UPDATE! How to race on a poor track with drag radials

Fairly new driver, and we have a 1/8 track that is not great prep.

I am learning and trying to get consistent
I am getting better at the light but need help on this track as my 60 changes a lot


1968 Plymouth RR
About 3500 lbs plus me at 200 lbs = 3700 approx
Ladder bars are 32 inch
Single Adjustable strange shocks with 170lbs springs


I am not experienced but on a good track its
9.6-9.7 1/4 mile times
1.48 60 foots
140-142 mph



I am racing at a pretty poor track and 60 foot at 1.6-1.7s

Radial ET Pros 15 lbs

I spin pretty bad and let off and then get back in and its fine for the rest of the 1/8

Ladder bar is in middle hole. which is parallel to the ground at 0 degrees

Suggestions have been to go to the upper home

Get a lighter spring for the shocks.



Should I leave in 2nd?

Its hard to test and tune at this track as it has no prep on those day (I have tried)

Not sure about the bad track, but 9.60 on a good track with a 1.48 60ft is leaving a lot on the table. Probably should go a tenth better in the 60ft on the good track.

Put big slicks on it and don't worry about it....Or, invest in traction control...Ruining a car for no reason is silly.

Stock eliminator cars with good HP and 9" radials have problems hooking up on bad tracks. It can be worth -.5 on their good track ET. As you know, SE cars are well thought out when it comes to weight transfer. Have you tried uping the tire pressure until you get a better result? 2nd gear is an option.

Rear springs are way to stiff off the bat. Need 120-125.
Doug

A friend suggested that as well.

We were going to corner weight the car to get a baseline

Change them dang radials out to a decent set of bias ply tires for now
Save the radials for next year or later this year after the track gets some more rubber on it
Radials on a bad track are worthless once they start to spin they go up into smoke until you let off and let them grab again
Bias ply tires may spin a 1/4 to maybe 1 and 1/2 full turn and then grab or start to grab, not go up in smoke right away.
Try them, you will probably like them
What size tire, brand and compound are you using now?

Here is a video of a race day.
I needed to learn to do a burnout
Foot Brake Launch at 2000-2200 rpm.

https://www.youtube.com/watch?v=xX3YxC0IjNE

100 percent throttle and then 42 percent and then back up


Watch till end for slo motion on suspension

Test and tune

Learned a better burn out

https://www.youtube.com/watch?v=7qysZqdJRw8

I have space for a bigger tire

315 - 60 - 15
Drag ET Pros

I need to measure and order rims

I see no separation in the rear. By watching the video the stiff rear springs are not doing you any favors. It may need the IC raised with radials.
You need to hit them harder.
Doug

yes I agree I didn't see any separation either.

Will any brand spring fit on the strange shock?

Are the radials supposed to wrinkle too?

Before changing the tires try raising the pressure up to17 or 18 lbs. and make sure you get thet tires hot, make them smoke in high gear around 6000 RPM for 3 to 15 seconds in two seconds increment up from 3 seconds to as high as 15 seconds, You'll know if the longer burn outs helps or not immediately on the launch from the starting line, don't break your neck or back AKA aside, a 1.50 60 ft. will hurt your back and or neck if you do not stiffen up for the launch, 1.20 60 fts. Are serious fun :hammerdevil: Can you say rocket ship launches

Radials wrinkle very little if any. Without frame by frame you won't see it. Any 2 1/2" spring of the correct length for you shock will work. I'm assuming on the rear you are probably running 12" long springs. But that is a guess.
Doug

There may be some guys that can make a radial work on a bad track, I'm not one of them though. I've been to my local track when it was bad, make one pass, then load up and come home. No point slipping, sliding and beating on my junk.

If your radials are wrinkling a lot, you've probably killed the sidewalls. I had a set of MT 325's that would wad the sidewalls up even with 21# of air in them.

We did some street races with drag radials.

While not the best tire, 100 lbs. of weight over the rear bumper and 2nd gear leave allowed us to get down the worst surfaces.

This car runs 9.30s at 140 , any track anywhere. It’s on a 295 radial

What you need is probably a 110 or 95 rear spring . Ladder bars level or 1 or 2* up , and you need a double adjustable shock with at least 4” of travel . Loose on extension, somewhat firm or stiff on rebound . You want to smash the tire and keep it smashed , don’t let it bounce back . Front may need to be more travel and somewhat tight on extension, you want a controlled rise in the front .

The nova runs a 2.10 first with a 3.70 rear
Not sure what your rear gear is but yes a little less SLR can help

Some may not agree , but I think I have some experience with radials

As above^^^

As a marker so to speak for Bias tyre, our '69RR, less hp than you, only 690 through street muffs, mild big ci motor, big torque, 3800lbs@line, rubbish 90/10's on front, caltracs/bars, c/trac 9-ways single adj on 7 stiff, 2 turns preload on bars, 4.10's 10x29 Hoosier bias@17psi, been a best of 1.42 60 normally 1.43>1.45 and a best of 10.30@130 on a good day, normally 10.4's>5's. Lots wrong with it but respectable 60's.

Take it to Quebec, radial guys own the track and know how to prep it

https://www.youtube.com/watch?v=FQX65E3iv24

Thank you
I can definately see some wrinkle I think i need to raise the spring for more shock extensions? I think this will raise the rear.

Do a search on Yellow Bullet, lot's of info on this subject.

FYI 3.54 gears in a Detroit locker

Fairly tight converter

32 inch ladder bars

Street racing..

3.54 rear , should go right down

Read my post earlier ,please

Thanks I will absolutely try your suggestions. that car is moving.

That's what we run

I say upper hole on ladder bars, reset pinion angle, and set the shocks up with looser extension and stiffer compression to hold the extra hit you are putting on the suspension.

I just redone my car this week because I was having trouble on the bad track with slicks. Upped the Antisquat to 110 percent and it worked. Car was great today.

I'm looking at your shock picture. What is the travel of your shock? On a radial you want the shock compressed at least 60% at ride height. When light springs are installed they will need to be compressed. The platform will end up being screwed way up to maintain the current ride height. Can't see from this pic. Is there a height adjustment where the shock bolts to the lower mount? Also agree it may be tough without double adjustable shocks. also agree that the bars may have to point upward.
Doug

Sorry for the long post, but hopefully this is helpful for those that take time to read it.


Couple of ideas.

1) As mentioned it needs a spring change as what you're running is really stiff.

2) Most Radials are run at much higher tire pressure. 15psi is really low. I run 18.5PSI on my 275 Pro Radials.

3) The front and rear shock settings are key to making it work. In the rear you need to balance having the shock loose enough to initially "hit" or plant the tire, but not so loose that it runs out of travel. For the front, you need to make it loose enough that you're allowing the body to move and waste some energy that you don't have traction for, but not so loose that it runs out of travel quickly and unloads the tire too hard.

It's a balancing act for sure. The radials are not very forgiving... once they spin... they spin HARD. A regular bias ply can spin but still recover and get the car moving.




This is a video I made quite a while ago when I was working to get my car to leave on the radials. https://www.youtube.com/watch?v=jr1VILyS7WE

Run #2 is an example of the shocks being too loose, the car hits the tire hard and runs out of travel quickly and spins the tire about 1/8 of a tire rotation (watch the valve stem).

Run #4 has tighter rear extension on the shocks, hits the tire and you can see the slower separation allows the tire to turn a LOT further before spinning. This setup ALMOST worked.

Run #5 is an example of the rear extension on the shock being too tight. You can see that it does not hit the tire hard enough, and spins almost right away because the tire doesn't get planted and the body doesn't separate.


(Note that the 16psi shown in the comments at the top of the video's are PSI of turbo boost, not tire pressure. All tire pressure was at 18.5)




Not to complicate things further, but ultimately the settings from run #4 above got me to reliable 1.37~1.41 60ft times EVERYWHERE I ran the car. The rear setting from run #4 allowed the rear tire "hit" to plant the tire nicely, and the shock was set as a nice smooth body separation. Ultimately TIGHTENING the front shocks from 10 clicks down to 6 made this setup really really reliable. If you watch run #4 towards the end of the video when you can see the whole car, you can see the rears spin at the moment the front suspension runs out of travel. By delaying that front from running out of travel with tighter front shock settings, the rear would stay planted, get the car moving, and ultimately 60ft reliably.


I know that's a lot to digest, but take some time and watch the video's, read the comments above, and it should get you pointed in the right direction.

Thank you all! This experience is very helpful.


The shocks are positioned at the lowest setting. I have double adjustable afco in the front.


The plan moving forward...


1. I will set the ladder bar front to the upper setting


2 . I will increase air pressure to 18-20lbs and trial it. Should I start at 20 and work down or 18 and work up in pressure?


3 I will get what is available but I believe my options are 110 lb and 130 lb springs. Available in 12 and 10 inch. Where would you start?


4. Shock setting (I got some learning to do LOL) Would happily look at any suggestionsfor a double ajustable here

Spring length is dependent on how much shock travel you have If it is 5" or more the 12" would be my choice. My car actually runs 11"springs. They are a barrel shaped oval track spring. You can see how far up the spring platform gets with a short spring. This car weighs aprox 1500lbs on the rear with about 310lbs of that being unsprung. Springs are 122lb.
Doug

im not sure that having slight wrinkle is a big problem . I know iwill see some intermittantly on my Satellite . I run 19 - 19 1/4psi in my PBR 29.5x10.5 . I feel the wrinkle is more often a sign of hook than psi especially if you are above 18psi to start with . This is both foot and trans brake though more obvious wth tbrake . The PBR is probably the most forgiving radial , i find it "walks "out mostly rather than spins , chirps/ scrabbles if it doesnt hook then picks up and keeps going . That said i have had a couple passes where they flat spun but not too common for me .
As to suspension setup , cant help as i am leaf spring Caltrac and a little nose heavy with a World iron block .

Tex

We still get a slight wrinkle using the M/T Pro Drag Radial, we've been as high as 22psi (warm) and still seen it, As above car is on Caltracs and Leafs.

Everything the above racers said, plus seat time. The more you race better you will get. Glad to see you out racing that RR. Now lets get Ron in the Charger Back Out

Not to hijack the thread, but NSS has to run 10.5 tires and I have messed with 4-links for a long time, and I can get it to hook on just about any track, on the starting line, but since the last engine rebuild it makes enough torque that on a slick track it wants to break the tires loose on the big end of the track. I watch the drag radials, and no prep guys and wonder as well what they do to get those cars to hook. I would not mind trying a no prep car, but it looks to me like it is not if you will wreck a car but when. So I am all ears to getting a car to hook down track.

You own a mid 9 second car.. that is really fast, regardless of what the internet says... one important question: Have you ever driven a car with bias ply slicks at low air pressure before? They hook amazingly well compared to drag radials, but they have very different feeling at high speed. I am far from an expert, but my low 10 second car hooked very well with 28x10.5 bias ply at 12 psi on test and tune tracks... but made me a bit nervous at 140 mph... when I tried 325/50R15 drag radials it felt like cruising on the highway with one hand on the wheel at 140... but did not hook well at all... just my 2 cents...

One thing to remember when letting off on cars with bias tires that start to wiggle at low pressure, the back of the car has to follow the front when coasting, don't overreact try and correct it when it is sashing, it should slow down enough to not wiggle after 3 to 5 seconds

Thanks... I drove a 12 second car with slicks and it did wag at the top end. What you said is why I originally didn't want slicks as it the wag would make me nervous.
'

"This"......especially "quality valved" DA shocks, more seat time, and tune for the below average track conditions. There is no separation, needs more extension, slow down the front a bit, and squash the tire more to keep it planted. Only foot-braking, no transbrake? Lastly, you could always work harder with what you currently have if your budget is tight by making cost effective changes. You have more than enough tire, and the gear is no problem.

I have the ability to fit a shock with a 5 inch extension.
A friend suggested i change the setup for atleast 7 inch extension. This will be a pile of work

Would a 5 inch extension be sufficient or would it be worth the work for the extra 2 inches (40% more extension)

Evil B1 it is a foot brake car

I'd like to see the 7" with the radial. Though it may not need all that travel. An adjustable lower mount should get you there. You can run the shock compressed 5"
Doug

I have a single adjustable AFCO front shock

it has 39 clicks of adjustment

I set it at 20 for each Is this a good starting stop?

Work with what you have now except...!!!Put pair of 125lb hypercoils on it!!! Like has been mentioned, adjust springs so you have about 1.5" of compressed travel 3.5" or more extension. If you do move the front of the ladder bar then you'll obviously have to correct the pinion angle...is it 'correct' now? A biased tire is probably the most forgiving, and put the biggest one you can fit currently.

^^^

"Poor track" and "radial" don't typically go together. Maybe the newer "bracket" radials from M/T and Hoosier are more forgiving, but radials traditionally have been highly dependent upon track prep to work well.

Yes true.....BUT depends on the power level and the car.
My sons car (11.teens on motor) runs the same street or track, he beat a Red Eye Challenger pretty easily on the street.(295 radials)
The Nova i posted the pic of, that car runs 9.30 at ANY track its been to. Im sure its borderline at some tracks, but it just flat out works. I cant recall a time that car has ever spun the tire. We had to take gear out of it to keep it off the bumper

we do a lot of racing in F.A.S.T. factory appearing stock tire never full throttle off line, part throttle , dont floor it till second gear have gotten very consistent you will have to find sweet spot, we have cars running 9's with G60-15, have gone 11.0's with F70-14 360 duster

@Tony - The Hoosier 9x30 stocker radials I used to run on my '73 were the epitome of a radial that either dead-hooked or simply spun 'til ya' let up, which seemed to be the rep radials have had for years. My ET Street S/S appear to be better about "iffy" conditions -- on my slow-a$$ 1320, at least. When the '73 comes back, I'm gonna have a new learning curve to deal with.

@lebaron - I have AMAZING respect or the F.A.S.T. cars, but ya' gotta admit those aren't racing against a dial-in or an index where you need round-to-round consistency like w/ your new Stocker. BTW, I enjoy your progress reports on the new car.

Switched to 130lb springs (available)
compressed to 7 7/8 inches (35%)

I did a quick video on the street run (track day rained out)
It was rolling but it looks like we have separation!


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https://www.youtube.com/watch?v=fL98hbllN40&feature=youtu.be
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Definitely need a longer double adjustable shock

Finally out to the same track

Scaled and balanced the the car
and had some significantly better runs,
Same front shock setting (in the middle )
Rear shocks (single adjustable)
Changed 130 lb springs with preload of about 35%

Ladder bar at top measure at about 180% anti -squat. CHART at end of video

Here is the video

https://www.youtube.com/watch?v=rqI8EkKJ85I

That was a partial throttle run (Still learning to keep my foot in it)
ET 6.234
60 foot 1.456
MPT 113.75

Made some adjustments and lost traction ( I should have left it)
Got it back to base and ran a

ET 6.155 (personal best) 6.25 dial in
60 ft 1.446
114.45 MPH

What did it run now compared to before? It looks like you are closer to 50% collapsed so you have room to go down in compression IF YOU NEED TO. It looks like it's working good! I would sort-out what you have now. Of course double adjustable are better but based on your incrementals we can surmise how much more there is left. GOOD WORK, CONGRATS!

Thankyou HardcoreB


I was really wondering what improvements I may expect with a better shock and hope to get a guess from the Moparts group here...

Prior runs at same track (but I believe less track prep here)
https://www.youtube.com/watch?v=7qysZqdJRw8
https://www.youtube.com/watch?v=7qysZqdJRw8

I would lose traction almost immediately and then get back in

ETs 6.572, 6.749, 6.646
60s 1.682, 1.568, 1.636
mph 112.71, 104.83, 110.21

Very inconstant ... I was on and off the throttle

The 6.23 and 6.15 were improvements