I am running a 454 ’70 Chevelle w/ EFI, T56 6 spd, and 4.56 gears. I ran @ the strip the other day w/ 9”x 30” slicks w/ the following results:
60’ – 1.64
594’(?) – 7.342
1/8 mi ET – 7.824
1/8 mi MPH – 93.38
¼ mi ET – 12.033
¼ mi MPH – 114.62
With a 60’ and MPH #s like above, I would think I would run quicker. The car did run 116.7 mph last year ( I loaded the wrong calibration this year), but still ran 12.0s. I know my driving technique needs some improvement, but I didn’t think these passes were that bad. Any ideas?

I'm far from an expert, but it looks to me like the car is laying down on the front half of the track. Your 1/8 mile time seems slow for your 60' time and MPH. I'd expect to see your 1/8 mile time somewhere around 7.4 - 7.5. Are you over-reving or missing any shifts? Clutch slipping? Just for comparison my 60's are around 1.85 and my 1/8 times are 7.83 @ 89.5.

Good 60 ft and good mph. I was in the same situation as you and finally this year after getting my 60 fts into the low 1.6s I got my first 11 second pass. I know there are guys here running 11's with 60 fts in the 1.7's but I guess it all depends on where your car makes it's power. What kind of 60 fts did you get when your speed was 116.7?

Jeff

Chris, isnt there an anomoly between his 1/8 mph and 1.4 mph. I mean I run 92 in 1.8 and 117 in 1/4. Look like it laying down at the top end???

I think you're on the right track. Remap that EFI. They're mint street deals, but not much beats a Holley carb at WOT.

If its a Holley unit, Doug Flynn is the guru. You might email him direct. He'll get it spot on and get you your 11.

Gene,

1/8 mph to 1/4 mph looks okay to me. I'm thinking a grunt motor with 4.56's in a heavy Chevelle is going to pick up between 20 and 25 mph. His 21 mph seems to be in the ballpark. I'm still thinking the problem is in the first half. Bruce - do you have any 330' times? Can you post your complete combo?

"Remap that EFI. They're mint street deals, but not much beats a Holley carb at WOT."

Watch it there Gene, I might have to post some dyno sheets from some EFI/Carb shootouts. smile.gif

I'd definately say there is a performance issue between probably 100 and 400 ft as your 1/8 MPH is there but the 1/8th ET isn't but the 60' is decent.

How many times are you shifting ?

Do you shift fast ?

I thought I shifted fast, but I'm not so sure anymore. :rolleyes:

594?...594 feet is the first light for calculating 1/8 mph...10% of 660' is 66', 660-66=594'. The mph is calculated with the tme between the 594' light and the 660' light. Never saw a timeslip give an ET for 594' though.

Doug, thanks for chiming in. Forgive me, I know not what of what I speak, never having played with one.

Do you think the issue is in the fuel map?

Yeh,it is a grunt motor(detailed below). I put the 4.56s in to give me a little more twist to reduce loads on the trans w/ sticky tires, but I guess I end up w/ the same issue using tall tires. I have 325-50 Drag Radials I run on the street and have wondered how I would fare w/ those and more conservative gears.BTW,last year's 60' times were 1.62-65 range w/ 116.7mph. The strip I was at has no 330' times.
454 + .125" (481)
KB Hyperutectic flat tops (9.1:1 comp.)
Merlin oval ports (2.25&1.88 w/angle mill-109cc)
Custom EFI w/ Performer RPM (shoulda went single plane)
228 & 234 @ .050" .558" & .564" lift 114 L.S.
made 420 #-ft @ 2000rpm & 470hp @ 5500rpm(and still climbing) w/ Holley 750 and old S.Port heads years ago.
This car was featured in Super Chevy Feb2000
Thanks All

Guessing by the incrementals I'd say it had to do with a shift recovery or shift. He mentioned he loaded the "wrong" calibration file so that could have various effects depending on what was wrong. The 1/8 to 1/4 mph gain isn't too abnormal for a car not pulling super hard on the top end but I'd expect 1-2 mph more for a stick car.

My guess your pulling 2 shifts before the 1/8th. Though with those gears and a kinda low RPM motor, I wonder if your over reving it at times. But I think your losing a few tenths from shifting. Just a guess though.