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Old 03-29-2008, 12:13 PM   #1
crm318
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iron intake or performer for best MPG

i have a 78 swb chevy sport van that im trying to squeeze every last MPG out of. it has a goodwrench 350 in it and i was wondering which intake yielded the best MPG. i saw a goodwrench 350 buildup on one of the chevy publications and they said that what the performer made in hp, it lost in tq. the iron intake is a pre-emission intake.
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Old 03-29-2008, 01:42 PM   #2
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Re: iron intake or performer for best MPG

huck said he saw a drop in 2 MPG with the performer verses stock.
I saw a noticeable increase in torque (measured in finally being able to spin a tire) and also increased MPG, 1 to 2 MPG.
So it's a tough one to answer.
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Old 03-29-2008, 09:11 PM   #3
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Re: iron intake or performer for best MPG

Ita also a good 30lbs or more lighter too....less weight = motor working less to move all the weight = better gas MPG.
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Old 03-29-2008, 09:13 PM   #4
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Re: iron intake or performer for best MPG

Quote:
Originally Posted by Longhorn Man View Post
huck said he saw a drop in 2 MPG with the performer verses stock.
My bet is becuase he couldn't keep his foot out of it.
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Old 03-29-2008, 11:23 PM   #5
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Re: iron intake or performer for best MPG

no, huck was testing and tuning and trying everything to get that last MPG out of it. I found his discovery to be quite odd, but as far as I'm concerned, his word is gold.
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Old 03-30-2008, 05:44 PM   #6
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Re: iron intake or performer for best MPG

I don't know what performer intake you are planning to use, but I choose a Wieand Stealth mated to an Edelbrock. So far, I have been getting a very consistant 18 mpg highway. You would think that the aftermarket intakes would give better milage, because the passages are better designed, but it may be that many people are running aftermarket carbs on the new intakes, and not q-jets!
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Old 03-30-2008, 07:04 PM   #7
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Re: iron intake or performer for best MPG

You must remember that aftermarket intakes have bigger runners which do use a little more fuel. The only way to test it would be to change just the intake. I've seen people take off iron intakes with an adapter plate for a Holley and seen an increase, but I've never seen someone leave the Q jet and and just change out intakes. I would think that with all things being the same, that the stock would be better due to the smaller runners.
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Old 03-30-2008, 08:57 PM   #8
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Re: iron intake or performer for best MPG

2X; this is one of those situations where it's very hard to do an apples-to-apples comparison.

IMHO, I'd take the intake question out of the picture, put on a decent set of headers and pay for a good tune.
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Old 03-30-2008, 11:14 PM   #9
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Re: iron intake or performer for best MPG

all great info. thanks guys.
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1972 Cheyenne
Chevrolet red and white
357ci, Vortec heads,
GM Performance high rise intake,
Comp 268H .454/.454 218/218 110 LSA
Quadrajet carb, Flowtech headers, 2.25 40 series
HEI, Curve kit, TH 350, 3.07 gears
275/60/15s on 15x8 rallies
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