Estimated 1/4 mile - 71 Roadrunner 340 4 speed

[340runner]

We used to just turn the timing down, but yes an msd nitrous retard box would be ideal.
I would not bother with any of the electronic c**p ( stuff). Expensive, unreliable, complicated, zero gain. Put that $$$ towards a stroker kit. IMO

Well, why I'm not wanting to just turn it down, is wouldn't it be kind of a dog when not using nitrous? I'd understand for a race application but even if its a heavily favoring race street/strip car it sounds like it would be a big downside

 

[RemCharger]

You would turn it down when you are going to make a nitrous pass.
If you intended to just " drive around on it all the time " just get an auto retard box.

 

[66 Sat]

You can call me a boring old man...but I think you have a great car as it stands and you should maybe re-think your goals.
Why 11 seconds? What prompted that goal? Once you get to 11's you'll want 10's and so on.
I'm in a similar boat to you, but just have a few more years of thinking.
I'm at 14.1 at 99.80 mph. I started at 15.3 at 95 I think.
My goal was always 13.5 at 105, which was road test speeds for a street hemi back in the day, but breaking 13 seconds and 100 mph is the next step.
I'm having as much fun (and frustration) finding these small increments as I would be trying to find whole seconds.
I'm back at the track tonight with the new carburetor I put on over Christmas, very exciting!
My car is a 100% street car. If you're going to run more on the track and not much on the street then it becomes purely a numbers game: more $$$ in = less time down the quarter.
My point is, sometimes it's good to step back and think about what your doing. How often you get to the track vs how often you could drive the car and enjoy it on the street.
If you keep it as a nice street car, and work on small incremental gains you can still take girls out on dates in it etc. Try doing that in an 11 sec car with a cage etc. You won't be able to get in the back seat!

 

[torredcuda]

I started out in the low 14`s and I was a little dissapointed in that ET but with nothing more than swapping carbs and tuning them, changing timing curve and lowering tire pressure I was able to get it down to low 13`s. I agree it`s fun and sometimes frustrating trying to get the same basic combo to run faster - it`s a challenge for sure but rewarding in the end. While I`d love to have an 11 second street car it really is about "how fast do you want to go / how much money do you have" and I just don`t have a lot so I`m fine with what I have. The good thing about bracket racing is it doesn`t matter ho w fast or slow you go - you can still have fun and even win. I`m not one to brag but am pretty proud that I won first with a 727 and then with the four speed.

 

[weedburner]

I recommend starting with your 700hp capable street extreme clutch, which needs to be tamed for your application. Fix that, you will be able to hook the car consistently without breaking parts or bogging the engine. That will also give you the ability to launch on drag radials consistently, no need for two sets of wheels/tires.

My first attempt to tame a clutch like yours was using a hardware store hydraulic screen door closer to control the release of my clutch pedal. Just a simple install between the pedal arm and a slide bracket bolted on the lower lip of the dash. Two adjustments, how fast the pedal returned and where in the pedal's return travel that it became active. Cost me like $20 and a little fab time around 15 years ago. It's the most cost-effective solution there is for bringing an engine and chassis together for an efficient launch. If you can handle basic fabrication, I would do this first before you break anything else, should be within a 16yo gearhead's budget!
Here's a link to pics and info about how I did that first install... https://grannys.tripod.com/hillbillyclutchslipper2a.html

If that DIY off-the-shelf hardware store cylinder is too long for you to work with, I make shorter versions for my ClutchTamer customers. For more info about how the above DIY 'tamer works, go to my website CLUTCHTAMER.COM

Grant

 

[340runner]

You would turn it down when you are going to make a nitrous pass.
If you intended to just " drive around on it all the time " just get an auto retard box.

Ahahhaha see that's what I mean, at the end of the day, I still would like to drive it on the street and have every once in a blue moon or whatever.
Wouldn't be very cool to run out pop the hood and mess with the dizzy now eh? The other side to it though is that can the tires even hold up to a hit of nitrous, which i already know the answer to as a resounding no

 

[340runner]

You can call me a boring old man...but I think you have a great car as it stands and you should maybe re-think your goals.
Why 11 seconds? What prompted that goal? Once you get to 11's you'll want 10's and so on.
I'm in a similar boat to you, but just have a few more years of thinking.
I'm at 14.1 at 99.80 mph. I started at 15.3 at 95 I think.
My goal was always 13.5 at 105, which was road test speeds for a street hemi back in the day, but breaking 13 seconds and 100 mph is the next step.
I'm having as much fun (and frustration) finding these small increments as I would be trying to find whole seconds.
I'm back at the track tonight with the new carburetor I put on over Christmas, very exciting!
My car is a 100% street car. If you're going to run more on the track and not much on the street then it becomes purely a numbers game: more $$$ in = less time down the quarter.
My point is, sometimes it's good to step back and think about what your doing. How often you get to the track vs how often you could drive the car and enjoy it on the street.
If you keep it as a nice street car, and work on small incremental gains you can still take girls out on dates in it etc. Try doing that in an 11 sec car with a cage etc. You won't be able to get in the back seat!

Well, 11s is just a number and I set it as a goal because it doesn't sound as terribly hard to hit as 10s. I'd be happy with any improvements, I just almost feel like its kind of sad on the 1/4 mile time, a lot of modern cars can best it as for 1/4, which i know isnt fair but still, I like to at least back up how my exhaust sounds with good performance . I drove it during summer as a daily without ac, and no wing windows, and i really didn't mind it at all. I'm still at a point in my life where comfort is kind of secondary up to a point to be honest, and as long as it isn't too terribly bad such as a cam large enough to shake all the bolts loose or complete race buckets, I think I'll still enjoy it.

 

[padam]

My suggestion is if you really like drag racing, put a 727 back in it.

 

[340runner]

My suggestion is if you really like drag racing, put a 727 back in it.

Not that much haha, I'll take that concession of having a stick, that's one thing where the fun outweighs the time slip in my opinion, plus there's more of a challenge and skill to it, especially if I ever get into bracket racing

I find a satty or a /6,318 or 360 A body for the right price I don't care if there's a 4 speed in there there will be a 727 and a big inch wedge by the time I'm done with it. Probably little interior either

 

[71Beeper]

Also just wondering, for reference how much does your car weigh and what does it run?
For pure curiosity, you think the 340 since it has a forged bottom end will eat a 100 shot? Sounds like a fun time but I'm getting tires first and if it's a big risk I wouldn't run nitrous

I do not know how much my car weighs. I just finished it in August of last year, ran it for 6 weeks then my head issue happened so I didn't get a chance to weigh it.
Same with running it at the track, that won't happen till I get all the little bugs sorted out and the car is reliable.

I looked at the cam card you provided - it's not too bad. It says the rpm range is 2500 to 6400 rpm - so why are you buzzing your engine to 7 thousand if it runs out of power at 6400? if not earlier depending on how much flow the 'J' heads provide.

To run a 100 horse nitrous in it - your 340 can certainly take it.
I had another buddy with a 1979 Volare with the E58 360 engine, bone stock with the exception of a 340 cam and the 100 horse nitrous.
stock 14" tires on Magnum rims - the nitrous knocked off 1 second from his elapsed time, it went 14.5 without nitrous and 13.5 with it till he crushed the bearings in the rear universal.

As for changing to EFI and Hyperspark - I agree with RemCharger...save your money and stick with what you have or invest in a stroker kit..
EFI conversion is not as easy as you think plus it is costly.
Get some experience working on a carburetor, they are not that difficult.

Kudo's and applause to you young Buck - many guys your age don't bother with these older muscle cars. A lot of the guys here (myself included) started off just like you with a passion for cars.
I never took a single auto class in high school but I read just about every Hot Rod, Car Craft, Popular Hot Rodding and any other car magazine back in the day. I learned by reading the tech articles and taking stuff apart to see how it works.
The experience will come with time. I messed up alot of stuff when I was learning, but don't let that hinder your progress.
And keep asking questions here - as you can see, the rest of us want to help....

 

[340runner]

I do not know how much my car weighs. I just finished it in August of last year, ran it for 6 weeks then my head issue happened so I didn't get a chance to weigh it.
Same with running it at the track, that won't happen till I get all the little bugs sorted out and the car is reliable.

I looked at the cam card you provided - it's not too bad. It says the rpm range is 2500 to 6400 rpm - so why are you buzzing your engine to 7 thousand if it runs out of power at 6400? if not earlier depending on how much flow the 'J' heads provide.

To run a 100 horse nitrous in it - your 340 can certainly take it.
I had another buddy with a 1979 Volare with the E58 360 engine, bone stock with the exception of a 340 cam and the 100 horse nitrous.
stock 14" tires on Magnum rims - the nitrous knocked off 1 second from his elapsed time, it went 14.5 without nitrous and 13.5 with it till he crushed the bearings in the rear universal.

As for changing to EFI and Hyperspark - I agree with RemCharger...save your money and stick with what you have or invest in a stroker kit..
EFI conversion is not as easy as you think plus it is costly.
Get some experience working on a carburetor, they are not that difficult.

Kudo's and applause to you young Buck - many guys your age don't bother with these older muscle cars. A lot of the guys here (myself included) started off just like you with a passion for cars.
I never took a single auto class in high school but I read just about every Hot Rod, Car Craft, Popular Hot Rodding and any other car magazine back in the day. I learned by reading the tech articles and taking stuff apart to see how it works.
The experience will come with time. I messed up alot of stuff when I was learning, but don't let that hinder your progress.
And keep asking questions here - as you can see, the rest of us want to help....

I'm not shifting at 7k, 7k is my please engine don't explode redline for if i miss a shift or anything, my shift is at 6000, but i might test out moving it up a couple hundred rpms, maybe to 6200 or 6300. As for J heads, I don't have them I have speedmaster alu heads which I bet flow better. I'll definitely learn how to work carbs and set timing myself, and I'll invest eventually in a MSD digital 6+, since it seems like the best bang for the buck package out with 2 step, start and nitrous retard. Plus i already have a 6al non-digital I don't want to just turn the dizzy to retard timing, as I like to drive on the street and you never know.

 

[RemCharger]

MSD Ignition 8987 MSD Start and Step Timing Controls | Summit Racing MSD Ignition 8987 MSD Start and Step Timing Controls | Summit Racing