DragRaceResults.Com    Bracket Talk    Bracket Talk Forum  Hop To Forum Categories  Tech Talk - by Abruzzi    Lets talk about tire shake
Page 1 2 
Go
New
Find
Notify
Tools
Reply
  
Lets talk about tire shake
 Login/Join
 
DRR Top Comp
posted
I put a set of bead-loc rims on my dragster and now get horrendous shake at the hit. I also put a smaller set of tires on at the same time. The only way I could calm the shake down enough to make a run was drop the launch RPM down from 4800 to 4300 and raise the tire pressure up to 6 1/4 psi from 4 3/4.....even then it still shook but just for a second. I didn't lower the launch RPM anymore or up the tire pressure more because I started loosing 60' time
This is a hardtail so there's no suspension adjustments I can make


.
Dave



F J B

 
Posts: 4476 | Location: Earth | Registered: February 08, 2006Reply With QuoteReport This Post
DRR S/Pro
Picture of Big Steve
posted Hide Post
What size wheel and what tire? Rear gear and engine combo info will help to
 
Posts: 2439 | Location: Moving back to the door side | Registered: April 30, 2010Reply With QuoteReport This Post
DRR Sportsman
Picture of 329L
posted Hide Post
quote:
Originally posted by imakehp:
I put a set of bead-loc rims on my dragster and now get horrendous shake at the hit. I also put a smaller set of tires on at the same time. The only way I could calm the shake down enough to make a run was drop the launch RPM down from 4800 to 4300 and raise the tire pressure up to 6 1/4 psi from 4 3/4.....even then it still shook but just for a second. I didn't lower the launch RPM anymore or up the tire pressure more because I started loosing 60' time
This is a hardtail so there's no suspension adjustments I can make


Keep going up on air until it quits, that air psi IS normal on a hard tail car.


Jeremiah Hall
 
Posts: 711 | Location: Evansville, IN | Registered: February 24, 2010Reply With QuoteReport This Post
DRR Top Comp
posted Hide Post
Shake is too much traction. Adding air pressure is traction.

I'd lower the air pressure and tighten the low and high speed clickers on the two way adjuster on compression, for a tight track four link dragster.
 
Posts: 9398 | Location: Madeira Beach Fl. | Registered: June 12, 2018Reply With QuoteReport This Post
DRR Pro
posted Hide Post
quote:
Originally posted by Mike Rietow:
Shake is too much traction. Adding air pressure is traction.


Someone texted me this today & said to lower the pressure along with lowering launch rpm; very good source! The dragster is a hard tail. You have good people in your corner Dave, get after it. Wink

2BKing Big Grin


1980 Camaro
Taking the Best Working Small Tire Shyt Box & making it Greater Than Before!
3000 lbs.
Pump Gas 436
 
Posts: 2585 | Location: NV. | Registered: October 20, 2006Reply With QuoteReport This Post
DRR S/Pro
posted Hide Post
quote:
Originally posted by imakehp:
I put a set of bead-loc rims on my dragster and now get horrendous shake at the hit. I also put a smaller set of tires on at the same time. The only way I could calm the shake down enough to make a run was drop the launch RPM down from 4800 to 4300 and raise the tire pressure up to 6 1/4 psi from 4 3/4.....even then it still shook but just for a second. I didn't lower the launch RPM anymore or up the tire pressure more because I started loosing 60' time
This is a hardtail so there's no suspension adjustments I can make


Since no one asked, what tires? How fast are you running, etc...
 
Posts: 2161 | Location: Tewksbury, MA,USA | Registered: November 03, 2000Reply With QuoteReport This Post
DRR Sportsman
posted Hide Post
since it is a hard tail, do you have any weight in the nose? i always ran about 30# in the nose of my hard tail.

ep
 
Posts: 767 | Location: dodging double wides... | Registered: November 28, 2007Reply With QuoteReport This Post



DRR Top Comp
Picture of Curly1
posted Hide Post
quote:
Originally posted by pauley:
since it is a hard tail, do you have any weight in the nose? i always ran about 30# in the nose of my hard tail.

ep


With a hardtail tire selection, air pressure and nose weight is critical. I went through 5 different rear tire combinations on my Front Engine Hard tail dragster before I got it like I wanted. Air pressure is much more critical and less room for error. Some tires are noted for tire shake and that will not go away until you change tires to a different one.


https://postimg.cc/gallery/np3zpruo/
"Dunning-Kruger Effect"
-a type of Cognitive bias where people with little expertise or ability assume they have superior expertise or ability. This overestimation occurs as a result of the fact that they do not have enough knowledge to know they don't have enough knowledge.

Before you argue with someone ask yourself, "Is this person mentally mature enough to grasp the concept of a different perspective?" If not there is no point to argue.

4X NE2 CHAMPION. 2020 TDRA NE2 Champion
 
Posts: 4044 | Location: United States of Texas | Registered: April 02, 2011Reply With QuoteReport This Post
DRR Top Comp
Picture of wideopen231
posted Hide Post
agree sahke is too much traction. There is reason pro stock, TF and TF/FC all concern themselves with controlled tire speed. Either more power or less traction will normally fix shake on lower power cars.

I would either drop pressure and see if cna blow tires off or try smaller tire.Lowering pressure for few hits pretty cheap.




America home of free. Brought to you by 2nd amendment.
 
Posts: 4214 | Location: Greensboro NC | Registered: May 24, 2011Reply With QuoteReport This Post
DRR Pro
posted Hide Post
quote:
Originally posted by TOP38:
quote:
Originally posted by imakehp:
I put a set of bead-loc rims on my dragster and now get horrendous shake at the hit. I also put a smaller set of tires on at the same time. The only way I could calm the shake down enough to make a run was drop the launch RPM down from 4800 to 4300 and raise the tire pressure up to 6 1/4 psi from 4 3/4.....even then it still shook but just for a second. I didn't lower the launch RPM anymore or up the tire pressure more because I started loosing 60' time
This is a hardtail so there's no suspension adjustments I can make


Since no one asked, what tires? How fast are you running, etc...


I was pretty busy & was not pitted with Dave, but did check on him from time to time. I know the tires were brand new sticker tires & I didn't pay attention to the brand. He was running 4.80's.

2BKing


1980 Camaro
Taking the Best Working Small Tire Shyt Box & making it Greater Than Before!
3000 lbs.
Pump Gas 436
 
Posts: 2585 | Location: NV. | Registered: October 20, 2006Reply With QuoteReport This Post
DRR Pro
posted Hide Post
quote:
Originally posted by pauley:
since it is a hard tail, do you have any weight in the nose? i always ran about 30# in the nose of my hard tail.

ep


Yes, he had weight in the nose. It seemed like a good amount.

2BKing


1980 Camaro
Taking the Best Working Small Tire Shyt Box & making it Greater Than Before!
3000 lbs.
Pump Gas 436
 
Posts: 2585 | Location: NV. | Registered: October 20, 2006Reply With QuoteReport This Post
DRR Sportsman
Picture of TD3550
posted Hide Post
I was at the divisional and had to get tires Always ran GY. No GY truck. (H) truck there. Decided on the CO7. What a mistake that was.
Shake is an understatement no matter what. Went back to GY. No shake. Stiff sidewall tire. There are a lot of guys i know with HT's. Stiff sidewall. Like the 2533 D2A. It is a high growth tire The sidewall will go away before the tire
 
Posts: 1409 | Location: Under a Truck | Registered: August 23, 2013Reply With QuoteReport This Post
DRR Top Comp
Picture of wideopen231
posted Hide Post
Makes sense that stiff side wall help a lot. Limiting squat and deadhook. Funny people use to think dead hook was great. We found out that a slight haze off tire was faster and smoother back in 90's. Now spinning may not be most consistent,but neither is shaking your brains out or worst parts off of car.




America home of free. Brought to you by 2nd amendment.
 
Posts: 4214 | Location: Greensboro NC | Registered: May 24, 2011Reply With QuoteReport This Post
DRR Sportsman
posted Hide Post
quote:
Originally posted by B KING:
quote:
Originally posted by pauley:
since it is a hard tail, do you have any weight in the nose? i always ran about 30# in the nose of my hard tail.

ep


Yes, he had weight in the nose. It seemed like a good amount.

2BKing


removing some weight may take some bite out of it

ep-i agree with Curly. converter, tire and nose weight are what you have to work with.

also the OP said he started at 4 3/4 on tires. don't think you can go lower there.
 
Posts: 767 | Location: dodging double wides... | Registered: November 28, 2007Reply With QuoteReport This Post



DRR Top Comp
posted Hide Post
Let the air out, it'll wind the tire up more and jump up on the tire when it unwinds.

Regardless of what anyone says, bead locks stiffen the sidewall, evidenced by it shaking more now with bead locks.

Let the air out.
 
Posts: 9398 | Location: Madeira Beach Fl. | Registered: June 12, 2018Reply With QuoteReport This Post
DRR S/Pro
posted Hide Post
Let the air out, pump them up, take weight out, put some in, beadlocks, no beadlocks!!

Look!!!!!!
There is absolutely no reason for a 4.80 hardtail, 4 link, 15 link or whatever to shake the tires! It doesn't matter who's tire he runs too! There is no reason to have this issue.... Something is way wrong!
 
Posts: 2161 | Location: Tewksbury, MA,USA | Registered: November 03, 2000Reply With QuoteReport This Post
DRR Top Comp
posted Hide Post
OK, this is the entire story......

Had #18600 33.0/16.5-15 CO7 4-3/4lbs 13" rims
Went to #18255 14.0/32.0L-15 CO7 4-1/2 to 5-1/2 14" beadloc rims

Had a HUGHES #168997 GM-95 +1/4 7SC+1
Installed a B&M 20908

Launch 4300 to 4800 rpm....didn't go lower than 4300 but shake got better the lower I went

4.10 gear 1.76 1st gear

45lbs on the nose....1950lbs w/driver...

4:80 / 145 in Vegas (2500' ?)

582" 985hp

I'll flash the RPM when the rain stops here in the next couple days....

The RPM is about 400-500 higher between the two different tires and/or convertors (6900 to 7400)

That's about all the info I can think of....ask me if you need more


.
Dave



F J B

 
Posts: 4476 | Location: Earth | Registered: February 08, 2006Reply With QuoteReport This Post
DRR Pro
posted Hide Post
quote:
Originally posted by imakehp:
OK, this is the entire story......

Had #18600 33.0/16.5-15 CO7 4-3/4lbs 13" rims
Went to #18255 14.0/32.0L-15 CO7 4-1/2 to 5-1/2 14" beadloc rims

Had a HUGHES #168997 GM-95 +1/4 7SC+1
Installed a B&M 20908

Launch 4300 to 4800 rpm....didn't go lower than 4300 but shake got better the lower I went

4.10 gear 1.76 1st gear

45lbs on the nose....1950lbs w/driver...

4:80 / 145 in Vegas (2500' ?)

582" 985hp

I'll flash the RPM when the rain stops here in the next couple days....

The RPM is about 400-500 higher between the two different tires and/or convertors (6900 to 7400)

That's about all the info I can think of....ask me if you need more


I'm assuming you didn't have the tire shake before. That being said; the only things that changed was the tires/rims, torque convertor & the track.

Maybe you could change back the parts, if possible, one at a time or make changes to existing combo to fix the issue.

2BKing


1980 Camaro
Taking the Best Working Small Tire Shyt Box & making it Greater Than Before!
3000 lbs.
Pump Gas 436
 
Posts: 2585 | Location: NV. | Registered: October 20, 2006Reply With QuoteReport This Post
DRR S/Pro
posted Hide Post
quote:
Originally posted by imakehp:
OK, this is the entire story......

Had #18600 33.0/16.5-15 CO7 4-3/4lbs 13" rims
Went to #18255 14.0/32.0L-15 CO7 4-1/2 to 5-1/2 14" beadloc rims

Had a HUGHES #168997 GM-95 +1/4 7SC+1
Installed a B&M 20908

Launch 4300 to 4800 rpm....didn't go lower than 4300 but shake got better the lower I went

4.10 gear 1.76 1st gear

45lbs on the nose....1950lbs w/driver...

4:80 / 145 in Vegas (2500' ?)

582" 985hp

I'll flash the RPM when the rain stops here in the next couple days....

The RPM is about 400-500 higher between the two different tires and/or convertors (6900 to 7400)

That's about all the info I can think of....ask me if you need more


The Hughes converter is way too tight and agressive. I assume you have a typo error on the B&M (20608 vs 20908). The 608 converter should work very good and it is not aggressive. Ran one of these behind a 565 dragster running 4.50's and 60's at 1925 lbs. Used the 16" Hoosier C06 33.5 tire. No issues either other than some shake in the burnout if you were not careful. Do you need weight in the nose of this car? Especially with the B&M? What ither differences did the converter swap make? I haven't ran a 15" for a long time but I know a number of racers like the MT3084 tire.

In the long run you will be better off running a 16" tire with or w/o bead locks.
 
Posts: 2161 | Location: Tewksbury, MA,USA | Registered: November 03, 2000Reply With QuoteReport This Post
DRR Top Comp
posted Hide Post
quote:
Originally posted by TOP38:
quote:
Originally posted by imakehp:
OK, this is the entire story......

Had #18600 33.0/16.5-15 CO7 4-3/4lbs 13" rims
Went to #18255 14.0/32.0L-15 CO7 4-1/2 to 5-1/2 14" beadloc rims

Had a HUGHES #168997 GM-95 +1/4 7SC+1
Installed a B&M 20908

Launch 4300 to 4800 rpm....didn't go lower than 4300 but shake got better the lower I went

4.10 gear 1.76 1st gear

45lbs on the nose....1950lbs w/driver...

4:80 / 145 in Vegas (2500' ?)

582" 985hp

I'll flash the RPM when the rain stops here in the next couple days....

The RPM is about 400-500 higher between the two different tires and/or convertors (6900 to 7400)

That's about all the info I can think of....ask me if you need more


The Hughes converter is way too tight and agressive. I assume you have a typo error on the B&M (20608 vs 20908). The 608 converter should work very good and it is not aggressive. Ran one of these behind a 565 dragster running 4.50's and 60's at 1925 lbs. Used the 16" Hoosier C06 33.5 tire. No issues either other than some shake in the burnout if you were not careful. Do you need weight in the nose of this car? Especially with the B&M? What ither differences did the converter swap make? I haven't ran a 15" for a long time but I know a number of racers like the MT3084 tire.

In the long run you will be better off running a 16" tire with or w/o bead locks.


The next time there's a race/TnT somewhere out west I'm going to take my old pair of slicks and try them just to see if the new tires and/or rims are the issue.....
I learned quickly I had better not burn out to the line or I'd have to wait a few seconds for my eyes to focus again....lol
20908 B&M is the number on the box


.
Dave



F J B

 
Posts: 4476 | Location: Earth | Registered: February 08, 2006Reply With QuoteReport This Post
  Powered by Social Strata Page 1 2  
 

DragRaceResults.Com    Bracket Talk    Bracket Talk Forum  Hop To Forum Categories  Tech Talk - by Abruzzi    Lets talk about tire shake

© DragRaceResults.com 2024