Need help with truck 60'

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I have never been able to get my c10 to leave like I feel it is capable. It's had 315/60/15 Et streets on it up until this past weekend. Tried 14-18psi with them. Tried a 29.5 11.5w hoosier slick on a 12" wheel. Truck has never 60' quicker than 1.67 on the radials. On slicks it went 1.63 with 11psi in the slicks first pass. I used the recommended shock settings from qa1 for my qa1 double adjustable rear coil overs 200 lb rear springs. Tried a few different settings with radials but none helped. Comp engineering front shocks always at 90/10. I sprayed it with a 100 shot on progressive at 50% out of the hole and went 1.55 60'(quickest ever prior was 1.60). I have moog 6082 front springs. Adjustable trailing arm mounting points. 4800 stall. 4.11 gear ford 9" with spool. I have some videos I'll try and attach from last weekend. On 100 shot progressing out of the hole it spins and hops and rear goes right. Will front shocks help this? Rear? Both?

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https://youtu.be/ChI3E4AHgak
Motor pass 1.63 60' 7.14@96

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https://youtu.be/5P5aVnlAcvM
1.55 60' 6.68 103 mph 100 shot 50% 0 seconds and 100% at 1 second

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https://youtu.be/e_oLYRYQjos
1.54 60' 6.70@ 103 50% 0 seconds 100% at .7

[dustin72]

Try lowering the pressure in the Hoosiers. I'm running the same exact tire and size on mine and would get it to dead hook on 8.5psi. This was on an airport runway prepped with VHT. It hooked so well I spun the diff housing on the axle tubes. My truck also likes to hop to the right on launch. Running stock suspension with Lakewood drag shocks and adjustable front trailing arm mounts. My 60fts. Are similar to yours. 496BB all motor.

[hotrod 80]

First pass you can see the tire working , Just doesn't seem like there is much transfer or rear separation to me . Seems stiff to me .

Second pass you were deep . Took a big bite into prestage and as soon as you moved it was staged . Take your time you have 7 seconds and it is longer than you think .

Last pass it spun

[Super73]

I see:

First pass - Very little weight transfer but still hooked
Second pass - It spun with little weight transfer
Third pass - It spun with little weight transfer


Comments/Questions:

I feel your spring rates are too stiff both front and back.
-I can't find the advertised spring rate on the moog PN, but they are not known to make springs with a lot of stored energy (think long light spring rate)

-200lb rear spring on a coil over?
-Can you provide the QA1 shock part number
-What length spring?
-Where is the ride height adjuster nut on the shock body, towards the bottom of the thread or towards the top?
-Where is the rear shock in relationship to travel? Centered or 75% out?
-What are the "recommended" settings? How loose/stiff?

-What is the height of the front lower control arm bolt?

-Any idea what the truck weighs both front and back?

[dinnut]

Super 73 I'll give you as much info as I can while I'm at work today. I can get the rest of the info tonight.

200 lb springs on the coilovers. Qa1 part # DD501
I have the springs setup with very little preload. 12" long spring.

truck weighed 2500 front 1500 rear less than a year ago and not much has changed since then.

I need to verify rear shock settings tonight.
I can measure lower control arm bolt tonight. It's on a 2.5" drop spindle.
I had a front spring prior to this that sat on the bumpstops and recently switched to these to get it off the bumpstops. This was a long travel high stored energy spring but could not get the ride height right with it.

[dinnut]

Moog #6082
Spring rate 722
2400 lb load
10" install height
13.18 free height

[dinnut]

Rear shocks have 18 settings per knob. Currently between 12-16 from full loose on compression and 4 clicks from full loose on rebound reading over my notes I have at home

[Marv D]

the optimum 60' time = 0.12 * 1/4 mile et + 0.17

so first we have to equate your 1/8 mile ET to 1/4....
(1/8 ET + 0.22)/ 0.655 = 1/4 ET



7.14 @ 96 equates to a 11.23

60' NA of 1.52,, remember that is OPTIMUM for a well set up vehicle.

The hosed pass
10.53 quarter
1.43 sixty

I think you have some great guys offering advice here,, so just offering some targets to work towards.

[Super73]

It is nice to see someone bring their homework to class

Originally Posted by dinnut

truck weighed 2500 front 1500 rear less than a year ago and not much has changed since then.

I had a front spring prior to this that sat on the bumpstops and recently switched to these to get it off the bumpstops

-Did this spring change put you at your desired ride height? (10” compressed height)
-I am assuming the front of the truck came up a little with the spring change? If so your front/rear weights likely have changed some with the ride height change in the front. You should re-weigh the truck to be sure. Remember, you want the weight with you in the truck.

Originally Posted by dinnut

Moog #6082
Spring rate 722
2400 lb load
10" install height
13.18 free height

-Wow.. 722lbs is extremely stiff. No wonder there is zero weight xfer.
-Did a little math for you based on the weights you provided above along with the assumption your ride height with a 10” compressed spring height is what you desire.
-18” spring = 280lb rate
-17” Spring = 320lb rate
-16” spring = 375lb rate

-You will get little movement with a loose shock/stiff spring because there is no stored energy
-For your weight/power level, I would probably steer you towards the 18” spring provided you can compress it 8” without inducing coil bind.
-CE 3-way adjustable shocks are not great when it comes to control, they just aren’t very adjustable and you can’t clamp the explosively fast extension you’ll see from a long/light spring.
-I suggest a shock change to help control the above recommended springs.
-I recently switched to a stiffer spring as my Rancho 9000’s could not control the 17.75” 170lb spring that was in my truck. I plan to complete my MII front end at some point and did not want to buy $1,000 shocks twice.

Originally Posted by dinnut

200 lb springs on the coilovers.
Qa1 part # DD501
I have the springs setup with very little preload. 12" long spring

Rear shocks have 18 settings per knob. Currently between 12-16 from full loose on compression and 4 clicks from full loose on rebound reading over my notes I have at home

-Looks like the shock has a total of 5.375” of travel.
-You mention there is little preload but is the shock in the middle (2.7” extension / 2.7” compression available)?
-How much available preload do you have?
-Taking a wild guess that your rear spring is compressed to 9.25-9.5” at ride height?
-I want to suggest a different spring, but need the info for above.
-For starting bound I would suggest 8 clicks from the loosest (middle)
-For starting rebound I would suggest 4-5 from the tightest

Did you get a chance to measure the height of the rear LCA bolt?
-This will affect instant center, shock setting may be different depending on antisquat percentage.
-Without knowing center of gravity height, we will be guessing antisquat percentage.
-But a lower IC will have a lower AS percentage

[71Dragtruck]

Originally Posted by Marv D

the optimum 60' time = 0.12 * 1/4 mile et + 0.17

so first we have to equate your 1/8 mile ET to 1/4....
(1/8 ET + 0.22)/ 0.655 = 1/4 ET



7.14 @ 96 equates to a 11.23

60' NA of 1.52,, remember that is OPTIMUM for a well set up vehicle.

The hosed pass
10.53 quarter
1.43 sixty

I think you have some great guys offering advice here,, so just offering some targets to work towards.

Well damn Marv, mine works out exact, my work is done LOL.

[Super73]

Marv, what is wrong with my turd? My 9.41 dead hooked a 1.35.. Far cry from the 1.29 your equation comes up with. I know a TH350 1st gear could help my 60' provided I could hook it. But I like the glide..

[71Dragtruck]

Originally Posted by Super73

Marv, what is wrong with my turd? My 9.41 dead hooked a 1.35.. Far cry from the 1.29 your equation comes up with. I know a TH350 1st gear could help my 60' provided I could hook it. But I like the glide..

Just turn all the kits on full at WOT.

[dinnut]

Truck was weighed with me in it. I can reweigh the truck this weekend. The last springs I had were with stock spindles. They were long and had a lot of stored energy but I couldn't get the truck off the bumpstops. These are a stock replacement spring that I used with the drop spindle hoping the truck would work better.
I may try 175 lb Rear springs and play with shock settings and tire pressure this weekend before I order the parts for the front end.
I don't have the truck at my house right now...I need to go measure the lower control arm bolt and shock travel after work tonight didn't get a chance to last night. I built adjustable brackets for the mounting points and they are in the middle setting right now. I tried the lowest setting but it had too soft of a rear spring and bad shocks at the time and it just blew the tires off on the street.
Where could I get those front coil springs you mentioned from?

I had ordered some 175lb rear springs to try. I'm Gonna Order Some Front Shock As well.
How do you feel about qa1 front shocks? They make one version with stiff compression and you can adjust only the rebound and then the regular single adjustable that adjust both at the same time

[Marv D]

Shaun, if it's dead hooking you probably need more converter or gear.

My pig of a truck usually makes the equation,,, 1.5 sixtys with a 12 second pig,, BUT.. with 34" of slick on the ground too, 5.43 gears and a stock 2.43 1st gear TH350 gear.
I put more motor in it, kept the same 4800 stall 10" converter, down to a 4.30 gear and it went 10.9's with a 1.44 sixty.

The Nova I screwed with for a long time before I found it HATED dead hooking. We fought with 4link and double adjustable shocks trying to MAKE it dead hook,, Probably wore the motor out enough it was mission accomplished LOL, but 60' was off 6-8 hundredths.
A buddy of mine Roger Copeland said his car (although a clutch car) would 60 better if he got about 1 turn of the tire at the hit.. HU???? Welp we started using high speed HD video about that time and went to moving the shocks 1 click at a time trying to screw up the launch to get at least 1 turn of the tires,,,,, On fresh tires managed to pull out a couple of 1.27-1.29's compared to the 1.3x it usually went. John put a few of the launches on youtube and low-def but you can see it dead hook, then hit the wheelie bars and turn the tires about a turn, then hook again. That's where I got the best 60 the car has ever done. Don't know if it's the extra tire speed, torque curve, or simply off the 'flash' of the converter,,, but it worked for me. Will it work for you rdrag radials,,, ????...

[regan wilson]

I dont think you should go down to a 180 spring. I changed from a 250 to a 225 and it helped me alot. It enabled me to control the hit with the shock and stop the porpoise affect of me going on the T stop. I know these two trucks are different but some rules still apply.

You need to keep your shock within its operating limits. When I went with the 225 on mine it shortened the loaded length of the shock by around 3/4 inch. It is shorter than it should be by a little bit. If you get it too short your at the risk of bottoming out the shock. The end result will be blown seals.

My rear weight is around 1700 if that helps you.

[dinnut]

I have a set of 250lb springs, a set of 200lb on the truck and just ordered a set of 175. Should I get a set of 225 to try as well?

[Super73]

Regan,

I went from a 130lb to a 110lb in mine. I must say I like it.

[regan wilson]

What is your rear weight? And what is the shock length?

[Super73]

1400lbs..
12.5" compressed - 19.5" extended

Spanner is turned up almost all the way plus I have a 1" spacer between the spring and spanner.
Shock has roughly 75% compression available.
With a 57/6.75" ic it squats

I am going to try changing ic to be a bit shorter and higher in hopes to separate the chassis with the radial. Likely going to need to remove the spacer in the shock to allow a higher percentage of available rebound.

[dinnut]

I'm gonna try and work towards getting my 60' down to where it needs to be. Gonna try new qa1 front single adjustable shocks, try a lighter rear spring and readjust rear shocks and see what that does for me.

I'll get some measurements off the truck Saturday when I unload it off the trailer

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Any idea where to find some better front springs?

[Super73]

Call landrum springs..