I'm looking to buy an MD 5/16" plenum spacer in the next week or so. I've read plenty of threads and also the MD site, but haven't quite found a direct answer to my question. I live in FL and seem to be having some heatsoak issues as it is with my intake. My question is...is the extra $30 for the Iso Thermal spacer really worth it over the just the basic one? I realize that the difference, if any would be very minimal, but if anyone has personal experience between the two, I'd love to hear it!

 

The ISO-Thermal gasket for in between the lower plenum and engine block made a difference as far as I can tell. As to the spacer itself...for $30 you won't have to ask this question after you installed it. Besides, it's a bit easier to install since the material is applied to both sides of the spacer and you won't have mess with the stock gaskets if you don't reuse them. Though some put them on as well to get an extra 1/16" lift

 

The Aramid gasket is well worth the money if you live in a hot climate like Florida. It will keep the plenum and the air it collects a little cooler. I added the Aramid gasket this past winter and my car has run significantly cooler this summer than last and we've had a brutal summer here in Texas.

 

I think the iso thermal is definitely worth it.
After putting it on, and driving around for awhile, the engine bay isnt nearly as hot as it was before.
Well worth the money indeed!

 

good to hear! I really appreciate the input guys!

 

Does size of the plenum spacer make an effect to heating or overall performance then?

 

isothermal upgrade....do it. 5/16 is best overall size to go with. 1/2 if you're FI. the end.

 

+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!

 

i have one for sale. Check out my thread

 

Hey whosisthis, I've been keeping an eye on your classified post. I'm interested but was looking to pick up a used one for slightly cheaper. Is your price $195 shipped? or shipping in addition to that? Please PM me the lowest you can do shipped to 32608, if you're willing to do lower. Thanks!

 

$195 shipped? Can't you buy new for just $30 more?

 

Just ordered from a vendor on the boards. MD 5/16 copper iso thermal (from jersey = snow) for $255 shipped.

 

I AM selling a BRAND NEW spacer for $195. Uneventually, for now, i'm only selling it locally sorry