Originally Posted by chevyart
hey cpx went to lebasnon valley(ny) yesterday. first pass dont even count. spun tires so bad i was embarresed. forgot to check air preszsure). 2nd pass was race time. car launched good and ran good but et was only 11.47 and mph was off by about 1-2 mph(lost race by 11 thousandths of a second) i let off just before end because i couldnt see the guy(didnt use my mirror and just looked to side.he caught me and i lost by maybe inches. they let me do a time trial and the car spun alot again(didnt care about that) and when i shifted around 7500 the car had like a bad miss(stutter) or something and it lasted for only a second. i checked the fuel pressure guage(in car) and it read 7 lbs(thats ok). car picked right back up but ran a loust 11.7 (60 ft tome was partially to blame for that. problem is that come and go miss ive been getting since switching carb . i really think it is the 3.5 power valve in there(too low a number), i am putting the vacum guage on there today.still havent seen the power valve that was in old carb, but it definitel the right number power vaLve.. and will try the power valve (the right size if the wrong one has been in there. if it was the right one in there then i will go to straight jets on front anbd rear and step the size up to 84 square.i worry about loading up in the pits, but quick fuel told me i could adjust the idle circuit air abeeds to lean out the idle circuit to help prevent loading in the pits. in my old cargb the power valve in there was definitely the right size. still trying to get the metering blocks off old carb. they are like welded onto the main body. ill keep you posted. any more suggestions ,i am listening thanks art
As far as the air pressure whoops, I aint never done that :roll: ...lol I think we all have, no biggie.
Damn ya'll only get one time trial? Whats up with that?
We usually get 3 for sure, sometimes 4 but I race at a laid back outlaw track in north mississippi, that would be in god's country if your wondering :wink:
Man I see your still stuck on them PV's, I'd loose them sum bitches before I did another thing to the carb, but 84 sqaure is wicked fat IMO for a 750cfm DP on a 350 anything. I'd go 80 sqaure and work my way up or down till it's dead nuts on.
Note:
As a comparrison I'm jetted 88 sqaure on my 1050 dominator which sits atop a 500CI bigblock.
Also, plugging them and squaring or not squaring up the jetting will NOT make it load up in the pits, that would be the idle circuit causing that problem, just lean that sucker out with a couple turns of the mixture screws (IN), if that dont do it, you got other problems, a BLOWN power valve comes to mind, another reason to loose them suckers.
In certain circumstances you have to add additional air to the idle circuit, a couple small 1/8 inch holes drilled in the primaries will take care of that with a quickness.
Ok, let me know what you decide to do and how it pans out.
Goodluck>Cp