Amazing what new tires can do

Bolted on a new set of Hoosiers over weekend. Wow. Old ones had about 110 passes. The car had slowed a little, mainly in the 60'. Was wondering if it was maybe an engine issue.

Wrong, it was just tires. Lately my car had slowed up with the 60's in the 1.23-1.24 range. The tires had some wear holes showing, I guess the sidewalls were gone.

New set of tires, no other changes, weather very comparable. Bam.....1.180--to 1.185 over 6 passes on a track that wasn't the best by any means. It's got more in it, this was with my 5.30 index setup in it.....Got one of those races in a few weeks. Last 3 passes..5.311, 5.312, 5.310, I figure about 100 more rpm on both the leave and shift should put it dead on.

cooler track temps help also lol

goes to show you can run them till the holes are gone on a fast car.......

nice 60' David

David I was thinking of switching to a hoosier tire very soon they were the only ones that would talk to me on the tech line and give me some advise. I am now running a 33x15x15 mt stiffs and are not happy with them at all. The hooked real good for about the first ten passes then they crapped out. Now they won't even pick up rocks on return road. My best 60's were 1.26 on the brake but the car was all over the track. Can you tell me what part number hoosier tire you use and a good air presure to start with. We run the same alston chassis and ladder bar set up that you do. Just trying to get a handle on this car before it puts me in the the mental ward! One more thing can you tell me what the rear ride height is from the top shock hole to the center of the axle housing is on your car? Thanks

I'll have to measure the ride height when I get home.

The tires are Hoosier # 18370 15x33
Running them at 8 lbs. Work well.
Before these I was on the Hoosier 14.5W x32
That was a stiff sidewall. It was the same width as the 15x33 but is - little shorter and 2" less rollout. Ran those at 7 3/4 lbs

Hoosier told me that the 15x33 is not a true stiff sidewall like the 14.5w
But .... It is a "little" stiffer than normal. "all" there 33 and larger tires are stiffened a little they said.

Thanks for the quick reply, those werer the ones that hoosier had suggested. I have been chasing my tail tryin everthing else but changing the tires. It is a shame a set of 700 dollar tires are done in with only about 50 passes and most of those with my pump gas 429.

BUZZ BUZZARD wrote:Thanks for the quick reply, those werer the ones that hoosier had suggested. I have been chasing my tail tryin everthing else but changing the tires. It is a shame a set of 700 dollar tires are done in with only about 50 passes and most of those with my pump gas 429.

you have other issues if the m/t dont work.i run the same 15x33 stiff and and have at least 100 passes on them.i run 6-6.5 lbs in them without tubes and 60' under 1.20 on a good track leaving at 4800.i think i also have the very same ladder bar setup David has.what rear shock you run?

I am running stange single adjustable aluminum rear shocks. 12 inch shocks alston eliminator ladder bar and stut car. I am not doubting that something else could be wrong with the car. I have tryed so many different things, rear springs, front spings, shock settings front and rear. I just need a good starting point to regroup and try to make this thing run straight and hook. I bought this car from a very good friend while he was on his way to meet his maker. The car was a brand new chassis that was done at a race car chassis shop in texas or mississippi. I have no one left alive that knows much else about the construction. The car was in a state of partial completion when I purchased it. I have no experience with this type of car exept for the last couple of years that I have been trying to get it right. If anyone has some baseline sugestions on chassis setup it would be greatly appreciated. Here are the specs. The car has about 90 passes on it now.

1986 t-bird
alston eliminator chassis
alston ladder bars
diagonal link
stange single adjustable aluminum rear shocks
stange single adjustable aluminum struts
rear springs-95,110,130,150lb sets
front spring strange hypercoils 325 lbs
mt 33x15 stiffs 8psi lower air presure car sways bad on top end
557 bbf tfs streets
ford c6 full roller setup probrake
411 rear gear
5500 9inch convertor done by Paul Yerger spragless
best et foot brake 9.28 152 1.29 60
best et transbrake 9.28 144 1.26 60

any suggestions?

A couple of things stand out to me.

1. Single adjustable rear shocks. You really need double adjustables once you dip much lower than what you already have. My car was a handful until I started playing around with the rebound settings on my Koni's. Moving the compression around (what your shocks have) didn't really seem to matter one way or the other.

2. The C6 trans. The C-6 is good no doubt, but combine it's low first gear with ladder bars and it's gonna stay violent on the launch. Either use a timing retard to pull a BUNCH of timing out on the launch or better yet....A glide. The car will be quicker and a lot calmer on launch.

^^^ X2

Converting over to a glide would be the easiest but I have a pile of c-6 stuff and now is not a good time for me to dump three grand in this car. I may try to go to a 3.70 or taller gear since the motor likes to be shifted between 6300 and 6400. One of my main problems with the car now is that it sways around alot on the top end. Untill I can get this thing to drive straight I don't really want to go any faster.

the first thing i'd get is good double adj. shocks.with ladder bars its about keeping the car from hooking too hard.more power makes the bars hit the tire harder so the extention or rebound on the shocks needs to be under control. i run strange dbl's and run the extention 2 clicks from full tight.the c6 is gona make it hard to deal with,having that 2.46 low gear like David said.the top end problems can be a frontend alignment or air under or over the car upsetting it.i only run 1/8 mile so i cant be much help with that.what launch rpm do you use? do you run wheelie bars?

No wheelie bars. Leaving on 3500 pill. Left one time on the convertor at 5500, it was like being in a train wreck. It hit so hard knocked my leg back off of the throttle. I was looking at the strange doubles but didn't know if they were any good. I had the bars on the top hole in the front bracket. I don't know if it needs to be there or on the bottom one. I will try both. The car weights 2780 with driver and has 48% on the rear and 52% on the front. I think after the suggestions given I will get the shocks and go to a taller gear to settle it down on the launch. I would really want to make the c-6 work in this car, I think it can be done Frank runs much quicker with a c-6. It might take more work to get it there but it should be worth it. I am always rooting for the underdog, I guess the c-6 is my underdog. I appreciate all the advise and will try to give you updates on the progress.

BUZZ BUZZARD wrote: I had the bars on the top hole in the front bracket. .......... Frank runs much quicker with a c-6.

Start off with the bar in the lower hole. It will hit the tires easier.

Yes Frank runs very quick with a C-6.....with a 4 link.......Ladder bars gonna be more violent.

My plan of attack in order would be :
Lower ladder bars in front, set them up neutral. Add preload if the car goes one way of the other.
put different rear gear in it, a 3.70 will still give you a 9.10 starting line ratio, My car at is at 8.22 with a 1.80 1st gear X 4.57 rear
Double adjustable rear shocks, I like Afco
timing retard
if all that fails.....bite the bullet and put the glide in...this winter you could sell the C-6/converter and offset some of the cost.

Thanks a bunch for the input. I now have some choices of gears to compare to since I now know your (David) starting line ratio. A 3.3 to 3.4 ratio would put me in the same ballpark as your t-bird, NOT et but starting line ratio. What do you think about 7.822 ratio that would be a 3.18 rear gear. The reason I asked is my engine probably makes it power at a lower rpm then your monster, with the smaller heads that I run. I found some used nascar gears from roush for 99 bucks. That could be a cheap gear just to try a different ratio. The ratio they have closest to what it may need is a 3.18. Shocks will be changed also I like the stranges for the two knobs are located on the bottom in easy reach.

On a ladder bar the bottom bar should ideally point directly at the CG (center of gravity) when it is in the center hole on the front brackets (most have 3 holes some have 5 and even seen a couple with only 2) raising the bars in the front bracket should hit the tire softer and lower should shock the tires harder. Buzz it sounds like you may need to baseline the ladderbars and ride height.

Find the CG and if your brackets have 3 or 5 holes in the front set the ride height so as the bars would point at the CG if you drew a line forward when in the center holes. This is the nuetral setting if it hits the tires too violently raise the bars one hole, if it spins initially go down one hole.

Most high power ladderbar cars need some preload does your car have an Anti Roll Bar?

No anti roll bar. I don't think you could call it a high powered car. It is just a tfs street headed 557.

Around 700+hp? I noticed you stated your leaving on a chip but it goes 5500 on the converter, if so you are getting a run at the converter and can cause some traction issues.

It never went on a dyno. Went 9.20's at 153ish foot brake. Horsepower???????

I have only made 4 passes with this motor on the transbrake. First pass left at 5500 with no two step. It was very violent to the point that it knocked my foot off the gass very abruptly and made for a very ugly pass. I will creep up on the pill once I can get the handling fixed. This convertor liked to be transbraked at about 4800 with the small motor.

bigblok2000ranger wrote:On a ladder bar the bottom bar should ideally point directly at the CG (center of gravity).......

I think you might be referring to the point where the neutral line crosses the vertical line down from the center of gravity, and not the center of gravity (C/G) it's self. It would make for a fairly steep upward ladder bar angle install on the average drag car if you tried to point it's ladder bar's bottom bar centerline directly at the C/G. It might be easier to do on a nose heavy long wheelbase truck (because of the C/G being farther forward). But hard to do on the average passenger car platform having the C/G sitting at/around camshaft height off the ground & for/aft C/G distance sitting somewhere in the 50-50 to 58-42% of the wheelbase on say a car with around 100 to 108" w/b.

Too many people bad mouth ladder bars, when in truth it is possible to go damn fast on them. And it should be pointed out that there really is no reason to use an anti-roll on the "average" ladder bar car since the complete ladder bar/rear end housing assembly it's self acts as if it was all one giant anti-roll assembly. The only reasons you might want to ever use an anti-roll on a ladder bar car is if (A) the ladder bar spacing installation is very, very narrow/close together (thus increasing the chance for body roll to happen), (B) you have very, very long ladder bars, (C) you have "Pro Mod" power to work with and have Pro Mod sized slicks (again forcing a narrow ladder bar install), or (D) if the rear housing, or ladder bars, or chassis design are weak enough that they twist or flex a lot under launch loading.


Some basic ladder bar initial setup points I usually use.....

The car needs to be sitting on the ground (or on setup blocks) with the full race weight compressing the suspension (car race ready & loaded with water, oil, gas & driver's weight) before any adjustments are done.

First the rear housing's centerline is checked to see if it's square with the car's nose-to-tail centerline. This needs to be done because you can't always use the car's ladder bar crossmember as a starting point to measure from. Sometimes even a brand new jig built car does end up with a ladder bar crossmember a little off just from all the welding. And assuming a used/abused race car is still dead nuts perfectly square is just asking for trouble.

Then with the suspension still compressed to ride height choose the the front L/B hole that makes the ladder bar's bottom bar sit either at/around level with the ground, or pointing down hill at a slight angle. Raising the front ladder bar pivot point hits the tire harder, lowering it hits the tire softer. Don't confuse a harder "hit" with a harder "hook". Sometimes a slick will actually hook harder with a softer hit if it was being over worked (hit too hard) in the first place.

At this point with the suspension still compressed check the rear coil over's center-to-center (C/C) installed heights. If at desired ride height, the shock's C/C installed height measurement falls within the specs the shock maker calls for, then the shock's current spring rate is probably in the ballpark of what is needed. If a car on the ground needs the shock spring seats spun way up a bunch to reach the correct shock C/C installed height measurement and the desired ride height both at the same time, then the springs are probably little too weak. If the spring seats are spun all the way down, and the car still sits higher than the desired ride height, while at the same time the shock's C/C measurement is also too tall/long, then the springs are probably too stiff. If the car has adjustable shock mounts do not use them as a crutch for an incorrect spring rate choice, get the correct springs instead.

Next I usually set the U-joint's driveshaft-to-pinion operating angle (aka pinion angle) with the driver side bar, and set the static side-to-side preload with the passenger side bar. The side-to-side preload's full range can be plotted out, & static starting point set manually all by hand without the use of any scales just by paying attention to what effect spinning the ladder bar's adjusters/turnbuckles has on both front ladder bar bolts.

After setting the pinion angle with the driver side bar (and locking it's adjuster jam-nuts) I adjust the passenger side bar (removing static weight from it) until I can easily slide/remove it's front bolt in/out. At this point the passenger side bar is technically at "zero preload" (at/around 100% of the static "at rest" weight is on the driver side bar). Then I slowly adjust weight back into the passenger side bar (and keep count of how many adjuster/turnbuckle wrench-flat turns there are) until the suspension finally reaches the point where the driver side bar's front bolt now becomes loose & slides in/out with ease. At this point the driver side bar is now technically the "zero" static preload bar & the passenger side bar is the one at/around 100%. The total number of passenger side bar adjuster wrench-flat turns it takes to go from one extreme to the other (zero passenger to zero driver) is the total amount of static side-to-side preload range the car has to work with. So now that you know the total range from one extreme to the other you can use that to find the theoretical "center" or "neutral" static preload setting by cutting the total number of wrench-flats in half. Lower HP/TQ ladder bar cars might do well & launch straight at/around the center/neutral side-to-side preload setting. But as power increases more & more some static preload might need to be removed from the passenger side bar to keep from launching to the left as increased engine rotational torque can increase the launch loading of the passenger side slick, improving it's traction, & driving the car more & more to the left.

A faster ladder bar car with enough power to run in the 5.00 - 4.80 range might need a side-to-side preload setting at/close to zero static (at rest) on the passenger side bar to offset the big rotational torque loading numbers generated to go that fast. It's kinda like what's needed for a 4-link with anti-roll at that same power range since a ladder bar setup it's self acts much like a giant anti-roll and loads the slicks in a similar fashion while fighting body-roll.

Then the initial rear shock extension & compression valving/dampening choices are made depending on how much power the car has to work with, and if it's got wheelie bars. I have never been a fan of starting at 100% full-loose or 100% full-tight on any shock valving choices on a new car or unknown combo. When starting from scratch with no prior data I usually start with the extension valving set somewhere around 50 to 70% tight, and the compression valving somewhere around 40 to 60% tight.

I had a response typed out but I musta forgot to hit submit lol. Dave pretty much summed up what I was gonna say but with a lot more detail.

I dont consider mine high hp, but it has no arb, and the left rear wants about 30 more pounds than the right, driver in the seat race ready....... I do have a very stiff housing and ladderbars etc, not the mail order stuff.

very good info to get me started on getting this thing set up.

richter69 wrote:I had a response typed out but I musta forgot to hit submit lol. Dave pretty much summed up what I was gonna say but with a lot more detail.

I dont consider mine high hp, but it has no arb, and the left rear wants about 30 more pounds than the right, driver in the seat race ready....... I do have a very stiff housing and ladderbars etc, not the mail order stuff.

That's where mine is on preload and down one hole from neutral setting, Dave did bring up good point I am used to working on trucks with ~104-108 wheelbase with ladderbars. Its pretty easy to point the lb at the cg on a truck. The harder/softer thing has me a little confused now though, I have had to go down one hole on all 3 of my lb set ups or it would just spin down one hole it dead hooks. Live and learn maybe it was shocking the tires too hard.