GT-40 intake holding my back??

Thomas302

Member

Jan 9, 2004

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16

Alamogordo, NM

Sep 12, 2004

#1

• Sep 12, 2004

• #1

GT-40 intake holding me back??

Hey guys I need some advice, I have a N/A 331 with AFR 185s, comp cam xe274 .555/.565, 70mm tb, 76 ma/ 24#, 1 5/8 LT headers, 3.73 gears, and a gt-40 intake match ported to the heads. A friend of mine told me that the gt-40 intake was holding back some hp. He suggested a holly systemax 2 or a RPM 2. I dont have the dyno numbers, but the car ran a 12.11@113.55 / 1.67 60' on et streets with stock suspension except eibach drag launch kit @ 1200', I shift at 6000rpm. Do you guys think this is true, would I run faster with a different intake. I thought the gt-40 intake was good to around 400-450fwhp. Any advice would be great, Thanks.

 

N8Miller

I need NOS....make it 2 of the big ones

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Jul 26, 2000

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Kingston, PA, USA

Sep 12, 2004

#2

• Sep 12, 2004

• #2

dude, our setups are similar...very similar. however, i run 1 sec slower and -8mph... my car must be f'ed up. I am getting 185s this winter and most likely an RPM2 intake.

anyway. yeah, i would opt for the systemax or the RPM/RPM2 for you option. Not sure what RPM range the gt40 likes, but RPM is a great one and RPM2 made like 10 more hp over the RPM in a 5.0 mag shootout.

 

8

86/92stang

Founding Member

Aug 18, 2002

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Charlotte

Sep 12, 2004

#3

• Sep 12, 2004

• #3

Actually have you ever had it on a dyno? If you read the vacuum on it and it doesnt drop much then yes the intake is not flowing well. Which will hinder performance

 

Grn92LX

Fidanza Man!

Founding Member

Jan 14, 2001

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New York

Sep 12, 2004

#4

• Sep 12, 2004

• #4

Like I said on MW, it IS holding you back. Look no further than a TFS R intake for that engine.

N8Miller, something is very wrong with your combination. Dont go swapping parts, find the cause of the problem. You should be running around 113mph with that mild 331. Ever dyno it? Whats the timing at? I'd fix the problem before spending $1300 on a set of heads only to not see much of a difference.

 

N8Miller

I need NOS....make it 2 of the big ones

Founding Member

Jul 26, 2000

2,661

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Kingston, PA, USA

Sep 12, 2004

#5

• Sep 12, 2004

• #5

Grn92LX said:

N8Miller, something is very wrong with your combination. Dont go swapping parts, find the cause of the problem. You should be running around 113mph with that mild 331. Ever dyno it? Whats the timing at? I'd fix the problem before spending $1300 on a set of heads only to not see much of a difference.

Click to expand...

PM me to discuss possible solutions/causes.... thanks

 

5spd GT

"the 5.0 owns all"

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Aug 7, 2002

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Arkansas

Sep 12, 2004

#6

• Sep 12, 2004

• #6

I would choose the RPM 2...obviously the GT40 isn't holding you back to much...but with the added "torque" of the 331 you don't need a "torque" intake...but don't over do it on the intake...RPM 2 is what I think...

 

Kdubslugga

Active Member

Jun 7, 2003

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Akron, OH

Sep 12, 2004

#7

• Sep 12, 2004

• #7

There was just an article about this in a recent 5.0 and super fords mag! They dyno tested this guys car with a cobra intake, and then with Holley Systemax 2 and the Holley made 52 HP. Not sure if that was rear wheel power or not but still 52 is a lot. This guy was supercharged and everything. I think you are right on your limit with the GT40. The article said they are good to 450hp flywheel, and then then start to become restrictive. I would suggest the Holley. Ive seen the runners on those things and the Cobra and GT 40 Runners pale in comparison.