First of all, if I have posted this in the wrong forum, I apologize, but this seems to be the place with the most action. If the moderators feel this belongs in the motor forum please feel free to move it there. I have an idea but I am not sure if it will do anything in regards to adding either horsepower or torque. I have enclosed a photo of what I am thinking about. If I were to machine 3 spacers from 6061 aluminum and installed them at the points indicated, would there be any gains?
My aplologies to stealing the picture from Greg's garage, but it is the best picture I could find without ripping my engine apart.

 

so if i correctly understand you, you're trying to increase the length which the air/fuel has to travel - essentially having a more uniform and less chaotic velocity profile before it enters the combustion chamber...

i don't think the spacer between the throttle body will help, neither will the spacer between the plenum and the port leading to the throttle body. if anything the only one that might possibly help is the spacer between the cylinder head and manifold. but 5/8" isn't a considerable distance and you probably won't see a gain - if any at all.

porting the manifold on the other hand will give you gains. i'd suggest that you look into dyno's of guys that have had their intake manifolds ported.

my .02, someone correct me if i'm wrong...

 

No fuel travels inside the intake

 

Very impressed Knight!!! I assume you deduced this through looking at 350Z and G35 intake plenum gaskets. It is funny that you are brining it up now as I am completing the final stages of a plenum spacer for our VQ35DE motors. The materail that you are planning to use will not work well at all. As we all know, metal conducts heat, therefore the purpose of spacing the plenum to decrease air intake temperature is null. It might give the engine a "throatier" sound, but will have no performance gains whatsoever. I actually have already developed the part that you are looking for and have the eyes and ears of a 100 people already for a waiting list. I have a "test" gasket in place right now and I am waiting to pull the car 3 times on the dyno to post results. I figured 3 times pulling (with it on, wihout it on, and then again with it on) would leave no doubt of the performance gain. With cold air intake on my test vehicle, the spacer I have created dropped the air intake temp (measured internally with a specially designed tool) a SIGNIFICANT amount. It also retained the intake temp drop through driving only increasing minimally. I can post all the results once the test is complete and the product is available. Email me if you have any questions, as I am working with a leader in the industry for performance on our cars. The VQ30 is also a test subject as we speak. Blackfinny2002@yahoo.com

 

i've seen those pieces available for 350z/g35's. is there any way to take a 350z plenum and intake manifold and bolt it onto our maxima vq35's?

 

http://forums.maxima.org/showthread.php?t=462415

http://forums.maxima.org/showthread.php?t=460317

 

The answer is NO 03on18s. Do not waste your funds on it. The plenum to the 350Z and G35 VQ35DE is COMPLETELY different than our cars plenum. Even call Skunk2 racing and ask if their spacer fits the Maxima which they have listed it does. It does not fit ours. There are about 16 bolt holes to their plenums as there are only 5 bolts to ours. Like I said before to Knight, I am in final stages of development for the Maxima/I35 plenum spacer. It will come in two seperate sizes when I am done. 5/8 and 1/2 inch (1/2 inch cannot use FTSB) Email me with any questions as I am more than knowledgable about this specific subject. To clear something up, the peices are not the same between the two cars even thoguh the motor coding is the same. The plenum/intake manifold is sideways in our cars b/c of our front wheel drive systems. It would have been alot easier if they kept the plenum the same for both, just fitting it in sideways, but no Nissan HAD to make it hard otherwise they would not be Nissan.

 

I stand corrected after Puppetmaster's previous post that I did not see. God bless you Puppetmaster for doing all of that work. Do you have a dyno sheet before and after? I am VERY curious to see the dyno reults before and after of the 350Z plenum. I am very surprised that you went through all of that work to mount that plenum up there. Is the air flow greater on the 350Z plenum? That is unreal...... good job.

 

thanks for the info. i read those threads and it looks like the only major problem is hood clearance. so i could buy a 350z upper and lower intake manifold and bolt it right on? as long as it clears my hood, it should be a quick bolt on, correct?

 

Yes sleeper I spent most of Tuesday night reading all the forums and info on plenums. I was looking them up on the internet and all I could find was the skunk 2 plenum. But it didn't look to me like it would fit the max. After seeing Greg's how to on how to do the plugs and seeing the collector openings to the heads it seemed to me that I could make the spacer between the collector and engine very easily out of aluminum. Being a toolmaker gives me access to mills and lathes at work so I could make this out of any material. Just wasn't sure what the best material was. But I didn't think the spacer between the engine and collector would be big enough to do much so I was hoping that by adding the other spacers, it might actually help. I thought a bigger "storage area" for the air would be a plus so by adding the spacers I guesstimated I would be adding about 50cc +/- in the entire assembly. I did think of one drawback to the spacer between the collector and the intake manifold. Due to the torque of the engine and the fact that WOT causes the engine to move significantly towards the passenger compartment, a 1" spacer may be too big.

 

You are correct. You might be able to stabalize the motor better with different motor mounts as I have done with my VQ. WOT on our cars moves the motor significantly. Another drawback when I first created the spacer was the intake connection space itself. if you move the intake tube higher and away from the plenum intake port, it leaves another issue of lining up the connections. I wouldn't put the 4 bolt gasket/spacer where the throttle body is. No use there. The spacer itself doesn't matter as much as lowering the air intake temperature for more power. IMO. The longer the air has to travel the less of an effect you will have on what you are trying to do. Message me to go over something between us. I think your idea is great and would like to ask you a question. Blackfinny2002@yahoo.com

 

sleeper, im definitley interested in the spacers you are designing and hopefully will be selling soon.

the question i have after joel posted those links is why the 2 intake manifolds look different? it appears the first one, Nismos, is modified to stick out straight. the second one goosenecks around and makes it impossible to close the hood. is that correct, is his modified?

however, what we are talkin about in this thread is our intake plenum and putting spacers in, so sleeper, do you know what kind of torque and hp will make? im sure it wont be huge, but an increase nonetheless.

 

the manifold that sticks out straight was modified to work like that. the manifold with the curve is a stock 350z manifold.

 

In response to KCMC582:

The purpose to the plenum spacers is to decreas air temperature without INCREASING the distance the air has to travel by a large amount. Think of it like this...the cooler the air, the greater combustion because of the density to the air. Superchargers force air into the system, and compress that air in very lartge amounts. I am hoping that the air intake temp when it reaches the intake manifold will be a greatly decreased by using a thermo soak composite. The material that I have chosen "supposedly" through previous air tests lowered the temperature about 11degrees F. Another positive so far was the fact that the material did NOT have to be as thick as I thought originally, so therefore not compromising the setup Nissan has given us. I will only find out when I can get to the Dyno machine and post results. Through my tests though, it lowered air intake on the VQ35DE (front wheel maxima/I35 motor) but 9 degrees CONSISTENLY through various heat tests. I am hoping the gains are somewhere in the TRUE 7 to 11 HP range, and then it will all be worth it. I will post the ACTUAL results when I can. If you have any suggestions, (as this is a maxima community) or any other thoughts on it, please let me know Blackfinny2002@yahoo.com

 

Oh one more thing. I also have a friend with a 9.2 second STI and he informed me of a little extra that he got from insulation. He insulated his fule lines with heating tape found in the local hardware store to keep the fule temperature down as well. We all know that wonderful felling of getting in a cool car on a summer night and putting our foot to the pedal and getting alot more response from the car because its cooler. Insulte your fuel lines for an APPROXIMATE 1-2 HP gain across the band! Every bit counts.

 

Does anyone have the dimensions of the collector holes which mate to the engine? I know they are slightly oval, I want to render a few ideas for a custom intake on CATIA and see what some people think. Are there 2 different sizes? or is it a trick of the photo angle?

 

Do the runners have to be curved at 90 degrees or flared? Was thinking of a plain jane design on the inside, shortest possible straight runners, just enough to clear the heads, and the largest possible plenum on top hooked to oem throttle and intake. I'll try to post pics in a few days .

 

http://www.outlawengineering.com/index.html

I'm guessing you are doing something similar to the spacer used on the SR20s. It provides pretty good gains- bout 6-8WHP gain.

Problem with the 00-01 Manifold is- its composite plastic which doesnt heat up as much as the 95-99 and 02-03 manifolds do- which are aluminum. I doubt there will be any gain with a DE-K manifold and a thermoblock spacer installed.

 

Anybody try and port a DE-K manifold?

I would be interested to see the gains from that as I would like to keep my variable IM.

 

The reason for my development of the thermo spacer is primarily for that reason. To decrease heat into the manifold. Onve the air reaches the plenum, any typ of thermo soaking composite will HELP the heat intake. It's the whole reason behind what I am doing. I pulled Dyno over this weekend, and need to take a picture of the dyno to show my theory works. Now for a manufacturer.....