As we all know the aluminum intake manifold on our cars gets hot and thus we loose power. This is the basic premise behind phenolic spacers, which prevent sections of the intake manifold from conducting heat via direct contact. The issue is, however, that the intake manifold is heated not just by metal to metal contact but also by radiant heat. Even with phenolic spacers, the plenums location over the rear head as well as high under hood temperatures effectively turn the intake manifold into a heat sink that heats incoming intake air.


As a complimentary mod to intake spacers, Ive thought up the following solutions:

1. Heat Shield Over Rear head

• Fitment might be an issue
• doesn't address ambient heat
• fairly inexpensive

2. Insulation/Reflective blanket

• Addresses high ambient heat
• Would probably look like crap
• could be cheap depending on material

3. Thermal Coating

• Would look the best
• Questionable Effectiveness (unless coating was thick)
• Cost?

4. Any Combination of the above...

5. Plastic IM swap

• Potentially expensive
• Tuning Required?
• aesthetics?

Ive had the NWP spacers on my car for a while now, and its a great mod but after driving for a while the IM becomes hot to the touch kinda defeating the purpose of spacers.

I think this would be a great mod to compliment the NWP spacers.

Your thoughts and input please!

I have been seriously considering doing the manifold in the DEI silver adhesive tape. Done right I am sure it wont look bad.

You should do it and post back with how it looks and performs. Only thing though is if you dont like it its gonna be a real pain to take all that tape off. A sticky mess no doubt.

Well I have tons of time on my hands what about like a header paint? Is that supposed to reduce heat? And the foil tape you mean like insulated tape or what? Was thinking bout taking it off and wrapping the underside with some sort of heat wrap....

I think header paint is merely heat resistant meaning it doesnt crack under heat but I dont think it blocks heat. Depends on which header paint you use I guess. Foil tape isnt really insulated, it just reflect heat rather than transmitting it.

You may want to verify that the under hood ambiant temperature is higher than the manifold temp. If it isnt, insulating it will deprive the manifold of cooling and cause further heat soak. Maybe consider removing the weather strip from the rear of the engine bay and let airflow work to your advantage to cool the manifold.

Thats a really good point.

I am not sure the foil tape insulates as much as it deflects the heat. I imagine that with the use of the IMS the manifold temps would have to be lower then ambient underhood temps on a 90+ day in traffic

I am planing on removing the weather striping soon.

Same here.
how do.you minuter ambient temp under the hood while driving?

I really don't think it makes that much of a difference.

All of my dynos are directly after a 2h ride and it still seems to have adequate power.

My IAT's ... I've been through this before, but yeah, it's really not that big of a deal, and the only time they rise high enough for concern greater than ambient, is when you're in stop & go traffic, the last place you want a boatload of power,

all IMO though.

I covered my intake tubing with DEI insulating tape and felt a difference... I think you would feel a difference if you did your IM... especially in the summer

I've got both done on my 4th gen I feel there's a difference as well, especially in or after traffic. The car feels less "sluggish" than it normally would.

I'm using the DEI reflect-a-gold tape BTW.

http://forums.maxima.org/5th-generat...cool-tape.html

Here's a link to the thread I made about the insulation tape on the intake tubing... I wanted to wrap up the IM as well, but I'm afraid it'll look like crap

I could careless about power, I have my other car for that. for me this is to help prevent pinging. Its embarrassing, and really pisses me of in a otherwise perfectly running car

Colder plugs? PVC delete, and clean manifold?

Ceramic coating?

Expensive, but very pretty.

Copper heat-sinks, anyone? I wonder if Zalman would be interested in the aftermarket auto industry?

Cleaned the manifold when I did the headers, I just installed new plugs when I did the headers. All less then 1k ago. Trying not to have to buy new plugs if I can.

Its gonna be a process. Trying different options and seeing what works

I am confused why you would modify your car intake (tape or whatever method) to prevent pinging when it seems that there is an actual problem with your car. Why not address why you have pinging to begin with? Running low octane, low octane with timing advance, issue with coolant system, etc?

I know exactly what the issue is. Its heat soak. Combine that with a already lean condition around 2100 and a base timing thats too high. It causes the pinging.

Its only on hot days, only if its in traffic. Hot day on the highway there is no problem because there is enough air moving through the engine bay to prevent large amounts of heat soak.

I always run 93, new pcv, catch can, clean IM, new radiator, working cooling fans, etc.

Car runs perfect spring winter and fall, just not summer.

Do you have an aftermarket intake? If yes, try to put the stock intake back in...

My car used to ping also on hot days when I had a short ram intake. The pinging was drastically reduced with an Injen intake (bent so it wouldn't sit behind the radiator). It almost went completely away with NWP spacers, and the DEI cool tape on the intake tubing

carbon fiber will be your best bid.
I'm going to build one for my friends 5th gen since the only good ones I have seen are non.
Stillen offers a great one but not for the 5th gen.
The battery location is whats killing the chances of having a good cold air ve system.

I will post it op when it's done.
Probably should make a mold just in case you guys need one tho.......
Hope not I hate working carbon and composites.lol.

I would avoid trying to use a heat shield like the plague. The plan for my SFR IM is coating it with a thermal inhibitor on bottom and a dispersant on top. I'm going to wrap my intake as well but I'm not sure which route I'm going to take with that.

There is a great write up about rotating the battery and opening up the area behind the drivers headlight. I did this a couple weeks ago; took about an hour taking my time and fixing/painting surface rust areas on the battery pan.

I did that a while ago. adding a little bit more piping to the intake puts the filter right behind the headlamp

My car runs like a pig on hot summer day, so much so that WOT doesnt even break the tires loose though I have suspicions that its somehow related to transmission fluid temperatures.

And in traffic a boat load of power isnt a bad thing if you need to merge over in a hurry .

Lol Zalman does wonders for my processor, but in all honesty I dont see it helping the situation. I vaguely sense sarcasm there Rochester as I know your conscientious about engine bay appearance (which copper heat sinks on the IM would like crap). Anyway, If you think about it, adding heatsinks to the IM would simply equalize the temperature of the IM with that of the under-hood air. They'd only work if the IM had a higher temperature then the ambient under-hood air temperature.

I had thought about somehow rigging up a series of thermoelectric plates however they arent cheap and Im not sure theyd be effective.

What does pig mean?

If you don't have spacers- get them!

If you have the spacers- then just do a simple heat resistant paint or a heat resistant spray similar to plasti dip(plasti dip is only rated to 200 degrees, but I'm sure there has to be a similar product that is heat resistant)

The other option is vent some cool outside air in the engine bay.

Are you being facetious...

The only thread I found here had no pictures.
Can you pm me some pictures?

Here is a cheap solution to your heat soak and pinging.

http://www.designengineering.com/cat...cooler-sprayer

Where exactly do you buy a thermal inhibitor/dispersant?

It's been said many times on here the Maxima's VQ35 suffers from poor under-hood air flow especially around bank 1. Which is also where the intake collector sits.

You forgot another option is to research under hood air ducting/channels to direct air flow to the bank 1 area.

Interesting, but I dont know where id duct the air from. I want to avoid drilling holes in the fenders and the area between the rad/hood doesnt allow for much airflow either. I Dont know how effective the ducting would be either. You'd need some serious airflow to make a difference.

Also some serious measuring equipment to even visualize the airflow. Unless you went ghetto and mounted a slim slim fan under the hood.

There are a few products on the market that you can "paint" on but they won't work for what you guys are trying to do. You need something to act as a thermal barrier like techline's IC-1 which reduces heat transfer and acts as a barrier to heat. They recommend using this on firewalls and floorboards as a heat barrier. I'm not sure if this will work on an aluminum intake that is already sitting in a hot compartment. This is to stop the heat from the engine bay getting into the cabin of a race car

http://www.techlinecoatings.com/hi-p...-coatings.html

It's typically proprietary stuff and unless I find a place closer to me my headers and IM will be going to..

http://swaintech.com/race-coatings/automotive-coatings/

Would we have to sand off the paint from off the stock IM to apply these thermal barriers?