So I am finally going to be purchasing a SRI for my '07 Si. I have settled on the Injen. Is the heat shield really necessary? Is there that much of a performance difference between heat shield and no heat shield? Injen's heat shield is an extra $50 on ultrarev.com (they have the best price on the intake). If there is no difference in performance between with or without, then I will save $50 for something else.

I will also be purchasing an exhaust at the same time. While I have not settled on which exhaust to get yet, I am wondering about size. I know that I would need a 70mm exhaust for a FI setup, and a 60mm exhaust would do for N/A. If I am planning to add a supercharger to the mix at some point (probably a while in the future), should I just go ahead and get the larger exhaust now, or will it hurt performance in the N/A setup due to lack of back pressure?

Any help will be greatly appreciated.

 

I say not necessary.

for everyday driving the change in performance is minimal. you probably wont even notice it.

I'd also get the 70mm but thats just me....N/A or boosted

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dirtySOHC’s &raquo;</TD></TR><TR><TD CLASS="quote">I'd also get the 70mm but thats just me....N/A or boosted</TD></TR></TABLE>

Why would you get the 70mm? Do you just like the way it looks, or is there another reason?

 

I have the 60m LSD and I like it, but I am also building for N/A less tunning IMO just build it and go' fix when broke! and keep all bolts tight. I have the heat sheild and beleive it to be a good add on. the intake manifold is cooler after a few runs @ the track, then without it. cooler air = more power but thats just me. after all its $50. dont get the thermal gasket between the intake tube and intake its a waste of money IMO I am going to take mine off the next time im working on the car. good luck.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by chiggin &raquo;</TD></TR><TR><TD CLASS="quote">

Why would you get the 70mm? Do you just like the way it looks, or is there another reason?</TD></TR></TABLE>

because the small amount back pressure lost from the 70mm isn't enough for me to choose otherwise. It's a 2L motor....70mm is fine. And if you ever do decide to boost then you already have an exahust that compliments the setup.

 

I ordered the Injen SRI and went ahead and got the heat shield as well. Now I just need to decide on the exhaust.

I have narrowed it down to the Greddy Evo2, the Vibrant Performance, or the HKS Sportmax. The Greddy is obviously the most popular and as a result, there is a lot more information and reviews out there. Can anyone provide information on the Vibrant and HKS exhausts? How do the three stack up against each other? I am leaning towards the Vibrant because I really like the way it sounds, but I am not sure on its performance. Can anyone help me out?

 

SOrry but you just wasted $50. Simple logic alone will show you how worthless it is.

Heat given off by the motor is ambient under the hood, it doesnt' come off in something like infrared heat rays. Because of this, a simple shield won't do jack ****. What you'd need is a heat-resistant material that completely encases the filter and forces it to pull in air from the factory cool air tubing. A simple shield will do nothing - heat will still surround the intake.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by elohel &raquo;</TD></TR><TR><TD CLASS="quote">SOrry but you just wasted $50. Simple logic alone will show you how worthless it is.

Heat given off by the motor is ambient under the hood, it doesnt' come off in something like infrared heat rays. Because of this, a simple shield won't do jack ****. What you'd need is a heat-resistant material that completely encases the filter and forces it to pull in air from the factory cool air tubing. A simple shield will do nothing - heat will still surround the intake.</TD></TR></TABLE>


Yes, the heat given off by the motor is ambient under the hood. However, you are wrong when you say the heat shield will not do anything.

Think of it this way....In the middle of the summer, the sun gives off a lot of heat. If you are outside, the heat completely surrounds you. Even though the heat completely surrounds you (much like the heat surrounds the intake in an engine bay), the temperature will be lower in the shade than in direct sunlight because you are being shielded from the source of the heat.

While the heat shield does not completely protect the intake from the heat of the engine, it does make a difference.

 

ur analogy for the heat is pretty good. but i have the evo 2 and its very nice. but the 70mm dosnt loose that much back pressure. the 60mm and 70mm skunk2 exhuast are pretty loud but the 70mm gives one of the best hp gains. also if you do a header and the evo2 its still not as loud as the skunk2 60mm.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by chiggin &raquo;</TD></TR><TR><TD CLASS="quote">


Yes, the heat given off by the motor is ambient under the hood. However, you are wrong when you say the heat shield will not do anything.

Think of it this way....In the middle of the summer, the sun gives off a lot of heat. If you are outside, the heat completely surrounds you. Even though the heat completely surrounds you (much like the heat surrounds the intake in an engine bay), the temperature will be lower in the shade than in direct sunlight because you are being shielded from the source of the heat.

While the heat shield does not completely protect the intake from the heat of the engine, it does make a difference.</TD></TR></TABLE>

That would make sense... if the motor gave off heat the same way the motor does. The motor doesn't send off rays of heat like the sun does, which is why something blocking it WOULD stop some of the heat. The heat under the hood is ambient. It's all around - putting up a piece of plastic won't do anything.

 

Chiggin wrote"That would make sense... if the motor gave off heat the same way the motor does."

the motor does give off heat the same way the motor does. lol.

 

the geasket between the head and intake is called a heatshield and is made of a heat resistanint plastic and does not let as much heat transfer from the head to the intake manifold, like the stock gasket does!

 

u mean intake mani ^^^ and since the gasket is thicker it pushes the manifold off the head which allows less heat transfer. But yea the gasket does work ive seen it on Hondamanforlife's car. if i wasnt so lazy i would but one an put it on

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by elohel &raquo;</TD></TR><TR><TD CLASS="quote">That would make sense... if the motor gave off heat the same way the motor does. The motor doesn't send off rays of heat like the sun does, which is why something blocking it WOULD stop some of the heat. The heat under the hood is ambient. It's all around - putting up a piece of plastic won't do anything.</TD></TR></TABLE>

Heat is heat. Whether it comes from the sun or an engine, it is all the same. If you put a shield between an object and the source of heat, the temperature of that object is going to be lower than it would be without the shield. If you don’t believe me, then here is something for you to try. Turn on a space heater and stand in front of it. Put something between yourself and the heater that is large enough to block the heater. You will definitely be able to tell a difference in temperature.

With the shield in place, the heat is getting to the filter indirectly. By the time it makes it around the shield to the filter, it has had a chance to move through the air and bounce off other parts of the engine bay. Whatever the heat is bouncing off of in the engine bay is also absorbing some of that heat. Also, the heat will dissipate while moving through the air.

Will the heat shield completely protect the intake from the heat of the engine? No. But installing it will help to lower the temperature of the intake manifold.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by chiggin &raquo;</TD></TR><TR><TD CLASS="quote">


Will the heat shield completely protect the intake from the heat of the engine? No. But installing it will help to lower the temperature of the intake manifold.
</TD></TR></TABLE>

but for what...daily driving? its useless IMO. even if i road raced i wouldn't buy one.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by chiggin &raquo;</TD></TR><TR><TD CLASS="quote">

Heat is heat. Whether it comes from the sun or an engine, it is all the same. If you put a shield between an object and the source of heat, the temperature of that object is going to be lower than it would be without the shield. If you don’t believe me, then here is something for you to try. Turn on a space heater and stand in front of it. Put something between yourself and the heater that is large enough to block the heater. You will definitely be able to tell a difference in temperature.

With the shield in place, the heat is getting to the filter indirectly. By the time it makes it around the shield to the filter, it has had a chance to move through the air and bounce off other parts of the engine bay. Whatever the heat is bouncing off of in the engine bay is also absorbing some of that heat. Also, the heat will dissipate while moving through the air.

Will the heat shield completely protect the intake from the heat of the engine? No. But installing it will help to lower the temperature of the intake manifold.
</TD></TR></TABLE>

Yes, you're right. In an open room, putting a 'shield' in front of the heater will block the heat. However, the engine isn't in a big open area, it's stuffed in a very cramped hood.

You try this - get in a small box with a space heater. Place a plastic shield partly (the heat shield doesn't cover the whole filter) between you and the heater. Now come back here and tell me the heat doesn't transfer over to the other side of the box. My point is, for maybe 2 seconds the heat will bounce off the 'shield'. Then the rest of the air under the hood will heat up and it'll seep all around the 'shield' rendering it useless. Believe me, nothing short of completely encasing the filter and causing it to draw in air from the stock piping will have an SRI be free of the heat of the bay.

The reason your analogy makes no sense is because there is so much volume in a large room that it would have to heat up the whole area before it seeped past the shield and heated you up. Unfortunately, under the hood isn't that way.

 

you guys keep going back and forth about boxes and rooms and space heaters.

plain and simple....the IM is almost instantly heat soaked by heat generated from the motor and outside tempurature.

WTF is a little peice metal going to do to stop that.

its useless.....end of story

 

elohel's logic is correct.

/discussion.