To burnout, or not to burnout...that is the question.

I took the car for a ride this morning and it really seems to be running so much better than it did at the track this weekend.

I am wondering if I should skip the burnout...in seems like (in my imagination) that the burnout makes it run like crap the next time I rev it up.

For example, if I burnout for 10-20 seconds, almost immediately when I let off the gas and start to bump up toward the lights, the idle drops and it acts like it wants to stall, and sometimes does.

This last weekend, I started to rev it a couple of times to "blow it out" just to get a fresh refill of gas to my bowls. It still ran like crap and the fuel pressure dropped to 3psi before I hit 2nd gear, then stayed low and sputtered through the finish line.

The first two runs were good without spitting and sputtering, and then today, on the highway, it ran beautifully (even better after I put a Pertronix unit in finally!).

Would I be better off going around the water and just going from idle to takeoff without the burnout revving?

I will try this this weekend, if the weather holds out. If it makes a difference, what would be the reason(s) behind it?

Also, I am almost out of tread, and I need to take it easy on what is left of these tires...I used my tire money to buy the Pertronix kit.

 

i would think that if your gas pressure is dropping to 2 or 3 pounds then the fuel pump is not keeping up and you need a higher pressure pump. also when you take off the fuel always goes toward the rear. is your carb a center or a side hung float? another thing to try is fuel extensions on the jets. sorry i just noticed your using an edelbrock carb. i'm not familiar with them at all. don't know if some of the same stuff applies to them or not.

 

All I know about Edelbrock carbs is 1) they are very pretty and shiny, and 2) anyone who seriously uses their motor says to go to a Holley.

So, a Holley is in my future...probably a double pumper, since it seems like my carb is "weezin' da joo-ooz" when I gun it, and cannot keep up. Also, need a better fuel pump that pushes, rather than pulls (electric rather than mechanical).

 

Ummm, number 2 isnt correct. maybe almost everyone, but i hate hollys and the grabber isnt the only pumped engine i run. the fuel loss isnt the carb, its the pump and lines supplying the fuel to it. the 390 under load at full barrel doesnt empty the carb 600cfm edelbrock. and i know for a fact its too small of a carb. ran a 460 with a 700 edel. in my dads pickup, never emptied that one either. your fuel pump or lines are not bringing the fuel to the carb.

 

Carb: might look into a Quick Fuel carb (I run the Q Series ) they tend to run a little cheaper than a Holley. And they are made with Holly parts

1) If you are running street tires, there is no since in doing a burnout. All you are doing is getting them greasy. Just a couple quick dry hop's to get any rocks and what-not off them should be fine.

2) A 10-20 second burnout with any tire is way to much, unless you are posing for pictures

 

When my wife and parents are there...I AM posing for pictures

Weather is clearing up and should be nice and chilly for good driving. I will hopefully get a chance to test this out.

As far as picking up rocks and stuff...I have no tread...I am down to the wear bars (wonder how that happened ) so nothing comes onto the track with me.

Will be buying new tires in a couple weeks.

 

burnouts on street tires (not DOT slicks) usually just make them slick & do nothing to promote performance. just drive around the water & do a couple of dry hops.

 

Whats a "dry hop" ?

 

just spin the tires a little once or twice without water, before staging. as tho you were leaving the line. the car will hop forward a few feet each time.

 

just remember. the pressure drop is on the line going into the carb. that means no matter what the carb, the supply line pressure will continue to drop until your lines and pump can keep up with the engines demand.

 

if u run a filter and keep the crud out of the air bleeds, holleys need minimal care & feeding. maybe fresh gaskets and needles each season, if u keep them clean.

 

Are you clearing the cars throat after your burnout? Stick it in neutral and give it a quick rip up to about five grand to get the pooled up fuel out of the intake (especially if you run a big single plane). See if that helps.

 

Yeah, I have been revving it pretty good after the burnout. And I do have a big single plane (heavily ported torker 289, the old one, not the torker II). I get close to the line, put it in neutral, then rev it pretty hard, then idle up to the line.

I seems to run better if I just skip the burnout. I find find out for sure tomorrow night.

 

I think you have a fuel pressure or flow problem also. Some fine tuning on the metering rods and springs may be necessary. The float level may have to be reset too. Have run both Edelbrock and Holley carbs, depending on engine spec's, the Holley seems to be more responsive and easier to tune in my opinion. Have a 750 DP that was given to me to use, man could not get it to run right on his BB Chevy. Took it apart and found he had used pipe sealer on the fuel inlet threads, some of this white "dope" got into a jet and stopped it up. Put a kit in it, set it up for my 302, then the 331, and never touched it for 5yrs. Just checked it each year and renewed some gaskets etc. Most problems with them, especially used one's, is worn throttle shaft bores. Causes air/vacumm leak. Can be repaired with bushing kit.

As far as burnouts go on street tires. waste of time unless you have some high dollar Toyo's with softer compound. Tread is for channeling water, mud etc. out from under the contact patch. Also for gripping the road in corner's, the compound is harder for long wear. Slicks are "bald" tires with softer compound and you get them "hot" to enhance the sticking abilities of the contact patch. They also have thinner sidewall for flexing to aid in this launch. Do know a fellow who runs in the 10in street radial class, who has an old rear end set up on stands with an electric motor than turns the pinion. The tires are on a set of old wheels mounted on the axles and sitting in tubs of WD-40 or similiar solution. Turns very slow for days, this supposedly softens up the rubbler. Must work cause he runs low fives in the 1/8th at 120+ mph. Damn Chevy though, 60ft's are better than some slick equipted race cars. Has the right tranny. gearing, and ability to drive which helps. Sorry to ramble on, but never ceases to make me cringe, when I see the fellow on street's, blow the tire's off for no reason other than show. Makes nice little rubber marbles, left on the track for the next guy in line to fight too.

 

Good info. THanks for the feedback.

I think the next tires will be drag radials...something street legal AND sticky. Then I don't have to mess with "wondering".