my original TB and its untouched. If needed I'd send it away so it can be made into an 84mm and keep the standard as a backup.

 

[Wild one]

Have you always had this TB or did you only add it once the cam went in? Planning a cam install as you know and am currently running the Fastman standard mod TB. Curious if the difference is noticeable when jumping to the 84mm over the standard?

I've still got my original TB and its untouched. If needed I'd send it away so it can be made into an 84mm and keep the standard as a backup.

It's been on the truck for a few years Andrew.It went on when the nitrous went on, about a year before the cam went in.

 

[BrBlack]

It's been on the truck for a few years Andrew.It went on when the nitrous went on, about a year before the cam went in.

Gotcha. And you added the bottle before a cam? What TB did you have on it before?

 

[Wild one]

Gotcha. And you added the bottle before a cam? What TB did you have on it before?

Home ported/polished one that i'd knife edged the blade on.It actually worked good,honestly there wasn't no differance between my homemade version and the true bore at the dragstrip.I didn't actually open up the bore on the stocker,but i had about 8 hours into polishing it to a mirror finish and knife edging the throttle blade,then got talked into a true bore by my tuner,lol.
The bottle went on pretty early,it was alot cheaper and easier to do then the cam,lol.

 

[WY.Ram]

Home ported/polished one that i'd knife edged the blade on.It actually worked good,honestly there wasn't no differance between my homemade version and the true bore at the dragstrip.I didn't actually open up the bore on the stocker,but i had about 8 hours into polishing it to a mirror finish and knife edging the throttle blade,then got talked into a true bore by my tuner,lol.
The bottle went on pretty early,it was alot cheaper and easier to do then the cam,lol.

So If you could do it again Would you stay with the ***** version or still go fastman?

I don't often read any mention of port matching. I would really like my new ported intake to be matched to my newly ported heads but seeing how the machinist and my manifold have never been Introduced I highly doubt both will be hogged out to same dimension. Same thoughts with My TB to intake to have them match.

Are the rewards not worth the efforts? I can see If the head's opening Is bigger, no lip to Interfer with "laminar" flow but vice versa could cause flow disruption. Any I figure as long it's apart I may Just see what I can f up.lol

Actually I leave well enough alone but the stock Intake was basically all atrocity. Obstructions protruding into the path of flow in many areas with a little effort some decent improvement could be realized.

'16 Wagon Greene tune feed'n & fire'n 6.4L with 6spd • 5.13 AAM, 37" KM3, -12mm Fuels • Thuren Overland, DOR, Purple Cranium • CAI, ARH, Solo Mach44 • z36, EBC • Custom vinyl AVS, 4% tint • Morimoto, Rigid, Diode Dynamics • AlfaOBD, Diablo, Nanny Kill, Locker bypass •.................

 

[Wild one]

So If you could do it again Would you stay with the ***** version or still go fastman?

I don't often read any mention of port matching. I would really like my new ported intake to be matched to my newly ported heads but seeing how the machinist and my manifold have never been Introduced I highly doubt both will be hogged out to same dimension. Same thoughts with My TB to intake to have them match.

Are the rewards not worth the efforts? I can see If the head's opening Is bigger, no lip to Interfer with "laminar" flow but vice versa could cause flow disruption. Any I figure as long it's apart I may Just see what I can f up.lol

Actually I leave well enough alone but the stock Intake was basically all atrocity. Obstructions protruding into the path of flow in many areas with a little effort some decent improvement could be realized.

'16 Wagon Greene tune feed'n & fire'n 6.4L with 6spd • 5.13 AAM, 37" KM3, -12mm Fuels • Thuren Overland, DOR, Purple Cranium • CAI, ARH, Solo Mach44 • z36, EBC • Custom vinyl AVS, 4% tint • Morimoto, Rigid, Diode Dynamics • AlfaOBD, Diablo, Nanny Kill, Locker bypass •.................

The home ported one was alot cheaper,lol.I had maybe all of 20 bucks into sandpaper and polishing compound. I did open up the intake mouth till it's about as close to the O-ring ,that i figured it'd not give me any issues with breakage.

 

[RedSRT4Me]

HELLCAT!!

 

[Wild one]

HELLCAT!!

View attachment 232432

Just to let guys know,the Hellcat throttle body doesn't bolt on to either the factory 5.7 or 6.4 intakes ,you need an adapter for it to bolt on.But the hellcat throttle body swap is gaining favour these days.MMX has the adapters,and somebody else is also making them,but i forget their name

 

[WY.Ram]

HELLCAT!!

View attachment 232432

Hellcat, 92mm? What kinda setup are you running that on?

 

[WY.Ram]

Just to let guys know,the Hellcat throttle body doesn't bolt on to either the factory 5.7 or 6.4 intakes ,you need an adapter for it to bolt on.But the hellcat throttle body swap is gaining favour these days.MMX has the adapters,and somebody else is also making them,but i forget their name

So what kind of engine response would be predicted with a 90mm or 92mm TB vs an 84mm? More top end maybe? How bout throttle response if you were to go wot from a slow roll, would an 84 hit harder or would the larger bore hit harder?

 

[ScLeCo]

Don't mess around. 105mm

 

[crackerjack1957]

Don't mess around. 105mm
View attachment 232436

I think that would work stroked/boosted applications.....

 

[Wild one]

So what kind of engine response would be predicted with a 90mm or 92mm TB vs an 84mm? More top end maybe? How bout throttle response if you were to go wot from a slow roll, would an 84 hit harder or would the larger bore hit harder?

It shouldn't make much differance,as they feed into the bigger plemium behind the TB. The runners are what gives you the majority of your intake velocity not so much the throttle body itself.

 

[ScLeCo]

I think that would work stroked/boosted applications.....

It was a joke.
I don't think larger/ported TB's are worth much if anything by themselves.
I honestly doubt the OP needs one and seriously doubt he'd notice the difference between a stock and ported one.