Hi all,

Looking for some advice on getting more consistent 60' times on radials. I've lost my last three times out because the car decided to spin. Not looking for a magic bullet, just some pointers. The car usually pulls mid 1.4's but it seems like as soon as I get into the money rounds it will cough up a 50-something.

I'm running MT 275/60/15 at 18 psi. Tire patch is pretty even, no cupping or crowning. Staged the same every time by just lighting the bottom bulb. Launch RPM is 2500. The car has 90/10's in the front, 50/50 in the rear, Spohn torque arm and LCA's, no front sway bar, stock WS6 rear sway bar, Moroso trick springs up front and V6 rear springs. TH400, 3500 Hughes converter and 3.73's. Burnouts are the same every time. I burn them until they just start to smoke.

Thanks!

 

Double adjustable rears is a hell of a start on radials. You need to keep the power planted to the track after the initial hit and hold it down the track.

 

Hope I can 1.4 60 with my auto, lol, just sayin.

 

my car needed d/a rear shocks. but i do know of a couple of cars getting by with some qa1 singles.

 

Adjustable shocks are definitely a big help getting a car dialed in. - My buddy's stang that I do the suspension on will go 1.52-1.54 all day with a 275/50/15 & a clutch.

 

Problem is that it's not consistent.

 

Are you allowed to run slicks? The radials are a good tire but they are not as forgiving as a slick would be when the track starts to go away. I don't see a lot of radial tires in classes trying to run consistent numbers.

 

I understand. I have never had a inconsistent issue like that, seems as if the track conditions are getting worse, that is the only time I have starter losing a 60.

 

Allowed? Yes. Want to? No. For two reasons. One, it's a street car that I drive often and I don't want to switch tires back and forth. Second, stock 10 bolt rear.

 

Throw your second reason out the window, the radials are harder on the drivetrain than slicks.

 

tire shake/chatter is a b*tch.

 

Do you have LCARBS?

Did you try running a little less psi in the tires?

 

I have been 1.20 on the rear tires with single adjustable QA1's on the rear of the car.

 

Do I need to say it again? Double adjustable rear shocks. Don't go with a off the shelf shock either do your self a favor and buy a custom valved dual adjustable set up for your car.

They will not only help you plant the rear tires on launch, hold the power down the track, but give you adjustment for when the track goes away.

If you don't want to tune for the conditions put a small motor in a big tire car and then you will have consistency.

 

i have given up on the street drag radials. i have a manual car though. im told they are alot easier to dial in on an automatic.

i got 24 good passes on mine running 1.8 to 1.85 then they went away. it will either run a 1.9-2.0 or a 2.4 now. granted im dropping 5000 to 5500 clutch dumps on them.

im going to an et drag tire and not looking back. may try et streets next year for some dot fun though.

i did the drag radials for the same reason didnt want to switch at the track. im learning if i want to run for real i will have to do that.

 

For bracket racing I would recommend slicks (Hoosier 29X10) or a power glide...but since you like to drive it on the street maybe you should consider a 50 shot of nitrous for those times you spin. You have to make sure you do your job on the top end also so you don’t run under.

 

If you spin at the hit you'll likely loose at least a tenth in 60', thus even a 200 shot of nitrous up top won't make up for it.

 

Umm...i run STOCK shocks and have no trouble going 1.39. 5 passes in a row on little 255 radials...i added weight to the trunk...quick 2nd to 3rd burnouts and run them 17psi.

 

What shocks would you recommend? Are you using a Drag bar?


Wow, thats good. Is that consistent? What rpm are you launching?


I'm in the same boat as Dialed_in is. I just switched from a standard slick to a 275/50-15 Drag radial. Pulled off a 1.51 60ft, but the car was very inconsistant trying to get it to hook. Spun more times than hooked. With slicks I was launching at 5600rpm off of the brake. With the drag radial I was launching at 2500rpm and rolling into it to get it to hook. How much better would a larger drag radial help? I was thinking of going to a 295/55-15, or a 325/50-15.

 

Well the larger tire will only help because it robs gear from the car. If when you do hook the rpms at the finish are correct...dont get bigger tires!!!

Mine is literally dead on consistent. But i weighed my car and made it as balanced as i can for now...like 52% on the nose. .but i had to add 100# lead bar to rear.

Dbl adj shocks will help plant the tires...but balance is key that everyone misses!!! I leave at 3500 on the transbrake with no issues...the higher i leave the higher the front end goes...but it 60's the exact same every single pass in a day.

 

Just so everyone is clear...the car chassis needs to be balanced...everyone wants to be lighter and lighter...but you need weight over the rear.

My car has spohn and pa racing stuff...stock shocks and weighs 3100 with me in it...with 100 lb bar added. Theres no trick there...car went FASTER heavier

 

Should have explained myself better. I'm looking to put more rubber to the ground and would change the gear to match. Right now I'm running a 3.89 gear and would go to either a 4.10 or 4.30 to go wth the new tire diameter.
So you added #100 to the rear of the car and it started hooking? I havn't weighed my car so I have no idea what the weight, or balance for that matter. Will definetly look into it though.
Are you using a drag bar? Right now I'm running with an air bag in the right rear @ 15psi and preloading the stock sway bar to try and keep it flat on launch. This winter it will be getting a drag bar and better shocks.

 

yes...i have an anti roll bar as all race cars should. LOL im not sure about your combo but for me i run a 4.10 gear with 27" tall tire...if i use a 275 i need a 4.30 gear. more tire will help no doubt, just make sure the gear is right. once you add the bar take out the air bag. the balance thing i learned from stock/super stock and now the x275 stuff...and its worth it to add weight.

 

adding weight in the rear will help get it hooked for sure. my biggest problem has been keeping the front end down. i never added any weight to the car, but i am running a battery in the trunk, and still have the rear bumper support. ~3050-3100lbs with me in it. it would have gone a good bit quicker if the nose would have stayed down. bought a glide and was going to try that but never did. should have helped.

 

the "trick" to the balanced car comes in the gearing...i have a different 1st gear so that the car doesnt stand up...i have a crank and pistons to make mine a 406" to run 9.50's with ease...but have a 355 really makes people think. hahaha

we have tested 3 spd transmissions to be faster than the glide with proper gearing.....

 

Understood. I'm running a 350 NA on the street, with best of 10.97et at the track. I felt the car needed more gear so I picked up these drag radials on the cheap. They are 26" tall vs the 28" slicks I was running. When I could get the car to half *** hook it was much faster. I just need to figure what components I need to get to keep the tire/gear ratio I'm running now and get it to hook consistantly.

 

thats quick for a street 350 NA...props there for sure!!! if you go to a test day grab some lead shot (come in 25lb bags) and put 50 lbs in the rear area...see what happens..if that dont work..add some more...if its a street car im betting its at least 200lbs nose heavy...mine was 194 before i added weight.

you can try to change shocks, etc or do whatever you want to try, im not telling you what to do...haha im just telling you what works for my teams cars.

 

also...dont foprget that radials dont like a john force burnout...just a 3 second 2nd-3rd is all i need for mine. they would spin worse the hotter i made them.

 

ET STREETS for the street. dont drive like a import. and you will never have a prob.
run better on the track. and use a tube with them. a few ricky racers dont..and leak.

ran them on the street for overs 10 years...always worked for me.
have been looking at the drag radials. but dont know if i like them..yet

 

slicks- plug n play
radials- have to make the car work on them

for the majority, anyways.

 

Really? My old slicks would hook better the hotter I got them. So those big burnouts I was doing with these drag radials trying to get them heated up good was just screwing me up. huh.


Do drag radials always require a softer launch? I'm used to hammering it at 5800rpm off of the brake. Once I get the suspension right, the right gear and more rubber under it, will the radials hold launching it like that?

 

Well...slicks need a longer burnout than radials. Like i said..mine are better with a short burnout.

Once evrything is set up right...you should leave wherever the car works best. I stay low on the brake because it works. Havent tried any higher.

 

Along with the right suspension parts, radials also rely on power management with either rpm launch control, power adders management or the combination of both. While a slick likes wheel speed a radial needs to dead hook. If the car goes faster with more weight over the rear the tire isn't planting hard enough (this is to certain point which is different for each car) I had a 4 month issue this year where the car would not hook on some if the best prepped tracks in the country on slicks. Right after I had a few wheelies cutting 1.20 60's on the rear tires this spring and after a few hard crashes down from the wheelies, I had to replace the front struts which in heinsight was acting like a bandaid for the spring radial passes. After putting the correct adjustables on the front along with a new torque converter that would multiply the torque a lot less, the 60's went to the high 1.4x blowing off every tire combination from slicks to radials no matter how much power I took away. At that point, I focused on the rear suspension and found a lot wrong compared to some of the countries fastest stock suspension cars. The excessive weight transfer of the struts covered up most of the problems that werent identified because I thought the car was doing well. I spent 4 months evaluating each and every part that has to do with the launch of the car and came to to some surprising revelations but I also understand how each component affects the car now. My car usued to leave squatting the rear and lifting front tires off. After some adjustment on the car it now lifts the rear and plants the tire with the front barely coming off. Our local track prep is probably one of the worst in the country, but the car went 1.26 on an easy tune last weekend on drag radials. Prior to that it went 1.28 on slicks last year with more power off the start all on sigle adjustable rears at that track. I did just switch to AFCO DA because I travel a lot to other tracks and wanted some more adjustability if their surface wasn't the best. Before investing into all these sweet parts for the rear make sure the car is set up correctly front weight bias to the geometry. I thought mine was dead on for the last few years but came to finbd out it wasn't. You can add all the parts you want to, but without the basics being correct, the SA's, DA's, LCARB, will do you no good because you will not see consistant results from the adjustments you make.

 

Good post^^
There is no substitute for the right parts...and thats why they are so expensive.

My motor only made 595hp on the dyno...but i know my suspension and chassis is where it needs to be...the shocks and struts are next to be replaced...then i can actually adjust mine. Stock stuff will hook the car though if the trans gearing and everything else works together...just not like i want it to.

Good info there.

 

1BADRZ28 Nice post but what were the changes you made exactly to help it launch better. Thanks

 

I droped a tenth in my 60s since the last time out so I got some 50/50s cominf and adj lcas what sort of improvement do you guys think ill get from stock if I get that tenth 0ack ill be happy but these companys claim they pick up more

 

Since starting this thread I installed 90/10's and Moroso springs in the front and 50/50's in the back. Also moved the battery to the trunk. The 60's are dead on now in the 1.44-1.46 range and the last time out in the heat it was running mid 10.7's. Not bad for 3500lb car with a lil pump gas 383.