best engine compartment insulation?
01-30-2012, 04:47 PM
#1
Instructor
Thread Starter
best engine compartment insulation?
Hello all - I am hoping many will join in the following discussion
What is the ideal engine compartment pad? Is it to suppress sound, heat, or both. I ask because I have the engine out, and just finished removing the droopy cracked original pad.
Several of the aftermarket alternatives have a reflective surface (e.g. the AppBiz ones available on pelicanparts), which would indicate they are trying to reflect heat back to the engine. Is that a good thing?
To offer full disclosure, I installed the "Ultimate Engine Sound Pad" (ordered from Pelican) on my '90 C4, and can not say I notice it being any quiter. I am not saying it isn't, but to my aging ears in a convertible, it is as sonorous as always. No clue about the engine compartment temperature before vs after
Trying to decide what is best for the C2.
All comments appreciated.
Cheers,
scped
What is the ideal engine compartment pad? Is it to suppress sound, heat, or both. I ask because I have the engine out, and just finished removing the droopy cracked original pad.
Several of the aftermarket alternatives have a reflective surface (e.g. the AppBiz ones available on pelicanparts), which would indicate they are trying to reflect heat back to the engine. Is that a good thing?
To offer full disclosure, I installed the "Ultimate Engine Sound Pad" (ordered from Pelican) on my '90 C4, and can not say I notice it being any quiter. I am not saying it isn't, but to my aging ears in a convertible, it is as sonorous as always. No clue about the engine compartment temperature before vs after
Trying to decide what is best for the C2.
All comments appreciated.
Cheers,
scped
Great Question
01-30-2012, 09:31 PM
#3
My son completely removed the old engine sound pad and added a g-pipe. The car is somewhat louder than my 993 but it's a nice sound. To my knowledge nothing bad has happened without the sound pad and it did save some weight.
01-30-2012, 10:02 PM
#4
Get the lightweight one from Porsche (I'm sure Pelican has it). None of them do an outstanding job of blocking noise but running no pad at all will be noisier. The shiny ones really don't make that much of a difference over the stock pads.
Part of the problem (if you can call it a problem) is that you're in a Cab. The insulated cloth material will never do a very good job in reducing the amount of noise compared to a coupe. Being an air cooled engine, it will always be louder as well (compared to a similar vintage water cooled car).
I've added about 18-20 pounds of additional sound insulation to my car in an effort to make it quieter. I think I've got the quietest 3.2 Carrera around but it is still noisier than a modern car. Is that a lot of weight..? I'd say about three and a half gallons of gas worth in weight. I certainly can't tell the difference in a few gallons.
Part of the problem (if you can call it a problem) is that you're in a Cab. The insulated cloth material will never do a very good job in reducing the amount of noise compared to a coupe. Being an air cooled engine, it will always be louder as well (compared to a similar vintage water cooled car).
I've added about 18-20 pounds of additional sound insulation to my car in an effort to make it quieter. I think I've got the quietest 3.2 Carrera around but it is still noisier than a modern car. Is that a lot of weight..? I'd say about three and a half gallons of gas worth in weight. I certainly can't tell the difference in a few gallons.
01-30-2012, 10:28 PM
#5
Get the lightweight one from Porsche (I'm sure Pelican has it). None of them do an outstanding job of blocking noise but running no pad at all will be noisier. The shiny ones really don't make that much of a difference over the stock pads.
Part of the problem (if you can call it a problem) is that you're in a Cab. The insulated cloth material will never do a very good job in reducing the amount of noise compared to a coupe. Being an air cooled engine, it will always be louder as well (compared to a similar vintage water cooled car).
I've added about 18-20 pounds of additional sound insulation to my car in an effort to make it quieter. I think I've got the quietest 3.2 Carrera around but it is still noisier than a modern car. Is that a lot of weight..? I'd say about three and a half gallons of gas worth in weight. I certainly can't tell the difference in a few gallons.
Part of the problem (if you can call it a problem) is that you're in a Cab. The insulated cloth material will never do a very good job in reducing the amount of noise compared to a coupe. Being an air cooled engine, it will always be louder as well (compared to a similar vintage water cooled car).
I've added about 18-20 pounds of additional sound insulation to my car in an effort to make it quieter. I think I've got the quietest 3.2 Carrera around but it is still noisier than a modern car. Is that a lot of weight..? I'd say about three and a half gallons of gas worth in weight. I certainly can't tell the difference in a few gallons.
01-30-2012, 10:50 PM
#6
The three things that made the biggest difference were: Insulation on the floor/under the carpet, a new windshield (the new rubber seal actually that cut down on wind noise) and new motor mounts. I also added additional insulation behind the rear seats.
Porsche added more sound insulation under the floor mats when they went to the 964, they didn't have that in the 65-89 cars. I did the same as the 964 but my insulation is thicker/heavier. It is Mass Loaded Vinyl (MLV) backed with 1/4 inch closed cell foam. it cut down on road and tire noise.
The new motor mounts reduced a little bit of the engine noise coming from the back (not exhaust noise). I purchased the stock mounts made by Porsche, the stock OEM ones are inferior. My exhaust is stock except an M&K pre muffler and is pretty quiet.
The additional insulation behind the rear seats is also a sheet of MLV. This is heavy stuff but it does work.
As mentioned I've added at most 20 pounds - about three and a half gallons of gas worth of weight. I'm glad I did it!
Porsche added more sound insulation under the floor mats when they went to the 964, they didn't have that in the 65-89 cars. I did the same as the 964 but my insulation is thicker/heavier. It is Mass Loaded Vinyl (MLV) backed with 1/4 inch closed cell foam. it cut down on road and tire noise.
The new motor mounts reduced a little bit of the engine noise coming from the back (not exhaust noise). I purchased the stock mounts made by Porsche, the stock OEM ones are inferior. My exhaust is stock except an M&K pre muffler and is pretty quiet.
The additional insulation behind the rear seats is also a sheet of MLV. This is heavy stuff but it does work.
As mentioned I've added at most 20 pounds - about three and a half gallons of gas worth of weight. I'm glad I did it!
