Both aluminum (preferable from a weight standpoint) and stainless work.  People have also used sound deadening material, but make sure it's glued/anchored well, especially around the fan intake, as it could get sucked towards the shroud and overheating will result.

To add to that, anything else on the firewall should be firmly attached also. Such as fuel lines...

sounds like you have a fun project ahead,  For belts and suspenders, I used  both sound deader/heat deflector between the aluminum and firewall.  I personally liked what it did to the tome/volume of the engine/road noise ;-)

I picked up the aluminum at a local hardware store, and cut to fit after making cardboard templates. Used self tapping hvac screws to hold in place.

some pics from my installation in 2014… easy to keep clean, looks as it did 10ths ago.

Like the aluminum - makes it a little more fireproof with sound proofing behind it.  Maybe add some machine turning to make it look vintage.

And maybe add bead rolling to edges.  HF/Eastwood has a tool for doing it.

Be the first one on your block:

I’m sure if you were to cut some templates for your engine compartment, this guy would make you a set. Or just sell you the raw material.

eta: The Real Deal: Long Form

Hope you guys find this as interesting as I did. (It’s no wonder these rusted out like they did)

I have used : Semi gloss black paint, Herculiner bed liner and powder coated black aluminum sheeting available from trailer dealers.

Thanks guys! Did any of these ideas get installed after the body and engine was fitted? I guess there’s limited access …

I installed sound deadening with the engine in but it was more difficult and the results weren't especially good.  It didn't deaden the sound that much, either.  Much better to do it with the engine out.

I used that black bedliner that comes in a gallon can..

@WOLFGANG posted:

Like the aluminum - makes it a little more fireproof with sound proofing behind it.  Maybe add some machine turning to make it look vintage.

And maybe add bead rolling to edges.  HF/Eastwood has a tool for doing it.

I kind-of get the vintage aspect of this, but it really doesn't fit IMHO. It either indicates you're really old(WWII airplanes), or nostalgic(1970s hick-boy Firechicken)

Now, about the engine bay sound deadening:

95% of engine noise comes from the intake. Everybody wants to put a quieter exhaust on, and that does help some, but never makes the difference they're looking for. The reason is the noise at the other end of the air pump is never addressed.

What's the difference between a modern car and our retro contraptions with respect to noise? Intake. Think about it, your modern car has a 3 foot long maze of curves and resonance-damping plenums in it, so much so that you can't even hear the intake.

Then you take our cars, which often have a thin foam and steel mesh a couple inches from a velocity stack and that's about it. Couple that with the fact that there are 4 individual noise sources a foot or two directly behind your head and you start to understand.

I measured 107 dB(A) at full throttle in the cabin of my Spyder with the top up. Instant ear damage with more than a few minutes of exposure. (At least I think it was 107, it may have been higher.)

The only Speedster manufacturer to ever address this was Henry at IM. He bought some CB Performance intake hats that install in place of the open and flat air cleaner tops we all have. These are actually designed for Turbocharged cars, to seal the intake and allow piping from the compressor side of the turbocharger.

I installed these on my Spyder along with a couple of 2" neck cone air filters. The reduction was amazing! It was at least 10 dB. Every 3 dB is a 50% reduction in sound pressure, so from 107 to 97 is a TON of reduction.(Do the math: the first 3dB is now at 50%, the second at 25%, the third at 12.5% of the original value, so we're at about 10%. Now, the scale is logarithmic, not linear, but still.)

If these hats were connected to longer tubes that extend further from your ears they'd be even better at noise reduction.

Now, exposing your ears to over 90 dB for two hours or more is permanent hearing damage. I know this because of many rock concerts and MANY days working in concrete manholes/echo chambers over 30 years. I have permanent tinnitus and some loss.

If you want a quiet car, buy a modern one.

If you want to reduce the sound level in your Speedster or Spyder, fine, put in some sound deadening and get a quieter exhaust.

But if you want to make a REAL difference, silence the intake. That's where you'll see the most improvement.

@DannyP posted:

I kind-of get the vintage aspect of this, but it really doesn't fit IMHO. It either indicates you're really old(WWII airplanes), or nostalgic(1970s hick-boy Firechicken)

I feel violated

... or validated. I'm not sure which.

Help a brother out?

@Stan Galat posted:

I feel violated

... or validated. I'm not sure which.

Help a brother out?

You're right, Stan; it's both

Fire Chicken

It's not just for Street Racing, anymore.

It can also be your wedding escape car...

I'ma git me a F-body and roast the tires in front of y'all's houses.

... oh wait, that's my neighbor, the village idiot.

I recall Cory using the bead roller to make finished aluminum panels - believe Ed did too on his 550.  Tool is about $150.  It makes the panels stronger by adding controlled "creases"  and also prevents them from drumming.  Yes, the engine turning '70s hot rod - guess the carbon fiber craze of the day!

@Stan Galat posted:

I feel violated

... or validated. I'm not sure which.

Help a brother out?

Validated in a violent sort of way is my guess.

I've got my engine out and am doing a bit of this 'n that in my spare time (insert eye-roll here). The 2234 is going in, and I'm going to do the EFI I've been talking about for years.

My ECU is a microsquirt, and is water resistant (OK for engine compartment mounting), but I'm me and wanted an enclosure for it to keep it as dry as possible. I got the box done, the components mounted inside, powdercoated it, and applied my own engine bay trim today.

Behold:

I like that. Translated.

@Stan Galat posted:

Love it!

@Stan Galat : excellent choice with the Microsquirt.  That is the same ECU I am running with my 2180.  It’s so much fun driving around while my copilot makes adjustments on the fly on the laptop.

The best part is we save each data set so we can always go back to square one.  That and we can save data specific to the environment we are driving in at the time!

@DannyP posted:

If you want a quiet car, buy a modern one.

If you want to reduce the sound level in your Speedster or Spyder, fine, put in some sound deadening and get a quieter exhaust.

But if you want to make a REAL difference, silence the intake. That's where you'll see the most improvement.

Personally, I think the whole “sound deadening” engine compartment is more cosmetic than auditory. When the foam started deteriorating in my SC, I just pulled it all out. I enjoyed hearing the engine.

I have a pair of Sonic Defenders in each of my leather jackets.

@TheMayoMachine posted:

@Stan Galat : excellent choice with the Microsquirt.  That is the same ECU I am running with my 2180.  It’s so much fun driving around while my copilot makes adjustments on the fly on the laptop.

The best part is we save each data set so we can always go back to square one.  That and we can save data specific to the environment we are driving in at the time!

Mostly the same with Speeduino(users Tunerstudio as well).

My copilot(wife) doesn't really do tech stuff. So I have MSDriod downloaded on my phone, and a bluetooth module on my ECU. I datalog continuously as I drive. Then I crunch the data later and make changes in Megalog Viewer HD. Works really nicely!

I do understand that a bluetooth module may not be possible with Microsquirt.

EDIT: Sometimes I email the datalogs and current tune to one @Michael Pickett, and he does magical things to my tune and then emails it back to me. That guy is a) a genius and b) a national treasure. THANKS!

The current tune is a culmination of two logs, the rides both to and from the Lime Rock Vintage Festival last September. LOTS of data tweaked, it's over 1.5 hours each way.

I agree that it's really tough, and can be expensive, to try to get your engine compartment quiet.  It takes a lot of work for minimal results.

I've been using these Ear Peace plugs for several years, now, love them.

https://www.earpeace.com/pages/earpeace-moto

They quiet things down to a purr while allowing conversation and keep external noise, like wind, down to a reduced level.  You might have to buy two sets before you find the right fit.  I found "standard" to be a shade too big and they kept slipping out but the small version stays put.  Both are tuneable in three different attenuation levels.

@DannyP posted:

Mostly the same with Speeduino(users Tunerstudio as well).

My copilot(wife) doesn't really do tech stuff. So I have MSDriod downloaded on my phone, and a bluetooth module on my ECU. I datalog continuously as I drive. Then I crunch the data later and make changes in Megalog Viewer HD. Works really nicely!

I do understand that a bluetooth module may not be possible with Microsquirt.

Ditto that on the Speeduino using TunerStudio, MSDroid and Megalog Viewer HD over bluetooth. My copilot has helped tune the various beasts over the years, but most of the tuning over the last few years has been just tweaking.

The Megasquirt/Microsquirt systems have been around a lot longer than Speeduino (I was using a MSII system nearly 20 years ago). They're very mature and have a large following. Speeduino is newer, cheaper, and totally open source. Over time, it's gradually adding the bells and whistles, but has everything that most of us need (like nitrous oxide control ).

In any event, for us perfectionists, any of these systems give you a lot more control and and can eliminate some of the endearing shortcomings of our ancient powerplants.

I have the Ear Peace plugs based on Gordon's earlier mention.  What I like best about them is they eliminate the wind noise in my ears.

I do have to say that I usually don't bother using them.  Maybe I should try to use them more often.

I hang them from the frunk release knob.

Mine are right on my key fob to make sure I use them.  

I damaged my hearing with a DIY cannon back in the 1960’s so I’m trying to preserve what’s left as long as I can.  Ear Peace plugs help.  A lot.