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2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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Lots of posts and threads on this in this forum and in Seville a year ago.

It may be good for a couple of hp up above 6,000 rpm.
 

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Porting the throttle body is not going to get you much, if anything.

Boring the throttle body and installing a larger (80mm) butterfly will gain you about 5hp and 10-15 ft-lb from 3000 rpm up.
 

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94 ETC,97 STS
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3,531 Posts
I havn't done it but most of the dyno tests show an improvement on FI engines without hurting bottom end as a bigger carb would.
 

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2001 cadillac sts
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I say , if you have the stuff in your possesion....DO IT!...It wont cost you anything and your looking at at least 5hp.......I know I would.....then again people around here now me as a mod junkie.......please refrain SUBMARINER.
 

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2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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msta, If the OP wants to modify a car, then he/she certainly may do so. The thread asks for info and experience on porting a throttlebody and that's what it got.
 

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There was someone selling ported TB's here a few months ago. I don't know if anyone bought one. They could give a review/opinion.
 

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90 Eldo -SOLD-, 98 ETC -SOLD-, 86 XR4Ti Track Car, 07 Ranger
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I have a bored out 80mm & oversized BFV from one of the fellas here on the board a couple years back. Any gain you won't feel, though I consistently measured a small mpg boost ~ 1-2mpg but that could just be statistical noise and it was only on highway tanks, is it worth it? not really imo, if you want power spray some juice or read the mega post to get more ideas...
 

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2001 cadillac sts
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SUBMARINER...I should have put a smiley face after my statement...it was tongue in cheek...I was just kidding around...:).....Your response leads me to believe you took my posting the wrong way....Hey, I respect my elders:canttalk:
 

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1997 ETC (GAVE TO STEPSON 2011), 2000 DTS (RIP)
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I did not perceive this post to be offensive or disrespectful to anyone

I say , if you have the stuff in your possesion....DO IT!...It wont cost you anything and your looking at at least 5hp.......I know I would.....then again people around here now me as a mod junkie.......please refrain SUBMARINER.
 

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98 sls
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1,305 Posts
Discussion Starter #13
Tell me, will a intake manifold from ANY year northstar swap over or was that changed in 00?



I am not looking for gains at the moment, i want to see what i can do within that intake manifold.
 

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2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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There are a couple of different manifolds with different relief valves and connectors. Find one for your year to experiment with.

Take some advice from an old head porter and racing engine builder: Don't get crazy, just clean up flashing corners and sharp edges. Imagine where the airflow is going before you grind, and keep it simple. Those sanding drums you have, as well as the stones in the die grinder kit, will shed abrasive grit and leave it everywhere in that manifold, and, because of the curved tuned runner configuration a thorough cleaning is nearly impossible without hot tanks and high pressure cleaners. Pay an engine or carb shop to properly clean up your mess...........:yup:

To polish a manifold such as you are going to try will give you a slight airflow gain above 5,000 rpm or so. You will see nothing below Wide Open Throttle. A good engine or head shop could do before and after flow bench comparisons........you may be disappointed. Not saying "Don't do it"......just saying don't expect miracles (even minor ones.)
 

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2006 STS V8 AWD, '95 Ford Ranger
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What may look like an unwanted lump in the airflow may turn out to be a design feature. I remember one guy who tried to clean up the intake ports in his GM engine and killed it. It turns out that what he perceived to be obstructions to air flow were in fact design features engineered to improve cylinder filling. It seems to me the engine was an OLDS 4-4-2.

There is some science and skill involved in head porting. A good set of NASCAR heads goes for $25,000 to $35,000.
 

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2006 STS V8 AWD, '95 Ford Ranger
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He's not porting the heads, he's porting the intake manifold.
Intake is intake. Polishing the intake manifold only is like cleaning only one end of the sewer pipe. The same rules apply to the whole thing. What appears to be lumps and casting flaws to the untrained eye may be design features. The biggest gains may be made in port matching; matching the intake ports at the intake gasket with the ports in the head so there is no step. This can be tough to do without a fiber optics bore scope. Usually the best you can do is make both sides match the intake gasket. Polishing an intake and removing turbulence can kill the lower RPM ranges. A prime example was the early Ford Boss 302. The engine builders had to reduce the size of the intake runners and ports with DevCon plastic to get the thing to run any way but WOT. An amateur should be prepared to throw the whole thing away and start over at any time.
 
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