manifold question

is there any real difference in manifolds between the HF and the SI? they both are mpfi manifolds but the HF looks a bit smaller, could someone let me know please as i found an auction for both and i really wanna have mpfi!

the hf manifold has the cat attached right on to it. it looks similar to a turbo manifold and is sometimes used to make custom turbo kits for d series motors. it will bolt onto a si motor.

the hf manifold has the cat attached right on to it. it looks similar to a turbo manifold and is sometimes used to make custom turbo kits for d series motors. it will bolt onto a si motor.
Hes talking about intake manifolds

WEll i mean think about it- the Si manifold is used to produce 100 hp while the HF is used to produce 60. The Si is going to flow better.

my mistake :banghead:

actually I know for a fact that there is a difference in the size of the throttle body the hf is way smaller.

well IMO the hf manifold weould hold you off untill you find an si one. depending on how much they want for it, i wouldnt pay more than $25 shipped off of egay.

Hes talking about intake manifolds

WEll i mean think about it- the Si manifold is used to produce 100 hp while the HF is used to produce 60. The Si is going to flow better.


thanx man, thats all i needed to know
and the hf manifold is started at 5 bux us plus what ever shipping will be, i wouldnt mind picking up both and making the ports bigger on the HF to see if i could get more flow, i think it would be interesting

I have a SI intake manifold for sale, comes with injectors, throttle body and fuel rail. 60bucks shipped

The Si is definately better considering it came off a 1.6 liter. <---= better flow= more power.

I have a SI intake manifold for sale, comes with injectors, throttle body and fuel rail. 60bucks shipped


is that american or canadian funds?

PM me and we'll discuss this :)

also, would the HF manifold still give me some horsepower gains? like 1/2 of what the SI manifold would?
and how hard would it be to open up the throttle body to make it have more airflow coming in???

http://files.automotiveforums.com/gallery/watermark.php?file=/503/168002hf.JPGhttp://files.automotiveforums.com/gallery/watermark.php?file=/503/168002si.JPG



the hf throttle body on the left is alot smaller than the si one, but they look as if the can be interchanged.

4g4d lx
d15b2
custom 2.25 catback ,greddy exhaust
custom intake w/ hks filter
fatboy coilovers
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what exactly would i need to do to do the mpfi swap on my d15,,,I alreadly have the mpfi manifold

http://files.automotiveforums.com/gallery/watermark.php?file=/503/168002hf.JPGhttp://files.automotiveforums.com/gallery/watermark.php?file=/503/168002si.JPG



the hf throttle body on the left is alot smaller than the si one, but they look as if the can be interchanged.


alright
does anyone know for sure if they can be interchanged???

and a funny thing about the pic of the HF throttle body, thats off the auction that i'm thinking of getting the intake from. either that or the same guys got an Si manifold for sale as well but it already has one bid on it :( :banghead:

alright
does anyone know for sure if they can be interchanged???

and a funny thing about the pic of the HF throttle body, thats off the auction that i'm thinking of getting the intake from. either that or the same guys got an Si manifold for sale as well but it already has one bid on it :( :banghead:


yeah i got the pic off ebay, only place i could think of to get a quick pic.
if u look closely everything on the two throttle bodys look identical except for the size of the opening. i've been told they are interchangable but i maybe someone else out there knows for sure.