(4/13/07 update)13.36@102 looking for 12.xx looking for 12.xx this year. just got back from the track. car was very consistent. 13.36 four times in a row. i tried shifting at 5500 up from 5000 but that didn't change anything. i bumped the timing from 31 to 34. that didn't change anything. left off idle and tried bringing it up on the converter, that didn't change anything either. i'm going to try a bigger carb with annular boosters and a 1" spacer, maybe some shorter drag radials. any other ideas appreciated, thanks dave :3gears: 60' 1.96 330' 5.56 1/8 8.56 mph 82.27 1000 11.15 1/4 13.36 mph 102.05
Did you have any wheel spin ?? what is your combo ?? we have to get that 60ft down.....then you will get into the 12s
Need more info about your car. Engine build up, gear, converter, carb, weight anything else you can think of. What do you think you might like to try (how much you wanna spend)?
9:1 compression,recurved hei all in by 1900rpm,stage 1 fuel pump,750 edelbrock carb,performer intake,poston 113 cam,stock small valve heads,headers,2 1/2 exhaust,th400 trans w/2800 stall. 3.42 posi,air bags set at 12psi rtside and 5 leftside, 295/65r15 drag radials. stock weight 71 skylark. 1/2 tank of gas. no wheel spin. trying to keep it low budget. i have a 830 holley dp annular carb. i'm going to try. would a 1" spacer be helpful? i also want to get 275/60r15 drag radials.they are 1.5" smaller so that should help.(as long as they don't spin). would running open headers or going to a 3" exhaust help? any thoughts would be appreciated. thanks, dave
You're already making the power you need to get into the 12's as noted from your MPH. You need to somehow improve traction (though you might not think you have wheel spin and you have been darn consistent!). Roughly, for every 0.1 gain in 60ft time, you will gain 0.15 to 0.20 at the end of the track. If you can get a 1.75 60ft time, you're there. Try more air in the pass side bag. Try adjusting tire pressure (including the fronts). Try more or less burnout. Try different slick/drag radial (as you stated). Good luck and have fun.
Go with the 830 double pumper for sure. You will have to try it with and without the spacer to know how it will work. I liked using 1" spacers on my car, but I used a different manifold. I know you don't think you are spinning, but you can't always tell. When my slicks started to go away my 60' times would drop. I could not tell any difference in the launch, but when I bought new slicks the 60' times would come back. I like the idea of trying the smaller tire (295/65/r15's are dang tall). With the MPH you have your 60' times should be at least .2 quicker. I don't know if the exhaust will help, but it won't hurt so go with the 3" for the cool factor. I always ran the 3" system on mine so I don't know if the 2.5 is really hurting you that much. You could try going with open headers once to see if it picks up over the 2.5" (I think everyone should race their car with open headers at least once). Holy crap that's loud!!! Compared to open headers on my car the 3" exhaust was about .05 seconds slower, not worth the trouble to unhook.
You're running a 29.6" tall rear tire, that's takes away a lot of your bottom end. I would recommend borrowing someone's 26" tall slicks and see how you do. Before tinkering with anything else, you want to make sure that you're coming off the line clean, with no tire spin. I'm guessing you're barely using your power band in drive by the time the you run out of track. Take advantage of those 3.42's by trying a shorter tire. Once you've done that, start messing with the other things - one thing at a time.
i would go with the 830 cfm carb. those 455's seem to like cfm's. and i would go with the lower tires also. even try a set of 275-50-15. what are your rpm's across the finish line in drive? or are you still in 2nd :grin: those are awful tall tires you currently have. check your plugs after a w.o.t. run with the new carb. make sure you have enough jetting in it. the 34 degrees of total timing sounds good. do you have decent mufflers on it? sounds goofy but if they are cheaper turbo mufflers they could be slowing you down also. 2.5" should be enough with decent mufflers. good luck and let us know.
12's A big thing that comes to mind to me is doing some basic head porting. Some mild porting won't really cost you much $$$, just supplies if you do it yourself (it's not as hard as it sounds, but it it time consuming to do a good job) - or enlist one of the experts on this site like Greg Gessler. I think you'd like the results. Heads = Power :TU: Just my .02 (not that it's always worth .02 :laugh: ) Todd
I agree with most of the above. You are deffinitely losing time in the 60 ft. More carb can't possibly hurt. And if the tires are as tall as someone else posted, you are killing your gear ratio. 2-1/2" exhaust is plenty for the speed you are running. You will gain nothing with 3". You can (almost) always run quicker with open headers, but why bother? 12s are within easy reach with what you've got.
My 3800 lb 64 runs consistent mid 12's with small valve heads and no porting with an 800 Q-jet. I would definitely run open headers to see what that picks up, shorter tires, and have someone watch your launch to try and detect wheelspin. Your mph says you have enough power to be in the high 12's. Best advice I've seen here is "change one thing at a time". If you don't you will never know what change made the difference. Have fun!
Yup, with almost all of the above. I should just copy and paste Steve's response :TU: Those BFG 295/65's are way too tall for a 3.42 gear. I run those on my car and I have 4.33's. Switch to a set of 275/60 stickies. I wouldn't doubt if you'll get close to your target with just the tire switch. Then plop that 830 on there. Make sure you have enough fuel pump and pressure/volume, with jetting in the high 70's to maybe 80, all square. Mid 12 second combo. once its sorted out at 108 mph or so. The 3" exhaust switch will most likely be a wash, just noisier, cost more $ and weight more. Then fine tune everything, making one change at a time with at least three passes per change and log each change. That's the way to learn how it all works together. Good Luck
Get a good ignition system as well. HEI's suck. Use a stock recurved distrib as a trigger for an MSD 6AL.
thanks for all your replies. i will try the carb first,(because i have it).next will be the shorter tires. thanks, dave
I would not use the 830 it has annular boosters. They feel great and drive great but have a really fat hook at high rpms. My 830 slowed both of my old cars down but felt great driving around. It also slowed the regal down over the HP 750 by 4 tenths. If you are going to buy a carb i'd buy the down leg booster 850 or 950. You can buy a mighty demon 850 for $499. If you go this route be sure to take it apart and clean out every passage. They have shavings but you do this and jet down a couple jet sizes they are killer. Holley or Quick fuel 850 will run great out of the box. I run Quick Fuel now. I had touble on one of my cars right at the 12 second boundry. It was fuel flow issues because of a brass fitting with poor flow. I would make sure you have no brass fittings anywhere in your fuel system. It ran 12.53 first pass after getting rid of that fitting.
at what rpm will it go fat? what if i opened up the high speed air bleed? i had a demon carb once on another car, i would never buy a demon again. do i need a better fuel system than stock w/ stage 1 fuel pump? i already have the 830 so it costs nothing to try. if it doesn't work out i'll sell it and try something else.
You can tune an annular for a single carb application it's hard. The booster signal is very strong, they where designed for road racing cars with small engines like the 302 chevy. Great for a overcarb'd small block or a tunnel ram. I would enlarge the power valve fuel jet passage. The hole behind the power valve threads. Decrease the jets by 5 sizes or so before doing this. Drive the car at part throttle pulls making sure it's not blowing black smoke. Go up in hole size until you start to see a wisk of smoke. You can add a piece of wire in the passage to reduce fuel flow once at that point. Now reading plugs at the end of full throttle runs continue leaning out the motor by opening your bleeds. Emulsion holes can reduce the fuel lifted used to fine tune the fuel curve. You will need a wide band O2 sensor to do this. Or just simple send the carb off for down leg boosters or just change the body for one with downleg boosters.
I had a 1050 dominator with annular discharge boosters, great carb at the track and on the street. Just try the carb and see how it runs. Don't waste your time fixing things if you don't even know they are broken. If you try the carb and it does not perform, then worry about what ifs.
good advice. i'll bolt it on as is. if it doesn't help i'll sell it and put the money towards shorter drag radials.
My dominator is annular also. The bore is way to large to have a good signal. 4500 to a 4150 is apples and oranges. Just trying to pass on what I've learned in the past. What feels great may not run great. Quick fuel will give you advice on the correct carb for your application and some insight as to why. The flow engineer from holley who created the HP carb series is the founder of quick fuel. You can go the cheap route to a great carb with your 830. I just did this for my friend Ed with my old 830 annular. Car: 85 regal with 455 buick pistons - speed pro at 9.5:1 stock rods with arp bolts stock 70' small valve heads with 3 angle valve job TA310 cam hooker headers B4B Carbs and results: At the 02' nats we did not have time to get a new carb so we ran an old style holley 750dp with choke tower. Factory jet settings for the whole race. car ran between 12.62 and 12.69 the whole week. Next I took the 750 and added a proform 750 body. Still a two corner idle system which kind of sucks for idle. Took the car to Navasota raceway for street fighter night and won with 12.50 times but rear was starting to grind and lost mph. Car should have picked up .2 or so. After a new ring and pinion we tried our John Osborne Qjet just for grins at the Texas buick bash. The car won the event but 60ft and 1/4 ets where off. 12.90s down 4 mph. Everyone was off some so not all from the carb. Next we ran my box stock 830 annular. Car ran 13.00s but left hard and idled great with the 4 corner idle system. Next I took apart the 830 to remove the body and use the 1.72 base plate and jet plates with 4 corner idle and added the proform 750 body. Rejetted to factory settings. Car finally broke into the 12.40s with 5 inches of air under the tire. This car is a great testing plateform for changes like this. Its very consistent and the motor is very mild with a smooth idle.
