Joe, If you read the few dozen previous posts, you'll see that I'm looking for help with my combo in this thread. If you wouldn't mind starting your own if looking for input, that would be greatly appreciated.
Try changing to a larger squirter on primary side of carb . Car still has some more et in it if you fix the bog. sometimes short shifting 1/2 helps too. good luck, mostly enjoy. I got to get back to my Buick, ughh.
No problem Joe. I didn't mean to sounds like a jerk. I always find it interesting to read about your BBB Nova on this board. 70GMmuscle, thanks for the tip. I think I'll try playing with the squirters and the vacuum secondary spring to richen things up on the launch.
i use to get a slight bog when i brang it up on the brake.i have a little more convertor but what i found was hapening was that i was way into the pump shot on the acelerator pump so i set them on the loose side so i could bring it up hard on the the brake and i still had a full pump shot left when i floored it.my hesitation/bog went away.just a though.sounds like you got a great runing car there just some tuning away from some real great passes.its already runing great.but theres alot more there to unlease/good luck with it keep us posted.like i said earlier sorry for jumpin in on your post.sometimes i just get carried away and not thinkn.hope i didnt piss you off too bad.wasnt my intentions ...everyone on here are some real good people/they have helped me out with good advise n tips..:3gears: good luck racin n tuning
Joe, I was thinking that might be the case with mine, as I did a search for bogs when foot braking. Again, no hard feelings and I apologize if I came off sounding like a jerk. Paul, maybe you have someone else confused with me. I don't have an afr meter installed in my car. I had gotten some previous afr measurements, but that was off a chassis dyno.
Hi Jon,you're doing great,some of my ideas for you that work great for me,I run the same tires you do and mine work best at 17-20lbs.,I shift alot lower than you,5,200-5,400,and have a 3,800 convertor and launch/flash it from 1,500-1,700 rpm. Rather than write it,here is a link to my car for you to read pretty much from soup to nuts about my combo and where I'm at with it. Paul http://www.v8buick.com/showthread.php?t=228300
I don't see an indication of which carb you are running, but if it's a Quadrajet, it could use a little tightening on the secondary air valve. If that fixes it, you'll know, because you'll get even more wheelspin.
850 cfm annular Speed Demon carb with vacuum secondaries. Runs great on the street, I've got my A/F dialed in after running the car on a dyno, but just have this slight bog at launch. Sherwood, thanks. We have pretty similar combos, though you have more converter, gear, and less weight, while I have some port work done. I'll try lowering air in my tires, since I checked with M/T and noticed 14-19 lbs. while I was running 20+.
Bog at launch?? Squirters ,what are you running???? To small...lean bog,to big...fat bog.I know all carbs are different,but on mine 37,37 is a sweet spot.Tried 33,35's and it hicups,41-37's it slows down in the 60'.
Sounds like I'm leaning out. I have 31 squirters in it, so looks like I may need to step up. What do you think of the earlier suggestion that I may be already partially into the accelerator pump shot since I'm brake torqing it and not getting a full accel. pump shot?
Holy crap,31's!!!!Way under what that thing wants!!!! When I tried my friends Demon last year before I got the Quickfuel,it also had 31's,the car dam near stalled,fell right on its face when I nailed it!!!!! At minimal,before you blame the acc pump,try larger squirters, 35-37's.You might be real suprised at how the car is going to react. I had an AED 1000 on the car when I bought it,ran decent at the track but very sluggish on the street.My friend who owns that machine shop and is a wiz with carbs,been racing a long time, made me take one of his(Quickfuels),and holy cow what a difference,very snappy throttle responce,starts up and drives unbeleivable,and ran the quickest at the track. NTM,that Demon was the worst of them all and ran the slowest. And,read what I wrote about spacers,and how my car reacted to the three difff ones I tried.My combo really liked the HVH 2''. Beleive me,after going to the track numerous times now,I am very happy with what my car runs as to whats in it.Get alot of compliments at the track when I describe the motor,don't know wether I am going to leave as is,or remove heads next winter to send out for work,or pull the trigger on T/A Satge 1 aluminums. As touched on before about convertors,the one in my car is by no means a"good" one,when we did the slip calc it comes out to around 13-15%,yuck!!! My rear suspension has no air bags,but all aftermarket arms/braces.Front sway bar still on ,and the car leaves nice and straight.
For what it's worth,another topic,my friend tried the KN filter-top lid like I have,when he dynoed his car his dropped 13 HP when it was put on(3" air cleaner),so again at at track rental,I tried his reg chrome solid lid,my car slowed down!!!!!! There is a cowl scoop on my car,and the air cleaner(4" on mine) is way up inside it.Then made a pan with a foam seal to seal to underside of hood and take in 100% outside air,the car 60's even harder,but goes lean by half track and slows down in MPH.Yes,I know I can upjet it,but just took the pan back off that particular day. There are so many things(tricks) to do to pick cars up without really doing motor/tranny/gear work,you just have to experiment alot.My front skinnys,I run 60lbs of air in them for less rolling resistence at the track is just one of them.
just reading this thread for the first time and am still stuck on the fact that you broke into the 12s with a 2.X gear and a 'one tire fire' to boot- thats awesome!!!:beer
I had the same bog a long time ago played with Squirters and pump cams also changed the pump shot from 30 cc to 50 cc it took awhile but i got the bog out good luck :TU:
Hi Jon; I noticed you said you picked up 1mph shifting at 5400rpm. Ever considered running a highspeed retard at the top end? Not sure if thats the proper name, but it basically drops your timing by "X" degrees at some RPM above 4000 that you specify. MSD sells a module for it. Most of their "programmable" boxes have it built in. Quick test to see if youd benefit from this. Drop your TOTAL timing by 2 degrees and pay VERY close attention to how the car behaves above 4500rpm. If it wakes up around 5000rpm and pulls harder then youd benefit from this. Found this out on my SBC between 34* and 36* total. 34* pulled hard after 4500rpm, and 36* pulled hard up to 4500rpm. Usually the car is faster if you run the advanced timing because torque rules. But the technology DOES exist to benefit from both. :3gears:
