The 1947 - Present Chevrolet & GMC Truck Message Board Network

The 1947 - Present Chevrolet & GMC Truck Message Board Network (https://67-72chevytrucks.com/vboard/index.php)
-   Racing and high performance (trucks haulin more than hay) (https://67-72chevytrucks.com/vboard/forumdisplay.php?f=60)
-   -   weighed truck...help (https://67-72chevytrucks.com/vboard/showthread.php?t=285183)

bigjimzlll 03-28-2008 05:16 AM

weighed truck...help
 
My truck..127" wheel base weighs 3448 with my 265lbs in it. Do to the LWB and cab design I'm real front heavy.
Here are the corner weights:
LF 1080
RF 944
LR 744
RR 680

I can add ballast to either side of the rear with out much trouble.
It's a ladder bar rear/ A arm front with coil overs on the corners.
Where do I start. Can I adjust the ladder bars to move some weight? Do adjusting the coil overs help?

I'd rather hook more consitantly than worry about ET.
540BBC alky dominator(new this year) Dyno'd 850 on gas
TH400/brake 5800 stall 4.86 with 32x16 slicks

djracer 03-28-2008 06:15 AM

Re: weighed truck...help
 
That is about how bad mine was when it had the steel heads. I haven't checked front to rear since I swapped some stuff around. Can you move the motor back at all?

bigjimzlll 03-28-2008 07:03 AM

Re: weighed truck...help
 
naw..it's in my lap now. I can't pull the distributor with out surgery.
I'm seriously concidering putting a 100+ pounds in da rear

Super73 03-28-2008 08:32 AM

Re: weighed truck...help
 
Jim,

When I first started my truck had almost the same weight bias yours does (was 59% / 41%).

I'm sure most of this has been done, but I am at 55/45 now with:

Front draglites vs 7" steel wheel
215/75/15 vs 275/50/15
No front bumper or frame horns that held them on
Swapped from power steering back to manual
Moved the batterey to the rear
Removed heater

Since that weigh in, I also filled one of my tailgates with scrap steel I had laying around. Must have put 100lbs in it. Not sure if I need it yet, but it will be with me on the 5th..

The next few things I am planning:

Removing factory radiator support and inner fenderwells. I will be making a radiator support from 1/2" square tube and angle.

Possibly cutting out the factory front crossmember and installing a 2x3 or 2x4 .120" wall square tube to replace it. Then add some 1/4" plate and gusset it for the lower control arm.

Need to buy a glass hood.



If it is easy enough to add ballast, do it next time out.

Where do you have front weight to shave?

What do you have for front springs / shocks?

How about your rear coil. Where are the coil over adjusters sitting (Bottom, Top, Middle)? Can you send a picture of it at ride height?

Does your truck have a rake? Sit level? Higher in the front?

Any video's of it launching?

bigjimzlll 03-28-2008 08:41 AM

Re: weighed truck...help
 
No rake now. Rear shocks are DA koni's set ab out in the middle...a little less. Fronts are QA1's the adjusters are loose and the springs are compressed. There is no where to remove any more weight.. MustangII front end, glass hood, gutted core support

Super73 03-28-2008 09:00 AM

Re: weighed truck...help
 
Are you saying the front spring adjusters are screwed all the way down or up? Do you know the length and rate of the front spring?

Doesn't your truck have a coil over in the rear? Where is the adjuster, top or bottom? Do you know the length and rate of the rear spring?

bigjimzlll 03-28-2008 10:10 AM

Re: weighed truck...help
 
front springs are 400lbs at 7" and the adjuster is down. The rear springs are 14" 175lb with the adjuster about half way up

71Dragtruck 03-28-2008 10:15 AM

Re: weighed truck...help
 
Wonder if a glass front clip would save you much? Did you ever go to glass doors?

Kinda funny mines 4128lbs. without me in it and I'm trying to get it closer to 4000 and your not happy??? LOL

bigjimzlll 03-28-2008 10:41 AM

Re: weighed truck...help
 
I gutted the doors and went with lexan for windows. Their pretty light now. I can't see how a glass front would loose that much.
The LWB, I think throws the bias off more than a SWB.
I think I'm going to add around 140lbs of ballast to even the weights on the rear and help the bias.

djracer 03-28-2008 03:12 PM

Re: weighed truck...help
 
Where is your battery? I have 2 16volts at the very rear of the truck. I figure atleast its usefull ballast! I agree on leaving the stock sheet metal on the front. I don't mind my glass nose but I hate my glass doors. 1 fits decent the other fits like $hit!

bigjimzlll 03-28-2008 05:40 PM

Re: weighed truck...help
 
I have 2 optimas out back.

Super73 03-29-2008 09:27 AM

Re: weighed truck...help
 
Jim,

One thing I learned from the Dave Morgan book and his DVD is that you want the lightest front/rear springs as possible. Then you crank your adjusters up as far as you can. This stores a lot more enery.

Is your front spring 7" static or is that the length of it compressed? Reason I ask is I have a set of 350lb 14" long Hals sitting at my shop. I'd be happy to let you give them a try and I'm not using them now.

You also have a 4-link in the rear. Can you try to adjust it the center of gravity upwards.

If you draw an line from side view, IC is where the bars intersect. If you move the IC up, you are going to add antisquat. It's going to slow the front raise down but want to hit the tires in to the ground harder. So when you add AS, loosen the front some after making a couple passes and see what that does for you.

If your IC is too much it's going to hit the tires too hard, then it will want to bounce back up. If your 60's get worse, then try lowering your IC. You can normally tell if you have to high a IC as the tires will hook for the first 3-5ft then let loose.

If your toping out your front end travel, that might be a problem too. As it comes up on the limit and hits, then it has no where to go but down, again causing the tires to unload. But this is normally with in the first 5 feet.

Take some white shoe polish and draw a line at you valve stem. Have someone video from the rear quarter where you can also see the front tire. Have your videoer get as close as they can with out a zoom. Zooming makes things jittery.

I'm no expert, as there is sooo much to learn about this stuff. Just trying to pass on what I have learned / been taught.

bigjimzlll 03-29-2008 09:35 AM

Re: weighed truck...help
 
the front springs are 7" out of the box. They are almost compressed with the weight on the truck. The rear us ladder bar and once I get the weight squared away I will locate the CL and find the IC to calc. antisquat.
I ordered dave Morgans book and CD's last night.

For now I am going to equalize the rear weights..
I always pull the front wheels for 15-20' or so...that was b4 alcohol...so we'll see

Super73 03-29-2008 09:49 AM

Re: weighed truck...help
 
Wait, your wheels up for 15-20' ???

What are your 60's?

What happens afterwards? Are you unloading the tires?

When you say you want to hook more consistantly, can you give us say 10 of you recent passes?

My first guess is you need to tighten the front up a little.

bigjimzlll 03-30-2008 03:20 AM

Re: weighed truck...help
 
I moved some weight and added a little ballast. Here are the numbers. To even the weight on the rears can I perload the right ladder bar some?
LF 988
RF 916
LR 766
RR 728
This puts me at 3398 going down the track with 56% on the front and 44% on the rear. A lot better than it was

regan wilson 04-01-2008 05:56 PM

Re: weighed truck...help
 
Jim I had to really work with my front springs to get mine to scale right . It will have to real heavy on the drivers front to ever get the rear were it needs to be . With your ladder bar setup you will need to be at least 20 lbs heavier on the right rear .

PA-IndianRider 04-02-2008 08:42 AM

Re: weighed truck...help
 
Quote:

Originally Posted by Super73 (Post 2650631)
Jim,
.....I have a set of 350lb 14" long Hals sitting at my shop......

Was wondering how tour truck "sat" with the larger 350lb 14" SPRINGS in the front??? (how much fender to tire clearance)

I am in the process of building (collecting parts stage) a '70 C10 SWB stepside .... old school gasser look. Currently it's dropped 3" in the front & 5" in the rear giving it a noticeable lowered look with a "level" stance.

I have been debating what to do with the frontend. After months of debating.... I am STILL debating...ha!!!

Have looked into the classic "straight front axle" which is the way to go for "looks" but not necessarily for streetability (it's going to be street/strip).

Also thought of using larger/heavier rated springs to do the job (big block 3/4 or...).

Not necessarily looking for a "sky-high" frontend stance but more like a "higher in the front than in the rear look".

Thanks....

Super73 04-02-2008 11:09 AM

Re: weighed truck...help
 
Well the 14" 350lbs springs sit about where the new 17 3/8 240lb springs sit. I'll have some video of it this next weekend.

PA-IndianRider 04-02-2008 06:17 PM

Re: weighed truck...help
 
Quote:

Originally Posted by Super73 (Post 2657216)
Well the 14" 350lbs springs sit about where the new 17 3/8 240lb springs sit. I'll have some video of it this next weekend.

I will be looking forward to seeing it.... still have plenty of time to look into possible ways to do what I "want" to do.

Weather here in Pittsburgh is improving... will be getting out the "hacksaw" soon.... chopping the roof 5" is 1st on the list of things to do.

Thanks.... John


All times are GMT -4. The time now is 10:10 PM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2026, vBulletin Solutions Inc.
Copyright 1997-2025 67-72chevytrucks.com