Help me get my 1968 Coronet coupe into the 12's...

[daniel_depetro]

I don't care if it is a 12.999 E.T., I just want it to hit a 12 second pass.
My father doesn't think it can be done with the car (basically) the way it is.

Here is the car information (if you want/need anymore info please ask and I'll answer as best I can).

1968 Dodge Coronet coupe base model (not even a 440). Absolutely no options (except for chome body & belt mouldings, chrome b-pillar moulding and AM radio). Was originally a slant six 3 on the tree car, but now sports a 1968 440 HP2 engine, 4-speed, 8-3/4" rear with 3.55:1 gears and a sure-grip.
The engine has a 770 cfm Holley 'Street Avenger' dual feed 4-bbl. carburetor on top of an aluminum Edelbrock 'Performer RPM' 4-bbl. intake manifold. It does have a Mopar Performance 'Purple Shaft' camshaft, however I have no idea what size it is as it was in there when I bought the car. I could hear it was cammed, but confirmed it when I recently installed the double row roller timing set (installed at 0). It also has headers and has been converted to electronic ignition via a brand new Mopar Performance kit (ECU, distributor, harness, ...). Other stuff includes an Accell 'Super Coil', Mallory 'Super Wires' ignition wire set, Moroso chrome valve covers (same shape as the factory pieces), and Moroso chrome 14-inch drop base air cleaner (with a new Purolator 14x4" standard paper element). I installed a 19x28x3" aluminum radiator so the extra fluid capacity might have gained me a couple pounds even. A Stant 'SuperStat' 180 degree thermostat, an aluminum water pump housing, aluminum water pump, and aluminum thermostat housing help shed some heat and a couple pounds as well.
I also installed the lightweight 1-1/16" bore aluminum master cylinder & adaptor kit, but to be honest it isn't much lighter (1 lbs., maybe 2 lbs. max) than the non-power drum brake cast iron original piece.
It has a mint 1968 Super Bee power buldge hood and 15x7" aluminum mag (slots) wheels wrapped in Kelly 'Explorer' 205/70R-15 (F) & 265/60R-15 (R).
The fuel pump, fuel filter, and alternator were all recently changed as well.
The spark plugs are brand new too.
It has synthetic fluids in the transmission/rear end (with sure-grip additive also) and Redline 'Water Wetter' in the coolant.
The car is "light" (~3,400 lbs.) for being an all steel car with an iron headed 440 and all iron 4-speed (car weighed 3,340 lbs. with the small 7.25" rear & smaller brass radiator, original iron engine parts, and about 1/3 tank of fuel).
I tried a lightweight high torque mini starter but it was rubbing on the starter so I had to stick with the full size unit.
The interior is a basic bench seat taxi cab stuff.
I assume the torsion bars & leaf springs are the stock slant six stuff.
I am going to try to get a pair of slicks for the rear when it comes time...

 

[69HEMICORONETR/TCONV]

Have you got a time slip with the car "as is" so you have a general idea of how much time you have to shave to get to the 12.999 that you are aiming for ?

 

[daniel_depetro]

Nope.
Just got the car this summer, and haven't drove it much honestly.

 

[69 Runner]

4.10 gears

 

[daniel_depetro]

I knew a gear change would come up. :blush:
I may go with a 3.73:1 which isn't going to do much, but with the 3.91:1 our Dart is just screaming to many RPMs for me to want to take 2-7 hour trips in it. That's what I like to do with these old heaps. Afterall they have to be street car first, drag car second.

I was hoping to not have to spend much more money, and I'd like to keep it street/highway friendly as it will be a near daily driver (unless plans drastically change).

I know too many complications, I can't have everything without spending money...

 

[69 Runner]

To keep it highway friendly AND run 12's, you might as well just build a 500+ cube stroker. That should pull it down the track without really big gears

 

[daredevil]

that should be good for 11s

 

[Mopar873]

4.10s and a touch bigger carb, then hook it up with the lightest rear tire that will hook halfway decent.

 

[daniel_depetro]

To keep it highway friendly AND run 12's, you might as well just build a 500+ cube stroker. That should pull it down the track without really big gears

Heh.
Im not spending anymore money, certainly not building another engine.
I'll probably run a little more gear (3.73/3.91) and do a few other tweeks (maybe a bigger carb?), but I didn't think it would take a 500" big block to get it there.
I'd like to get the 440 Source 'Stealth' aluminum heads, but not sure if it'll actually happen by spring...
I just figured if a heavier Coronet R/T 440 could run mid 13's stock, better prepped tracks these days, the addition of slicks, and my performance parts I added I though I'd be a lot closer then I apparantly am.

 

[Meep-Meep]

Can you run slicks? I agree you will need more gear to optimize 1/4 mile performance.

Separating the important parts out of your description I get: 440, some kind of cam, dual plane intake, headers, 3.55 sure grip, 4 spd, 3400 lbs.

Can you shift a 4 spd without falling asleep between gear changes? Good! Now that we got that out of the way. It would be nice to know compression ratio. You can do a compression test (with the throttle open) and hopefully you have at least 150 PSI or cranking pressure. This will make or break your plan. If you have a big cam with an 8.5:1 engine you might as well hang it up - or put a lung on it!

It really doesn't take much to put a 440 B body into the 12's. I did it with a basically stock 383 and a lot of gear.

 

[daniel_depetro]

Can you run slicks?

Why couldn't I?

Separating the important parts out of your description I get: 440, some kind of cam, dual plane intake, headers, 3.55 sure grip, 4 spd, 3400 lbs.

That's the basics.

Can you shift a 4 spd without falling asleep between gear changes?

I guess that remains to be seen...lol

It would be nice to know compression ratio. You can do a compression test (with the throttle open) and hopefully you have at least 150 PSI or cranking pressure. This will make or break your plan. If you have a big cam with an 8.5:1 engine you might as well hang it up

I can & certainly will do a compression test, but the car is stored now.
The engine looks pretty fresh internally, so I don't think I'll be surprised.
It runs really strong so I wouldn't think it is a "low" compression, but who knows.

 

[MarPar]

I assume the torsion bars & leaf springs are the stock slant six stuff.

Yikes!! with a 440? i know bigger bars probably aren't good in this case for drag racin', but i'd be worried bout breakin stuff on a launch...:confused: am i off here??? :grin: keep slimmin' her down, take the rear seat and the pass seats out, the spare tire, any other unnecessary weight...she'll get there!!! :yes:

 

[Meep-Meep]

I assume the torsion bars & leaf springs are the stock slant six stuff.

Yikes!! with a 440? i know bigger bars probably aren't good in this case for drag racin', but i'd be worried bout breakin stuff on a launch...:confused: am i off here??? :grin:

I had six cyl bars in my 68 383 RR for a long time and never any problems. It was a bit spongy though :tongueflap:



keep slimmin' her down, take the rear seat and the pass seats out, the spare tire, any other unnecessary weight...she'll get there!!! :yes:

If the engine pulls like it should just some gear and traction should do the trick. A diet can only help the situation.

 

[383man]

You can run 3.73 gears and still run fast at the track. You can just run a shorter tire if you think it needs more gear at the track. I run 4.30's but I also run a 30" tall tire so I cruise at 60 mph turning about 3500 rpm. I wanted the tall tire to fill the large wheelwell on my 63 Sport Fury. But I know a guy running 3.91's with a 28" tire and it is about the same over all gear ratio as mine. In fact my 440 is a very mild build and has pushed my 3700 lb 63 to mid 11's. You can see my build on this post here. Good luck with your Coronet. Ron

http://www.forbbodiesonly.com/moparforum/showthread.php?t=5218

 

[wingcarenvy]

I think your combo should be good for 12s. The key is not if you can make enough power, but is the chassis efficient enough to capitalize on it. Your /6 springs will help just make sure you run a pinion snubber. Even on normal radials I think you can make it. The important thing to remember is to go out and get a baseline and systematically change technique and tune ups till you have arrived at some conclusions on what you'll need to change to get some more out of it. This is my favorite thing to do with a new (to me anyways) car. I just ran my stock 383 Roadrunner at the track and it ran 8.80's at 82 mph. Which is solid 13 second territory. On 195 whitewalls no less!

 

[67Satty]

Get a copy of the Mopar Chassis book. There's a lot of little tricks in there that don't involve spending much money. Like to reduce wheel hop, make sure your rear shocks are long enough, at least 24 inches extended. You can get some Dodge pickup shocks from rockauto.com for like $22 each. Clamp the front of your springs, run slicks or drag radials. Like others have said, just run a shorter tire, no more than 28" with your 3.55 gear.

 

[daniel_depetro]

I finally saved up enough to get a set of the 440 Source 'Stealth' aluminum heads.
This will help shed some more weight and make a tad bit more power.

As far as the chassis goes, I haven't done anything to it yet.
I have only got a couple hours drive time with the car and most of it was with the engine only putting out ~200 Horsepower.
The chassis will slowly be tweeked throughout the summer.

Thanks for all the suggestions so far.
I'm sure I'll have many other questions as I get into it further.

 

[godfatherofchry]

I agree with meep meep it don't take much of a 440 to run in the 12s 391 gears take the clamps off behend the rear axl about 4to6 degres. wedge under thespring perchs bring her off around 45 or5000 shift it like a man and you mite be serprized.

 

[wedge5]

You have enough power to put the car into the 12's. You now need slicks and a little more gear, 3:91 gears are a good all around gear. As stated, just adjust your tire size from street to strip and that will effect your gearing.

 

[t67power]

Get your slicks and go to the track and see what she's got.
While your there re- way the car.
I run a 67 coronet all steel with a small block 360 \ 904 \ 8 3/4 rear and she ways 3570 on the scales with out me in the car.
3700 with me in it.
How is your car only weighing in at 3400???????
It's got a big block and i think the 68 dodge's weighed more then the 67's???
That is very light \\\\\ good for you