Traction Control Needed...

[famous bob]

You could just slap some drag radials on it when you go to the strip. With the right wheels a 235/60-15 Hoosier DOT Drag Radial or a 235/60-15 M&H Racemaster Radial Drag tire would work.

Am I the only one that runs drag radials on the street full time ?

 

[KnuckleDuster]

Summit lists ZERO drag radials in 14in.

 

[7milesout]

First off, ditch the air shocks before you crack your shock mount stud sheetmetal!
Get the springs re-arched or buy some new ones if they sag.
I can't understand putting a 215 on the rear if you are looking for traction, even for normal driving.

The air shocks have been on there for 25 years. I think they would've cracked by now. I'm not disagreeing with you, but I don't know what you call "normal" driving. It has 225/60s on it now. And for normal driving, they're just fine. 215/60's will be just fine for normal driving in my opinion. They just may not be the best choice at the strip.

But, my choices are limited, as long as I stay with 14". Which I prefer to do, I like the original look.

Here's my thinking. 265/50's are the widest I can get with 14" wheels. And at that, they're 2 inches wider than what I have. How much additional traction is that going to be? I can't say for sure. But it seems the general concensus on here is that it is NOT substantially more. Not in a street radial anyway. And the 265's seem to be guaranteed NOT to fit.

But the 215's ... they're a skosh more narrow. The other side to that coin is, they offer a bit more "gearing," and the rubber is bound to be more compliant than what I have on there now. The gearing and the new rubber may offset any traction loss.

I think that is a couple good reasons to put the 215's on it. The only down side is I'm losing 10 mm's of width. I will live with more narrow for now, to get the 25 year old Maypops off there.


7milesout

 

[7milesout]

You might try a traction aid...

AJ/FormS,

All good info there. I looked up all those items. Let me see how it shakes out at the track first. If I hit 13.99 as it stands, then I probably won't be interested. I have a feeling if I hit 13.99, I'm going to get interested in a squirt of NOS (future). Just for sh1ts-n-giggles and maybe a 12.99 second ET. But again, I don't know. I kind of like the car in it's original form.

I will add this. I found a bunch of drag slips from the previous owner. No way he ever hit 13.99. And to be honest, with all the slips I have, and the slips / data I have from June last year, I doubt it ever saw 14.99. 15.4 is the best this car ever ran. But it was always RICH, with very poor exhaust. And the timing was way advanced.

With all the data, I have put it all in xls. And using the most common h.p. from ET and h.p. from trap speed formulas I can find, there is always a fairly substantial difference in h.p. from ET and h.p. from trap speed.

H.P. from trap speed is always higher. Which, I believe means that traction has always been an issue (open diff). Now that issue has been improved with the Truetrac. We'll see how it works out.

Based on the math, to hit 13.99 seconds, I need an additional 62.4 hp (ET based). I need only an additional 20 hp (trap speed based). What these 2 numbers mean to me is ... it needs way more traction improvement than it does actual power.

I think I have 20 more engine horsepower based on the tuning I've done. But, I suspect that even with the TrueTrac, I may not have an additional 62 hp ET wise. Don't get me wrong, I know these numbers are estimates, and that trap speed best represents actual horsepower. I'm just thinking out loud here ... trying to convey what these estimates indicate.

Based on these estimates, I think it's going to be very close, and likely not enough traction to break the 13 second barrier. But it is a fun project.

Last of my long-winded post. When I was at the strip in June last year, there was a tubbed-out 55 (or so) Chevy there. Looked good, sounded bad ***, big ole drag slicks, gauges, yada yada yada, and he ran a 14.2. It would be fun to out run him (or some similar vehicle) with a very original looking Scamp on 215/60 R14s! As it was, I beat him on reaction time, but then watched him drive away. The Scamp wasn't feeling so good back then.


7milesout

 

[7milesout]

UPDATE:

I took the Scamp back to the strip on March 2nd (Friday). I’m discouraged after having done it. Almost everything about the trip was negative. It’s about a 100 mile trek for me to get there, and this time I decided to trailer it. Because I had purposely removed weight and fuel to make it as light as possible. In retrospect, I think that was more of a disadvantage than advantage to remove that weight.

More or less I live on the opposite side of Atlanta from the strip. The traffic was horrible, so I got there late. As soon as I rolled into the lanes, the track was shut down for about an hour. Friday was nice, fairly warm, Friday night was cold at the track. I got only 1 measly run down the track. And when I did I lit the pizza cutter tires up, feathered the throttle and still had to drive it due to the long (must have been sweet looking) drift probably for the first 200 feet. No refund, no concession of any kind. And topped off the trip with sucky midnight traffic going back through Atlanta.

I can drive pretty good. But regardless, a man's foot needs more practice than one trip down the track, in order to maximize a launch. Pizza cutter tires, on 35° to 40° pavement is not a good recipe for traction. I've also been reading some that even if the car were heavier, likely the E.T. would be lower if that weight were in the trunk. So, back in the trunk goes the spare tire, jack and jack tools (for next time). As well as a full tank of gas. That's like 100 more pounds in the rear of the car for next time. I also read about pulling the pins on the sway bars. I'm going to figure that out, and do that too. (If there's a good thread with pictures, I would appreciate a link).

The numbers:

• 60': 2.393
• 330': 6.565
• 1/8 E.T.: 9.911
• 1/8 Trap: 74.07
• 1000': 12.730
• 1/4 E.T.: 15.070
• 1/4 Trap: 96.83 (much better, and the only NON negative aspect of the trip)

This translates to 196 E.T. horsepower, and 240 Trap Speed horsepower. Based on before / after trap speed horsepower, that's a 36 horsepower improvement due to the TLC and carb tuning I've put into the car. I've just got to get the hp to the ground ... with pizza cutter tires. As bad as I spun, even after feathering, it still ran 96.83 mph. That, I was very happy about. It has the power for 13.99, but it doesn’t have the traction. If I have to live with a 14 second car, that runs on street tires, I will. But, I will still chase 13.99. The problem is ALL about traction.

PLAN:

• Wait for warmer weather.
• Put all the stuff back in the trunk.
• Fill the tank.
• Disconnect the sway arms.
• And, learn more about, and seriously consider the traction aids in the links further back in this thread.

7milesout

 

[AJ/FormS]

Stuff in the trunk will slow you down, even if it's just 200 pounds of feathers.
Forget ET; Concentrate on the MPH.
It, together with your weight, tells you how much HP you're making. Getting the ET to match for the trapspeed can cost a zillion dollars. Once you have a consistent trap speed, you can back calculate how much more power you need, or how much less weight you need to be at, to achieve your ET goal.
Your 60ft is about same as mine with 400hp, so we are both leaving a solid 1/2 second or more on the line.That's the way it is with a street suspension, and it's not just tires cuz I ran 325/50-15 BFG DRs to get that chitty 60ft. Like I said it can cost a zillion dollars to get the ET to match the trap. In any case I think it will be cheaper to add 20 horsepower, and get the ET at the top end of the track. A lil more cam and a lil more finesse and you're there. Or maybe just a decent amount of compression.
I attacked it from all sides; compression, cam,headflow,and finesse; and was rewarded with 93 in the 1/8th, still with that chitty mid-2.2x 60ft,lol. I don't care about the ET now, cuz Daymn! that car goes.
lol.
I gotta tell you tho, in 1970 I was a young kid with a 340 powered 1970 DartSwinger, and I drove the nuts off that car for 5 years, and it was F-A-S-T. 98mph in the qtr fast,lol. You're only 1 mph off that benchmark. But My Dart was at 14.4 and change, and it spun those E70-14 belted pos tires most of that qtr,lol. But guess what; so did everybody else on those tires, so we were all on a level playing field,lol.
Fast is relative. For me; in 1970, 98 in the qtr was fast. Today 93 in the 1/8th is fast, tomorrow, who knows. I could be dead tomorrow.

 

[roccodart440]

Get some traction. You have a 13 second car.

 

[7milesout]

Getting the ET to match for the trapspeed can cost a zillion dollars.

I don't like to spend a zillion dollars.

I had an idea, that if I put a linear motion damper inline with the throttle cable, then I could just shove the pedal to the floor, and let the damper more slowly open the throttle. And with an adjustable damper, the rate could be played with until it dialed in pretty darn good. Even though a linear opening of the throttle may not be absolutely optimal, it would be better than opening so quick the tires just spin. So, I'm working on a solution. I'm an engineer, I (try to) find solutions daily. And I'm also a vendor on another website selling another item I invented.

This damper would allow a driver to hold the throttle open on the line, and then slam the throttle down while the remainder of the throttle to be opened, would be opened via the rate of the damper. Old School Traction Control. It may take me some time to figure it all out.


7milesout

 

[AJ/FormS]

This damper would allow a driver to hold the throttle open on the line, and then slam the throttle down while the remainder of the throttle to be opened, would be opened via the rate of the damper. Old School Traction Control. It may take me some time to figure it all out.

Until you get that to market,
I think that the right torque convertor, in combination with the vacuum secondaries,and with ignition timing a contributor, do a pretty good job.

 

[famous bob]

I don't like to spend a zillion dollars.

I had an idea, that if I put a linear motion damper inline with the throttle cable, then I could just shove the pedal to the floor, and let the damper more slowly open the throttle. And with an adjustable damper, the rate could be played with until it dialed in pretty darn good. Even though a linear opening of the throttle may not be absolutely optimal, it would be better than opening so quick the tires just spin. So, I'm working on a solution. I'm an engineer, I (try to) find solutions daily. And I'm also a vendor on another website selling another item I invented.

This damper would allow a driver to hold the throttle open on the line, and then slam the throttle down while the remainder of the throttle to be opened, would be opened via the rate of the damper. Old School Traction Control. It may take me some time to figure it all out.


7milesout

I don`t believe all of this: get your traction problems worked out, the rest will definitely come to you ! Widest tires u can fit under it, a cheap set of used superstock springs will do more for it than playing w weight in the rear of a car like ur describing !

 

[roccodart440]

THis /\ /\ /\

offset the shackles and put a 10.50 section width tire under it. IF you want a stret tire and not a slick buy some MT sportsman pros. They will dead hook under that thing.

 

[7milesout]

I'm planning to do another run down the track this coming Friday. I've been sorting out issues all summer long and never made it back. Just this past Friday (9/14) I removed the air shocks and put monotubes back there. The ride is way better. I haven't specifically tried to launch the car on the new shocks (I'm going to have to double check the torque on the fasteners first, make sure they haven't loosened). But the few times I got on it, seriously, it felt like it hooked better.

Maybe the air springs were jouncing the suspension. I'm no suspension expert, but as the rear of the car itself is moving up, but slowing down while moving up, that would tend to lift the suspension. Maybe now that motion is much better controlled, and that was the additional traction I was feeling.

I would prefer to tow the car there. But I just filled the tank on Sunday, and won't have a chance to run it down before Friday. So, likely I will just drive it there, and blow another 42 pounds of fuel out of it. I'm going to start messing with these front sway bars. I haven't even looked at those, and what is required to "pull the pins."

That and I will take all the extra weight back out of it again.

 

[Mattax]

Your missing the basic physics. Friction (and sticktion) will become more effective as the normal force increases.
The car is not on slicks, so all the issues of shifting weight during launch have practically no bearing.
The back needs static weight and if the back is squatting, correct the spring and geometry as needed.

 

[7milesout]

UPDATE:

The track was perfect. The weather was perfect. Getting there wasn't nearly as bad this time. But the Scamp kept running out of fuel.

The numbers:

• Item Last Time This Time
  
• 60': 2.393 2.211
• 330': 6.565 6.077

It would run out of gas between 330' & 1/8 E.T.

• 1/8 E.T.: 9.911 9.596
• 1/8 Trap: 74.07 67.17
• 1000': 12.730 Let Off
• 1/4 E.T.: 15.070 Let Off
• 1/4 Trap: 96.83 Let Off

Even out of gas I beat last time's 1/8th of a mile. I heard lots of diagnosis. Here are the facts. There was little tire spin on the line as I had practiced a bit. Some said, "I bet you're boiling your gas in the bowl." But I didn't agree. Because if that were the issue, it would have launched horribly and possibly ran better at the end of the track (as the air through the carb cooled the carb as it went down the track). Lots of other crappy diagnosis too. But what I think is...

It was simply running the float bowl empty. It was very consistent when it would run out. It was in the 6 to 7 seconds when it would run out. And my AFR gauge would tell the story. Perfect AFRs, until it ran out. And because it would hit like 19 and 20 AFR, I would just back out of it. After a couple throttle pumps it would run hard again (collecting some fuel in the bowl). But since each run was screwed up, I would just putter across the line. I'm going to start a new thread in order to learn about what kind of fuel pump in which to replace my current mechanical fuel pump.

I cut it off after 5 runs because I didn't want to break anything. And, believe it or not, even at Atlanta Dragway, where you'd think there would be really great drivers, more than 50% of the street drivers had no idea what they were doing. I beat every single car up to the point where the Scamp would run out of fuel. Even faster cars. They'd just sit on the line, see the light turn green, check their emails, scratch their ***, and then they'd go. And those guys would slam through both stage lights, deep stage and red light continuous. Or be a car length away from the lights and barely move. The track operators were getting fed up with it. They could not understand how I could beat them. I would really really shallow stage and just GO on the 3rd yellow. Very easy. It was fun … for about 300 feet worth.

 

[roccodart440]

your 60' is super slow. If it isn't spinning the tires, it means you aren't making any power there either or you are babying it to get it to hook up.

Check your fuel line from sump to the carb. Check the filters (there should be 2) If that checks out (size, no kinks and clear) get yourself a new pump, preferably an electric and re-test.

If it were boiling the fuel there are other tell tale signs. Like hard starting. Is it hard starting?

 

[7milesout]

rocco - 2.2 seconds is slow? Maybe the front tires were in the air, and that measured the rear tires! I am indeed babying it … on 215/60 R14 pizza cutter street tires … babying required. However, I'm proud of that 2.2 seconds. That's the best the car has EVER done, and I have all the old time slips to confirm it. Maybe I can do a bit better with more practice, but I can't imagine it EVER clipping better than a 2.1 second 60' time. At least not with these pizza cutter tires. However, at this time I don't care about the 60' time. It's the E.T. I want to hit a 13.9999999999 second time, with the pizza cutters.

Fuel line is good. There's only one fuel filter that I'm aware of, and I changed it when I replaced the fuel tank. No kinks in the fuel line. The tank fuel sender is new too.

It is not hard to start, it fires right up. I changed the fuel tank when crap was collecting in the filter and carb. So, that crap has either "gummed up" or in whatever way, negatively affected the fuel pump (my guestimation). The car drives very nice on the street. The filter I replaced was notably heavier than the new one. And the new one still looks new due to the new tank.

 

[roccodart440]

Wasn't meant as an insult. But in a v8 car, a 2.2 60 is slow. It's great that you are improving and that's the best it did though. Put some rubber under it. 215's in the rear isn't even touching stock wheel and suspension clearances.

Does it fall on it's face or just go lean on the AFR?

What size line?

Should have a filter pre and post fuel pump.

 

[7milesout]

I didn't take it as an insult. It falls on it's face. Which prompted a glance at the AFR gauge and a, "wow." When seeing 19 - 20 AFR follow with a snap off the throttle. I drove it to the track and was on about 1/4 tank when I got there. I thought maybe what remained was just sloshing away from the sender, so I drove out and added 7.5 gallons and went back to the track. No difference with the additional fuel.

Prior to the fuel tank replacement, is when I replaced the sender. And fuel line at the tank. At one point I needed fuel to (prime) the pump so I pushed some compressed air to the tank through the fuel line at the fuel pump. After pushing some air in there, I waited about 2 - 3 seconds and gas gushed out like old faithful.

Which sort of makes me think there's no filter pre-fuel pump. I wouldn't think it would have flowed that hard with a filter in the way. But I'm not certain. This is new territory for me. I think it's all 3/8" lines.

In the future, I'm going to do a leaf spring relocation, and then put wider tires on it. I hear 245's are about as big as will go on it now. But 245's were near impossible to find on 14" tires. And since I was given the car with 35 year old tires, I just went with readily available 14" tires to get off the maypops ASAP. The 14" tires on it now are great tires. Just not made for launch pad traction. I didn't want to buy big wheels, big tires and do a leaf spring relocation kit all at the same time. Step-by-step. Penny by penny.

 

[roccodart440]

Get it to run right first.


Here are your tires
BFGoodrich Radial T/A Tires 87449

Coker BFGoodrich Radial T/A Tires 548000

 

[7milesout]

Exactly. And I have already identified the wheels and tires I want. Wheel Vintiques I think they're called (they're saved in my Summit Wish List). The look like Mopar Rallye wheels. Once all running issues are sorted, I will do the leaf spring relo, and big wheels and tires.

 

[Mattax]

With a mechanical fuel pump,
There should be a coarse 'sock' filter on the fuel pickup in the tank.
A standard factory type fuel filter after the pump on the line going to the carb.
+ The outlet must be higher than the inlet.
Any porosity in the suction line to the pump and it won't pull as much fuel as it ought.
That could be cracked rubber connector lines or a pin hole in the steel line.

Interesting that it shot lean so quickly. I've gone done the track with the pressure dropping from 3-4 psi to zero but there was enough fuel to make to the line. We thought it was the pump but it turned out to be the feed line.
Vapor lock would/will occur if a portion of the line gets heat soaked. Hard to see how that would happen during the run and not other times but its possible. Has only happened to me when there's still winter fuel in the tank, and the weather is hot. Make sure your lines are away from heat and or insulated. If there's any pre-June fuel in the tank - get rid of it.
This all assuming the AFR gage is telling you fuel in the bowl ran very low.

 

[7milesout]

With a mechanical fuel pump,
There should be a coarse 'sock' filter on the fuel pickup in the tank.

There is, and it is new and clean.

A standard factory type fuel filter after the pump on the line going to the carb.

There is, and it is new and clean.

+ The outlet must be higher than the inlet.

It is failing here. It is mostly horizontal with a slight increase in height to the carb inlet.

Any porosity in the suction line to the pump and it won't pull as much fuel as it ought.
That could be cracked rubber connector lines or a pin hole in the steel line.

I think I'm ok here.

Interesting that it shot lean so quickly. I've gone done the track with the pressure dropping from 3-4 psi to zero but there was enough fuel to make to the line. We thought it was the pump but it turned out to be the feed line.
Vapor lock would/will occur if a portion of the line gets heat soaked. Hard to see how that would happen during the run and not other times but its possible. Has only happened to me when there's still winter fuel in the tank, and the weather is hot. Make sure your lines are away from heat and or insulated. If there's any pre-June fuel in the tank - get rid of it.
This all assuming the AFR gage is telling you fuel in the bowl ran very low.

The Scamp guzzles fuel. The winter fuel has been gone for a looooong time. You can see pictures of the horizontal fuel filter (which, is how it was set up when I received the car, I only replaced that filter) if you look at this thread. Best Fuel Pump Advice for Newb...


7milesout

 

[7milesout]

UPDATE!

I took the Scamp to the track on 10/12 (the 3rd column). Here are the results.

1st 2nd 3rd​

• 60': 2.393 2.211 2.181

• 330': 6.565 6.077 6.033

• 1/8 E.T.: 9.911 9.596 9.178

• 1/8 Trap: 74.07 67.17 78.00

• 1000': 12.730 Let Off 11.895

• 1/4 E.T.: 15.070 Let Off 14.179

• 1/4 Trap: 96.83 Let Off 99.01

I only got one good run on it (the first run). I accidently shifted early. So I think if I had more good runs, and held gears just a bit longer, I could have hit my 13.999 target. I'm only 180 thousandths off target. And that's on pizza cutter street radials!


7milesout

 

[roccodart440]

work on that launch and get the 60ft. down. That's where you can pick up some time.

 

[Tech857]

What was the fuel problem?