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

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...

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 ?

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

4.10 gears

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...

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

that should be good for 11s

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

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.

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.

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.

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:

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.

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

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!

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.

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.

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.

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.

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

I will definitely re-weigh the car again, as I get free weighs on a local certified scale.

It was a super lightweight (if there is such a thing..hahahaha) base model Coronet.
Do I mean base model.
The only thing it originally came with were Am radio & the chrome mouldings (drip rails, belt line, B-pillar, and rocker panel).
I mean the dash is all steel with no plastic trim panels covering it even. I didn't even think they made them like that in the 1968-70 B-bodies.
Of course everything is manual and being a coupe I don't have any window winding mechanisms in the rear either.
I do not carry the jack & spare tire around in the car either.
Granted neither is serious weight, but just helping show why this one maybe lighter then most fully dressed B-bodies.

There is definitely more weight to be lost though as the body is 100% steel and I have not cut anything up, though I doubt I ever will on this car.
However I would like to get a new set of headers so I can get a mini-starter to fit, as well as upgrade to the 10.5" clutch & flywheel set-up with a blowproof belhousing (right now I am using a stock 11" flywheel, cast iron 11" belhousing, and 11" 23-spline perfection clutch).
The transmission is a 1970 all cast iron 4-speed unit and the driveshaft is a factory 1968/69 Road Runner piece.

You really need to take a look at your suspension. IF you still have all of the stock /6 stuff under there, you are leaving a lot of potential on the table. All the power in the world won't help you if you can't put it to the ground.
Side note: Running 12's is great, but not a lot of fun if it takes you longer to stop.
How are the brakes?

They work great, but will definitely be upgraded.
Manual 4-wheel drums; original small finned drums in the front, original 11 x 3" finned drums in the rear.

I know it's not ideal, and I'm a fan of big brakes and hard cornering but obviously not with this car. The only time I really run it hard is at the track. On the streets it's just a "mean" cruiser that's in no hurry to go anywhere.


I will definitely be upgrading the suspension over the summer as paychecks allow for it.
Afterall making $8.60 before taxes doesn't leave a lot of room for my Mopar obession.
Most of my paychecks go towards the family and the rest towards paying insurance and fuel for these old pigs.

Since you said you wern't going to spend much more money, which I can understand.

Sometimes small things can get overlooked.

Check and see if your engine has a windage tray installed, it should but could have been overlooked.

A windage tray in the oil pan is usually good for about 15 horsepower and this is cheap horsepower.

Hang in there you can do it.

A windage tray in the oil pan is usually good for about 15 horsepower and this is cheap horsepower.



:yes:

Tunede and driven properly it should run 12.5 area with what you have.

Make sure to have the dist. recurved. They rarely package those for each individual engine. And those new heads might not be the hot ticket on a stock motor. They have the same chamber volume so your compression ratio stays the same. On top of that, they are aluminum so they conduct too much heat out of the motor that it doesn't already make.

They work great, but will definitely be upgraded.
Manual 4-wheel drums; original small finned drums in the front, original 11 x 3" finned drums in the rear.

I know it's not ideal, and I'm a fan of big brakes and hard cornering but obviously not with this car.

I wouldn't be afraid of those brakes (as long as they are working perfect). I run the same ones on my Roadrunner running 10.90-11.00 and they work great. They are light and have less drag than disk brakes. Again, have a look at them and make absolutely certain they are working perfectly and they'll do fine IMO.

my brother's 71 GTX with a stock 440 6 bbl with a 509 mopar cam,727 tran's and 3.55 gear's On drag radial's has gone 12.85@107mph.

my brother's 71 GTX with a stock 440 6 bbl with a 509 mopar cam,727 tran's and 3.55 gear's On drag radial's has gone 12.85@107mph.

Pretty darn respectable with those gears....:yes:

replace the heavy advance springs in the distributor with the lite type springs.

Ok, long time and no update.

I'm finally going to bring the car out for the first time this coming weekend.
We'll see what happens!

4.10 gears will help...A holley 750 dominater will also help!!!!
Petty Blue 67 GTX

Ok, long time and no update.

I'm finally going to bring the car out for the first time this coming weekend.
We'll see what happens!

So what happened? How did it go??

LM

I don't know yet, I just posted that about 50 minutes before you quoted it!
:icon_lol:

It will be going as is. I don't have time (or money) to swap any parts out. I'll also have to make do with the gears and the old street tires the car has on it.
Unfortunately our "local" track (~4 hours away) had some washing out issues and went to 1/8th mile for the rest of the year (this is the last weekend for racing).

I don't know yet, I just posted that about 50 minutes before you quoted it!
:icon_lol:

It will be going as is. I don't have time (or money) to swap any parts out. I'll also have to make do with the gears and the old street tires the car has on it.
Unfortunately our "local" track (~4 hours away) had some washing out issues and went to 1/8th mile for the rest of the year (this is the last weekend for racing).

Silly me, should have looked at the dates. I'm going this weekend too...

What should I aim for with the timing?

What should I aim for with the timing?

Whatever your engine likes. I'm still a fan of using a vacuum gauge to set timing.

My quick list:
- Disconnect vacuum advance, if equipped.
- Ensure your mechanical advance is all in by ~3000 rpm.
- Determine initial timing by advancing to achieve the highest vacuum then back timing off for a 1-2* drop in vacuum. Write down this number (best have a timing tape or a degreed balancer).
- Determine total timing by holding rpms above all in rpm, advance timing until highest vacuum is reached. Write down this number, and reset distributor to initial timing number.
- Adjust mechanical advance to match these number. For example, if your motor liked 18* initial and 38* total, set mechanical advance to provide 20* of advance.

start taking weight out the car. things you don't need and remember every 100 lbs. is a tenth off your et.

Other then spending a lot of money (that I don't have) or cutting the car up I don't think I can get it much lighter?!?!
If I can, I'd love to hear some tips/pointers.
I'm not removing seat springs, a fuel strap, or window regulators to do it either.



OK, I got the numbers, and they're not pretty!
I wasn't expecting much as this is the first time I drove the car at the track and in fact, it's the first time I drove the car since it went in storage back in October of 2009! Worst of all I only have about 10 miles in the car in the limited time I had it together before it went to storage.

At the very least I have a baseline and now we can go from there and the weekend went extremely well.


My 2001 Ram with the 1968 Dodge Coronet 440 4-speed loaded on the 2006 18' Road Warrior trailer.

http://img831.imageshack.us/img831/9765/project4a.jpg

http://img827.imageshack.us/img827/7909/p1010803b.jpg

http://img29.imageshack.us/img29/9182/project8.jpg



I was kind of bummed that W.I.R. is running 1/8th mile since they have had the wash out issues, but anything is better then nothing.
Unfortunately it rained the entire trip down and they cancelled the Real Street Drags / Test 'N Tune Friday afternoon. At least we're able to have a nice sit down dinner, do some swimming, and get some rest at a nice Motel.
I woke up took my son swimming for a bit (again), cooked us some golden malted waffles for breakfast, packed everything up, and we left for W.I.R.
Saturday morning was the final points elimination race, and we arrived just in time to get two qualifying passes in. I wanted to unhook the tiny 1-7/8" exhaust that would surely be plugging up the 440, but being in the street class "full muffled exhaust" is mandated.
I found a spot to park both rigs (Dad brought down the 1972 Dart with the supercharged 360 and we hustled to unload the Dart & Coronet. We were pretty late so I jumped in and drove up to the staging lanes immediately while dad stayed back with the Dart to check the fluids.
Shortly after it was time for me to make my first pass in the Coronet. I launched from idle and let the clutch out slowly. First gear was still useless and when I hit second it wheel hopped like crazy. It went into third with a chirp and it finally settled down but I was already at 1/2 track at this point. The car pulled pretty strong, but I knew a good time was never going to happen that day with the old hard 265/50R-15 radial all seasons, weak/tired slant six sleaf springs, non functioning shocks, and puny exhaust. I was surprised how well the OEM parts store clutch worked actually. No doubt limited traction helped it survive.
I hit the return road and rolled down my window to pick up my time slip. A disappointing time, but at least I now had a baseline. 10.42 E.T. @ 71.45 MPH was all I could muster. I left the time slip shack and saw the Dart charging down the strip and the could hear the supercharger spinning. Sounded great!
I drove around and got right back in the staging lanes for my second qualifying run and waited for dad to catch up.
Once he showed up in the staging lanes he said the car hesitated hard on launch and then came on all at once and spun the tires out of the gate in first and then a tiny bit in second. His time slip still put mine to shame. He ran a 9.5x E.T. @ 80.x MPH.

My second run was actually worse. I left basically the same way but rolled on the accelerator pedal at a much slower rate to avoid so much wheel spin. When I hit second the back end stepped out and it was like the car was on ice. I put it in third and just finished with it pegged from there. 10.62 E.T. @ 70.89 MPH.

My dad had much better luck in the Dart this run and ran a 8.85 E.T. @ 81.xx MPH.

Qualifying was over and it was time to race. I dialed the Coronet in with a 10.35 E.T. and I dialed the Dart in with a 8.90 E.T.

Round 1 of eliminations paired me up against Brian Hegemeister from Ishpeming, MI in his mid 2000's Camaro. He redlighted and I ran a 10.70 E.T. WOOT! I was moving into Round 2.
Dad's Round 1 luck was not as good and he redlighted. Too bad because he ran extremely close to his dial in and probably had a good shot in Round 2. We loaded up the Dart then & there.

In Round 2, I decided to bump my dial in back a bit to a 10.50 E.T. I was against a vehicle with a similar E.T. (though I forget what it was). I took off even easier and it was the same old, same old. Though I found myself in third a tad earlier then the past three runs and the other guy was nowhere to be seen. Instead of hitting the brakes and hoping for a win, I just ran it through to a 10.00 E.T. @ 73.55 MPH. Of course I seriously broke out which put me on the trailer. This run also had my best 60' time of 2.475 E.T.
The others were 2.616 E.T. (Qual #1) / 2.680 E.T. (Qual #2) / 2.618 E.T. (Rnd #1).

Good news is we had a ton fun and nothing broke. Other then an extreme shortage of time neglecting me to get the tachometer installed in the Coronet or the much better flowing B&M street scoop on the Dart (stopped by Advance Auto parts in Escanaba, MI to get all the parts needed for both) we didn't even have any problems!


Now hopefully the car will be "ready" first thing in the spring. Then I can start swapping parts and trying new things (and will be surely asking for a lot more help).

well atleast you got her to the track, sounds like the first thing you need to do is get some good meats under that thing and do some suspension work to get that thing launching/ hooking a little better. good luck, glad to hear you had fun and nothing broke!!

Yeah, the car will come around, especially with the help of everyone on this forum! I'm fairly confident it'll get to my goal of a 12.999 E.T. with a lot more tuning/practice.

I'll hold off putting the heads on at least until the chassis is set up quite a bit better.

I didn't have time to do anything, even hook up a tachometer. I rolled it out of storage, air the tires up to pressure loaded it and raced it for what I could.
Too bad the test and tune was calcelled, would have been nice to try some different timing adjustments launching strategies and air pressures. Oh yeah and with open headers so it could breathe.

Wished i would of known you were going to WIR,i am 45 minutes from there and would have came and watched.

Glad to hear you didn't break..I wish I could say the same...I ran a 10.91@118mph (1/4 mile) short shifting it at 6000rpm and shutting it down early (Hence the 118mph) and as I hit the return road I had coolant spraying out the overflow and my oil pressure was gone....I think my little pump gas iron head (906's) 440 may have spun a main bearing. This all happened on my very first run of the day.....bums me out because I think the car had a 10.50 in it yesterday...well that and the need for a new motor...Not sure I'm going to go back to the stock appearing motor again...might be time for some good aluminum heads and some more displacement....

Just glad it happened at the end of the season so I can work on it over the winter...

Would have been nice to meet more Mopar people!
Hopefully next year we'll get back there a few times.


Well hopefully you get things fixed up for the spring Lazermule!

Thanks man...I'll get it sorted out and back faster than ever. I may not be a street car anymore though...we'll see..

This past fall I purchased a 1974 Plymouth Duster 360 4-speed that was pretty much all original except it had a 1971 340 in it. The engine was already broke, so I pulled it out & set it in the garage and sent the car off to storage. Upon further inspection of the engine I noticed it had a Holley 4777-2 650 cfm double pumper carburetor. The more I thought about thing the more it made sense to try out one of those Holley 750 cfm HP main bodies on it and putting it on the 440 in the Coronet. The upsides of this main body are stunning good looks, slightly better flow capacity then a standard Holley 4779 750 cfm double pumper, and down-leg boosters instead of the original straight leg booster arrangement on the 650 cfm carb.
I'm hoping that there will be a performance gain when I swap it onto the car in place of the current Holley Street Avenger 770 cfm vacuum secondary carburetor.
I ordered the main body in dichromate finish to match the rest of my current carburetor. $137.35 shipped was the price for it brand new off eBay.
The main body retrofit kit includes non-stick metering block gaskets, non-stick fuel bowl gaskets, main body gasket, fuel bowl screw gaskets, and brass 72/84 jets. The accelerator pump discharge nozzles are both .031".
I'm hoping once properly set-up & tuned it'll make more power in the mid to top end power range without losing any low end and most importantly I can even get it properly set-up and fully tuned correctly.
The 1-11/16" throttle blades with a 750 cfm venturi size should also keep it ultra responsive at any throttle position / RPM for use on the street.

http://img839.imageshack.us/img839/7210/holley750cfmhpmainbodyi.jpg







Turns my current Holley 4777 650 cfm double pumper mechanical secondary carburetor with straight leg boosters:

http://img576.imageshack.us/img576/9700/holley4777c650cfmcarbur.jpg




Into this Holley 750 4150 HP carburetor with down leg boosters:

http://img560.imageshack.us/img560/7780/holley750cfm4150hpcarbu.jpg

I still need to pick up a power valve, primary & secondary accelerator pump kits, float, notched float, rear jet extensions, ...



Here is my carburetor after I test fit a few things and snapped a couple photographs.

http://img153.imageshack.us/img153/303/project1k.jpg

http://img209.imageshack.us/img209/9324/project2g.jpg

http://img827.imageshack.us/img827/7988/p1020261l.jpg