TB size for S-trim 5.0L recommendation?

drudis · 11-30-2001, 01:59 PM

What size TB to get? Read the 3 posts:
@@@@@@@ 1 @@@@@@@
Background: Currently have a 5.0L with a Vortech S-trim
that makes 330rwhp. Has 80mmMAF, 30# injectors with
custom chip, Cobra intake, and 1-5/8" longtubes...

My (winter) motor mods are to replace stock heads
with TFS TW heads, new 36# injectors, reprogram the
chip, looking for a conservative 400rwhp all under
6000rpm for my roadracer.

Would like to add a new TB and EGR spacer.
What size 65 / 70 / 75 ? ...and why that size?

What I have found (data reputable?):
Meter----Size----FlowRate@28in
Stock----58mm----606cfm
Cobra----70mm----815cfm
ProM----Bullet---964cfm
C&L------73mm----1171cfm
C&L------80mm----1415cfm
Ford-----80mm----1017cfm
Ford-----80mm----1200cfm <--- MY Pro-M ported/flowed
ProM-----83mm----1598cfm

Throttle Bodies
Size----Make-----CFM@28in
60mm---Ford-------526cfm
65mm---Accufab----616cfm
70mm---BBK--------726cfm
75mm---Accufab----845cfm
90mm---Accufab----1190cfm

84_GT350 · 11-30-2001, 03:04 PM

I'd go with either a 70mm or a 75mm. You've got two things to consider. One would be the size of the opening at the inlet to the intake. A TB bigger than the inlet really isn't going to do you much good. If anything, I would think the air would get backed up there if the TB was too big. The second would be the driveability. As the TB gets bigger, part throttle applications will become much more touchy. For the same throttle application there will be quite a bit more air coming into the engine vs. a smaller TB. Obviously, with a blower this will be even more true. And how in the world would you ever fit a 90mm TB onto an intake? Hehe. That's like a damn manhole.

jonnyk · 11-30-2001, 06:02 PM

I would say 70mm irregardless. Most aftermarket intakes will "like" this size, it flows plenty of air, and if you're staying under 6000 rpm I don't see the need to go any higher.

Nitrous Al · 11-30-2001, 07:51 PM

Don't go any bigger than a 70mm TB. Street Renegade Mustangs are able to run mid 10's with the 70mm TB and a S-trim.

NO SLO PK · 12-01-2001, 12:03 AM

I use a 75 Accufab and it seems okay with the blower. Although intakes may be better matched for a 70, an hour with a die grinder will fix that. I'd blend about 3/4" deep into the intake.

11-30-2001, 01:59 PM	#1
drudis Moderator Join Date: Dec 1999 Location: Livonia, MI, USA Posts: 1,194	TB size for S-trim 5.0L recommendation? What size TB to get? Read the 3 posts: @@@@@@@ 1 @@@@@@@ Background: Currently have a 5.0L with a Vortech S-trim that makes 330rwhp. Has 80mmMAF, 30# injectors with custom chip, Cobra intake, and 1-5/8" longtubes... My (winter) motor mods are to replace stock heads with TFS TW heads, new 36# injectors, reprogram the chip, looking for a conservative 400rwhp all under 6000rpm for my roadracer. Would like to add a new TB and EGR spacer. What size 65 / 70 / 75 ? ...and why that size? What I have found (data reputable?): Meter----Size----FlowRate@28in Stock----58mm----606cfm Cobra----70mm----815cfm ProM----Bullet---964cfm C&L------73mm----1171cfm C&L------80mm----1415cfm Ford-----80mm----1017cfm Ford-----80mm----1200cfm <--- MY Pro-M ported/flowed ProM-----83mm----1598cfm Throttle Bodies Size----Make-----CFM@28in 60mm---Ford-------526cfm 65mm---Accufab----616cfm 70mm---BBK--------726cfm 75mm---Accufab----845cfm 90mm---Accufab----1190cfm __________________ Darius Rudis, Moderator Corner Carvers Delight 1989 Mustang LX - Open Track Car http://www.dariusrudis.com

11-30-2001, 03:04 PM	#2
84_GT350 Registered Member Join Date: Apr 1999 Location: Overland Park, KS, USA Posts: 1,631	I'd go with either a 70mm or a 75mm. You've got two things to consider. One would be the size of the opening at the inlet to the intake. A TB bigger than the inlet really isn't going to do you much good. If anything, I would think the air would get backed up there if the TB was too big. The second would be the driveability. As the TB gets bigger, part throttle applications will become much more touchy. For the same throttle application there will be quite a bit more air coming into the engine vs. a smaller TB. Obviously, with a blower this will be even more true. And how in the world would you ever fit a 90mm TB onto an intake? Hehe. That's like a damn manhole. __________________ 1984 1/2 GT350 (#842 Hatchback w/ T-tops)

11-30-2001, 06:02 PM	#3
jonnyk Being stroked is great Join Date: Oct 1998 Location: Alberta, Canada Posts: 772	I would say 70mm irregardless. Most aftermarket intakes will "like" this size, it flows plenty of air, and if you're staying under 6000 rpm I don't see the need to go any higher. __________________ Novi 2000 now spinning off the snout of the 331... Mods Pics

11-30-2001, 07:51 PM	#4
Nitrous Al Registered Member Join Date: May 2000 Location: Everett, MA Posts: 417	Don't go any bigger than a 70mm TB. Street Renegade Mustangs are able to run mid 10's with the 70mm TB and a S-trim. __________________ Nitrous Al

12-01-2001, 12:03 AM	#5
NO SLO PK Registered Member Join Date: Mar 1999 Location: Arcadia, CA, USA Posts: 731	I use a 75 Accufab and it seems okay with the blower. Although intakes may be better matched for a 70, an hour with a die grinder will fix that. I'd blend about 3/4" deep into the intake. __________________ Russ L '91 LX - 331 w/ Procharger '03 Cobra Convertible - Pullied '94 Lightning '65 Mustang Coupe

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