Which Throttle Body

[Ramsfan78]

Get the best, cheapest 87mm you can. If the 87mm is designed to run with a stock truck then why not pony up the extra $50 over the 85, and never worry if you want to add a set of headers??
I can't speak to the quality of Moe's, but the Bully's piece was brutally rough on the inside after they bored it out. (That was the only reason I polished mine. That's clearly not an issue for anyone else here because I have not heard of anyone else caring enough to do something about it.)

I thought by running to big of a tb without the headers, it would cause problems. Mpg would suffer, mixture being to rich causing the tailpipes to have black buildup on them, throwing check engine lights, etc...? As I said, I would like to run headers but this isn't in the immediate future.

 

[Picton]

I thought I read that after testing, Moe's found the 85mm presented no benefits on the 13+'s so they only offer an 87mm.

Interesting. Something must have changed somewhere.

 

[audio1der]

I thought by running to big of a tb without the headers, it would cause problems. Mpg would suffer, mixture being to rich causing the tailpipes to have black buildup on them, throwing check engine lights, etc...? As I said, I would like to run headers but this isn't in the immediate future.

It had better work haha!
"Moe's Performance has raised the bar again with our new 87MM CNC ported throttle body for the new 5.7L Hemi. While this throttle body will work on a stock truck, it is designed for the guys with full boltons and a tune. The more mods you have, the better this throttle body is going to perform."

I want a tuner badly but keep reading crap one way and the other, so why not spend the extra $50 instead of needing to change your $300 85mm TB later?

 

[Ramsfan78]

It had better work haha!
"Moe's Performance has raised the bar again with our new 87MM CNC ported throttle body for the new 5.7L Hemi. While this throttle body will work on a stock truck, it is designed for the guys with full boltons and a tune. The more mods you have, the better this throttle body is going to perform."

I want a tuner badly but keep reading crap one way and the other, so why not spend the extra $50 instead of needing to change your $300 85mm TB later?

I've got the Trinity and I couldn't be happier. I was worried at first because I was hearing some ping at the top end of the RPM band between first and second. I changed from 87 tune to 93 and filled up with 93. The ping is almost completely gone. I am thinking I had a little residual 87 in the lines and now that it is burning off, nothing but "get up n' go". As far as the tb, I'm not one to believe a sales pitch. I know Moe's says it'll work on a Stock to Mildly modified truck but unless they're willing to write a check for about 35 grand, then I'll do my own research and form my own opinion. That way, I have only myself to blame if something goes wrong. Lol.

 

[TylerB]

The Moe's 87mm TB worked great on my truck before installing headers. I ran it that way for 5 months then installed some longtubes and it ran even better.

 

[0212353]

The Moe's 87mm TB worked great on my truck before installing headers. I ran it that way for 5 months then installed some longtubes and it ran even better.

quit that.....quit making me think of longtubes........NOW!

 

[Hemi450hp]

On the 09-12's, I always recommend the 85mm to anyone that doesn't plan to add headers, and the 87mm if you do plan to add headers. For those of you that are unsure about installing headers, there is no performance loss by going straight to the 87mm, but you also wont gain anything over the 85mm until the headers are installed. In short, it is cheaper to go with the 87mm up front if you have any intention of adding headers. If you know that headers are out of the question, then save the $50 and just go with the 85mm.

As for the 2013's, their throttle body is a completely different shape than the 03-12 truck. It is about 1" shorter in height, and we found that the 87mm port actually showed better gains on a stock truck than the 85mm did. Because of this, we decided to only offer the 87mm on the 2013 models.

 

[AirborneSilva]

As for the 2013's, their throttle body is a completely different shape than the 03-12 truck. It is about 1" shorter in height, and we found that the 87mm port actually showed better gains on a stock truck than the 85mm did. Because of this, we decided to only offer the 87mm on the 2013 models.

Thanks for that explanation!

 

[audio1der]

And like my other posts, I'll call ya nuts for not taking the time to port match the intake manifold to the TB if you go that route. When you're chasing slivers of performance with bolt-ons like we are, how can you ignore the fact that the IM opening will now be a restriction?

 

[Picton]

And the plot thickens. That's a good piece of information to have. If by going to an 87mm TB...the intake manifold is now an issue...essentially robbing you of some of the extra diameter of the 87mm TB. Seems like porting the IM would be an issue. Where would I even have that done?

 

[Ramsfan78]

Ok well just out of curiosity, what would be the performance loss if going with the 85mm and adding headers later? Is there a significant loss of performance with that setup?


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[TylerB]

PM sent.

 

[09SMOKINHEMI]

And the plot thickens. That's a good piece of information to have. If by going to an 87mm TB...the intake manifold is now an issue...essentially robbing you of some of the extra diameter of the 87mm TB. Seems like porting the IM would be an issue. Where would I even have that done?

Good question! I would like to know too!

sent from my Samsung Galaxy S3

 

[Hornet]

The lip is on the tail-end of a venturi,and creates a reversion in the intake manifold.
Most air reversions in an intake manifold show up as flat spots in the throttle response usually in the 3,000 to 4,000 rpm range.

Not a big deal for most guys,but like Audio says,if you're gonna spend the money on a high dollar ported throttle body,why not get the most out of it,you can.

 

[Hemi_Express2013]

Get the best, cheapest 87mm you can. If the 87mm is designed to run with a stock truck then why not pony up the extra $50 over the 85, and never worry if you want to add a set of headers??
I can't speak to the quality of Moe's, but the Bully's piece was brutally rough on the inside after they bored it out. (That was the only reason I polished mine. That's clearly not an issue for anyone else here because I have not heard of anyone else caring enough to do something about it.)

The pattern cut does several things that render the hand ported versions obsolete. #1 is the texture breaks up the molecular drag of the air flow along the TB throat as the intake air charge enters. A smooth surface creates friction & slows the flow along the sides creating turbulence (a wet flow bench with a high speed video slowed down shows this). The texture breaks that surface tension (think golf ball dimples and what they are capable of) and allows the intake air to flow equally in the center as it does around the sides. A high polished surface causes the most drag due to the surface tension present (Darin Morgan demonstrated this years back on their wet-flow bench with cylinder head & intake runners). Then, the slight swirl blends the air charge even more so even though the blade size is untouched, the CFM flow is increased as seen on the flow bench, but even more important is the velocity of the intake air charge. Velocity makes power, not just flow.

Bottom line is, the instant throttle response & increased lower RPM range power gains that make this a must have

 

[Hornet]

Better look up how a venturi works.
A rough surface does not work in a venturi.
Yes a rough surface does work in an intake port,the boundary layer principle on intake ports has been around for years,but it's still standard practice to polish an exhaust port

Do you think every auto manufacture'r in the world would make their throttle bodies smooth if they didn't have to.
You sure don't give the factory engineers credit do you,just going out on a limb i'd say they know more then the average joe,and they wouldn't spend money on making something smooth if they didn't have to

A VENTURI IS NOT A PORT OR A PIECE OF PIPE,and as such works under differant principles then a port or piece of pipe.

While you're at it,tell the carb manufactures like Holley they don't need a smooth finish inside the venturi's of a carb too.

 

[Hemi_Express2013]

Hmm, I'm not sure that a carb and TB are the same or work with the same principle. I'm not here to argue a debate that is or isn't. All OEM polished TB are coated with a thin layer of a plastic resin or similiar material. This is why one should only clean a TB with a TB cleaner and not a brake cleaner because it will remove or damage this coating. . Manufactures don't even have to polish the bore because the machine process is that fine. I'm am talking shop CNC machine Porting that leaves a helix pattern within the bore which removes the surfice tension properties of a smooth wall that helps increase velocity if tapered correctly, isn't this the rational of the science of a throttle body spacer. Otherwise Moes and Bully is ripping us off. Most high end TB are ceramic coated to eliminate turbalance due to a smooth bore. A smooth bore without a coating of something reduces velocity, from my understanding. I'm no mechanic but I am trying to understand my machine. Thanks for the reply. I will research it more.

 

[audio1der]

And the plot thickens. That's a good piece of information to have. If by going to an 87mm TB...the intake manifold is now an issue...essentially robbing you of some of the extra diameter of the 87mm TB. Seems like porting the IM would be an issue. Where would I even have that done?

The IM is plastic(?Bakelite?). Seat the TB onto it properly, open it up, scribe the inner circumference with something sharp. Remove the TB, stuff a rag down the IM and Dremel the excess material away. I vacuumed for a LONG time once done to make sure I got all the filings, then bolted the TB back on.
There was a significant overlap once the 87mm TB was placed on the IM, and it seemed common sense if the new TB were to work to its potential.

I'm am talking shop CNC machine Porting that leaves a helix pattern within the bore which removes the surfice tension properties of a smooth wall that helps increase velocity if tapered correctly, isn't this the rational of the science of a throttle body spacer.

-This was no helix pattern like I've ever seen. They were nearly oure horizontal rings around the inner body, and they were DEEP. I could have played that thing with my nails like a washboard.
I'm not suggesting anyone is getting ripped off, but the finish work could have been better.

 

[Hornet]

I'll try to lay it out in laymen terms for you guys,so bear with me.

The throttle body is a smaller diameter then either the intake tube or the intake manifolds mouth.
As such it's 2 purposes in life,are to regulate airflow by means of a variable throttle blade,it's #2 purpose is to speed up airflow with-in the piping system feeding the manifold.
Air flow velocity increases through a venturi,which is basically what your throttle body is,as it's the "choke" point for airflow with-in a bigger pipe system.
If you've ever looked a Mikuni motorcycle/snowmobile carb over,with it's sliding barrel in it's venturi,you'll see our throttle bodies are no differant.
It's the easiest carb i could come up with off the top of my head,that is a virtual carbon copy of our throttle bodies.
A variable blade/slide with-in the venturi,is what a throttle body is.

 

[Hornet]

Some more laymen explanations for you guys to absorb.

Basically a Venturi compresses a moving column of air/liquid,and as such the shear factor from the now compressing moving column of air negates the boundary layer,as the compressing air shears it off,therefore you want as smooth a surface as possible with-in the venturi,with nothing to shear off and impede the compressing airs flow.
When the compressed air molocules exit the venturi they rapidly expand,almost explode back to size and push like hell on the next air molocule beside itself,thereby increasing the air velocity on the exit of the venturi.

Hope that makes sense and helps to simplify the principles behind a venturi for you guys