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Old 11-26-2022, 12:31 PM   #48 (permalink)
Talos Woten
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Join Date: Jun 2022
Location: Aliquippa PA
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Champrius v3.2 - '09 Toyota Prius
90 day: 58.73 mpg (US)
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Exclamation A suggested plan

Originally Posted by Phase View Post
Hereís what my hood looks like. Itís thin barely metal with some holes and open cavities. No insulation or anything. How should I go about this?
Hey Phase!

That indented area looks perfect to put a consistent layer of insulation in. You could lay down some rockwool, cap it with a stiff material, and use the already existing holes to fasten it down. I'd use coroplast and butterfly bolts, but that's more a function of because I have them lying around and not because they seem like optimal choices.

Alternatively, if you want a simpler solution, you could just get some adhesive insulation and stick it on. Someone listed some somewheres here.

By the way, filling in the hood with foam would also 100% definitely work and add more insulation. But it would also 100% change the acoustics, and most hood gaps are tuned to counter the engine frequencies. I don't know whether the added sound-proofing would be sufficient to compensate for the loss of the dispersion cavities. It would be interesting to try it out... though I actually think the incremental benefit that you would get using foam over simply trapping the air with your layer of insulation would be marginal.

Be wary of the kickstand if you have one. I didn't take mine into account when I did my hood and had to cut a hole in my beautiful seal.

Hope this helps!
Currently building Champrius 4.0! Follow starting here:

and ask in depth questions here:

The goal is 70 mpg this time around.

Stats from Champrius v3.2:
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