Organized Drag Racing and AutocrossDrag racing and autocross discussions and questions. Techniques, tips, suggestions, and "what will I run?" questions.
Welcome to ThirdGen.org!
Welcome to ThirdGen.org.
You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, at no cost, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, join the ThirdGen.org community today!
Ive got an 89 formula, that I installed a 357, 11 to one dome tops, edelbrock rpm heads, lunati solid lift cam. weiand xcellator intake and holley mech sec 750. Its a 5 spd car with 3.45 rearend and weighs 3120. I took it to the trasck for the first time tonight and ran a best of 13.42 at 109.7 ( yes it was blowing the tires off all the way through 1st and part of 2nd) Should easily be a 12 sec car. The only problem is it keeps dying at the end of the track like it floods out. On take off it also bogs severly when the throttle is fully mashed same with second. It has the choke horn milled off, 70,78 jets, 4.5 power valve in front, block in back, whisltes installed and jet extentions. Im running 25 degrees initial timing and 35 total advance. Ive always run quadrajunks and afb's in the past and this is my first holley. Im lost what to do next. It also has 10 inches of vacuum at idle. any ideas please ? thanks
You might want to check the squirters if it has them.. It was one of the common questions on holley's tech site. the bogging and such. it has to do with the pump shot. You may need the acceleratr pump upgraded along with the pump cam, and larger squirters. I have the same problem in mine, but have not gotten around to changing the squirters on it yet. Also you may need to adjust your acclerator pump lever... it is supposed to have .015" of space between the spring/screw and the lever..
Sounds like it could be a fuel slosh problem to me. I've had that trouble with holley carbs. Make sure your float level is correct..fuel at the bottom of the sight glass or plug. Also try attaching a rubber fuel line from the front vent tube to the rear vent tube to keep fuel from sloshing from the bowl vents into the carb and flooding during hard braking or acceleration. Don't forget to cut out a small slice at the highest point of the rubber hose for venting. Its something cheap and easy to try that may fix your problem.
Originally posted by jbenge Sounds like it could be a fuel slosh problem to me. I've had that trouble with holley carbs. Make sure your float level is correct..fuel at the bottom of the sight glass or plug. Also try attaching a rubber fuel line from the front vent tube to the rear vent tube to keep fuel from sloshing from the bowl vents into the carb and flooding during hard braking or acceleration. Don't forget to cut out a small slice at the highest point of the rubber hose for venting. Its something cheap and easy to try that may fix your problem.
fuel slosh would certainly explain the killing at the end.. but perhaps not so much the bogging in second gear with it mashed.... You could set the floats a little to make sure you are not getting the slosh, to eliminate the problem. does it bog whenever you mash the pedal in 1st and second. and does it to it as well when in nuetral? if it is in park and nuetral and it bogs a little bit when you mash the gas.. then that could not be caused by fuel slosh
got it fixed, ran larger squirters front and back it just needede a bigger pump shot and the dying at the big end is fixed by a dash pot i totally forgot about. Thanks guys for the help
Yep see told ya lol.. What size were the squirters that you got (mine has the exact same problem, only thing is i do not have a dashpot and it does not almost kill... not unless I really stomp on it and let off real fast.. lol I suppose i will have to get one at some point
the dashpot is nothing more than a selenoid that basically prevents the thottle plates on the bottom of the carb from slamming shut when you left completely off the gas (which can cause the car to stumble ot if bad enough to actually stall).. think of it like a pillow for your throttle.
that's cool. does jegs carry those? would it be considered a "bracket device" like a throttle stop? i've NEVER seen one and have been doing the street legal drags for YEARS now. but we're also not allowed "bracket devices" such as throttle stops and delay boxes.
No. actually it is standard eqiupment on street driven carbs. If you look at any of the stock Quadra Jets They have a dsahpot as well, only a different kind. It will have a wire runing to it to energize it when the car is started. I think jegs might sell it, although i have never seen it in thier catalog. summit may as well. But if you don't want to wait you can go down to your loacal parts store and buy one.. they are around 25-30$ and should come with all the parts needed i think.. I have yet to put one on mine....I just have the little thing it sets in. It is a little bracket but most carbs came with it.. although i could not see that it would be a problem since most OEM carbs came with one anyhow.
i got a .031 in front and .035 in rear. the dashpot is only really needed on a manual tranny its not a must just makes it act smoother on on off throttle
