going to the track on wednesday! lets see how close you guys can get to my track time. smile.gif

396 + 060 9.5-10.1 compression, somewhere in there
Holley 750CFM 4150HP
Performer RPM
stock 049 heads
240@050/ 278ADV / .53 lift / 108LSA
3.31 POSI
295 wide tires
TH400 + 3000 stall
Hooker comp, 2 inch primaries, 3 inch exhaust with H pipe and 2.5inch tailpipes with factory tips! (yeah.. its big, but it is here for future engine)

car is full weight, didnt remove anything, so I am guessing 2 tons with me in it?


also, what timing do you guys recommend? i also seem to have a stumble once in a while if i just punch it.... and white smoke from my tailpipes all the time.... about 200-250 miles on motor...

13.8 e.t. @ 99 mph

Have fun, be sure to post all your incrementals.

As for timing, set it so that total mechanical is ~ 36 degrees in as quickly as possible, like somewhere in the 2,500 to 2,800 rpms. Also, disconnect your vacumn advance and plug that port while you are drag racing. Can you adjust your carb pump shot to come in quicker, the bog/stumble/hesitation may just be a momentary lack of fuel.

Thomas

I had a 68 Camaro with a 402 that was slightly milder than your build and it ran 13.20's with 4.11 gears. I'm guessing you might get in the 13.20-13.30 range around 100 mph.

Robert, you are too generous (nothing wrong with that really), but how can you say that his Chevelle will only be a tenth slower than your old Camaro?

1) There is ~ 350 lbs difference in weight '69 Chevelle vs '68 Camaro, not in his favor.
2) His 3.31 gears vs your 4.11's, same story.
3) 2" primary on a 396 will give up a LOT of torque vs the more appropriate 1-3/4" primary. Heck, a lot of guys run better with 1-3/4" even on BB's into the 468 cube range.

Actually I would be pleased to hear that he runs 13.3x's vs 13.8x's. Good luck at the track.

Thomas

Originally posted by Bomber '67:
13.8 e.t. @ 99 mphThomas, I've gotta agree on the ET estimate but I believe the MPH is too high...I'm guessing that "2 tons" will run 95-96.

got my timing set... 20 initial and 36 around 3000rpm, it increases to around 38 in the 5000rpm ranges. the car sure feels alot quicker now! graemlins/hurray.gif

you guys will be the first to know how i did...

would 2 inch primaries be good for a 496? because i am planning on a 496 once i could save up enough money to build a shortblock.... flattops and 215s maybe? the UD 288/296 cam with around 10:1 compression maybe?

I didnt have headers on mine at that time,just a small Mellings street/strip hydraulic cam .500 lift range,running thru the exhaust manifods with 2.25 pipes. My sons mild 355 runs 13.50's-13.80's in a truck so I was giving him the benefit of the doubt.

Alan 2" primary is great on a 496, that is exactly what I run: Hooker #2455. After I massaged them where needed (a '65 has less space on each side of the engine compared to your '69), then I had them coated.

Robert, its all good - this guessing business is just for fun.

Alan, good luck on Wednesday. It will mean zip for e.t. improvement, but depending on how your track measures mph if you keep the hammer down for 66' past the timing stripe you could see more mph on your time slip. Some tracks average the speed starting from 66' before the finish to 66' after the finish line. Do you have drag racing experience? If not let us know. Just remember that you want to get off the line without a John Force style burnout (unless you are filming and want the smokeshow). Your 295 street tires will probably hook best between 29 to 32 psi. Avoid the water burnout box with your street tires. Just do a quick clean off spin of the tires before lining up. You may well find that your car will get off the best if you: 1) step on the accelerator 1/2 way on the last yellow as you simultaneously let off the brake (which you were holding with your twitchy left foot), 2) then quickly ROLL (notice I didn't say mash) the accelerator all the way to the floor. Adjust this procedure as needed for the quickest launch with minor wheelspin.

Thomas

I might even go as low as 22-25 psi with air pressure,I got a 1.86 60ft with Cooper Cobras and ran 12.69 with my Chevelle. Try different launch techniques,mine would get sideways on the 1-2 shift though, be prepared.

Thomas

Thanks for the advice... too bad i didnt check the post again before i race! i really could use that launching technique!

i also got new tires because my old ones were rubbing against the exhaust pipe... they are 255/60/15 now.... big O tires...

my first run, i did a little holding the brake, let go, then punch it... shifted at 5500rpm.

R/T .239
60ft 2.642
330ft 6.296
1/8 9.263
MPH 83.3
1000 11.823 (i wish that is my ET... hah)
1/4 14.006
MPH 103.21

on my second run, i step on the brake, and when i see the green, i pushed down on the accelerator 1/2, then 3/4, and floor it when the tach reaches 4500rpm... shifted at 5700rpm


R/T .367
60ft 2.312
330ft 5.971
1/8 8.944
MPH 82.98
1000 11.493
1/4 13.669
MPH 103.35

on this last one, i held the brake, hold engine around 2000rpm, let go, and punched it about half a second after the car started moving... it had traction for a little and when the tach reaches around 3800-4200rpm, it just broke loose and before i know it, the needle was pointing somewhere north of the number 7 graemlins/clonk.gif .. i let go and punched it again, then shifted at 5900rpm.


R/T .264
60ft 2.604
330ft 6.653
1/8 9.669
MPH 82.63
1000 12.243
1/4 14.427
MPH 103.31

my car was pushing out white smoke, i am guessing my headgasket isnt sealing correctly? will be taking my engine apart soon.... AGAIN! graemlins/clonk.gif

this time, mill the heads down a little :D and do myself a little porting...

Cool! I think you might even crack into the 12's if you can get the 60' down around 1.80.

Alan,nice job..low 13's/high 12's w/traction.
Get some sticky tires on there!

thanks for the good words!
looks like the first thing i would need to do is getting that thing to hook up!
I am also thinking of 4.1 for the rear... but how much would that help my ET assuming i could get it to hook?

hmmm...

i am wondering... which of these single change would make me faster... a set of 4.1 gears, or a UD 288/296F10 cam?

The single best mod you could do would be to ditch those street radials and use either drag radials or DOT cheater slicks.
Your best 60 ft. was a 2.3X,imagine hooking and getting a 2.0 or better=low,low 13 second timeslip..get less than 1.9X and you'll be in the 12's
The "hook" is more important than more mods at this point.