This looks interesting:

All of this throttle body shaft grind talk is ............. - MBWorld.org Forums

 

Been done here by Woody Waldig a couple of years ago, I'll dig up the thread.

 

I did a search but must have used the wrong terms.

BTW, has anyone noticed that the throttle bodies used on the new Hemi's look a lot like a MB throttle body? Except they are bigger.

 

Here's Woody's LINK.

Did both of my throttle bodies.

Thanks Woody!

 

Thanks, I just read Woody's thread and it doesn't appear to be the same mod. The mod I listed and Woody's mod together might be even better.

 

Hrmmm.... So i upgade to a 74mm throttle body and i practice my dremel skills? Sounds good!

Anyone know where to get a 74mm cheaper than the $200 + shipping on ebay?


CROSSFIRE 3.2 ENGINE UPGRADE THROTTLE BODY & MAF 04-08 | eBay

 

send the throttle body to maxbore for a bore to 78mm. then shave the butterfly rail then knife edge the butterfly. 3 mods in 1 part that costs less than 130$

 

Take your time looking for the TB, I have seen them for $75-125 on ebay. Do a search and save the search, besure to get the correct TB P/N.

 

This boring out the TB sounds interesting, please post details of the tread that tells how and where to get this done. Low cost HP ia always good.

 

Maxbore.com throttle body boring service your t/b isnt listed but i have spoken to them and they have done the mercedes t/b and the cost is the same as any non honda t/b

 

Killer, you have a pm.

 

Wow, Max Bore looks very reasonable.

 

You have the 74mm TB, you have no need to go bigger.

 

Doc got free HP and he has the hay bills to show for it.

 

Right now I want to get the 74MmmMAF on and working correctly. I have to change the sensor out with the 68mm MAF. Hopefully that will get it going. It runs very well now, so a little more HP will help. I think Exhaust will be the next big thing for me. Would like headers, but can't afford $1200. I'm going to get my devil horns in and bigger intake tubes in ASAP.

 

So does the n/a and SRT both have 67mm TB's? Rob suggested that I get something bigger than the 74mm that is stock in my V8. I am wondering what is the ideal size? I noticed that the Chysler Hemi 5.7 and 6.1 both come stock with 80mm and those guys are jumping up to 90mm in their n/a engines. I am thinking 78-80mm might be good for me. If I go with Max bore and the mod from MB world I should have the flow of 80-82mm. I am getting a bse line dyno this week and have a whole list of reasonably priced mods that I am hoping will get me to or past a n/a 55.

 

bob the n/a runs a 67 and the s/c 3.2 uses the 74mm t/b. a host of s/c m/b cars are using the sl55 80mm t/b or the 82 v12 t/b with a few mods to get it to work. not very cheap

 

Thanks Steve. I was reading about guys also trying to use the Audi TB. The Hemi 80mm can be bouught for less than $100 but not sure if it could work. I look very similar to the MB TB. I will probably go with Max Bore and and do the gringd mod. Here some Math to back up this mod from the Nasa Engineer who came up with it.

Here are the calculation courtesy of Exotic_metal55

74 mm = 2.9314 dia. = 6.749 sq. in. 9 mm (.3543 dia) shaft x 2.931" long = 1.0385 sq. in. 5mm (.1969 dia) x 2.931 = .577 So 6.749 - the difference in a 9 mm and 5 mm shaft is .4615 sq. in. Equivalent flow area = 6.2875 sq. in = 2.8294 dia. = 71.866 mm.
78 mm = 3.0709 dia = 7.4065 sq. in. - 9 mm (.3543 dia) x 78 mm (3.0709) long = 1.088 sq. in. = 6.3185 sq. in. = 72.044 mm equivalent.
Math can't lie.

Considering this is a relatively cheap/free mod, the benefits were incredible.
Right of the bat the throttle is much more responsive in terms of power the car feels a lot stronger at WOT. In a few weeks i will dyno the car and let you all know the outcome. My butt dyno definitely tells me i have gain a few hp (for free).
Once again thank you Exotic_metal55. It is because of member like him the automotive enthusiast community / forums are an interesting place.

 

Ok I've got a 74mm TB that I'm think'n of send'n off to max bore. Then do'n the knife edge and butterfly rail grind down and removal of the screen and baffle. My question is. If the TB is bored out will not the butterfly be to small cause'n the car to run Rich, or run Lean, or Idle like poop?

Thanks, Mike.

 

You will need a bigger butterfly plate, one that matches the new size bore.
But you have a NA and making the bore bigger is of no value as the hole it matches is 74mm diameter.
This would be a step backwards.