Ok guys, i need some help here. Everyone seems to recommend Motordyne 5/16...but whats the diff between isothermal and basic....Also what about brands like Skunk or Blox....still very new to this, and all i have is an Green High performance pop charger on... I am going to germany soon and its cold ALL the damn time...so should i go isothermal ?....im lost- malibu

 

im pretty sure the iso-thermal is to try and keep heat from the block getting up to the plenum so it wouldn't hurt to get it to keep the top cold. i dont know about any other spacers tho.

 

Motordyne has a detailed explanation of Iso Thermal. Doubt if I can do better.

 

If you're taking your car to Germany, I suggest going with the Copper Iso Thermal. It will let your plenum run cool and at the same time, it will keep your throttle body heated so it can't freeze up in the very cold weather.

As for the technical description:

The Iso Thermal and Copper Iso Thermal reduce heat transfer into the upper and lower intake plenum and reduces assembly temperature by 30'-60'F. Cooler intake air temperatures increase air density and reduces the tendency for detonation or ping.

There are two major heat sources that transfer heat into the upper and lower plenum.

1) Transfer from the lower intake runners which are bolted to the heads at ~250'F. The lower intake runners are made of heavy gauge aluminum so they transfer heat very efficiently into the lower plenum.

and

2) Heat transfer from hot engine coolant that is coming directly out of the engine at about 200-210'F. This hot engine coolant is flowed through the plenum to insure the throttle body stays nice and hot.

The plenum typically heat soaks to about 170'F. That's burning hot!

A Iso Thermal kit will reduce the whole plenum temperature to about 110' - 140'F. Depending on where its measured, that's basically warm to very warm to the touch.

A necessary component of either Iso Thermal kit is the Aramid gasket. It's installed between the lower plenum and intake manifold significantly reduced heat soak. Basically, the Aramid gasket blocks a major heat transfer source from heat soaking the lower plenum. Aramid is heat resistant and a very good insulator with a low heat transfer coefficient.

To block the two main heat sources, the aramid gasket is used with either:

1) The throttle body Coolant Control Valve (CCV).
The CCV allows you to selectively heat (or not heat) the plenum assembly. With local weather temperatures below 55'F the valve is left open. In warmer weather the valve can be closed for maximum thermal benefits.

or

2) The polarized Copper Throttle Body heater.
Copper Iso Thermal is a set and forget component that is used in place of the CCV. With the Copper, it doesn't matter how hot or cold the weather is. Install it and the throttle body remains heated while the rest of the plenum is thermally isolated. Keeping the throttle body heated prevents ice formation on the throttle body butterfly valve when driving in cold weather. If it snows or gets really cold in your area, use the Copper Iso Thermal so your throttle body remains heated and engine can still take full advantage of the cold air you are driving in.

Note: Nissan (Infiniti) intentionally heats the throttle body for safety reasons. Its to insure the throttle body doesn't get iced up when driving in very cold or snowy weather. And none of the Motordyne plenum spacers run an increased risk of throttle body freezing.


1) The basic spacer leaves the entire plenum hot all the time. (just like stock)
2) The regular Iso Thermal heats the plenum when you need it and doesn't heat the plenum when you don't need it. But depending on weather condition, the CCV must be switched on or off.
3) The Copper Iso Thermal is fully automatic. Just install it and forget it. It always gives the best results and doesn't need adjustment. But it costs more.

 

I am going with the copper iso thermal 5/16" want to get it tomorrow, thank you SOOOOOO much for breaking it down, u just earned my money and business from now on.