rebuilding after the crash

October 12th will be the next time out. Union grove wi. Let's see if I can get that elusive 200 mph.

 

It was a anything goes event. If there is 80 percent minimum nitro in the tank it's good. They don't care if you put a load in your golf cart.
The semi finals had one dragster. One funny car. Two fuel alterds.
The rings are fine. Mains fine. Crank fine. We have been having trouble all year with that cylinder trying to make it happy. I think we are good now.

 

That little project is done. The coupler connects the Bruno to the lenco when the gear set is removed. The other pic is all the guts that were removed. They will be bagged and boxed up. They will go in the trailer in case I need them. It's the same ratio 1.25 as what's in the trans. Perfect.

 

To fit the tires to the car there will be some surgery taking place today. The inner wheel house will get cut off and moved inboard several inches. I have the room to do it. I might have to change the radius on the outside of the car also. I will see how it all fits.
Here's some tech info. The car had a 11 inch rim. The tire was 13.5 inches. This made the tires sidewall bulge out. At speed the tire grows and stands up. With this setup it causes the tire to narrow as it grows. I have pictures of this happening. It's normal for this to happen. In my case without a wing driving the rear of the car down I won't ever get traction.
The new rims are 16 inches wide. The tires will be 14 W. So it will have a 15 inch contact patch. The sidewall will be stretched inward. This slight taper won't allow the sidewall to grow in the middle. The contact patch won't change. It will also stiffen the sidewall. This helps a heavy car.
Tires are a huge tuning aid. Big growth tires change the gearing. They help get mph. The new tires are larger diameter so they will make up for the lost growth.
Another benefit to all of this is the rear width. The new rims have a different offset. They will bring the tires in several inches. It will help get the tires in the groove of the track better. The old setup had me riding the outside edge of the groove It will also help keep the car more stable.
Tires seem like a simple thing but they are far from it. The old tires were fine for what we were doing. With where we are going it's just not going to work out anymore. Now we can tune up the engine and really make it fly.

 

I got this pic yesterday. See how the tire grows as it spins? See how narrow the contact patch is? This is why I'm changing things up. I hate to remove the bear claw wheels.

 

I agree, but sometimes compromises must be made in the name of progress.

 

When the tires have more serious stick will that make wheelie bars necessary?

 

It's all a big compromise. Changes are being made in the name of safety and speed. Rules start coming into play also.
The four link controls the hit. It's set up to pull the tires only a few inches. In Havanna I hit a 1.12 60 foot with the wheels barely off the ground. They touched down by 60 feet. The tire change is mainly being made for down track stick. There will be some starting line benefit as well.

 

Doing man stuff today. Cutting into a painted finished car. Moving the tires inboard required some modifications.

 

Watching a video of drag slicks during a burnout is a real lesson on how much they grow when they start speeding up.

Dumbass question for today: Do drag slicks need to be balanced? Opinions on the internet vary. The most common version seems to be that they do need to be balanced, but static balanced (on a bubble balancer) not dynamic balanced (on a rotating tyre-shop machine).

I can understand not wanting to run lead wheel weights (in case they become a missile at speed) but unsure if the stick-on variety (inside the hoop) is acceptable.

Asking for a friend who bought a bubble balancer but is now not sure on whether to balance his FED tyres

Cheers,
Harv

 

Tires need to be balanced with rim also circumference need to be taken to match set of tires, out side diameter,
You want 0-1/16 no more then 1/8 inch to match a set.
Buy ply slicks,,,
Drag radial do not grow as much very little if any,
I tried to zoom in on size of the M&H tire to see size , if that tire size made in a D-R, No tire change needed , would stay flat over the B-P slick ,more stable & grip , But No tire growth, changes to Lenco ratios needed ,
World Record on D-R 5:70ish 1/4 last time I checked .

Rules , I do not know if a certain speed or ET is passed if B-Ls are require over screws?
Add more screws ,


Bead locks in Last 20 years On Wide Rims /Wheels also have become critical ( for B-Ps) the tire will grow so much without the bead lock and Even screwed the tire will grow so much pull the tire off bead of rims/wheel .. typically cars / vehicles running
4:00 -3:80 1/8 & faster & 6:20 & faster in 1/4

 

I was involved with a 5.30/270 car and we mounted slicks in the shop and used a bubble balancer, adhesive backed lead weights inside the hoop and we also added 200mph tape over the weights as a protective measure. In my ten years on the crew I never saw a problem with that method.

 

At 200 beadlocks are required. I spin balance all of my wheels. I use tape over the weights. I have never lost one. The size is a 13.5W. So that's really about 14 plus inches. The circumference is 109. They will taper in on the 16 inch rim. Less bulge in the center at speed. 7 5 lbs of air to start.
No drag radials for my car.
Most tire manufacturers only sell slicks in pairs. They are matched sets for roll out. After mounting I always run a tape over them to double check. If one is small it's inflated to 25 lbs and set out in the sun. More air is added as needed.
If a car that has always gone straight and suddenly starts pulling to one side the tires should be measured.
I needed 5x5 centers for the rims. They had 4 75 centers. They won't be available until late november. One of my crew guys told me his dad had just replaced a set in his wheels. He told me to give him a call. Sure enough 5x5. They are now mounted to my rims. Sometimes you just get lucky. The tires were ordered. Should arrive Wednesday. We just might get one more hit in before it snows. Thus weekend was a rainout.

 

Thanks gents. I'll bubble balance the slicks, stick-on weights inside the hoops, and tape them.

Very much appreciate the responses - thankyou for sharing your knowledge.

Cheers,
Harv

 

So ordered the 200mph tape, put the bubble balancer together, lubed the pivot point and had my first go at bubble balancing. Wheels are brand-new 15x10 American Racing torque thrusts, and brand new M/T 28" slicks.

Some trial and error shows the bubble balancer is not the most accurate device in the world (then again, this is only a 10-second 6-banger nostalgia FED, not a 4-second fueller). I can see when a tire is unbalanced, and can also see the point where it becomes balanced (or at least near-enough). The near-enough point is where I can tilt the wheel and the bubble will stay wherever I put it - in theory it should tilt back to centre, but there appears to be enough friction in this thing that it is not accurate (will not tilt) down to the last poofteenth of an ounce.

Next dumbass question: how much balance weight is reasonable on a racing slick? One wheel is OK (I think) though it needs 4¼oz to balance it. The other wheel methinks is way off, as it needs 10½oz to balance it. Gut feel is that the first wheel is good to go (stick the weights on, tape it and be done), though the second one wants the tyre dismounted, rotated 180 degrees and remounted before balancing again.

Appreciate your views.

Cheers,
Harv

 

That is always something to try, maybe not 180. Doesn't hurt to spin the wheel first just to check it.

 

10-1/2 oz is abnormal. That's over 5/8 of a pound. I would spin it to make sure that it is round and doesn't have a bunch of run out. And if that's good, I'd rotate it on the rim. If you can't get it a whole bunch closer, I'd send it back.

 

That's where all the high tech stuff comes into play. Road force balancing etc. About 40 years ago Indy Car teams used Snap-on portable balancers and were running speeds over 200mph. Admittedly, the tires probably were hand selected and prequalified before the teams even got them. But the point is, when you start getting further away from perfect tires (and wheels for that matter) you need to figure out where the imbalance is coming from. You won't get that with a bubble balancer.
@Harv In your case, I would definitely get those wheel tire assemblies balanced on state of the art equipment. If you need more than about 4 oz. because of the tires, I'd send them back. If the wheels are out a bunch, get them in balance first. Not every shop can or will do this as it can be time consuming.

 

Cast wheels can be way out. A machined billet wheel is always right on. Tires can vary.

 

It was a major thrash to get the big tires on in less than a week. All i can say is the new tires work! So smooth so straight. Too bad the coil went away. It would have been 200 based on the down track times.
Today's fun is moving the tires inboard. This will keep the tires in the groove without the wide track. It will also look better.
The frame jig we are using has been building chassis since the 60s. Major surgery is needed on the body. The shocks will get moved in board. Wheel tubs need to be fabricated. The rear-end needs to be narrowed about 5 inches. The axles need to be sent out to be re splined. It's a major undertaking but we will get it done. We are preparing for the first week of April. That's the first nitro chaos in Dallas tx.

 

Howard knows his stuff. The execution will be flawless. I will have to stop by and “approve” the progress!!!

 

Stop by we will be working through Monday. Call first we might be making a wells bros run.

 

The opening on the side of the car needed to be bigger. A plug with a center was put in the axle. A adjustable rod with a marker was used to get a even line. Just swipe the panel. The paint was removed. A plasma cutter removed the metal. Some sanding finished it off. We needed some extra room. When the tires grew on the burnout it they lightly touched the body.

 

I like the direction you are going, but I may be a bit biased.

 

Were done for tonight. The wheel openings are done. The right side shock mount is made. The anti sway bar links were modified. With everything in place I have 2.5 inches between the body and tire. So at maximum growth it can go 5 inches bigger on the circumference. The larger tires raised the car 3 inches. We made new shock mounts to drop it back down to its original ride height. With the body down and the tires moved inboard it's going to look cool.
The drivers side shock mount and narrowing the rear-end are on tomorrow's list of things to do. View attachment 6227940

 

I should mention everything being done to the car will still allow it to be returned to the street.

 

No stopping you, Brian! Just an observation; those four link bars look really short. Does that affect how the car drives down track? I guess they had to be to fit the space with the seating.

 

They are a standard length bar. Four link bars don't have a impact like ladder bars. Ladder bars are usually around 32 inches. The bars do control the way it drives down track. Most fast cars are what we call rear steer. There's a few ways to do it. I have my crew man get in the car. I then adjust the upper left bar so the bolt slides through. When he gets out of the car I don't care how big the hammer is the bolt won't come out.
The other way is to have the car on jacks. The rear end hangs down and a full flat on the bars is put in.
Shortening the bar or making it longer steers the back of the car. You can make the car go right or left. With a good chassis the two ways I explained should be very close. I have always used the first. Good question.