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explain theory of intake spacer

  • Thread starter Thread starter silverback90
  • Start date Start date Jan 13, 2010
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silverback90

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#1
  • Jan 13, 2010
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just installed a tfs street burner intake w/ 1" spacer, will the spacer help or hurt, as in extending the rpm range or decreasing it. normally idle to 5500
 

liljoe07

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#2
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They tend move the rpm range lower.
 

Tanus

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biggest dif is that it keeps the intake cool.
 

BlownFiveLiter

have car, will race....wait, it doesn't run
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#4
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  • #4
The theory is that because they increase the plenum volume, they lower the RPM range of the intake and don't transmit heat to the upper plenum, decreasing intake temperatures. I doubt either of which are a noticible difference, but they're often very helpful for clearing tall valve covers.
 

Tanus

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temp wise the difference is huge, I can drive around all day and intake is cool enough to touch, not just for a sec, can rest my hand on it as long as I wanted too. gotta be like a 50 deg difference.
 

stykthyn

I want to measure mine. It doesn't look that tall.
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#6
  • Jan 14, 2010
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anyone have a dyno graph that shows the curve with and without a spacer?
 

NIKwoaC

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Tanus said:
temp wise the difference is huge, I can drive around all day and intake is cool enough to touch, not just for a sec, can rest my hand on it as long as I wanted too. gotta be like a 50 deg difference.
Click to expand...

I think performance-wise, its mostly bogus, but I will agree with this. When I still had the stock intake on my car I had a spacer, and it did bring down the intake temp quite a bit. The question is, does the intake air stay in the intake long enough to really be that affected by it?
 

SpartaPerformance

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#8
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  • #8
If you want an excellent explanation of the benefits of longer intake runners, read the article on the Edelbrock supercharger install in the February issue of MM&FF, the explain the benefits of longer intake runners.
 

Mustang5L5

That is…until I whipped out my Bissell
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#9
  • Jan 14, 2010
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NikwoaC said:
The question is, does the intake air stay in the intake long enough to really be that affected by it?
Click to expand...

Yes. I've done job-related experiments that prove this
 
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njoliver

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#10
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they do help, the fuel also gets atomized better on carbs. for a experiment my buddy took his hood off his 86 mustang and he kept piling on spacers every time he added one there was a little improvement finally he ended up with about a foot and 1/2 of spacers it looked ridiculous but there was a pretty big and definitely noticeable difference. Once he took them off and had no spacers the car felt alot more sluggish then it did with the spacers. This is just one of my experiences and it does make good senses have the carb high
 

stykthyn

I want to measure mine. It doesn't look that tall.
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#11
  • Jan 14, 2010
  • #11
this is an EFI application. any carb based gains do not apply to this scenario as no fuel is actually mixed before the spacer.
 

NIKwoaC

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Mustang5L5 said:
Yes. I've done job-related experiments that prove this
Click to expand...

Hmmmm, now I'm curious. Can you elaborate?

njoliver said:
they do help, the fuel also gets atomized better on carbs. for a experiment my buddy took his hood off his 86 mustang and he kept piling on spacers every time he added one there was a little improvement finally he ended up with about a foot and 1/2 of spacers it looked ridiculous but there was a pretty big and definitely noticeable difference. Once he took them off and had no spacers the car felt alot more sluggish then it did with the spacers. This is just one of my experiences and it does make good senses have the carb high
Click to expand...

What? Why did your buddy have 1.5 feet worth of spacers? Where did he find 18" bolts?
 

vristang

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#13
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Mustang5L5 said:
Yes. I've done job-related experiments that prove this
Click to expand...
Details please
 

nisreo

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#14
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njoliver said:
they do help, the fuel also gets atomized better on carbs. for a experiment my buddy took his hood off his 86 mustang and he kept piling on spacers every time he added one there was a little improvement finally he ended up with about a foot and 1/2 of spacers it looked ridiculous but there was a pretty big and definitely noticeable difference. Once he took them off and had no spacers the car felt alot more sluggish then it did with the spacers. This is just one of my experiences and it does make good senses have the carb high
Click to expand...

you drove a car with 18 inches of spacers between the intakes?
 

tmoss

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#15
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Tanus said:
temp wise the difference is huge.....
Click to expand...

you must not have coolant water flowing through an EGR spacer - if ther is, the intake will be reasonably close to coolant temp. It will defeat to some degree the cooling function of the spacer. the lower will be closer to oil temp as it has oil hitting it along it's length from the lifter valley.
 
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njoliver

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It wasnt my car it was my friends mustang and he just had some laying around he made, he has his own little machine shop. I am not too familiar with them since I have EFI but I was told because there is more room the fuel mixes with the air alot better also is cooler witch obviously is good for better combustion, also changes your powerband. nisreo what is so hard about believing that, why would it be hard to find and bolt that big make your own.. Im just passing down what I heard I friend is a very knowledgeable machinist, even built grave diggers engine before
 

rbonella

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That is one thing I might do this summer....Put 2 dozen intake spacers in my ride, cut a big hole in the hood, and show up at a gathering. Awesome!
 

Tanus

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tmoss said:
you must not have coolant water flowing through an EGR spacer
Click to expand...
yeah its disconnected, I live in az, so its pointless

rbonella said:
That is one thing I might do this summer....Put 2 dozen intake spacers in my ride, cut a big hole in the hood, and show up at a gathering. Awesome!
Click to expand...
hahahha, love to see that
 

NIKwoaC

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njoliver said:
It wasnt my car it was my friends mustang and he just had some laying around he made, he has his own little machine shop. I am not too familiar with them since I have EFI but I was told because there is more room the fuel mixes with the air alot better also is cooler witch obviously is good for better combustion, also changes your powerband. nisreo what is so hard about believing that, why would it be hard to find and bolt that big make your own.. Im just passing down what I heard I friend is a very knowledgeable machinist, even built grave diggers engine before
Click to expand...

OK, pictures or it didn't happen.
 

Mustang5L5

That is…until I whipped out my Bissell
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#20
  • Jan 14, 2010
  • #20
vristang said:
Details please
Click to expand...


Well, without revealing too much info since it's work related R&D, i can say that I have heated air up passing through tubing from room temp to over 400* F in the span of about 2 feet of tubing traveling at a high flow.

A Mustang intake is AL, which has better thermal conductivity than the materal i used. There are other factors as well. But i would definitely say that a heat-soaked AL manifold can cause air temp to rise in the span of 15" of runner lenght at a high flow rate.

Makes sense as to why the ACT is in the #5 runner...right before it goes into the engine.
 
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