I had some time tonight to look at the 02 data. Looks like I was on the right track leaning the car down. The spin thing is new. I am not sure what is going on with that yet.

After looking at the et's and data posted, I truly do not believe you have a fuel issue. It appears that you most likely need a new set of slicks.

If your slicks are new, as in this season and have 45 or less passes, then add some weight to the back of the car.

It is a soft 60ft car, and should be deadlier then that, especially at a 4000 leave.

How many passes are on those slicks?

P.S. Also, remove any sort of air pan that would trap or force air into the carb. Alky applications hate that stuff up top, and is very susceptible to water grains. Removing that seal of the carb, takes this out of the equation on alky applications.

Strange the Slicks are older you are probably right. There is no air pan on this car.

Since it seems to hook at first, maybe look at if you are hitting the tires too hard. Lower two step and/or add some air to the slicks and it should be appearant. It may start spinning earlier. In which case, it probably needs new rubber. Shocks could be part of the equation as well.

This the the 02 results from last weekend.



Yellow is 188 jets, green is 176, orange and magenta is 164. You can see it rpm and shift faster with less fuel. You can also see it start spinning after the hit with more power.

quote:

Since it seems to hook at first, maybe look at if you are hitting the tires too hard.

The opposite. Not hard enough. You have to keep that sidewall wound and under power to keep it hooked. Slapping it with low hp from a low leave will wind it and unspring it fast causing it to initial hook, then slip. Very common issue from a lack of mis-understanding of how to match a slick to it's vehicles power and weight.

In Bobs case, his slicks are old and he probably knew that but figured maybe he can get away with not having to put slicks on it, and just run it as is and with good consistent results. If you want to be competitive and have an advantage over the competition, then you really need to have fresh slicks on at the beginning of the season, and if need be change them during the season as well. No one said it's cheap to go racing, unless you are just out there to have some fun, but don't expect to be in the winner circle with bad and worn out equipment.

what rear suspension and front suspension do you have on the car

do you have any videos of it launching?

quote:

Originally posted by racerdude2054:
what rear suspension and front suspension do you have on the car

do you have any videos of it launching?

I need to dig up some video. The front is Strange struts and rear 4-link.

Strange is right. This has been a project for me the last couple years. I know i need to change slicks. The problems I have been having has not been suspension or tire related until now.

I had a friend go through the carb and it was messed up. heavy float in the rear and gunked up emulsions.

Strut front end drag cars require more negotiation of ballast in the rear, and a larger tire typically, then when compared to a rear halfed only car. Also, you have to load more power into a strut car to keep the sidewall wound, so it doesn't spring back. Just because a strut doesn't have a knob on it for adjustment, doesn't mean that the valving is not adjustable. Some Strange struts require you to remove the spring, compress the shaft all the way down until it locks in, then turn the shaft clockwise or counterclockwise to adjust the bump/rebound. The bump and rebound is a function together and not separately adjustable.

quote:

The car will run faster with more pressure but blow past the seats at idle.

Unlike gas, when you richen up alky it will typically increase the low end engines torque numbers. This is the opposite of gas, whereas by leaning down on gas, increases the torque down low, due to less fuel which shears easier in the plenum and runners. Increased fuel pressure, even without changing jets, will increase the bsfc and actually richen it.

egts and O2's to be put away. You jet alky accordingly to consistency and not overall performance. When an alky engine is tuned to be deadly, it is not tuned to run it's quickest or fastest. You get it to run it's quickest and fastest, then richen it up so it slows up a little, and you'll be deadly.

An alky engine will actually do better and run more consistent with less cfm when working with a carb application, then more cfms. A carb was never intended to be the vehicle to deliver the type of weight, and amount through it's metering blocks. The engines signal still remains the same regardless of the weight of the fluid needing to be delivered.

3 points. A B and C. A is the starting line, B is the 660 and C is the 1320. Alky through a carb can never be managed properly from A to C, it just can be managed on the average, and that average is to be seen by it's best performance on the slip. Not the way to tune alky. If you tune for A to B, your C will not be right for consistency. If you run 1/8th only, then you are very fortunate when on alky. A carb, no matter what, will never be tuned right when running the 1320.
With injection, you actually do have the ability to tune from A to B, and B to C, with mechanical devices to put in, or take fuel away. The devices should be set up on time or rpm, and not pressure.

This message has been edited. Last edited by: Strange Magic,

My opinion on this situation of consistency is to start in a shorter interval to measure the consistency.

New tires and tuning the suspension as well as adjusting air pressure to get optimal consistency on the 60' times.

looking at your log book the 60' times are not consistent enough. As stated previously by someone else, make sure staging is being done consistent as well

I can assure everyone I know how to stage.
below is video of the car launching.
https://youtu.be/ys5X88s5__Y

Bob, by viewing the video, that car looks very nose heavy. The tire doesn't even come off the ground, at all. Have you ever tried to put 30 or 35 pds of ballast in the back of it? That car needs to leave with the wheels a foot in the air. i haven't really witnessed a "deadly car" in that et range, that doesn't hike the front wheels up.

Is that a 16 inch rim with little bubbas on it?

quote:

Originally posted by Bob Payton:
I can assure everyone I know how to stage.
below is video of the car launching.
https://youtu.be/ys5X88s5__Y

have you ever had the car scaled? what are the weights on each tire?

It looks like the front suspension needs to be loosened up to me

quote:

Originally posted by Bob Payton:
I have a Door car I have been working on so my kids can start racing. I has a BBC 468 single alky 4150 900cfm pro systems carb with Magna 500 electric pump. Power glide trans.

This car is not very consistent currently and I believe its in the fuel system. It can move .03 from run to run. I have had the jetting all over and the pressure all over and it doesnt seem to make a difference in consistency.

The car will run faster with more pressure but blow past the seats at idle. I am not after et im just looking for consistency.

I would like to hear from people running electric pumps with alcohol.

I am wondering is the only way to get this to work is buy a new belt drive fuel system?

Aeromotive fuel pump controller. I had this exact problem. 900hp 565. Could not get a handle on it until I installed the controller. It is magic.

RIP

I know the car weight is 2700lbs with my son. I dont know front rear weights.

Slicks are 30751 which are 32x14.5x15
Front are 26x4.5x15s

Just started running this car a month ago. It had some problems I've been working thru. Ignition is good now carb will be good now.

It doesn't look like the suspension is doing anything. (front or rear) It looks like the launch of a hard tail dragster. Loosen up the shocks and struts to get suspension travel, then make whatever adjustments to get the right, controlled travel.

quote:

Originally posted by Strange Magic:
Bob, by viewing the video, that car looks very nose heavy. The tire doesn't even come off the ground, at all. Have you ever tried to put 30 or 35 pds of ballast in the back of it? That car needs to leave with the wheels a foot in the air. i haven't really witnessed a "deadly car" in that et range, that doesn't hike the front wheels up.

Is that a 16 inch rim with little bubbas on it?

My car will barely pull the front tire off the ground and is deadly consistent at his type of ET's........

quote:

My car will barely pull the front tire off the ground and is deadly consistent at his type of ET's.......

You might want to consider changing your profile picture.