I am planning to take my 68 coronet with the factory 225 out to my local drag strip to see what it can do. I have set my points to .020, set my valve lash to .021 exhaust and .011 intake, I have rebuilt my distributor, rebuilt my Holley 1920 carb, set plug gap to .45, set my timing to about 12° before TDC and replaced all electrical system components. I plan to run premium gasoline with NOS octane boost. I would like to know if there's any other little performance tweeks I can make for a better 1/4 mile time. And if an octane boost and premium will make a difference if any.
Anything anyone knows that will improve engine performance is much appreciated.

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1968 Dodge Coronet with the original 225 slant six and a904 torqueflite transmission. One family car with 67k original miles and mostly original parts.

For a completely stock car you've done all the right things, but you won't need the octane boost. Also, don't over-advance the timing. It may not ping, but it will run slower.

User dude0936 did a lot of dyno testing with small changes to the car. You can see all his posts here: http://slantsix.org/forum/search.php?se ... r=dude0936

The air cleaner is a small restriction. Some people have made a flat plate for the top of the air cleaner to make it completely open, and it helps, but ducting fresh, cool air to a late model air cleaner is almost always better. Here are some dyno results of air cleaner testing by dude0936: http://slantsix.org/forum/viewtopic.php?p=373359

The stock jet is a bit small. Try a 63 give or take.

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Joshua

Thanks for the advice, I am already running an open element air filter for daily driving, but I plan to pull the filter and housing altogether and just run an open carb. I had the advance set to 10° for daily driving as well, but with the distributor rebuild it shot itself way up, and with an octane boost I figure I might as well run a little higher advance to compensate for the higher octane.

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1968 Dodge Coronet with the original 225 slant six and a904 torqueflite transmission. One family car with 67k original miles and mostly original parts.

This is sort of backwards...using higher octane should only be needed if the engine is tuned or built and nothing else will keep it out of detonation... Octane boost is just Alcohol... which has some anti-knock characteristics but also only provides about 80% of the potential thermal energy that a similar amount of 87 clear would provide (same goes for 92 "super"... it has more anti- knock ingredients and will not improve things unless you upped the compression a lot and are on the ragged edge of detonation).

If you gotta have it... just go to the track with a 1 gallon gas can and go to the fuel depot and pay for 1 gallon of VP 110 leaded... put that into your tank...it will have the same effect... and a better knock index for the volume...

If you were down in Salem, you can get it from MNOP as well at a slight discount from the track price...

Instead of goofing with all this other stuff... I would listen to Charlie and Josh, and make those mods if you gotta...but, until you have taken it to the track for test and tune to get a 'benchmark' to what it is going to do, you are shooting in the dark to see what improvements if any are being made with your vehicle....

First run, I'd get the feel for how it's going to go... then I'd go back to the pit and make a change... then I would make a run and check it again... for the most part... Test and Tunes at Woodburn during the competitive season especially before a big event weekend tend to get you about 4 runs before you run out of time... it's easier in the pre season when the weather permits and you can get more in if you 'hot lap' run after run (in that case, work on judging your car and launch versus the light and your reaction time, then on cutting a consistent time... that's what's truly important if you are going to bracket race...)

Another item to watch is your stock comonents... a stock A904 in a heavy car, launched hard a lot may not appreciate the extra work being heaped upon it... if you are going to do this more often you will start thinking about upgrading some of the power train....

What do you have for a rear gears?

I would like to know how to time my car also so it is not over advanced . Can you please explain to us how to do that . I have a timing lite.

They also sell real TEL lead additive.

Maybe in Arizona and a few other states without massive environmental initiatives and organic farmers... TEL additive is not available over the counter at any auto parts stores in Oregon. To get "leaded" gas (with "TEL") here, you have to buy it for off road use only at a supplier/depot or at the race track... (or if you don't care how the quality varies bucket to bucket, you can buy pails from the local motocross shop...)

DI: Burning question department:

Humm, off road; ain't that where all those organic farmers grow their bug infested bounty?

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67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

This is a two-part series I put together for www.moparmax.com on how ignition timing optimizing can free up between 15-20lb/ft of torque and 10-15hp while actually increasing the fuel economy.


Timing is Everything: Distributor Tuning for Power and Economy Part 1

http://www.moparmax.com/tech/2015/x_11- ... ing-1.html


Timing is Everything: Distributor Tuning for Power and Economy Part 2

http://www.moparmax.com/tech/2015/x_12- ... t-2-1.html

Both slants were stock with one barrel carburetors that were untouched for the testing.

Chris

Chris- I just got done with the first articel and I am about to start the second. Nice work!

Just finishe the second article- great job! I like the butterscotch color on that 75!

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Casually looking for a Clifford hyperpak intake for cheap.

Thank you Reed. I like writing for the magazine, and I try and push the slant six angle when I can. Moparmax.com accepts the story ideas, and I have more stories coming. Of course, the V8 tech stories, especially the GEN III HEMI, are more popular.

My '75 Dart's color is called Inca Gold Poly. I like the color, it was the original color, and I am glad you like the color. Occasionally someone will come right up to me at a car show and ask what color it is because they think it looks like "baby poop brown". I guess they do not like the color. I think it is a nice color because I rarely see it on other Mopars.

Thanks for your comments about the stories.

Chris