Combo:
'69 Chevelle
427 BBC
9.5-1 compression, Crane 284 Cam (228@.050/ .544 lift, 112 LSA), Merlin Oval port heads with 2.19/1.88's, RPM intake, Holley 830 annular carb, Hedman 1 3/4" Elite headers, 3" full exhaust with Dynomax UltraFlo's.
9.5" BTE converter 3500 stall, flashes to ~4400-4500, 3.73 12 bolt, 26x9" Hoosier slicks.

Factory boxed lower control arms, rear sway bar, no front sway bar, stock cheapie shocks, urethane bushings throughout suspension.

Ran a 8.14 tonight, best so far.
adjsuted timing up till best MPH, then baclk when the MPH fell off.

I have light springs/weights in the distributor, and a crane adj vacuum advance.
I have not put a timing light on it yet, adjusted by ET/MPH to best setting. Will check for a baseline from there.
Plan to go back to a heavier (stock) weights on the distrubutor an dplay with the springs some.

I have a hesitation off the line if I try to launch from a high idle to "hit" the converter.
I have to lauch from a ~2000+ rpm stall.

Carb is setup as stock 78 secondary jets, 28 squirters.
May play with squirters next time, but it had 35 squirters on it last weekend before the 3" exh and ran a 8.33.

Best 60' was a 1.83 tonight. Car seemed to be hooking good, I think I mostly need to play with the accel pump setup and timing weights for the launch.

Looking for ideas to improve, basically what would be my next best improvement to do?

Jake,nice to know that cam works well..I ran one years ago in a 454 that never saw the track,and it ran damn good on the street..used to be called the Fireball 302H..
Have you tried leaving at a lower rpm? I leave around 1200,seems to work well for me.
I think once you get the timing curve dialed in,you'll find some ET
What rpm do you shift at?

If you`re up for it IMO a cam change is all you`ll need.
Check out some of UD Harolds Lunati cams.

Jake, a couple of thoughts:

The maximum torque multiplication effect of your torque converter happens when you have the greatest differential in rpm's between launch rpm and stall rpm. By launching at 2,000+ rpm you are giving away some of the launching power of your converter.

Have you tried adjusting the pump shot to feed more fuel in quicker. Really, you will shorten up your 60' and whole e.t. by fixing the off idle launch hesitation.

I also wonder if you wouldn't be quicker with less stall, as your engine should have terrific down low torque - and it seems like you might be flashing past the fat part of the torque rpm's.

Suspension wise I would suggest that you go through everything and loosen up those urethane bushings. Urethane bushings are very durable - unfortunately they often have poor movement. If your front end is too tight on launch it will keep your launch slower than it should be. Sometimes urethane bushings need to be removed and "massaged" for a "just loose" fit.

For sure you need to get a baseline on the timing curve. I would not be suprised if you found that the timing curve was lazy.

Thomas

Thanks for the suggestions so far guys,

Chris,
I've tried the low rpm launch and it has a BAD bog if I come off that low. That is what I'd like to do though, too "hit" the converter and chassis to make it transfer weight.

Big-Red,
A cam swap may be in the car's future but I would like to squeeze this one as hard as I can first. I'm not putting a cage in THIS car so if I get close to cage time, it is fast enough.
However that roller I have laying around from the 505 could accidently find itself in the 427 for giggles. 242/248@.050 .648/.654 solid roller.

Bomber,
I do think the timing curve and carb need some work.
You think it would be lazy with the light weights and lightest springs? Light weights too light?
I had 35 squirters in the carb and should have changed back to them, also had some 31's. Should have done some testing with them.

It really seemed to like the air cleaner element and lid off, dropped a tenth doing that. So I need to get a taller air cleaner at a minimum. 3" currently on a factory drop base open element cleaner. Not much room between the carb and lid.

I will put a timing light on it today and get an idea what the curve is.

Might have to go back tonight smile.gif LOL

Also,
The car has urethane bushings on it, and they have been on there for 2 yrs. They seem pretty loose as far as transfer goes.
Car lifts the front very easily on acceleration.

So far it SEEMS to be hooking. I did spin once last night with the slicks at 18 psi, but dropped them down to 16 and it never seemed to spin again. Still have some room to drop them more if need be.

Whats your rollbar cutoff Jake? My 1/8th mile times last night on drag radials(18psi) were 7.81,7.83,7.83,7.85...What were your 60ft times? I'll drop the DR's down to 16 psi next saturday and see if I can improve on the 1.74-1.77

When I had an 850 with annulars on my 350 I ran a 37 squirter with a hollow screw in the front and a 35 in the rear. Orange pump cams for both using the #2 hole. I had a very bad bog and this stopped it. More air cleaner clearance isn't a bad idea, however, I'd expect that problem to show up at higher rpm when the demand is higher. Make sure there is at least 3/4" clearance above the vents. A Moroso top works well. It is curved and adds more room above the carb than a flat top.

You should be getting better than 1.83 60' times. You are spinning even if you don't feel it. I run my slicks (Hoosier 28/9) at 11 lbs, you should try lowering yours. The weight of the car seems to be a major factor on tire pressure along with track conditions. A heavier car usually wants more (my car is 3400 at the starting line). While my 60's aren't great they are pretty consistant at 1.62-1.63. I have some spin.

What MPH are you turning?

Bob,
I'm not sure what the cutoff is at the local 1/8th. It is an NHRA track.. but I haven't checked. figured when I get there, I'll just keep it right there.

60's best was a 1.83, all my good runs it was a 1.83-1.85.

Pat,
Before I even ran last night I pulled the 35 squirters off and re-intsalled the 28's as were stock on this carb. I also de-jetted the back to stock specs from an 84 to a 78.
I will put the 35's back on and look for more 60'.
I don't THINK the car is spinning. I think it is just not motoring off the line any harder yet.
When it spun last night I could DEFINITELY fell it, probably only spun for 2-3 feet just off the line but I can "feel" it. I could also feel when it did completely hook.
It's gonna need some suspension work when I get it launching harder because it is already leaving with the front unlevel, noticeable in the car.

MPH was 83.88 last night, once I got the timing up to where it liked it. I need to record the current timing because it ran best there, best ET and MPH. Then I will alter the curve and see what happens.

My car is 3900 with me in it in race trim. I've ran with slicks as low as 11 psi on it previously and it seesm to do as well at 15 psi as it does at any lower.
If the track gets loose, or I have problems I let it down more but the car handles better and launches good at 14-16 usually.

I may let a little more out and try it just to see. I had a couple of buddies watch it last night and none seemed to think it was spinning.

I tree'd my buddy with the 9 second (1/4 mile)Cuda, but got to watch tailights the whole rest of the way smile.gif

You'll want to run the tire pressure as high as possible consistant with a good launch. Too low will cost ET due to increased drag. In my case, 12 psi and the 60's suffer, 10 psi and the car is squrmy and hard to hold straight down the track and the 60's are no better. At 7.49 and you'll need a bar.

Pat briefly touched on the pump cam.
You can really tune in the carb with the
squirters and cams.The squirter to control shot
volume and the cams to determine timing and duration of the shot.Unfortunatly, you pretty
much have to experiment and back into the right
setup.You'll get it with a little time and trial.