Having some old racing story swap seesion with racing buddy. He ran TA/Fc when we where running TA/FC and TA/D. After lots of bs and sories from those too fun days. Conversation turned to tire shake and working around it.

Short of it. There was two schools of thought.Take power away and add power to spin thru shake. I have always added power and eliminated or lessened the shake. He use to remove some power.

My reasoning points where.
1 you can see dip in criveshaft spd right before shake.A point Ralph Gorr and I spent hour os so talking with Newberry about one day.
2 you can drive a spinning car but not a shaking one. Although not best for a bracket car, it works great for heads-up.
3 Think about shake in burnout. Is it at beginning when you break tires loose? Is it in middle when tire is spinning at its least traction? Is it at end when tires is almost hooked up and right before it does hook?

With clutch car(no ignition control allowed at the time) I always added clutch and/or power. Normally it was gone or lessed.If less but still there I just added more. Not saying only way,but I figured idea is to put as much power down as possible and taking power just not natural. Kind of like why lean and lean a car when idea is to make it burn as much fuel as possible to make max horsepower.

Always been open ended conversation as to cause and cure. Lets hear some views and approach to getting around it.

I can tell you only my experience. Small block turbo. My tire is stuck at first and if it is going to happen, I drive into it as the power comes on. So delaying the power in any way usually avoids it for me. Also what has helped me is to pull tire pressure down. But....the cost with that is that even when not when hitting the power hard, the tire is a little unhooked, and the car is slower. But less prone to shake.

I am using a 15" 3080 mt tire. The bubba's are less shake prone than this tire is.

Question Bucky,

Since you are still eliminating shake by making it spin thru it. Have you ever tried more power at point you had shake? Not sure if extra power can be had with your setup. I know with turbo you can usually control boost amount with bypass and most can control timing some.

You are doing about same things I di but different way of getting there. Hey always curious and if was a cat I would gone thru all 9 lives.

I have always added power or raised the launch RPM.

Different ways to shake.

The tire has variable friction vs slip ratio. Slip ratio is just wheel speed over ground speed. The friction curve has two peaks with a dip in between as you increase slip ratio.

Most under speed shake is from approaching the first peak while running out of power to climb over it. Sometimes you can add a little power and ride it back down. Some combos can get over the peak but then you have to drop back through it at some point. Or you can pull a little power and stay in the flatter part of the curve. Once you get over the first peak it’s hard to get back under it without a little shake on the way down. I think this is what most current alcohol cars refer to as the shake zone. If ground speed is low, it’s easy to drive right past the second peak and go up in smoke.

The second peak was always there but nobody really knew about it or how to get there until a few years ago when a couple fuel funny car guys figured it out by accident. That was around the time they started laying the headers back too. I don’t really think the two gains were related but it was those two discoveries together that led to the huge jump in performance.

I doubt if there are many other type of cars that could hit the second peak (not enough power to produce that much wheel speed at a high enough ground speed that the window opens up), but there was this one T/S type car I used to watch years ago that I think found it by accident. Nitrous car that ran 4.30s with sub 1.0 60s. Car would haze the tires at the hit. No race pak. I asked them once, how do you do that, how do you carry that much wheel speed. They looked at me kinda funny like I was slow or something and too me “how can it be spinning, it’s going .960???” Track came in on them one night and it shook so hard it broke the trans in half.

Actually best runs we ever had on Top alcohol car was when rear tires had strong haze coming off them for first 30 feet. By strong I mean lot told me I smoked tires..90 60 foot times disagreed. At time that was strong even for fuel cars which where at best .87 on very strong runs. Ok by I ,I mean the car and me as crew chief. We found out that any good run almost required some smoke off tire. Fastest yet,most consistent probably not but did not care if fast. If we didn't smoke tire some at hit it was normally lousy run with shake.

Again this was clutch with lenco car and differs from automatic results I am sure..
I posted this for opinions and not disputing any.I am stating what I have experienced and appreciate that of others. It is meant to be fun and educational post.

Answering your question to me.....with a small block turbo combo there is only so much to get in the first half second if you aren’t getting silly with bump boxes etc.

quote:

Originally posted by wideopen231:
Actually best runs we ever had on Top alcohol car was when rear tires had strong haze coming off them for first 30 feet. By strong I mean lot told me I smoked tires..90 60 foot times disagreed. At time that was strong even for fuel cars which where at best .87 on very strong runs. Ok by I ,I mean the car and me as crew chief. We found out that any good run almost required some smoke off tire. Fastest yet,most consistent probably not but did not care if fast. If we didn't smoke tire some at hit it was normally lousy run with shake.

Again this was clutch with lenco car and differs from automatic results I am sure..
I posted this for opinions and not disputing any.I am stating what I have experienced and appreciate that of others. It is meant to be fun and educational post.

I forgot Billy Glidden had that figured out years ago too. Maybe more have than I realized. Bg was Sb nos on a 10.5 Mickey. Not sure if he could do it on a big tire. But That’s how he dominated Nmra and the like for years. They kept throwing rules at him instead of paying attention to what he was doing.

I tried to haze big mickeys on my dragster with limited success. Was about 1 for 4 with equal parts wheel stand, shake, or up in smoke.

I tried to sneak up on it with a set of Goodyear’s in another car. I knew better, you can’t sneak up on it, but wasn’t my car and I had eyes over my shoulder. Those Goodyear’s were the most unforgiving tire I’ve ever seen. They would square off for any reason at all. I always wished I’d thrown the sink at it to see if I could get it over the hump but it got parked before I got another chance.

My problem is I throw everything at it already and don't have anything left to increase the power, so i'm forced to back it down. Switching from Hoosier to M/T fixed it for a couple seasons, but the M/T's shook so bad at the last race that both doors flew open. Tires might have been to old. I'm still working on it.

quote:

Originally posted by Mike Nitzsche:
My problem is I throw everything at it already and don't have anything left to increase the power, so i'm forced to back it down. Switching from Hoosier to M/T fixed it for a couple seasons, but the M/T's shook so bad at the last race that both doors flew open. Tires might have been to old. I'm still working on it.

That's me as well. Most of the Hoosiers I have used just have way too much bite. Sounds weird for a drag racer to say.

Spray a little diluted popcorn butter on the tread through a nitrous solenoid, when your backing up. Hide the nozzle real good, or they'll ban you for life!

"Where in the rules does it say I can't spray a little diluted popcorn butter on my tires?"

quote:

Originally posted by Mike Nitzsche:
My problem is I throw everything at it already and don't have anything left to increase..

Where’s your wheelie bar at? How far out does it shake?

If you are running alky.Just dump about a 10% load in the tank. After all everyone has 10 gallons nitro in trailer.Hell I thought it was mandatory. LOL

Guy with M/T told me that with my combo, a 10 wide tire would probably be the fastest, and easier by far to avoid shake. But his concern was consistency with the small tire.

quote:

Originally posted by Bucky:
Guy with M/T told me that with my combo, a 10 wide tire would probably be the fastest, and easier by far to avoid shake. But his concern was consistency with the small tire.

Fundamentally that's confusing, considering that tire has way more energy loss than their new technology tires.

That's as close to Hoosier as M/T got. That tire was developed for ORSCA 10.5 heads up drag racing years back. Late 90's early 2000's.

The amount it grows tells you of it's high energy loss at all frequency's

You might wanna check back in with em.

quote:

Originally posted by Mike Rietow:

quote:

Originally posted by Bucky:
Guy with M/T told me that with my combo, a 10 wide tire would probably be the fastest, and easier by far to avoid shake. But his concern was consistency with the small tire.

Fundamentally that's confusing, considering that tire has way more energy loss than their new technology tires.

That's as close to Hoosier as M/T got. That tire was developed for ORSCA 10.5 heads up drag racing years back. Late 90's early 2000's.

The amount it grows tells you of it's high energy loss at all frequency's

You might wanna check back in with em.

It's all relative. I think the idea is to be able to keep the wheel speed up to avoid tire shake. And the lighter rotating assembly doesn't hurt either. NONE of the tire manufactures that I am aware of have announced intentions to make radial tires for dragsters.

quote:

Originally posted by Bucky:

quote:

Originally posted by Mike Rietow:

quote:

Originally posted by Bucky:
Guy with M/T told me that with my combo, a 10 wide tire would probably be the fastest, and easier by far to avoid shake. But his concern was consistency with the small tire.

Fundamentally that's confusing, considering that tire has way more energy loss than their new technology tires.

That's as close to Hoosier as M/T got. That tire was developed for ORSCA 10.5 heads up drag racing years back. Late 90's early 2000's.

The amount it grows tells you of it's high energy loss at all frequency's

You might wanna check back in with em.

It's all relative. I think the idea is to be able to keep the wheel speed up to avoid tire shake. And the lighter rotating assembly doesn't hurt either. NONE of the tire manufactures that I am aware of have announced intentions to make radial tires for dragsters.

When I say that tire has way more energy loss at all frequency's than their new technology tires, I'm not talking radials. The bubba tires don't grow much, same as a tire that grows a lot tells it's a high energy loss tire at all frequency's, so does a tire that grows very little, tells you it is a lower energy loss tire,meaning it has less rolling resistance. A less roll resistance, less energy loss tire is what you should be looking for, with a dragster.

The tire you're running is manageable on a 10.5 tire doorslammer, for the fundamental reason you can delay the damper changing direction and compressing using chassis & clicker adjustments on a doorslammer, to get it spinning.

You have the wrong tire.

Agee Bucky. Idea is to keep tire speed up. Its the up and down that causes shake,most of the time. Thats why I said you will see a deep in driveshaft spd right before shake.

On tire size/ The few passes I have gotten in with FED either had stupid driver screwups or some shake. I am thinking about trying to find a set of 12" tires to borrow to try. Issue will be finding some that are close to what I am running so as to know its actually tire size. I use to have cash flow to allow buying new setup and trying it,n ot now days.

With solid rear, no blower to allow throwing more power at it.No clutch to adjust.Limited amount of tuning info available its going to be fun.The tuning not the shake.Then there is that extra power in a jug thing.LOL

Any thoughts on first gear ratios? I was told to avoid 1.80 low and go with 1.69 by fairly knowledgeable FED guy.

Chris use the 1.69 low gear ! Go with the M+H 12x33 and you will be happy ! I am not a fan of stiff sidewall tires !

I’ll share a funny story and give a little insight to my posts above.

I had a guy working for me a few years ago. Older guy. We had worked together a couple years and he knew I raced and showed mild interest but mostly just asked questions. I knew used to be a tire engineer at Gooodyear but that was about it.

One day out of nowhere he says, “hey, I wonder, anybody ever still shake the tires in drag cars?”

Obviously I looked at him a little funny. “Ya, sure, all the time. Why?”

So he told me.

He says, well I was just remembering this one time when Don Garlits called me.

Go on.

Turns out this guy was working Goodyear’s drag racing tire development at the time. They had just given garlits these new stickier softer tires for his new rear engine car and he was getting this new problem he’d never had where they would shake violently. So after Garlitts calls, this guy grabs a couple guys with high speed video cameras and lights and goes down to Florida to film for a couple days. After reviewing all the video the guy tells garlitts, looks to me like you have too much traction for the power you got. Either make more power or take away traction. They couldn’t make any more power so they started lowering air pressure and it eventually quit shaking. The guy left the track and got transferred to Indy car tires when he got home and apparently had never thought about it again for 30+ years. He was slightly amused to know that we hadn’t figured out much more in the last 30 years than he did in the first 2 days.