http://www.motordyneengineering.com/index.php?cPath=1_5

please may someone give me a correct anwser to the difference in basic vs iso thermal, as well as the pro and cons of the size differences in the plenum spacers ( 5/16" vs 1/2")

 

You already have the MotorDyne web sight why not look up your questions at the source and get the facts not just our opinions? Or another great might be to call Tony 661-993-5111....!
Gary

 

i have a brand new MD 5/16" spacer for sale. PM me if you are interested.
5/16" is the one you need because it gives you the most efficient air flow.

 

Isn't there a thread just like this.......

Edit: found it.

https://g35driver.com/forums/g35-cou...um-spacer.html

 

i read up on the sizes and the difference between the two, but what is the advantage to iso thermal over the basic?

 

The Iso thermal setup helps reduce the amount of heat being transfered to the plenum.

 

+1 Copper Isothermal for the best performance. The difference in thickness, 5/16 or 1/2 is directly correlated to performance. The thicker, the more air in the plenum, the more hp gain! Also as it says on the MD site if it snows in your area get the copper. I think its worth it no matter where you live, but thats just me...

 

I don't know where you got the idea of the thicker, the more air in the plenum, the more HP gain, but that's not true. 5/16" produces the most efficient HP gain on our engine.
If you think that thicker, the more HP gain, then why don't you get 2 inches spacer. It'll get you 50 HP gain

 

Where can I find a cheap one for cheap?

 

The 1/2" spacer makes more HP in the higher RPM ranges while the 5/16" makes it in the lower more useable RPM range. Our engines don't like heat, the copper gasket and the valve that shuts off the radiator fluid from running thru the plenum is worth whatever the cost. I've never opened that valve in 5 years, living in CA. I don't need the extra heat....
Gary

 

Replacing the aramid gasket in between the lower plenum and block was very effective in reducing the plenum temp.
If you're going to remove the top plenum, it's only a little extra effort and cost but worthwhile.

 

is there a DIY on install for the iso thermal?

 

Yoo groll, have you tried a SEARCH, that's the thing between New Posts and Quick Links above....^
Gary