If you have a 6speed manual most people would install the MREV2 (bittom plenum replacement) and a 5/16 Iso thermal Spacer to get more power. I believe installing the MREV only gains you 2 more horsepower at the higher RPM range.

If you have an automatic, you need to only go with the 5/16 spacer. If you install the MREV2 your car will run lean.

 

He has an 04 so the MREV2 won't give him any gains.

 

Not sure if this was discussed before, but how does the 5/16" spacer effect gas mileage?

 

PowerLab Billet Plenum Spacer

Check it out and cheaper than $210 shipped. Forrum members get better pricing than the website price too. BETTER

 

^ any dyno's?

 

Enjoy!

 

Hi Janz,

On your non-revup engine, the MREV2 performs very much like a spacer but with a little more TQ and a slightly higher average power. But still similar to a spacer.

If you had a REVUP engine, it would make much more gain and particularly when combined with a spacer.

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As for the differences between the Copper Iso Thermal and the regular Iso Thermal.

Both of them will allow your plenum assembly to run a lot cooler and both will keep your throttle body heated when it gets really cold outside, but the regular Iso Thermal has a small valve that needs to be switched to the on position when it does get cold outside.

The Copper Iso Thermal is completely automatic. Install and forget it. You never have to switch a valve based on weather conditions. The purpose of the Copper throttle body heater is to reroute hot engine coolant coming out of the engine and heats your throttle body (like stock) but without heating the entire plenum assembly (like is done in the stock setup). The Copper TB heater gets hot on bare copper side where the TB bolts to it. And it stays cool on the insulated side where it bolts up to the plenum.

The regular Iso Thermal also cools the plenum assembly but by way of a switchable valve. If you use the regular Iso Thermal version with the Coolant Control Valve (CCV), keep the valve in the closed position during warm weather, but be sure to open the valve when it gets really cold outside. The purpose of opening the CCV is to also keep the throttle body heated so it won't get iced up or frozen during the cold season. The throttle body getting frozen to the open position could cause lean stalling when you let off the gas. If the butterfly valve is iced up while driving, it can cause a potentially dangerous situation. For example, you are driving on the freeway in cruise control on a snowy day, if the throttlebody is not heated it could get iced up. When you tap the brakes to let off the cruise control, the ecu will disengage the cruise control, stop flowing fuel to the engine and close the throttle body.

But if the throttle body is iced up and stuck in the open position, the ecu will still stop flow of fuel to the engine. This will lean out the engine and cause it to stall. Stalling is obviously is never a good situation while driving and this is why Nissan keeps it heated. Its for safety reasons.

What the Copper does is re-route the hot coolant flow from the plenum and directs the heat only to the throttle body. What Nissan does is heat the entire aluminum plenum which in turn keeps the TB hot. But its not necessary to heat the whole plenum to keep the TB heated.


Which one should you use?


In warm places like So. Cal., Texas, Florida, Hawaii or similar, freezing is almost non-existent. So you can use the regular Iso Thermal kit and in the rare occasion when it does get freezing cold, just open the valve.

But if you live in an area where it regularly gets severly cold... Colorado, Montana, Chicago, NY, Alaska, Canada, etc. ...Use the Copper Iso Thermal version.

The copper costs a little more, but it is completely automatic and fool proof. Install it and forget it. Your upper and lower plenum assembly run a lot cooler and your throttle body will never freeze up.

Note: Both systems need the Aramid thermal insulating manifold gasket to have the best effect.

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PS
I often get the question as to why the CCV should be switched on below 50'F (which is well above freezing).

Joule Thompson cooling effect... Otherwise known as adiabatic expansion.

As the air flows past a partially closed throttle body it undergoes a rapid expansion and decrease in pressure as it enters the plenum. For the same reason a refrigerator pump cools your refrigerator down, the same effect is happening inside your plenum.

On a cool 40'F day, the air flowing past the TB cools down significantly below ambient temperature. In fact, immediatly behind the TB, the plenum goose neck gets much colder than the incomming air and can go below freezing (32'F).

If the air is humid, the water vapor will freezout and stick behind the throttle plate. In most cases this won't be a problem, but it is good to avoid it anyways.

50'F gives enough thermal margin to prevent ice formation on the throttle body plate. 50'F insures safe and ice free driving.


Note: With the new HR and VHR engines Nissan/Infiniti is now using the same concept as the Copper Iso Thermal. A plastic plenum assembly for total thermal isolation, and the hot engine coolant is flowed directly to the throttle bodies to keep them heated and safe from freezing.

 

So in theory with the 2007+ motors (vq35hr correct?) you would not need an aftermarket plenum spacer because you would get the same gains?

 

Almost, but not quite.

A spacer can't even be used on the HR motor. It has a very different design. A spacer can't be made to fit without first destroying the HR intake manifold.

 

tony, i was looking at pictures of the isothermal spacer on your website.... which piece is the coolant control valve? is it the top left piece with the little screw in the middle of it?

also, im guessing that in the NC/VA area I would be better off with the copper isothermal one since in spring and fall the night/day temperatures sometimes vary between 30s/70s respectively?

thanks

 

which one if I live in ATL?

 

I just installed my Motordyne 5/16 ISO thermal spacer this weekend.. You feel the power immediately.. Motordyne is the way to go...

Coolant Control Valve for whoever was asking about it..Under the intake pipe

Sorry for large pics....

 

Yes. The valve now uses a small handle on it so you can switch it by hand (without a screwdriver).

Probably so, but I'm not familiar with the weather in your area..

 

so being in fl... knowing its hot...I never thought to close the valve switch **** i forget where exactly its at to to be honest... WOULD it hurt if i leave it open ????

 

nice feature - I need to upgrade