Random Little Question Thread
#6722
I can understand the properties of whatever materials they use being better in the fight against heat, but that still leaves the metal lower plenum sitting directly on an extremely hot motor, transferring all that heat to the intake air. So all in all, saying an upper plenum will reduce intake temps enough to make a real difference seems a bit far fetched. If anything, the upper plenum stays cool, so it's easy to believe your intake temps are lower.
While the Motordyne spacer does nothing against the heat, it can come with a kit that includes the Iso Thermal gasket that will keep the heat off of the intake plenum altogether, lowering the temps enough that you will be able to rest your hand on the metal plenums after running the car hard for a while. And this thing actually will reduce intake temps as it keeps the heat off of both the upper and lower plenums.
Either way, upper plenums like the V+ and spacers like Motordyne's do exactly the same thing - they allow more space with taller walls in the plenum so the intake air has a better path to flow into the motor. The 5/18 spacer is popular because it's the smallest size to show the best gains. Larger spacers have shown no real improvements over the 5/18 at all. They all do the same thing and they all work the same. And apparently one will not be better than the other.
And I don't meant to pick on you, I'm just trying to get some facts straight as it seems apparent from all of your posts that you've been terribly misinformed about a lot of things.
While the Motordyne spacer does nothing against the heat, it can come with a kit that includes the Iso Thermal gasket that will keep the heat off of the intake plenum altogether, lowering the temps enough that you will be able to rest your hand on the metal plenums after running the car hard for a while. And this thing actually will reduce intake temps as it keeps the heat off of both the upper and lower plenums.
Either way, upper plenums like the V+ and spacers like Motordyne's do exactly the same thing - they allow more space with taller walls in the plenum so the intake air has a better path to flow into the motor. The 5/18 spacer is popular because it's the smallest size to show the best gains. Larger spacers have shown no real improvements over the 5/18 at all. They all do the same thing and they all work the same. And apparently one will not be better than the other.
And I don't meant to pick on you, I'm just trying to get some facts straight as it seems apparent from all of your posts that you've been terribly misinformed about a lot of things.
![Bowrofl](https://g35driver.com/forums/images/smilies/bowrofl.gif)
The material used in the spacers IS low heat transfer material, this isn't for nothing. less heat from the Upper Plenum to the lower and vise-versa translates to overall lower charge temperatures. Lower charge temps result in more power and greater efficiency, put simply.
This is evident in something you yourself noted, that the differenc between a tiny 5/16" spacer and a much larger 5/8" spacer is little to nil.
I do believe that the flow the to front cylinders is greatly improved by a little more room for air up front of the plenum, but I also believe that the bulk, or at least, the big other half of this is lower intake temps.
This is further evident when you compare the 3.5 in the maxima, which has a completely different IM. The Maxima proves the same gains from these spacers, with the same negligable difference between a 5/16" and 5/8". The maxima doesn't suffer from this apparent 'lack of airflow' to the front 2 cylinders, so none of the spacers benefit can be attributed to that in that configuration (same engine).
Just something to chew on
![BOUNCE](https://g35driver.com/forums/images/smilies/bounce.gif)
#6723
Has anyone had the ignition switch fuse burn out on them before? My 03 gsedan's burnt out and its making me wonder what causes this. My mileage is almost at the 100K mark so is it possible that its one of those things that could just burn out over time or is there a problem that I am not seeing?
#6724
Personally I disagree with some of your disagreements ![Bowrofl](https://g35driver.com/forums/images/smilies/bowrofl.gif)
The material used in the spacers IS low heat transfer material, this isn't for nothing. less heat from the Upper Plenum to the lower and vise-versa translates to overall lower charge temperatures. Lower charge temps result in more power and greater efficiency, put simply.
This is evident in something you yourself noted, that the differenc between a tiny 5/16" spacer and a much larger 5/8" spacer is little to nil.
I do believe that the flow the to front cylinders is greatly improved by a little more room for air up front of the plenum, but I also believe that the bulk, or at least, the big other half of this is lower intake temps.
![Bowrofl](https://g35driver.com/forums/images/smilies/bowrofl.gif)
The material used in the spacers IS low heat transfer material, this isn't for nothing. less heat from the Upper Plenum to the lower and vise-versa translates to overall lower charge temperatures. Lower charge temps result in more power and greater efficiency, put simply.
This is evident in something you yourself noted, that the differenc between a tiny 5/16" spacer and a much larger 5/8" spacer is little to nil.
I do believe that the flow the to front cylinders is greatly improved by a little more room for air up front of the plenum, but I also believe that the bulk, or at least, the big other half of this is lower intake temps.
Last edited by dofu; 07-17-2012 at 01:22 PM.
#6725
#6726
#6727
Really?? Thought it wasnt true, buddy of mine told me but i didn't believe
Him. So i was searching on the suspension and brake thread and it sald that the g35 coupe tien s-techs lower the coupe 1.2“ front .9“ in the rear plus another .5“ on our sedans making it 1.7 front 1.2“ rear seems like this is the best even drop then since the front is higher??
Him. So i was searching on the suspension and brake thread and it sald that the g35 coupe tien s-techs lower the coupe 1.2“ front .9“ in the rear plus another .5“ on our sedans making it 1.7 front 1.2“ rear seems like this is the best even drop then since the front is higher??
#6728
While the spacer may give your upper plenum slightly lower temps by distancing it from the hot engine block, well, just try it without the Iso Thermal. You still won't be able to rest your hand on the upper plenum after a few dyno runs. I don't think that's cool enough to make a difference.
The spacer doesn't lower temperatures by increasing total distance from the block. That has little to no effect on the reaction here.
The bulk of the upper Intake Manifold temperature is from heat CONDUCTION (transfer of heat via actual contact), as such:
Block heats up >> Lower Intake Manifold heats up >> Upper intake manifold heats up
So by putting a spacer/insulator between the Lower IM and the Upper IM, you slow that heat transfer signifigantly. The result is incoming air being cooler.
Colder air is denser. Colder air helps the combustion flame move more steadily and predictibly, it also allows more advanced timing.
The benefit of cold air is plentiful, the end result everone here cares about is HP, Put simply: Colder air nets higher Output potential.
Any spacer material that doesn't conduct heat well will have this result. ie. Plastic, Cork, rubber. The thicker it is the greater the effect up to a certain point, and depending on the material used.
I don't mean to call you out, just as you didn't to the other dude. Just as you were, I seek to clarify.
There are 2 simple facts at work, that none of us can deny:
1. Isolating materials keep transfer of heat to a minimum, or at the least, perhaps better put, slow heat transfer.
This equates to another fact = Colder air nets more power potential in an engine.
2. Better "airflow" (using term very loosely to symbolize "ideal" flow) characteristics in the intake system allows better air flow into, and out of the engine.
This also equates to another fact = Better "airflow" in an engine nets more power potential
The truth is, none of us have signifigant factual research on which component has the most effect. What we do know is that BOTH factors are certainly being changed with the spacers readily available on the market. To what degree (no pun intended), and to what benefit hasn't really been figured out for the air flow portion, but the difference in temperature is evident and has been measured.
Last edited by TunerMax; 07-17-2012 at 06:42 PM.
#6729
Nah Brah!
The spacer doesn't lower temperatures by increasing total distance from the block. That has little to no effect on the reaction here.
The bulk of the upper Intake Manifold temperature is from heat CONDUCTION (transfer of heat via actual contact), as such:
Block heats up >> Lower Intake Manifold heats up >> Upper intake manifold heats up
So by putting a spacer/insulator between the Lower IM and the Upper IM, you slow that heat transfer signifigantly. The result is incoming air being cooler.
Colder air is denser. Colder air helps the combustion flame move more steadily and predictibly, it also allows more advanced timing.
The benefit of cold air is plentiful, the end result everone here cares about is HP, Put simply: Colder air nets higher Output potential.
Any spacer material that doesn't conduct heat well will have this result. ie. Plastic, Cork, rubber. The thicker it is the greater the effect up to a certain point, and depending on the material used.
The spacer doesn't lower temperatures by increasing total distance from the block. That has little to no effect on the reaction here.
The bulk of the upper Intake Manifold temperature is from heat CONDUCTION (transfer of heat via actual contact), as such:
Block heats up >> Lower Intake Manifold heats up >> Upper intake manifold heats up
So by putting a spacer/insulator between the Lower IM and the Upper IM, you slow that heat transfer signifigantly. The result is incoming air being cooler.
Colder air is denser. Colder air helps the combustion flame move more steadily and predictibly, it also allows more advanced timing.
The benefit of cold air is plentiful, the end result everone here cares about is HP, Put simply: Colder air nets higher Output potential.
Any spacer material that doesn't conduct heat well will have this result. ie. Plastic, Cork, rubber. The thicker it is the greater the effect up to a certain point, and depending on the material used.
#6730
The truth is, none of us have signifigant factual research on which component has the most effect. What we do know is that BOTH factors are certainly being changed with the spacers readily available on the market. To what degree (no pun intended), and to what benefit hasn't really been figured out for the air flow portion, but the difference in temperature is evident and has been measured.
#6731
Join Date: Apr 2009
Location: Tallahassee, FL (or thereabout)
Posts: 22,160
Received 851 Likes
on
639 Posts
Look... there's a simple solution to all of this.
1. Plastic intake tube, metal is just going to heat-soak.
2. Plastic plenum. Again, heat.
3. What good is a plastic upper plenum if you have a hot lower plenum.... so plastic lower plenum.
4. This of course necessitates: plastic manifold.
5. now obviously, this would be all moot if we didn't go ahead and... yes, you guessed it: plastic heads.
6. This leaves only the block itself, ideally you would also want to get a plastic block.
7...... you now have a Kia.
1. Plastic intake tube, metal is just going to heat-soak.
2. Plastic plenum. Again, heat.
3. What good is a plastic upper plenum if you have a hot lower plenum.... so plastic lower plenum.
4. This of course necessitates: plastic manifold.
5. now obviously, this would be all moot if we didn't go ahead and... yes, you guessed it: plastic heads.
6. This leaves only the block itself, ideally you would also want to get a plastic block.
7...... you now have a Kia.
The following users liked this post:
TunerMax (07-17-2012)
#6732
Look... there's a simple solution to all of this.
1. Plastic intake tube, metal is just going to heat-soak.
2. Plastic plenum. Again, heat.
3. What good is a plastic upper plenum if you have a hot lower plenum.... so plastic lower plenum.
4. This of course necessitates: plastic manifold.
5. now obviously, this would be all moot if we didn't go ahead and... yes, you guessed it: plastic heads.
6. This leaves only the block itself, ideally you would also want to get a plastic block.
7...... you now have a Kia.
1. Plastic intake tube, metal is just going to heat-soak.
2. Plastic plenum. Again, heat.
3. What good is a plastic upper plenum if you have a hot lower plenum.... so plastic lower plenum.
4. This of course necessitates: plastic manifold.
5. now obviously, this would be all moot if we didn't go ahead and... yes, you guessed it: plastic heads.
6. This leaves only the block itself, ideally you would also want to get a plastic block.
7...... you now have a Kia.
![Bowrofl](https://g35driver.com/forums/images/smilies/bowrofl.gif)
![Bowrofl](https://g35driver.com/forums/images/smilies/bowrofl.gif)
![Bowrofl](https://g35driver.com/forums/images/smilies/bowrofl.gif)
#6733
As for all of this... do your research, search Motordyne and all the research he did. The info is all here somewhere. There is a reason why his products are so good - he actually put the research into designing the parts, and a lot of it was shared here on this forum at the beginning. There were a lot of independent tests of all of this as well.
![Dunno](https://g35driver.com/forums/images/smilies/dunno.gif)
I'm not debating whether the spacer makes power, just saying there's more than one aspect to it.
Similar gains from the maxima, same type of guy as Motordyne, NWP engineering. Same story just for the FWD version. And the other side of things, focussed on the Temp drop.
http://www.nwpengineering.com/Phenol...rs.html#VQ35DE
IJS, there's more to it than one or the other. It was meant as something to think about, not as an argument.
![2](https://g35driver.com/forums/images/smilies/2.gif)
When you find something that works you roll with it, that's all these guys have done here, they didn't part the red sea. They found the same gains from a spacer. With the EXACT same relation in thickness differential, 5/16" being the largest gain point across the range.
Don't you think there's something to that? Research around on other cars that use spacers, the argument of intake runner length vs. temp drop is not a new one. Gains are usually similar on other engines with Aluminum/steel IMs.
You'll note that cars with Plastic plenums don't normally gain from a spacer, or gain very very little. Let that speak what it will. Again, I personally think both are at work here.
#6734
![Dunno](https://g35driver.com/forums/images/smilies/dunno.gif)
I'm not debating whether the spacer makes power, just saying there's more than one aspect to it.
Similar gains from the maxima, same type of guy as Motordyne, NWP engineering. Same story just for the FWD version. And the other side of things, focussed on the Temp drop.
http://www.nwpengineering.com/Phenol...rs.html#VQ35DE
IJS, there's more to it than one or the other. It was meant as something to think about, not as an argument.
![2](https://g35driver.com/forums/images/smilies/2.gif)
When you find something that works you roll with it, that's all these guys have done here, they didn't part the red sea. They found the same gains from a spacer. With the EXACT same relation in thickness differential, 5/16" being the largest gain point across the range.
Don't you think there's something to that? Research around on other cars that use spacers, the argument of intake runner length vs. temp drop is not a new one. Gains are usually similar on other engines with Aluminum/steel IMs.
You'll note that cars with Plastic plenums don't normally gain from a spacer, or gain very very little. Let that speak what it will. Again, I personally think both are at work here.
The thing that makes Motordyne's research significant, well let's put it this way: He found that the front runners were not getting enough air, so he found a way to machine it so air flows through much better. While all of this seems easy, take note that many people have tried to duplicate what he's done, but none have been successful. To him, it's all about the airflow, how every nook and cranny effects the way the air flows inside the manifold, or piping, etc... that's why even his exhausts are such a big deal to the guys on this forum. True, there are plenty of ways to get around this without the engineering know-how this guy has, but that just goes to show what we can learn from him.
I feel the manifold on the G could have been designed a bit better. It seems like they either rushed it out on a schedule, or they cut a lot of corners in production to lower costs. Plastic manifolds are much cheaper to build to the specs that you want, so it makes sense that they were able to make it an efficient piece leaving little room for improvements.
Last edited by dofu; 07-18-2012 at 12:09 AM.
The following users liked this post:
TunerMax (07-18-2012)
#6735
Look... there's a simple solution to all of this.
1. Carbon fiber intake tube, metal is just going to heat-soak.
2. Carbon fiber plenum. Again, heat.
3. What good is a carbon fiber upper plenum if you have a hot lower plenum.... so carbon fiber lower plenum.
4. This of course necessitates: carbon fiber manifold.
5. now obviously, this would be all moot if we didn't go ahead and... yes, you guessed it: carbon fiber heads.
6. This leaves only the block itself, ideally you would also want to get a carbon fiber block.
7...... you now have a LF-A.
1. Carbon fiber intake tube, metal is just going to heat-soak.
2. Carbon fiber plenum. Again, heat.
3. What good is a carbon fiber upper plenum if you have a hot lower plenum.... so carbon fiber lower plenum.
4. This of course necessitates: carbon fiber manifold.
5. now obviously, this would be all moot if we didn't go ahead and... yes, you guessed it: carbon fiber heads.
6. This leaves only the block itself, ideally you would also want to get a carbon fiber block.
7...... you now have a LF-A.