1970 GTO Version 2.0

[andrewb70]

As always, little projects tend to take on a life of their own. What started out as a simple subwoofer reconfiguration turned into a rear seat sound deadener project as well.

As I said before, I used products from www.sounddeadenershowdown.com. The methodology that they describe involves a two step process.

First, the metal is prepared using CLD tiles to deaden the metallic ringing that is common when raw steel is tapped or banged. The CLD tiles have an aluminum top and the bottom is a very sticky butyl material. The goal is to apply it to about 25-30% of the panel around it's center mass.

Second, a layer of closed cell foam is applied over the whole area and on top of that mass loaded vinyl is laid to block any sound from penetrating into the passenger compartment.

I applied the CLD tiles all over my package tray, the rear seat/trunk separator panel, and the area under the rear seat. Then I started at the top of the package tray and went all the way to the front of the rear seats with the foam and the MLV. The MLV is hard to work with as it does not mold well and it only bends in one direction. On the other hand, MLV can be bonded (almost welded) to itself using special vinyl adhesive. Using the adhesive I was able to form a solid sheet all the way from the top of the package tray and bond it solidly to the vinyl that was already there which stopped at the rear seat area.

Here is the finished product:





Ideally, I would have also covered the side panels the same way, but I discovered that the foam and vinyl add thickness which creates fitment problems with all the trim panels. Ultimately I decided that this was as far as I was going to go for now.

First driving impression is that what I did definitely reduced the driveline noise that was penetrating the cabin. This made for much quieter driving experience when going down the highway.

Andrew

[Rick Dorion]

Very nice job, Andrew. Do you have any other pics of the earlier stages?

[andrewb70]

I shot some video that shows more of the installation process of the sound deadener. The video is a little longer than I wanted, but it is what it is...



Andrew

[INTMD8]

Looks nice!

Did you notice any difference in cabin noise after the sound deadener?

[Later-A-body]

Looks like you got a lot of work done Andrew. I am getting ready to do the entire interior insulation on my fathers '65 GTO, so your video is timed perfectly.

[andrewb70]

Looks nice!

Did you notice any difference in cabin noise after the sound deadener?

Today I went on a 150 mile road trip and I think there is less road and drivetrain noise. I can't seem to get the rear end from making noise under coast conditions, despite just having had a new R&P installed last year. So there is still a little noise whine, but it is less than it was before.

I think if I was to do the installation as it was intended (forming a bowl all the way up to the top of the doors) that would help a lot. The issue is that with the added thickness of the insulation material, fitting interior trim panels becomes a challenge. If a whole interior was planned ahead of time with that in mind, it would be much easier.

Andrew

[andrewb70]

Haters are going to hate...LOL

https://www.facebook.com/highperformancepontiac

Andrew

[David LaBuda]

You should swap the 12 bolt for a 9 inch. Then the heads will really start to roll haha

[Nicks67GTO]

Haters are going to hate...LOL

https://www.facebook.com/highperformancepontiac

Andrew

Truth....I bet most of them don't even own running musclecars and if they do..... they sit in the garage.

[Interceptor5588]

Whateva. It's your car, build it how you want it and who cares what "they" think.

[andrewb70]

Whateva. It's your car, build it how you want it and who cares what "they" think.

Believe me, I don't care. I've had this car since I was 15, and it's been "done" for over 12 years. It's been in three magazines, has about 20k miles on it, and it still looks modern. Must have done something right.

Andrew

[ekmxryda]

Haha love the half breed comments! I love Pontiac engines too but removing 200 pounds from the front of the car really helps with handling.
I am bracing myself for the comments on my GTO when it is finished someday, I am sure some will say I ruined a real classic, and I will just have to smile and agree with them.

[andrewb70]

Haha love the half breed comments! I love Pontiac engines too but removing 200 pounds from the front of the car really helps with handling.
I am bracing myself for the comments on my GTO when it is finished someday, I am sure some will say I ruined a real classic, and I will just have to smile and agree with them.

I wonder how all those guys would feel about a whole frame swap...or having a 9" rear....or a Tremec transmission...They get so butthurt over the engine swap as if there is something magical about Pontiac engines or cars for that matter. They are just a collection of metal, plastic, and rubber...

There is nothing fun about driving cars that are restored to original condition. They are just newer junky old cars. I remember driving my GTO with stock suspension and it drove like a crappy old car. Then again, I haven't has stock suspension since 1990 when I first installed a complete package from H-O Racing.

Andrew

[Nicks67GTO]

Iv'e caught some hell for having a real 242 67' GTO with a 9" but somehow, putting a chevy 12 bolt in a Poncho is ok in their eyes...since its GM? Whut? Those guys are dip****s.

At this stage of the game the only thing left in my GTO that's actually PMD original is the 455, the sheetmetal and for a short time the driveshaft. Now we all know 67's didn't come with a 455, so that isn't quite right either but somehow I haven't desecrated the holy Pontiac grail since I have a Pontiac engine. The funny thing is I might stay with a Poncho mill for my own reasons but the only thing that will be PMD original would be the block.....that's it, the block and that's if I don't do an MR1 or IAII.....in that case absolutely nothing in my car would be PMD.

[Nicks67GTO]

I wonder how all those guys would feel about a whole frame swap...or having a 9" rear....or a Tremec transmission...They get so butthurt over the engine swap as if there is something magical about Pontiac engines or cars for that matter. They are just a collection of metal, plastic, and rubber...

There is nothing fun about driving cars that are restored to original condition. They are just newer junky old cars. I remember driving my GTO with stock suspension and it drove like a crappy old car. Then again, I haven't has stock suspension since 1990 when I first installed a complete package from H-O Racing.

Andrew

Agree 100% on the original restos. Iv'e driven enough musclecars in stock form to know I don't want one. The only way i'm restoring original is if I have something classified as unobtanium....a 69 Boss429, 69 ZL1, 71 Hemi Cuda, something super rare with tons of collector value.

The magic in the Pontiac mill is all in the aftermarket that's come alive in the last 10 years. It's pretty easy to build huge power for a reasonable amount of money now, where it wasn't easy 10-15 years ago unless you had deep pockets. Truth time.... I would love nothing more than to build a fuel injected IAII 535" McCarty RA-V for my car.....just for the cool factor. Oh man.... lots of cool factor there. Unfortunately that cool factor would buy me a nice truck and probably get about 8MPG. I completely get the LS thing. Its still on the table for me and I go back and forth on it about once a week. I was looking at LSA's a few weeks ago. The price on a 550hp LS swap vs a 550hp Poncho build is probably close enough to call it a wash.

[ekmxryda]

Hey Andrew, I was inspired back in the mid 80's by an article in Hot Rod (I think) where H-O Racing took a 64 or 65 GTO and made it handle with a set of taller 2nd Gen Camaro spindles.
I wish I could find the article, maybe I still have the magazine hidden away. They called it the Corvette killer, the skidpad results were impressive even by todays standards.
Maybe someone else has more details on it? For me that was the start of Pro-Touring.

[andrewb70]

Hey Andrew, I was inspired back in the mid 80's by an article in Hot Rod (I think) where H-O Racing took a 64 or 65 GTO and made it handle with a set of taller 2nd Gen Camaro spindles.
I wish I could find the article, maybe I still have the magazine hidden away. They called it the Corvette killer, the skidpad results were impressive even by todays standards.
Maybe someone else has more details on it? For me that was the start of Pro-Touring.

Eric,

I'm pretty sure I know the exact article that you're talking about. It came out right around the time when I got my GTO. I was a teenager so I couldn't afford any of those parts, but a few years later I installed everything except the tall spindles.

Andrew

[mikes2nd]

Haha love the half breed comments! I love Pontiac engines too but removing 200 pounds from the front of the car really helps with handling.
I am bracing myself for the comments on my GTO when it is finished someday, I am sure some will say I ruined a real classic, and I will just have to smile and agree with them.

Yeah idiots.. claiming a 2006 Pontiac isn't a Pontiac... So that makes all Pontiacs after 1981 not real Pontiacs?

GM is GM...

I have a GT500 Cobra rear axle going in my 70 I would love to laugh at them with that.

I'm sorry anyone can have a run of the mill stock GTO that can't turn, brake and accelerates like a dog. This old "stock" car scene is boring. Its fun to drive for once a decade and huff fumes and enjoy horrible body roll like your riding around on a marshmallow but it gets old real quick.

[andrewb70]

I am a big fan of the Hot Rod Garage show on the Motor Trend YouTube channel, and on the last episode, they did a LS3 swap into an A-body. Good stuff here, except they totally glossed over how they are managing the 4L65E electronics...



Andrew

[mikes2nd]

these shows get a little annoying... all fluff no meat...

Its hard to find detailed info.