12s There's a lot of good advice the best being one thing at a time. Unless I missed it I don't remember seeing anyone address your initial timing. Instead of being all in by 1900 you would see an improvement if you were all in by 1200 to 1400. Good luck Bob H.
stage2man is 100% right do not use that 830 annular carb it will choke the engine when you start to rev it.annular boosters are to big they restrict airflow into the motor in exchange for a good booster signal.a buick 455 has a relitively big piston compared to its port size wich=high velocity=good signal to carb thats why the like big carbs.have the 830 switched to drop leg,its smaller and will allow more room for air to flow.annular boosters are sometimes used to compensate for an over carbed combination thats why they mite work well on a dominator
i installed the 830 carb and 1" spacer tonight and took it for a :3gears: . all i can say is :shock: ... major difference in the way it drives. amazing throttle response and pulls alot harder. i am going to the track on sunday so i will let you guys know the results. dave
Dave, I'm very interested in seeing how you do as our motors are very simular. Same compression, same cam, same convertor and I have 3:42s to be installed. I would like to ask about your 113 cam. Did you degree it? How do you have it installed? Straight up, advanced or ? What is your initial timing and vacuum at idle? I'm having some issues with my motor and have been looking for someone running the same cam. Anyhow, good luck. I look forward to your results. :TU:
mike, i degreed the cam and ended up 2.5 degrees advanced from the 109 centerline that it said on the cam card. initial timing is 23 degrees, total 34 all in by 1900 rpm. idle vacuum is 12 to 13 inches. dave
results, it was 25 degrees warmer than last time out. with the 830 and 1" spacer, 13.37 and a 13.39. mph was down a little,60' and 1/8 were .02 better. I thought for sure it would have gone faster by the way it felt on the street. is it possible to have a fuel delivery problem and not feel it ? dave
I doubt you have a fuel delivery problem. The fuel delivery system has not changed, the size of the bowls of the holley are larger than the edelbrock, so if you had a marginal fuel system the holley should have worked better than the edelbrock carb (assuming you have float levels set correctly). The temperature difference is significant so it's hard to say that you are making less power, but usually the MPH is the best indication of how much power you are making. I would try some shorter tires, your 60' times are killing you. After trying the shorter tires you can switch back to the other carb and see what happens. The best way to do this is to switch at the track after a couple of runs and see directly which one is working better.
Open up your high speed air bleeds and then jet down. See if your mph starts to come back. Then go for a proform center section, you'll have a great carb with mph.
I guess like TA's 413 the 113s like a lot of initial advance too. Just out of curiousity, why did you go 2.5 degrees advanced from the 109?
i ran it advanced just to give it a little extra grunt off the line. at the time i built the engine i didin't have the money for a higher stall converter. dave
update stage 2 scoop and shorter 26" drag radials w/holley 830carb.13.06@103.28 1.84 60ft 70 degrees and 50% humidity. with some tunning of the carb i will have my 12.xx run.
Did you read the spark plugs? They are a simple way to tell you whether you might be rich or lean. -Bob C.
Dave, Use MPH as your gauge to whether performance mods have helped you. The 60ft time and ET is more just a measure of traction. Just a smidge better traction and you have your 12's. You gained 1mph since the last change and maybe some of that mph came from better air??? In a mid-3k pound car, that MPH is indicative of a 12.7 or so. I am wondering if you have something in the combo holding you back........ Ramin
i have been checking the plugs. not much color on them. maybe the plug is too hot. the ground strap shows the timming is real close. i think what is holding me back is the car doesn't launch real hard. i think i need to add a little more accelerator pump shot as i was having a slight bog on some runs. dave
It seems like you could have more 60-ft in it to me too. What is your launch technique with the current DR's, and does it spin at all?
i bring it up on the converter to 2300rpm and nail it on last yellow. no wheel spin. so far this has given me the best 60 ft.
Finally broke into the twelves. Good air tonight @ island dragway. Now you all know whats next, :laugh: got to go faster. My goal is reached for this year. I'm going to try the 750 hp main body with my 830 base plate and metering blocks. I think that the hp main body comes with jets. What is that the best starting point ? I am using a 1" spacer and hood scoop sealed to the hood. Should i go a couple jet sizes higher than what comes with the main body ? thanks, dave 1.818 60ft 5.273 330ft 8.186 1/8 84.20 mph 10.726 1000ft 12.888@103.94
Nice job Dave! 13.03 to a 12.88 that's quite a jump. Did you change anything between those two outings or was it just the good air?
the temp was 20 degrees cooler, i think that had a lot to do with it. i did install new plugs that were one heat range cooler. I also changed accelerator pump cams, that helped it get off the line a little cleaner. added 2 degrees of timming because of high humidty. I shifted manually @5200 instead of 4900 when left in drive. i need to modify my govenor. i think with some more carb tunning i can get the 60ft into the 1.7x range.
Glad you achieved your goal for the year. 12's are a tough number. I had a similar experience this summer at the Nats in Salem, OH. After two days of 13.1's and 13.0's, I decided to uncap the headers to get a 12. I got one and I was thrilled. I got in the Buick Comp class and had to put the exhaust back on and my best qualifying run was a 13.09. First run of real racing I broke out at a 12.93!! I was mad that I broke out but was thrilled that I got a 12 with full exhaust. I made another run right after that and went 12.88 @ 103.55. All the runs after that were 13.0-1's. Now the car sits in my driveway collecting leaves and pine needles awaiting a disc brake conversion before it gets cold.
