My 82 Silverado

[team39763]

Here's a video we took today.  It was a bit wet outside, but the streets were dry enough to drive on so I decided to take her out.  I attempted a burnout to clean off the tires, but I suck at it....I need a line lock.  Anyway, we got a shot of my usual launch method.  I stall it up to until I feel a little kick(3500rpms), then I let loose.  I noticed that back doesn't squat down, but the front does come up.  I hate the way my truck takes off so mild and tame...I think my next truck build will have a bigblock. 
Let me know what ya'll think of it.
 

[VileZambonie]

What's your actual stall speed?

[team39763]

I have 3500rpm converter.

Here's another one.  Again, you can see I have a weak launch when I do the usual.  So I'm gonna try a different method that Lorne told me about.  Maybe my launch method is what caused me to have bad 60ft's at the track?
I didn't stall it up as high on this one, but you can tell I didn't put my foot into it until it after it got going.

[Bowtie Bomber]

Eh, sure sounds nice though. 

Mine stalls up to 2.5k RPM, the tires squeel all the time.

[VileZambonie]

Team, do you have a tach? If so do you know how to do a stall speed test?

[team39763]

Yes, I have a tach, but it reads slow at times.  I've had my tach/shiftlight set for 5500rpms, but somehow I hit my 7000rpm rev limit before the shift light came on.
  No, I don't know how to do a stall speed test, but I'd like to know.  I take back what I said about stalling it all the way up to 3500, I get it to 3000.

[team39763]

I tried launching with Lorne's method, but I'm not sure if it made much difference.  My truck is just slow off the line no matter what I do.  I think I'm gonna need spray.  2nd gear is great, third gear is ok, but first just straight sucks.  I think I do come off the line harder with Lornes method since I managed to smoke the tires pretty good the first time I tried it.  But either way, my truck is just slow off the line.  I don't understand how guys in ECSB's[new body style trucks] are cutting crazy low 60ft's and they weigh 1000pounds more, have a bit less power, and aren't using any suspension mods. I think there's even a few cutting 1.9's on 20's.

[Captkaos]

How many leafs are in the rear of the truck?
What Rpms are you bringing the motor to before you launch it?  If you are starting at 1200 that is your problem.  Rev it to about 2500 and then hammer it when you let off the brake.  If you got a 3500 stall take it to 3000 and see it if will hold.  If you are launching at 1200, you are barely off idle.

Scratch that, saw the first one at 3500rpms.  It sounded like it was struggling and then started moving on when you started rolling.  Are you going full throttle immediately when you get off the brake?  Have you tried a higher launch rpm?  How high in rpms can you get the motor before it starts walking foward?

What happens if you just nail it from a stand still?

[HAULIN IT]

Team, What gears/trans do you have? What are you getting for 60 ft. times? What do you have for tires? Did it spin at the track off of the line or just drive away? I was  getting 1.71-72 60ft. on ET Street Radials for comparison, 700 trans/3.40 gear. Lorne

[team39763]

CaptKaos: I have the full amount of leafs(stock).  Yeah, I tried smashing it from standstill...it hesitated then just fried the tires.  1200 took off with no problem, but as you could see, it was still slow.  3000rpms were about the same as 1200.  No, I don't go full throttle right away....maybe that's part of the problem?  3000 is as high as I've tried to get it, I'll try higher tommarow.

Haulin It: I have 456 gears and Rebuilt TH350 with shift kit.  My 60ft's were in the 2.1-2.25 range.  I have ET Drags @15PSI.  At the track, it didn't feel like it was spinning at all(even with the open diff).  At the track, I would stall it to about 2000 and hammer it on green. 

[HAULIN IT]

Team, What was your MPH in the quarter? Did I see somewhere you posted that it has gone high 12's? Or is this a   " I beat a guy who says his... story?"  Why don't you go straight to the floor all at once on the launch? Is this when you get the bog? If you have a non-posi rear & 4.56's & it doesn't spin something is wrong! Either the engine has no snort, the converter is too loose, the carb problem, something is a miss. You need to figure this out before you start spraying it, you'll just have a slow truck on spray or worse, you'll hurt the engine. Start with the basics & move on from there. Lorne

[team39763]

My MPH was 107.  Yes, I ran 12.8@107.  I guess I don't go straight to the floor because I'm trying not to smoke the tires.  Off idle to full throttle is when I get the bog.  It's a posi rear, but at the time I raced at the track, it was only spinning one tire during burnouts.  Since then, I have drained and replaced the fluid and also adjusted my traction bars...now the posi works everytime and I lay two identical patches of rubber.  I'm pretty sure I can tune out the bog, but I don't know what else to do after that.  I'm gonna try a few different launch techniques tommarow.  I understand that I have a small motor in a big heavy truck so it takes some effort to get going, but my truck just seems crazy slow off the line.

[HAULIN IT]

Well the 107 MPH is in line for the 12.80, the engine is making some HP to get it to 107 & considering that you should be .4-.8 quicker in the 60ft. the truck recovers good to go 107. It sounds to me, like your thinking, you need to work on the first 60 ft. If the converter was way too loose you would not get to 107 either because it would not be able to pull in high gear. What carb do you have? Is the bog right when you floor it or does it start to go & then bog? Do you know how much your truck weighs? And how tall are the tires?

[smitty77]

In the first video you can hear the motor stumble a bit as your brining it to 3000.  Is this you doing that or the truck all by itself, and what was the RMP when it happened?  If it's the truck, I think that may be the source of your problem.

Nice ride though.  The motor sounds real healthy and I bet with a little fine-tuning and some practice with your launch technique you can post something in the low 12s.  Just for giggles, what was your reaction time at the track?

Smitty

[team39763]

Haulin It: I have a Holley 950DP(I know it's huge, but it runs 100% better than with my 750).  The bog happens when I get on the pedal too quick and then it goes...Maybe I need bigger squirters?  My truck weighed 4000 with 450pounds of driver and passenger, so I'd say it's around 3550-3600 without us(I weigh 220).  My tires are 28" tall.

Smitty77: That was me trying to bring the rpms up.  It seems like it struggles around the lower rpms, but when it gets to 3000, it seems happy. But it's not built for low RPMs anyway - large single plane intake, 3500 stall, huge carb, cam, so that's expected right?  The bog usually happens if I don't stall it up at all, so I'd say it just off idle. I have a good video of it...you'll have to excuse my wife(if you listen closely you can hear her)...LOL.  My reaction times were in the .8's.  The first run I had was a 1.5 because the truck bogged on the line, but I still ran a 13.0@105 and I believe the 60ft was 2.1 on that run.

Here's the backroad run where it bogged off the line.