[Mike S]

I am trying to figure out why my mph seems low for my et, I attached a time slip from Saturday. The run after the one attached was a 1.325 60' but had to lift. The one attached was all out.
I have the car set up to go 10.0. Weighed the car Saturday and was 3400lbs with 280lbs of ballast and me. I have 4.10 gears with a 30" tire and cross the strip at 6600 and a 5000 stall converter launching with a trans brake at 3800.
Do you think I should look at a bigger cam to get more top end? Or maybe a 3.73 gear?

My car is on the left B153

[J.C.you]

Retard the timing a couple degrees if u want bigger top end. Probably b more consistent too. That’s what we did bracket racing to soften the hit and mph better on other end.

[Keith Seymore]

Originally Posted by Mike S

I am trying to figure out why my mph seems low for my et, I attached a time slip from Saturday. The run after the one attached was a 1.325 60' but had to lift. The one attached was all out.
I have the car set up to go 10.0. Weighed the car Saturday and was 3400lbs with 280lbs of ballast and me. I have 4.10 gears with a 30" tire and cross the strip at 6600 and a 5000 stall converter launching with a trans brake at 3800.
Do you think I should look at a bigger cam to get more top end? Or maybe a 3.73 gear?

My car is on the left B153

Got him on the tree. Well done, you.

I have a couple observations:

1) It looks to me like your car 60 fts really well. My 10 flat runs are in the 1.40 - 1.42 range (foot brake). So you are making good time on the low end of the track and flattening out on the top end.

2) Light cars take less HP to make good ET. Conversely heavy cars take more HP, which I think results in higher MPH at the end. I'm at 3820 lbs with me in it (and would give my left [insert body part here] to be at 3400 lbs). My car is closer to 134mph and maybe as high as 136 to go 10 flat.

3) I don't think it matters. If you are hitting the ET you want then who cares about MPH, other than to compare your runs to yourself. I wouldn't bother comparing my MPH to other folks (...although I just did... )

Just my $0.03.

K

[steve25]

Please post up the details of your motor.

[Mike S]

I am taking 2 degrees out in high gear. going from 36 to 34 in third gear. Having one time shot and going right into eliminations doesn't give you any runs to play around with the car.
I am going to check the timing this week to make sure it is still at 36.

[Mike S]

455 .060 over. E heads that flow 330 at .700. comp it 12.0-1. Victor intake. 850 Holley. Ran faster with the 1050 but decided to use the 850 to slow it up instead of restrictor plates. Cam is a solid roller 282/286 at .050, .660/.662 lift. ground on 108 and installed straight up. 2" headers into a 3.5 x pipe and dyno max mufflers.

Car has all stock suspension.

[Stan Weiss]

Originally Posted by Keith Seymore

Got him on the tree. Well done, you.

I have a couple observations:

1) It looks to me like your car 60 fts really well. My 10 flat runs are in the 1.40 - 1.42 range (foot brake). So you are making good time on the low end of the track and flattening out on the top end.

2) Light cars take less HP to make good ET. Conversely heavy cars take more HP, which I think results in higher MPH at the end. I'm at 3820 lbs with me in it (and would give my left [insert body part here] to be at 3400 lbs). My car is closer to 134mph and maybe as high as 136 to go 10 flat.

3) I don't think it matters. If you are hitting the ET you want then who cares about MPH, other than to compare your runs to yourself. I wouldn't bother comparing my MPH to other folks (...although I just did... )

Just my $0.03.

K

This what I have found also. When a car 60' really well, it will normally not run its best MPH.

Stan

[J.C.you]

Personally I’d shoot for around a low 1.4 60’ with ur stock suspension setup. I think you would be a lot more consistent. I like the pull on the big end too, rather than feel like the rubber band is tight, hehee

[Dragncar]

Fuel system ?
Not sure if I would mess around with the cam and gearing if you have a winning bracket race combination.
There have been a few 455s blowing up with .275ish cams lately. You have a stock block that is happy as it is.
I could not hurt to launch at 34 deg and go down to 32 deg in high gear and see what happens.
You could drop to 3.73s but thats a lot of work and not cheap these days.
But your car 60 foots so well as is and I have always found out, drag racing is all about the 60 foot. Do it well and you have the best chance of winning and you are always going to have a good ET with a good 60 foot.

[Skip Fix]

I have the opposite problem in my IA Camaro 10.3 et, soft 1.53 60 ft but 132.5! New looser convertor and trans in just waiting for the 100 degree days to be gone to try it out -and a way longer drive since out Houston track closed.

[aaronman]

Your 1/4 mile et is slow for your 1/8 mile et. A 6.31 1/8 mile is a 9.90 et on most NA bracket combinations I have seen. (6.31 x 1.57). Recommend you look at gearing, converter & fuel delivery.

[cgeise]

what kind of slip do you have on the top end in the converter

[Mike S]

i have a Mallory 250 pump with 1/2" fuel line, I have 6.5 lbs at the finish line.

I just calculated the slip to be 10%.

[AG]

My car is at 134.3 mph for 10.00 et with 6.8% converter slip using a Mallory 140 fuel pump with 3 psi going across the line.

[Mike S]

I messed up on the convertor slip. It is 7.5%

[MUSLCAH]

My friends 2007 stock corvette ran a 10.81 @ 130.02....For what it’s worth

[PontiacFan428]

Got this formula from DCI unleashed. I'm actually surprised no one else has brought it up.

1320 ÷ 132.23 = 9.982

Looks like your MPH is too fast for the ET

[johnta1]

Try this calculator, it uses the most common 'rules' for converting ET's and MPH's.

ET Calc

Almost exactly his ET slip using different choices.

[Stan Weiss]

Originally Posted by MUSLCAH

My friends 2007 stock corvette ran a 10.81 @ 130.02....For what it’s worth

What that tells me is he had a very soft / slow 60' time.

Stan

[Stan Weiss]

Originally Posted by PontiacFan428

Got this formula from DCI unleashed. I'm actually surprised no one else has brought it up.

1320 ÷ 132.23 = 9.982

Looks like your MPH is too fast for the ET

Yes you want the et * mph to be in the 1320 range.

Stan