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  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech

70 or 75 TB

  • Thread starter Thread starter bigc2330
  • Start date Start date May 4, 2011

bigc2330

Member
Nov 13, 2009
78
7
9
May 4, 2011
#1
  • May 4, 2011
  • #1
What size throttle body would anybody recommend to run with Trickflow's topend kit (trackheat)?
The manifold has a 75mm opening.
I would not want to hurt low end power.
 

f8tlfiveo

My wife likes my spool and blow-off valve.
Aug 8, 2007
1,585
102
64
Lancaster, PA
May 4, 2011
#2
  • May 4, 2011
  • #2
If it has 75 go with 75..
 

84Ttop

They make new pistons every day, so why worry?
5 Year Member
Jul 2, 2009
5,222
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South Jersey
May 4, 2011
#3
  • May 4, 2011
  • #3
70mm all the way no need for a 75. even with a blower on this combo still no problems. my brothers car with trick flow top end and 70mm t/b with a vortech si and stock pulleys went 10.90 with the ac, p/s and 2 12" subs. on radials
 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,162
17,856
224
Massachusetts
May 4, 2011
#4
  • May 4, 2011
  • #4
You're gonna get 50 different opinions on this depending on which train of thought people subscribe to.
 

Kdubslugga

Active Member
Jun 7, 2003
1,515
3
38
Akron, OH
May 4, 2011
#5
  • May 4, 2011
  • #5
Im making 510 rwhp with a 70mm, Im thinking about a 75mm Ill let you know if I get any changes in HP.

Also, 84TTop what was your brothers trap speed? Just curious
 

tannerc91gt

This last 25% is foreign territory at this point
Founding Member
Nov 29, 1999
4,392
2,967
234
Indiana
May 4, 2011
#6
  • May 4, 2011
  • #6
I have a feeling an extra 5mm isn't going to destroy your low end power...yes there's always velocity, dead air, what the heads flow etc etc etc... Without knowing the whole setup it's hard to say. But I had a 75mm and a track heat on a mostly stock 91 and didnt notice a whole lot of low end power loss.
 

Rick 91GT

Mustang Master
Nov 29, 1999
9,692
95
99
PA
May 5, 2011
#7
  • May 5, 2011
  • #7
If you need to buy a tb go 75mm
 

84Ttop

They make new pistons every day, so why worry?
5 Year Member
Jul 2, 2009
5,222
3,254
204
South Jersey
May 5, 2011
#8
  • May 5, 2011
  • #8
Kdubslugga said:
Im making 510 rwhp with a 70mm, Im thinking about a 75mm Ill let you know if I get any changes in HP.

Also, 84TTop what was your brothers trap speed? Just curious
Click to expand...

his best to date is 10.90 @ 129 with a 1.46 60ft
 

Kdubslugga

Active Member
Jun 7, 2003
1,515
3
38
Akron, OH
May 6, 2011
#9
  • May 6, 2011
  • #9
84t-top said:
his best to date is 10.90 @ 129 with a 1.46 60ft
Click to expand...

Nice. Doesnt make me feel so bad then. Im running 11.70s at 124 and everyone tells me it should run 10s. Car is not a drag car at all, pure street car, but I always see guys with my trap speed running mid 10s or high 10s and it literally pisses me off! Im shooting for 10.9999999 and Im done with my car. The 11.70s are coming on 1.8 and 1.9 60fts so I know theres much room for improvement!
 

Gearbanger 101

Straight Outta Locash
20+ Year Stangneter
Aug 10, 2002
9,457
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234
Ontario, Canada
May 7, 2011
#10
  • May 7, 2011
  • #10
Go with the 75mm. Throttle bodies are one of those mods that "more, is better than less"
 

281pony

Active Member
Aug 31, 2003
2,681
2
46
Oly, WA
May 7, 2011
#11
  • May 7, 2011
  • #11
this (imo) is like replacing a fuel pump.

just put a 255 pump in instead of a 155, then realize you should have gotten the 255.

just start with the 75mm and dont worry about going bigger later on.
 

NIKwoaC

中國製造
15 Year Member
Oct 31, 2006
5,525
943
214
Chengdu Province
May 7, 2011
#12
  • May 7, 2011
  • #12
Get the 75. There is no sound reason for getting a 70 over a 75, especially in a situation like that.

I say it all the time, a throttle body is not a carburetor. All it does it get out of the airflow's way. That's it. It doesn't control fuel flow, it has no air/fuel mixing responsibilities. Air velocity through the TB is a moot point.
 
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