thunderstruck507

iTrader: (18)

TRACK RESULTS:

DA 534ft
slight head wind
mid 50s and sunny
first day track was open, fairly slick
race weight approximately 3750# with me in it

1.71 60ft
4.89 330ft
7.57 1/8
91.61 1/8 mph
9.92 1000ft
103.26 mph
11.94 1/4
111.39 mph

1-2 shift: 6600rpm
2-3 shift: 6500rpm

325/50r15 MT drag radials

12.6afr according to my lc1
log shows 25.5*
cutouts were closed


I think the lower 60ft (off idle launch) is a good sign the car picked up some low-mid grunt. I tried the rest of the day to launch off the converter but traction was hard to find all day.

Thoughts?

thunderstruck507

iTrader: (18)

http://youtu.be/X0M9y8t42SM

01 ss vert

iTrader: (1)

I feel like your 1/4 MPH is a little low compared to your 1/8th of 91+MPH. anyone else? I figured you would have been closer to 113, 114 MPH? I wish I could 60', but my 10-bolt scares me.

thunderstruck507

iTrader: (18)

That is exactly what I am thinking.

Possible reasons myself and others have come up with are the headwind, the slightly shorter 2-3 shift point, and the fact my car has the aero of a brick. I might still need to lean it out a tad, I would really like to compare my lc1 a/f reading to another just to be sure its close.

But I did really hope to gain more in the 1/4 with the new heads/cam over my old cam only setup.

It gained 1mph. Previous best 230/224 cam only was 12.24@110.38

01 ss vert

iTrader: (1)

Well a guess a few factors come to play here:

Large Front end
Head wind
Gear paired with the auto (what gear are you crossing the traps in, and at what RPM?)

I can see those being a few MPH

69LT1Bird

iTrader: (1)

Go here and play with the calculators:

http://wallaceracing.com/Calculators.htm

MyFirst01

Nice pass.

How was Mo-Kan? I've only been once to watch, but thats where I will be racing this spring. Track prep good and all that?

thunderstruck507

iTrader: (18)

Had some people tell me I might try starting at a higher tire pressure next time because sometimes on heavy cars the MTs like a few lbs more than you would think.


Track prep was not very good but it was the first day they were open. But don't ever expect good prep at the Fun Drags...too many street tire cars tearing up the rubber. Especially trucks.

Z28SteveA4

iTrader: (16)

congrats man i've been watching your cars progress since i first saw ur posts. Chevelles are hads down my favorite car especially 70 chevelles. Good to see you finally made it but your setup should have way more in it then that. The 1/4 mile mph is low as stated before it should be atleast 3mph faster. Take it back when shes not windy

z28241

iTrader: (13)

OP , Outside air temps along with track temp play huge in what tire pressure to run. What tire pressure are u running? I dont think ur 60' and run was off, given ur race weight and 3.42 gears and tall tire..

69chevelleSS

Well done

thunderstruck507

iTrader: (18)

Got an 85mm GM maf I'm going to put on and tune for and route my filter to draw air that flows under the bumper instead of pulling from the engine bay.

Also switching from 7.4 pushrods to 7.35 to reduce my preload from ~.124" to ~.074". From what I found in my searching the Vortec lifters I have been using are specced by GM to run .040-.085" preload. May or may not help free up some top end, guess we will see.

thunderstruck507

iTrader: (18)

Must have measured wrong on the pushrods, car ran and sounded like crap with the shorter ones so I put them back. A little over 1 3/4 turns from zero lash to 22 ft lbs.

Couldn't get rubber couplers to install the maf so I just routed the filter down to where it could catch air flow from under the car instead of pulling it from the bay.


I did go back to the track anyway. Ran 17# in the tires and it hooked a lot better. DA was up to 1340ft. Ran a new best of 11.92@111mph 1.69 60ft 7.54@91+ mph 1/8th.

Also ran a 11.93 and another 11.94 as it got warmer out. One of those passes was just under 112mph.