Solving heat and noice problems in cabin

Hello Sigmacars

Have you had a chance to reassemble your project?

Have you noticed any improvement? If so how much?

Thanks

 

+1 Lost

 

Hey Sigma I am getting ready to insulate my 328 next month to decrease the sound/heat issues a little and have been studying your tutorial

On question I have is did you create a flap in front to allow access to the fuses there?

I assume if you did you just taped the sticky side to another sticky side back to back to create a flap.

Also why didn't you just attach is to the back(on the inside so it wouldn't be visible)of the fiberglass molded cover?

I guess doing it the way you did would make a slightly tighter seal.

Thanks
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You should also think about adding a layer below the spare tire well towards the back.

 

Just found this thread. Terrific stuff! Interestingly, I just had my interior apart for a little mouse problem (!) but did no insulation during that process. Now I see this thread and am fired up to re-do it correctly.

I greatly appreciate everyone's input on this and can only surmise that though keeping heat out of the car is a great benefit (and my primary goal), I presume that when it is heated in winter, it'll also be more comfortable then.

Interested in any and all input on this thread. I'll post my own as I progress.

Thus far, I installed an aluminum/ceramic heat shield between factory heat shield and trunk floor. It was only 1/8" thickness, yet in a rough test with thermometer, dropped trunk temp after 10 minutes of idling from 106 degrees to 93 degrees (it was a 85 degree day). I would NEVER idle for 10 minutes, so I presume the difference would be greater once moving, but I'll take any drop.

 

Done a lot of this on my 928s4.
"Dynamat" products , I use Second Skin Audio, reduce a small amount of road noise as the extra mass makes the panel resonate at a lower frequency - below our hearing. The alu top sheet does more to reduce road noise & heat than the rubber stuff. It's why car audio use it to reduce panels being speakers.
Lining the doors will make a big difference here as the door panel acts like a big speaker cone.
Mass loaded vinyl (MLV) on top of a thin layer of closed cell foam will block the road noise. It's what car company's use as OEM solutions, usually under the carpet. To be effective you must leave no gaps, not realistic but try.
It's apparently not recommended to ceramic coat headers and then wrap with a heat wrap, but many still do. In fact you will get a better result just from the wrap to reduce under bonnet temps, but it doesn't look as good or as long lasting, I do have ceramic headers on my Ducati & a loose wrap on the rear header to stop the heat soak when stopped. My logic is the loose wrap allows the moisture to evaporate, but considering the heat I can't see it being the problem some quote.
There are some silicone backed heat shields, see hot rod products or aero nautical supplies, that cover starters etc, but also in sheet form that you would put on the engine side of the panel provide excellent heat rejection, better than just alu sheet.
In the 928 over the SSA damping layer I paint a ceramic bead paint 'spectrum' , then MLV.

 

I agree since that is right at the footwell level in the cabin. It looks like I will have to drill out some rivets to pop the shell off in the front trunk to gain access though

 

Possible Discovery?

My cabin seems to draw in warm air, as do many of yours. I LOVE this thread about insulation and isolation, as that is certainly key to resolving the issue.

I noticed that my spare tire well 'dips' slightly in the middle (328) where the front hood seal should fit straight across.

I put some vaseline atop this seal, and dropped the hood. To my amazement, the vaseline only transferred to the first 3" on the drivers side and maybe 2 1/2" on the passenger side.

To me, a terribly inept seal, leaving the entire central portion nearly 'open'. The hot air of the radiator is literally blown over this seal, into the tire well, and right into the interior through many spots (brakes, pedals, vent hose openings, cable openings, you name it.)

Unless you guys have already ruled this out. I'm going to attempt straightening the hood to seal mating alignment.

This atop the many other things already mentioned in this great thread.
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I have the same dip but my car has the "carpet" attached to the inside of the hood that overlaps the seal.

Though the "carpet" looks fairly porous. I'm sure some air is still getting in.

 

I pulled the entire spare tire well out to gain access. Of course I have yet to put it back.

 

I think the only way to get these to straighten is to brace it with a right angle bar secured underneath the lip. Maybe aluminum to keep the weight negligible.

I assume over the years the heat (and that end bakes close to the radiator) weakens it.

 

Great minds think alike! Considered all sorts of bonding options, none as invisible as I'd like. Now am onto a 1" weatherstrip seal attached to hood that would mate with crossmember behind radiator.

NOTE: I lifted the weatherstrip from crossmember so it would mate more ideally with hood and in my car, the flow-through of warm air into cockpit was noticeably reduced. I still ordered the sound/heat shielding material to do my firewall, footwell, cockpit for overall benefit.

The seal is definitely an issue; I'd recommend attacking this for those who have this problem.

 

I injected structural expanding foam into the firewall to fill the void between the panel in the engine bay and the interior panel behind the seats. This turns the firewall into a much more solid structure which does not "drum".

I think it would be possible to also use this type of foam under the floor between the fibreglass floor panel and the closing plate which is riveted to the underside of the chassis. Much quicker and more effective than sticking sheet material all over the floor.

In theory it would be possible to fill the chassis tubes with it as well, where the water pipes run. But this might need some careful thought as might cause some kind of issues (not sure what issues exactly though).

 

Sounds interesting. Can only find 'structural expanding foam' for boat builders and it appears to be a brush on type. Where did you find it in sprayable form? I presume this to be closed-cell foam?

 

Its easily available from builders suppliers. It sprays out of a can which is supplied with a long tube. There are several types including a fireproof building grade. Its rather evil stuff to use as it expands out of any holes and is incredibly sticky. If you get it on your hands it looks like you have a terrible skin disease so you cant go out in public for days.

The structural type has a very high expansion and so care is needed. I think if doing the floorpan a low expansion type would be needed as it could bend the closing panel when it expands as its quite a thin panel and large area.

 

Corvette had this used in frame rails. Supposedly makes the frame much stiffer.

I always wondered what benefit it would serve in strengthening the chassis on the 308. I'm sure a quick search can provide you more answers

 

caution re foam any where water can get. I have a 76 Alfasud. Alfa thought it would be a good idea to fill the top frame rail with foam to keep water out & prevent rust. Of course this is where they all rust away even more than normal. The foam holds the water not allowing it to easily evaporate. I have used closed cell foam in B panels & other cavities but only where short of dunking the car in water, a la Risky Business, water should never be.

 

You can get these vented panels from Dave at Scuderia Rampante in Boulder, Colorado.
Draws air from the spare wheel well and battery area out under the car.
I know it works because I have found leaves half sucked out the slots.
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Love Dave Helms' products, and the vented panel - that I had no idea he offered - looks like an excellent idea.

My 328 has enough upside louvers to seemingly exhaust enough heat, but in an earlier thread I pointed out the huge gap between the rad support seal and the hood. This was allowing gobs of warm air to enter spare tire compartment and then footwells.

Last night I took a piece of aluminum channel ('c' channel) and cut it to fit under this area. I sanded and epoxied it overnight, using a support to hold the spare tire well lip 'up' while the epoxy cured. Thank you Tricycle! At least it confirmed I mightn't be completely crazy all by myself!

After 12 hours of drying, it took out 95% of the dip, allowing my seal to now touch all the way across the top.

Below is Before, During, and After (I painted the aluminum support in satin black, basically invisible.)
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Excellent work Hudson!

Your ahead of me on this.

My project is to get started next weekend. The plan is to drill out the rivets to remove the wheel well.


1) Straighten out the dip much the way you did though I might add a few discreet screws to the aluminum bar (I don't know if I would trust epoxy alone)

2) Flip the spare wheel well upside down and see the feasibility of covering it with some B-quiet/Dynomat heat shield. The reason for this is I put my had against the inside of the wheel well after driving and it was HOT after baking near the radiator and fans. So even after all holes are plugged and radiator lines are wrapped there will still be a good amount of radiant heat coming in.

3) Look into wrapping the radiator lines since I will now have easier access

4) Cover the front near the dash as others have done in this thread with B-quiet/Dynomat.

This will probably eat up the rest of the month and part of Sept since I have limited time to work on it.

FYI
http://www.ferrarichat.com/forum/308-328/441890-spare-tire-bay-whats-missing.html
has some useful pics and info.

 

My Ford GT has a similar layout where the warm rad air is forced up and over (took up WAY too much room from trunk, though possibly required for that engine.) I mean, it was forced;l no other place for it to go. The trunk in the GT - if you can call it that - got decently hot, but nothing like the 328.

I think the insulation is the way to go, plus diverting the airflow better. Either around the spare tire well, out the bottom or over the top. The problem now, as I see it, is that it is being forced INTO the trunk and thus cockpit, along with the many holes you've already discovered (footwell, gas pedal, etc.)

THANK YOU for the link to the 'spare time bay, what's missing?'. Very revealing stuff there too. We're going to track down this tiger and tame it! Then the other dozen or so...

 

Ok I ran some tests over the weekend

1) Place paper streamers in basic locations in the front spare tire wheel well and tape a video dash cam to the dashboard side in the trunk(in a pinch you could use your cel phone), close the lid and drive. This is to observe the turbulence in air flow while driving. Duct tape is your friend.

Initial test is basic 35-40 MPH, stop and go with the video running.

Results:Not too bad on the turbulence I expected worse but I am getting air bleed through. So I will address these and retest. I also need to swivel the camera and retest each side for air.

Result: Ongoing. Will restest at highway speed

2) Infrared temp test. Light driving

Radiator at 172°F.
Inside of molded wheel well (for spare) 134°F (near the radiator but temp taken INSIDE)

Definitely needs heat shield. I hesitate to do this because the foil heat padding will show. The outside of the shell would be wrapped which would really only show at the front where the fans/radiator are located. I wonder if it can be painted to mask it like using Rust-oleum High heat spray (used for barbeques)

Result: Pondering
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Man, you are COMMITTED to ending cockpit heat forever! Great work.

I agree on the foil and it showing, but if you paint it black, doesn't that defeat the reflective quality? I'd think the dense black foam likened to pipe insulation would be inoffensive and effective if you go that route.

I purchased some 'lava mat' in a carbon weave look material, pretty subtle actually. I affixed that the the very front of the spare tire well and it worked pretty good. The top of the well (crescent shape that covers part of the spare) and the sides still got very warm.

On a side note, my rear trunk issues seem to be very resolved. The ceramic mat under the trunk is doing its job nicely.

 

I am wondering if GT4 has the same panel that can draw air similar to this?