Classic 1969 Mercury Cougar Restomod

[Rtharp1234]

Hi from Southern CA

I own a 1969 Mercury Cougar
that has been heavily modified.

It's now got a 351w overbored 0.03 so 357w.. Afr 205 aluminum heads a decent cam, aluminum intake, forged internals, internally balanced. An EFI Holley Sniper An Aod has been added

It's rated over 500hp..
Not exactly eco friendly.

BUT a lot has been done with efficiency in mind...

I first recorded my tank to tank mpg at 9.. the latest modifications have brought it to ave 14..

I also have a 2005 Civic so not shooting for moon as it has a few eco upgrades already and the Civic a daily driver... doing ok.

I'd like to shoot for 20mpg + on the Cougar which I think is doable while keep it close to looking original.

I'll list everything done later as well as projects.

Belly pan next on list.
Raise thermostat to modern 195 degrees.

[freebeard]

Welcome.

Is it as convertible XR-7? [probably not?]

The bellypan could start with sealing up the radiator bulkhead.

[me and my metro]

Welcome!

[Rtharp1234]

Originally Posted by freebeard

Welcome.

Is it as convertible XR-7? [probably not?]

Nope just a regular coup...

The bellypan could start with sealing up the radiator bulkhead.

I should mention I'm thinking engine Bellypan sealing up about 3/4 of it. I ll likely vent the hood near the radiator to extract heat amd get just a tad of downforce too by doing so.

[freebeard]

I mention the bulkhead to insure all the air is available to the radiator. If there is sufficient room ahead of the radiator behind the grillework a bellmouth helps more.

[cRiPpLe_rOoStEr]

Originally Posted by Rtharp1234

I'd like to shoot for 20mpg + on the Cougar which I think is doable while keep it close to looking original.

Might be achievable, but it will definitely involve some adjustments to the car and maybe to your driving style too. I guess it might be quite tempting to make the V8 roar loud once in a while...

[Rtharp1234]

So goal's already been achieved... new goal =25mpg

So the big change that made it possible was regearing the rear differential.
I was still with the original 2.75 rear end ratio.

I had somebody who mentioned to me in another group that this ratio was killing me. I'd say about 90% of the info out there just says that lower #'s equal better gas mileage. This poster had mentioned to me , nope it's making your engine lug.. It has to really work to get to your RPM and it's way below where your engine's rpm efficiency curve.

Well he is right. I had spent $1000 getting my rear end differential. The best bang for your buck upgrade and they aren't kidding. It will pay for itself though in gas mileage saving in only a few months.

I've got an approx 27% increase in torque with this new rearend. It's a definite jump in power. But I've also got a huge jump in gas mileage as my previous best was 14mpg and now I'm getting almost 22.. (and this is two fillups so not a fluke)

So I've got a 500hp 69 Cougar that's been lightened a bit, has an AOD, new rear end and Sniper now getting much closer to modern day fast cars.

now to lighten it a bit more. and more tuning the EFI Sniper.

[cRiPpLe_rOoStEr]

What differential ratio are you using now?

[Rtharp1234]

3.5 now.

I had debated between 3.73 / 3.5