Help in finding consistency

[David_D.]

First let me start with my current combo.

I have a 74 hatchback with front bench seat removed and race seat installed. Otherwise, it's pretty much stock interior plus 8 pt. roll bar. Car weighs in at 3380 with the driver.

Engine:
Block: 2 bolt main GM block with splayed billet main caps, 4.030 bore. Deck squared and height set to 9.005. Back of the block squared to the mains, and block clearanced for stroke.

Rotating assembly: Callies DragonSlayer 3.75 stroke crank, Howards Sport rods, JE forged pistons with 13cc dome. SpeedPro molly rings. All balanced, rods stroker clearanced.

Camshaft: Erson solid roller with a gross valve lift of .645"

Lifters: Comp Cams roller lifters

Rockers: Comp Cams shaft rockers 1.5 exh, 1.6 int. Manufactured by TD

Heads: AFR 210cc race ready head, 2.08 intake, 1.6 exhaust valves. Upgraded valve springs, otherwise, straight out of the box.

Intake: Dart single plane intake manifold

Carburator: Holley 750 HP

Headers: Hooker Super Comps

Damper: ATI super damper

Ignition: MSD pro billet distributor, MSD 6AL, Blaster SS coil

13.2:1 compression.

Electric Water pump
Electric Fan
Frame connectors (weld in)

Trans.:
TH350 with a TCI Group 2 converter and manual valve body

Rearend:
8 1/2" Moser spool with 4.10 richmond gears and 33 spline moser axles.
CalTrac bars
Summit adjustable shocks
M/T ET Drag slicks (28" tall x 9" wide)

I'm not looking to go quicker or faster, but I think the ET's vary too much and don't jive with the weather conditions. I'm jetted on the safe side of lean as well.

Currently, I shift at 6800 RPM and go through the traps at around 6500. I'm contemplating a gear change to 4.56 because I feel I'm not opperating in the optimal RPM Range for this engine, but I don't want to turn it to the moon even though it has good parts in it.

Anyone have any suggestions as to making the car more consistent?

Also, here is a link to my combo and Dyno results:
http://www.stevesnovasite.com/forums...ad.php?t=31922

[John_Heard]

Hmmm, MSD 7531 with the slew rate cranked down??

[sunsation540]

how about a 4.88 if the car moves off the line quicker it goes through faster and has less time to recover with that smaller tire make the car very soft fast transfer if nothing else it would be controlable spin.. or 3.73 to keep the mtr off the tire until further under way. how about a multi stage retard hooked up to a delay box cheep! how much is the car moving around 1-2 tenths how much varation.?

[David_D.]

The car varies just under 2 tenths. Sixty foots are all consistent. I'm just kinda brain storming as to how to get it a bit more consistent/predictable.

[sunsation540]

are you using a shift light, tack , if the 60 is consistant it shouldnt move much does it get loose in the middle what are you using for a fuel system? jet extensions.fuel slosh tube?

[David_D.]

Currently, I'm using a tach with a shift light (5" monster tach). The fuel system consists of a BG280 pump, Aeromotive filter, 8AN line from cell to Aeromotive regulator, then split to dual 6AN lines to the 4150 HP750 Holley carb.

My plan as of now it to put a 4.56 gear in the car, and install a larger carb. After doing quite a bit of research, I feel pretty confident that that will make the car more consistent. I will also be working on being more consistent with shifting.

[sunsation540]

ck your time slips 1/8th mph and 1/4 mph do they very.

[David_D.]

Yeah, the 1/8 and 1/4 MPH do vary. The last race of the season the 1/4 MPH varried 3 MPH.