How did it go at the track?

 

Actually how did it not go, we had no power in the whole south Cali region from 3:40pm, from a power malfunction caused by a employee through SDGE from the Arizona transistor and then from the power plant out east. we were hit HARD!!!

 

Man I'm fighting gremlins on this setup. Last week it was the pump rod linkage. Last night everytime I launched the car would fall on it's face and break up almost
like I was hitting the rev limiter then it would smooth out in 3rd and 4th. Thought it was timing and jetting so I faught with it all night long and it did not help. I am pretty sure I think the problem is the float in the carb is either too high or is sticking and causing the rear rotor to get flooded under high load and when the car pulls the wheels off the ground. I had about a 2foot + wheel last night. I am going to make some changes and hit the dyno this time. I'll get there. If it was easy everyone would be doing it. I still managed a 7.0 @98.5mph. Got some video and I'll post when I get a chance to edit.

 

It's probably the flooding of the rear rotor, I had those issues when I was all motor with ida.

 

i want to see some vid, hurry up and post up...

ps

you all weren't effected by the power outage?

 

Luke Luke!! fuel injection

 

7.0 is moving pretty good.
In for the video!

 

Ok here's the video of the 7.0pass. The 98.5mph pass was with a 7.1.
As you can see it falls off right after the launch and doesnt' clear up until
mid 3rd and fourth is pullin hard. I already made the adjustments to the carb and a couple other changes and will hit the dyno soon.

http://www.youtube.com/watch?v=Ag4ImcY2cyU

 

get some new ignition leads too , and recheck your body earths an ****

 

That's the first thing I checked but thanks for the heads up. It clears up in 3rd and 4th so I don't think it is ignition related. I checked for loose wires and everything already too

 

I thought you let off, I was like wtf man why did he let off lol...good **** tho

 

Thanks bro, trying to hit the dyno soon.

 

would be good if you could have a oscilloscope running on your ignition whilst under load , watch whats going on in all aspects , bit nerdy though

 

I agree with Jay, I'd be chasing fuel issues, either pump starvation or float or something along those lines.
Did you pull the plugs after the run? You are still running gas right?

 

Yep pulled the plugs but like I said earlier the engine cleans up in 3rd and fourth gear. Plugs are reading good and yes I am still on gas.

Made some changes. Going to hit the dyno and then it's out to the track again
to see what happens.

 

I think you still have an air issue/clearance between those huge velocity stack and the hood being so close.

If you launch the car and lays flat on its face and clears on the rest of your gears I would try run the car with out the hood, before chasing anything else.

My thought on the car clearing up on other gears, is that the speed of the air on 30-50+ miles is a lot faster than on launch. Being the car is on dead stop and trying to get the air in the carb. But what do I know about air speed and velocity?? Just my 2 sense.

Oh, and the High rpm launch on a lightened flywheel vs stock/mean mass weight and the low gear to get your deuce out out of the hole. Is all big factor to consider jay. Maybe its not the a fuel issue.

Maybe its just needs air to the stacks? Or a heavier flywheel to compensate for the law gear innertia.. Just throwing those idea to your mix..

Best of luck..

 

I appreciate the thought but I am running the same carb clearance and the same clutch and flywheel as I did with the 12a and I didn't have this problem before so I don't think that is my problem.

 

Put the car on a level surface and verify the carb is not leaking fuel into both front/rear barrels. Let the car idle and it if revs clean with no weird issues you know the float level is good. Then while the car is idling use a floor jack and pickup the front end of the car to the same height the wheels come off the ground at the track to mimic a wheelie. If the barrels start to dribble fuel into the rear rotor you will hear the engine want to shut off.
If simulating the wheelie causes the bogging situation to come back you have a couple of options to fix the problem.

1. Install a wheelie bar to limit how far the car comes off the ground.
2. Let some air out of the rear tires so the car does not hook as hard and spins a little off line.

Good luck
Those gremlins can drive you nuts.

 

All sounds like a good ideas BUT you are forgetting about the G forces while launching.

 

jay i saw u dynoed, what hp numbers? 230 to 250rwhp?

 

First off I am no professional with carburetors but.....


Building on these two posts. Maybe you can lower the level of the gas in the float chamber. Perhaps when you launch the gas is being dumped into the intake. I had an old time drag racer mention him having this issue back in the 70's and lowering the level in the float chamber fixed it. How are your carburetor vents set up? Can you post a pic?


John

 

Cmon Ito you know I can't lay that info out. I can tell you it is quite a bit more than that but not enough for my goals. I ran out of smaller air jets because I am running lean on the top end. I am changing a few things and will hit the dyno or track again.

 

I think lowering the pressure 2-3 pounds somehow for the launch and giving it full pressure by second gear should fix the problem.

 

i dont see the need for it to be a secret. remember your just starting out so what ever numbers you get will change as u start to fine tune. it will always be a progress. and we could estimate according to your e.t. weight and mph.. good luck..

 

I forgot to add the smiley after that sentence. That was a joke. I'm making under
300. The et and mph numbers are what matters anyhow. Got some things I am going to change around. May take awhile to get this thing dialed in and I may just end up going EFI but I will give this setup a chance till the end of the year.