AFR 165 vs. GT-40X

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eightyfour

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Aug 4, 2003

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Whitestone, NY

Apr 17, 2004

#1

• Apr 17, 2004

• #1

Would I gain much HP swapping out GT-40X heads for some AFR 165's?

 

umstang

New Member

Apr 12, 2004

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Apr 17, 2004

#2

• Apr 17, 2004

• #2

Your going to be able to noticeably feel a difference in the car. Do it

 

CRASH7772

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Apr 27, 2003

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NH

Apr 17, 2004

#3

• Apr 17, 2004

• #3

On a motor that made 306hp@5300 (avg hp 253.08)and 342tq@4000 (avg tq 316.00) with E7TE.

GT40-Y's made 353hp@5600 (avg hp273.75)and 363tq@4200 (avg tq338.19)
AFR's 165's made 396hp@5800 (avg hp288.89) and 342tq@4700 (avg tq353.86)

This is out of Sept 2003 MM&FF. I know the X's flow better than the Y's but I thought this info might help a little.

 

CRASH7772

Member

Apr 27, 2003

401

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NH

Apr 17, 2004

#4

• Apr 17, 2004

• #4

I just found flow numbers on both all from MM&FF.
.50 .100 .200 .300 .400 .500 .550 intake@28"
GT40-X 30 57 110 162 193 215 222 (230@.600)
AFR 165's 30.5 58 122.5 178 213.2 237 240

 

PURESTREET5006

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Apr 1, 2003

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In the tech line for tear down"AGAIN"

Apr 17, 2004

#5

• Apr 17, 2004

• #5

And if you port those AFR 165'S...Man, hold on to your hat!!!

 

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Highbredcloud

Active Member

Mar 4, 2003

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Palos Hills, IL

Apr 18, 2004

#6

• Apr 18, 2004

• #6

I was curious myself since I have GT-40X heads 64cc, however, they are ported and polished, and made about 20RWHP less than avg. AFR set up...that was without tuning but still...THE only difference I can say for sure is that the AFR's are 165cc as oppose to the X heads being 178cc so AFR's will feel better in lower RPM's...keep in mind that X's are not ported like the AFR's...for the money AFR's are a better head...but don't exclude the X's...they are really good even though overpriced...

 

87gn2

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Apr 17, 2004

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Apr 18, 2004

#7

• Apr 18, 2004

• #7

Why port 165s when you can get 185s for the exact same price?

 

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Highbredcloud

Active Member

Mar 4, 2003

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Palos Hills, IL

Apr 18, 2004

#8

• Apr 18, 2004

• #8

87gn2 said:

Why port 165s when you can get 185s for the exact same price?

Click to expand...

Just as my previous post a smaller head will make more TQ down low and will keep pulling hard uptop once ported...simple...velociyt along the cc's of the head determing the powerband...

 

90mustangGT

I felt sorry for girls because

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Jan 15, 2002

2,773

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Dallas, GA

Apr 19, 2004

#9

• Apr 19, 2004

• #9

I would choose the AFR's over GT40's anyday. Not saying the X's are not good but the best results I have scene is with the AFR's. There is more than flow numbers to take in consideration. The AFR 165's flow as well if not better than many other heads with larger CC ports. The smaller size will make more velosity which is definatly important.

 

Legendary

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Oct 10, 2002

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City of Angels

Apr 19, 2004

#10

• Apr 19, 2004

• #10

So is it better to get the afr 165s and port them vs. the afr 185's? This would be for a forced induction car.

 

NeQX

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Sep 30, 2002

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Infront Of You, NY

Apr 19, 2004

#11

• Apr 19, 2004

• #11

Legendary said:

So is it better to get the afr 165s and port them vs. the afr 185's? This would be for a forced induction car.

Click to expand...

Depends on size of block, 302-306 go with 165's, 331 or so forced use 185's

 

E

eightyfour

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Aug 4, 2003

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Whitestone, NY

Apr 19, 2004

#12

• Apr 19, 2004

• #12

whoa! ok thanks! btw, this is on a GT-40X crate motor. so will i need pedestal mounted or stud mounted versions? thanks!

 

GT40XStang9

Thanks to Tim, I get off pretty easy.

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Feb 26, 2001

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Scotland UK

Apr 19, 2004

#13

• Apr 19, 2004

• #13

Crate motors come with pedestal mount rockers.