65 vs 70 mm throttle body?

9

96darkhorse

Founding Member

Oct 2, 2001

693

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16

wilmington, california

Aug 14, 2005

#1

• Aug 14, 2005

• #1

ok guys ...im looking for a tb that will suit my needs....my mods are in my sig.....im planning to go with some tfs heads and a XE274HR cam in a couple of months....which size would help out the most? will a 65mm be enough?

 

DFG 5OH

Active Member

Aug 28, 2004

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36

Louisville, KY

Aug 14, 2005

#2

• Aug 14, 2005

• #2

eh, i'd gow ith a 70mm. I got a 65mm for my h/c/i, but its pretty mild. If you get the TF heads and stuff i'd get the 70mm. If i port my P heads i'm gonna switch to 70.

Good luck!

 

Grn92LX

Fidanza Man!

Founding Member

Jan 14, 2001

6,819

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129

New York

Aug 14, 2005

#3

• Aug 14, 2005

• #3

If you don't have a tb yet, get a 75mm. Open up the inlet with a dremel to match. Ask GTJake for tips if needed since I know he did it to his edelbrock performer manifold. That looks like a nice combo you got there. Degree the cam in exact and make sure you upgrade the stock tfs valve springs!

 

18mustangs

New Member

Jun 8, 2005

533

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0

Virginia Beach, VA

Aug 14, 2005

#4

• Aug 14, 2005

• #4

96darkhorse said:

ok guys ...im looking for a tb that will suit my needs....my mods are in my sig.....im planning to go with some tfs heads and a XE274HR cam in a couple of months....which size would help out the most? will a 65mm be enough?

Click to expand...

65mm or 70mm will be fine, you really don't need more than this. I just switched from my FRPP 65mm to a BBK 70mm when I did my Fox TB conversion and am happy with the result. Most intakes TB openings (and SN95 TB adapter elbows) are not more than 70mm to 75mm max. Personally I'd match my TB to the intake opening or the elbow opening.
Tim

 

M

mackey

Active Member

Jan 25, 2003

1,284

1

38

Beverly, Massachusetts

Aug 14, 2005

#5

• Aug 14, 2005

• #5

I run a 75mm with my trickflow combos. The 106.6 trap was before the TB. I'm still waiting on a nice day to see my increase.

 

9

96darkhorse

Founding Member

Oct 2, 2001

693

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16

wilmington, california

Aug 16, 2005

#6

• Aug 16, 2005

• #6

well. the opening on the edel elbow and on the mani is 70mm if im correct so i think that size would be good.....also, i think a 75mm with my current mods is gonna be too much...70mm was my choice but i had to ask what you guys thought...thanks guys

 

Grn92LX

Fidanza Man!

Founding Member

Jan 14, 2001

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Aug 16, 2005

#7

• Aug 16, 2005

• #7

96darkhorse said:

also, i think a 75mm with my current mods is gonna be too much...70mm was my choice but i had to ask what you guys thought...thanks guys

Click to expand...

How can a 75mm tb with tfs heads, a performer intake and a comp 274XE cam be too much? 70 is cool, but a tb can never be too big (as long as the tb matches the inlet) You would need to port match the inlet to match 75mm with a dremel like GTJake did

 

Black95GTS

Active Member

Jan 8, 2004

1,644

3

38

Marlborough, MA

Aug 16, 2005

#8

• Aug 16, 2005

• #8

Grn92LX said:

How can a 75mm tb with tfs heads, a performer intake and a comp 274XE cam be too much? 70 is cool, but a tb can never be too big (as long as the tb matches the inlet) You would need to port match the inlet to match 75mm with a dremel like GTJake did

Click to expand...

I love how excited you get when someone uses TFS heads.

In terms of matching a TB, wouldn't it make sense to do it like you would do it for a carb? I mean, figure out how much the Performer can flow, then match it with a TB that can flow a little bit more then this? Regardless of its size?

I mean say the Eddie performer can flow 1000 cfm. (This is just for example, I have no idea what it flows). So you should supply a little more then 1000 cfm with the TB. I'm assuming that the manifold is the bottle neck, not the heads, btw. So say you have a P.o.S. Professional Products TB thats 75mm that will flow 850cfm, but then you have an accufab 70mm that will flow 1050cfm, well I'm going with the 70mm over the 75mm.

Makes sense to me.

- Adam

(Is this the TB debate you were missing in talk??)

 

T

TMC

Founding Member

Jan 17, 1999

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Chicago

Aug 16, 2005

#9

• Aug 16, 2005

• #9

OH boy...love these threads...

I would use the 75mm tb but I don't really know what the he!! I'm talking about. You need to ask someone who has made good power and proven it to know for sure.

 

WHITE94COBRA

New Member

Nov 14, 2003

816

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HUNTINGTON BEACH

Aug 16, 2005

#10

• Aug 16, 2005

• #10

Are you done with this combo? are you going to add anything more (nitros, SC, turbo?) if not 70mm works, but 75mm will be better when you do more. I have both and until I go SC i'm staying with 70mm. I only lost a little tq from the 75 but I did gain a little hp up top. I also just thought about it i'm only port matched for a 70mm!!! So this could be a reason I lost tq??????? hmmmm? Now I wanna port match to the 75 and see what happens.

 

9

96darkhorse

Founding Member

Oct 2, 2001

693

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16

wilmington, california

Aug 16, 2005

#11

• Aug 16, 2005

• #11

i maybe going sc later on but not anytime soon....im leaning on the 70mm