Ladder bar basic

Stick Racing · Post by **Stick Racing** » Wed Apr 30, 2008 6:39 pm

I have a car that seems to turn the tires excessively on the starting line. Its an early Camaro with a ladder bar set up. Its about 3200# with driver. 468 BBC with a stick and 10.5x31 tire. 130# rate rear springs. It usually has mid to high 140 60's. We have the front very loose. Afco double adjustable. Mcleod adjustable clutch with 700# base. The ladder bars are in the middle hole-the bottom bar is now parallel to the body.
I thought about lowering the front of the ladder bar, but I feel this is just a band aid for another problem.

Any Ideas?

lazaris · Post by **lazaris** » Wed Apr 30, 2008 7:34 pm

Do you have a video of the car leaving?

Stick Racing · Post by **Stick Racing** » Wed Apr 30, 2008 8:40 pm

Unfortunately, I do not.

Horndog · Post by **Horndog** » Wed Apr 30, 2008 9:21 pm

How new/good are the rear tires ?
Stiff sidewall or not ?
Dbl adjustable on the rears? What is the extension or rebound setting?
Plenty of travel? Shocks not bottoming out?
How well is the track prep?

sc68z28 · Post by **sc68z28** » Wed Apr 30, 2008 11:58 pm

What is your MPH ?

I'll be watching this thread too.
I feel there is more in my deal also, it's similar to yours.
Also have my ladder bars in the middle, adjustable clutch, 10.5W 28" tires.

What is your first gear ratio and rear gear ?

---Bill.

Ed-vancedEngines · Post by **Ed-vancedEngines** » Thu May 01, 2008 2:38 am

Try moving front ladder bars up one hole and reset pinion angle to appx 3 1/2 degrees down. Because you will now hit the tires much harder, begin with your shocks tighter on the extension.

Ed

Stick Racing · Post by **Stick Racing** » Thu May 01, 2008 8:03 am

Tires were almost new. M/T with stiff sidewall.
Double adjustable. Set soft on the compression and mid range on rebound.
(I believe this is part of the problem)
Plenty of travel> 130# springs.
Track is pretty good.
308 first gear/ 529 rear.
Usually around 133-134 MPH.

sc68z28 · Post by **sc68z28** » Thu May 01, 2008 4:07 pm

Ed-vancedEngines wrote:Try moving front ladder bars up one hole , begin with your shocks tighter on the extension.
Ed

Ed, I am happy to hear you say that raising the instant center "hits the tire harder" I think thats in agreement with Dave Morgans book. A few people have told me to lower the ladder bars for a harder hit, that had me confused ??
I had moved mine UP one hole to the center hole (was 2nd to bottom, of 5 holes) this seems to help mine. At the same time I loosened up the extension on the rear shocks, thinking that it would allow some seperation and plant the tire better. Not true?? I'm at -2.5 degrees pinion.

Stick Racer, Wow, 5.29 gears!! You must be taching near 8K at the big end?
BTW my car weighs 3310 race ready, rear springs are 150#s. I am currently changing all my gear ratios, was 3.25 1st with a 3.50 rear. Going to a 3.09 low, plus my small tire, and not spinning the engine past 7K, a 4.11 rear should work. I leave at 6200 rpm, shift at 6800 or so, and plan on trapping around 6800 @ near 140 mph.

I'm NOT using stiff sidewalls, but I run tubes. In the pic below I had 11.7 lbs of air and they seem to be working.
---Bill.

norton · Post by **norton** » Thu May 01, 2008 5:05 pm

sc68z28 wrote:
Ed-vancedEngines wrote:Try moving front ladder bars up one hole , begin with your shocks tighter on the extension.
Ed

Ed, I am happy to hear you say that raising the instant center "hits the tire harder" I think thats in agreement with Dave Morgans book. A few people have told me to lower the ladder bars for a harder hit, that had me confused ??
I had moved mine UP one hole to the center hole (was 2nd to bottom, of 5 holes) this seems to help mine. At the same time I loosened up the extension on the rear shocks, thinking that it would allow some seperation and plant the tire better. Not true?? I'm at -2.5 degrees pinion.

Stick Racer, Wow, 5.29 gears!! You must be taching near 8K at the big end?
BTW my car weighs 3310 race ready, rear springs are 150#s. I am currently changing all my gear ratios, was 3.25 1st with a 3.50 rear. Going to a 3.09 low, plus my small tire, and not spinning the engine past 7K, a 4.11 rear should work. I leave at 6200 rpm, shift at 6800 or so, and plan on trapping around 6800 @ near 140 mph.

I'm NOT using stiff sidewalls, but I run tubes. In the pic below I had 11.7 lbs of air and they seem to be working.
---Bill.

do you spray that car or is it n/a?

Stick Racing · Post by **Stick Racing** » Thu May 01, 2008 6:21 pm

sc68z28 wrote:
Ed-vancedEngines wrote:Try moving front ladder bars up one hole , begin with your shocks tighter on the extension.
Ed
Ed, I am happy to hear you say that raising the instant center "hits the tire harder" I think thats in agreement with Dave Morgans book. A few people have told me to lower the ladder bars for a harder hit, that had me confused ??
I had moved mine UP one hole to the center hole (was 2nd to bottom, of 5 holes) this seems to help mine. At the same time I loosened up the extension on the rear shocks, thinking that it would allow some seperation and plant the tire better. Not true?? I'm at -2.5 degrees pinion.

Stick Racer, Wow, 5.29 gears!! You must be taching near 8K at the big end?
BTW my car weighs 3310 race ready, rear springs are 150#s. I am currently changing all my gear ratios, was 3.25 1st with a 3.50 rear. Going to a 3.09 low, plus my small tire, and not spinning the engine past 7K, a 4.11 rear should work. I leave at 6200 rpm, shift at 6800 or so, and plan on trapping around 6800 @ near 140 mph.

I'm NOT using stiff sidewalls, but I run tubes. In the pic below I had 11.7 lbs of air and they seem to be working.
---Bill.

Most likely turning this engine higher than it needs to be, but the tires are the 31 inch M/Ts. Through the traps at about 7500.
This car also has 5 holes of adjustment at the front of the ladder bar. It is currently in the center hole. I have yet to check the pinion angle, but I believe it is close to -2.
It just seems to spin the tires excessively at the hit. I have the clutch as soft as what I feel will still work. Less base and counter weight is a possibility.
Just looking for some input. Thanks.

sc68z28 · Post by **sc68z28** » Thu May 01, 2008 8:16 pm

norton wrote:
do you spray that car or is it n/a?

I do NOT spray at this time. Mine has been getting 9 psi boost from an F1 Procharger.

Stick Racer, the day the above and this pic was taken my 60' were going away, I was 1.44 and 1.46, not spinning. The data logs showed that I was not getting the clutch to lock up ( it was to loose ) there must be a pretty fine line on our clutch adjustments. I'm still learning that part too.
Our clutches (mine is a 7" two disc) are so different I do not think we can compare any of that.

A good forum for adjustable clutch questions is
http://www.umtrnorth.com/forums/default.asp
Post your combo in the Clutch Tech area. There are some very knowledgeable people there, see what they think.

I expect to see you there, or are you already a member?

---Bill.

Stick Racing · Post by **Stick Racing** » Thu May 01, 2008 9:05 pm

sc68z28,
There is no problem with the clutch. When I say I don't want to go any lower on the base, it is because I don't want to slip the clutch and spin the tires. Yes, I said that right. If you don't 'hit' the tires hard enough, the clutch will slip and spin the tires. Sounds like its not possible, but it happens. Been there.
I haven't had tuned under the car yet. I am just looking for different opinions on what to do to this car to get it to hook with alittle more consistently. I have a stocker with factory type suspension (Youngblood clutch) and another good friend has a 4-link car (Ram clutch). I have a handle on these cars. Never tackled a ladder bar yet.

Im alittle more east of the UMTA guys. You'll find me at www.prostickracing.com. Friend with the 4 link car is that yellow Chevelle on top. That would be me with the white Camaro just under. The car i'm working on is also in our group, but no pictures yet.

norton · Post by **norton** » Thu May 01, 2008 10:11 pm

i didn't ask the spray question to be a smart ass

was just wondering about the mph and the weight...if you were doing that with a n/a 383 i was going to do some serious brain picking

sc68z28 · Post by **sc68z28** » Thu May 01, 2008 10:18 pm

Stick Racing wrote: I have the clutch as soft as what I feel will still work. Less base and counter weight is a possibility.
Just looking for some input.

Andy, sorry

I misread the statement above. Looks like you would be someone who could help me with clutch set up. Got my dual 7" from Rob also. With his help I'll figure it out.

BTW your 69 is great looking car, and #2 in the points, that's a job well done.

Hopefully we will get more input on set up for a ladder bar car, I fell like I have hyjacked your thread.

Sorry again. I need to just sit back and follow this and stop interrupting.

---Bill.

sc68z28 · Post by **sc68z28** » Thu May 01, 2008 10:24 pm

norton wrote:i didn't ask the spray question to be a smart ass

was just wondering about the mph and the weight...if you were doing that with a n/a 383 i was going to do some serious brain picking

No problem here, I understood your question, you just did not catch the Procharger part in my sig.

---Bill.