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-   -   Drag radials or slicks (https://67-72chevytrucks.com/vboard/showthread.php?t=350112)

85_prairieboy 06-24-2009 09:46 PM

Drag radials or slicks
 
1 Attachment(s)
This past weekend I finally made it to the track. I ran better than I was expecting, a best of 13.76 at 98.99. I had major traction issues though. I am just using BFG street tires. My average 60 ft was around 2.25. All of those passes I tried to ease into the throttle but ended up spinning and letting off. My best was 2.0 with a passenger. Too bad I had to let off at the end, that would have been a good pass. I obviously need sticky tires but i am wondering if I will be able to hook well enough with radials. I plan to spray a 150 shot next time. Should get me into the 12s if I can get rid of the tirespin. I have a transbrake too but haven't used it yet for obvious reasons. By the way this is the truck. An 85 GMC with stock rear suspension

Attachment 472861

Jim_PA 06-24-2009 10:14 PM

Re: Drag radials or slicks
 
I'd go with a full slick.

71Dragtruck 06-25-2009 12:00 AM

Re: Drag radials or slicks
 
Quote:

Originally Posted by Jim_PA (Post 3378380)
I'd go with a full slick.

I agree, at very least a DOT slick like a QT-Pro or a ET Street.

Super73 06-25-2009 12:11 AM

Re: Drag radials or slicks
 
I'm going from a ET street to a ET Street radial. Why?

I can get more contact patch with less side wall
Radials tend to have a touch more mph.
Slicks aren't street legal.

Either tire can work well, it's all in the set up. What works for a slick, may not work for a radial.

There are guys cutting 1.3x's on drag radials. Here is an example: http://www.wolferacecraft.com/7s.aspx

djracer 06-25-2009 07:12 AM

Re: Drag radials or slicks
 
My buddy has been 1.57 in a 67 camaro with slapper bars and a drag radial. This is a street car that we drive to the track.

At the orsca race the other day a mustang went 4.67 in the eighth on a drag radial.

85_prairieboy 06-25-2009 10:26 PM

Re: Drag radials or slicks
 
The only thing is if I go with a full slick I have to buy another set of rims because the truck does get driven. I plan on narrowing a 9 inch and using a wide slick hopefully for next year so what I buy now will get me through the rest of the year. If I do buy drag radials and still spin I am no further ahead. Man I may have to flip a coin on this one. One of the reasons I am wondering if a drag radial will be good enough is a dilemma I have with my current suspension. I only have an inch of travel before my rear end hits the bumpstops. I can even see it in the videos my brother took. The truck starts to squat and then bottoms out the suspension and almost bounces back. It seems like that unloads the tires and they spin worse. I don't know if drag radials would do the same thing or not. Maybe any tire would do the same thing. Or maybe I am overthinking this

hotrod 80 06-26-2009 06:25 AM

Re: Drag radials or slicks
 
Do you drive it to the track or trailer ? I like a drag radial for a friday night street car deal . Just show up and your ready . Ive driven in and changed to slicks , it's a pain , locking up you tires , tools and jack to a light pole . I have a trialer also . To me it is alot funner to drive in on a drag radial , tech in and go make passes . I have always run the minimum tire i can and still get the job done .

Jim_PA 06-26-2009 07:55 AM

Re: Drag radials or slicks
 
Maybe I wouldn't have problems with drag radials either, but I didn't want to find out the hard way that I couldn't hook with them.

I think the only drag radials actually recommended for street use are the BFG's and Nitto's, most other drag radials I've read about wear and drive horribly on the street.

Alex1 06-26-2009 09:00 AM

Re: Drag radials or slicks
 
M/Ts drive fine on the street -put air in them!

85_prairieboy 06-26-2009 09:16 AM

Re: Drag radials or slicks
 
Quote:

Originally Posted by hotrod 80 (Post 3380785)
Do you drive it to the track or trailer ?

The nearest track is 3 hours away so I trailered it in case I broke

bigsnookmaster 06-28-2009 08:08 PM

Re: Drag radials or slicks
 
It sounds to me like you might need a little suspension work. My old 70 would 60' at 1.76 on Dunlop 275/60-15s at 3950lbs.with me in it.It was a coil spring rear setup though.Good luck:chevy:

Super73 07-04-2009 12:19 AM

Re: Drag radials or slicks
 
Quote:

Originally Posted by 85_prairieboy (Post 3380371)
I only have an inch of travel before my rear end hits the bumpstops. I can even see it in the videos my brother took. The truck starts to squat and then bottoms out the suspension and almost bounces back. It seems like that unloads the tires and they spin worse.


You are going to have the same issue with a slick. Perhaps notching the frame is an option or building some adjustable LCA brackets and induce antisquat.

85_prairieboy 07-06-2009 02:08 PM

Re: Drag radials or slicks
 
I picked up some M/T ET Drags. The price was right and I am towing the truck back and forth so I figured I might as well. I am heading to the track on Friday so hopefully I will come back with good news. I plan on doing some suspension work this winter so these will have to do for now

djracer 07-06-2009 04:26 PM

Re: Drag radials or slicks
 
Can you not cut the bump stops off some?

Ont67shortbox 07-06-2009 05:16 PM

Re: Drag radials or slicks
 
I agree with DJ,I cut my bumpstops and have over 3 inches clearance now.What are you running for a rear , if your going to use a slick .

85_prairieboy 07-06-2009 07:53 PM

Re: Drag radials or slicks
 
Yeah I guess I could cut the bumpstops. I wont be out anything.

The truck has the stock 8.5 inch with a set of Richmond 3.42s and a spool. I know :) it might break but I want to see what I can get it to handle. My cousin was running low 11s in his 76 Camaro with the factory 8.5 inch and slicks so I think the truck should survive for a few more passes. I don't think I am going to spray it off the line. Maybe towards the end of the season ;)

Ont67shortbox 07-06-2009 08:14 PM

Re: Drag radials or slicks
 
i was more worried about c-clips or F**d ends,too nice of truck to tear up the quarter with an axle,wheel and tire.

hotrod 80 07-06-2009 11:29 PM

Re: Drag radials or slicks
 
Slicks would be the way i would go if towing also . Imo the softer side wall will help with bad suspension also .

85_prairieboy 07-13-2009 01:28 PM

Re: Drag radials or slicks
 
The slicks worked perfect. I will post a video as soon as I can. I ran a best of 12.74 at 104. 1.82 60 foot. That was a nitrous pass. The nitrous didn't help as much as I thought a 150 shot should so I put a gauge on the bottle and it showed 600 psi. It was a cool evening.

hotrod 80 07-15-2009 02:50 AM

Re: Drag radials or slicks
 
Need more bottle pressure depending on your set up . I ran 63/71 with 5.75 psi fuel pressure and around 900 psi with a NOS cheater and had good luck .

85_prairieboy 07-16-2009 01:51 PM

Re: Drag radials or slicks
 
I am going to mount a pressure gauge on the bottle and get a bottle warmer. Just for kicks I revved the engine to 3000 and manually hit the switch and the rpm didn't really jump up. They did climb but not like I thought. That was on that cool evening with the low bottle pressure. A bottle with two passes on it by the way. I figured I should be able to gain more than 5 mph with a 150 shot. I went from 99 to 104. Not using slicks on the 99 mph pass either

Super73 07-16-2009 03:15 PM

Re: Drag radials or slicks
 
When I was testing at 700psi I saw a gain of about .1-.2 with 1-2mph at best. Moved to real pressure and picked up 7mp in the 1/8 on a 100 shot with out spraying in the first 60'

Wild83C10 07-16-2009 07:34 PM

Re: Drag radials or slicks
 
Quote:

Originally Posted by 85_prairieboy (Post 3415495)
Just for kicks I revved the engine to 3000 and manually hit the switch and the rpm didn't really jump up.

Just a tip never rev the motor to test the nitrous. You are asking for trouble there.
Second check out a NANO system. It is basically a pressure regulator. As long as it's not to hot and there is nitrogen or similair gas in the NANO tank your nitrous pressure will always be correct. You don't have to wait for the heater, just hit it.

NANO=Nitrogen Assisted Nitrous Oxide.

hotrod 80 07-20-2009 07:46 AM

Re: Drag radials or slicks
 
[QUOTE=Wild83C10;3416059]Just a tip never rev the motor to test the nitrous. You are asking for trouble there.


Not trying to start any trouble , but i have a " bang button " and a air/pressure/visual purge . I always "rough purge" the bottle with the visual ,then purge through the motor in short blasts above 3000 rpm to find the sweet spot on bottle pressure . I usually never purge through the motor more than 3 times a pass . This is dangerous if not done properly ! . Once you find the spot you can get there quicker and be more consistant . The purge takes some variables out of it . I always try to have extra pressure to adjust it down with . Just my style .

85_prairieboy 07-21-2009 12:02 AM

Re: Drag radials or slicks
 

I finally got my video uploaded. I only got 2 runs in so I was like oh crap when they lined me up against the Charger. I had gotten spanked earlier by my cousin's 406 powered RX7. But it turned out to be a good race and I beat him by a tenth.

85_prairieboy 07-21-2009 12:05 AM

Re: Drag radials or slicks
 
Quote:

Originally Posted by Wild83C10 (Post 3416059)
check out a NANO system.

I'll look into that. It sounds interesting and we have nitrogen at the shop I work at.

BigDan3131 07-21-2009 12:59 AM

Re: Drag radials or slicks
 
Have you thought to add Cal-Trac bars to it? Leaf spring rear? I read you think the rear will live compared to your buds camaro? I doubt that it will live much longer, your truck is way heavier and that alone will grenade it.

85_prairieboy 07-21-2009 07:32 PM

Re: Drag radials or slicks
 
Cal trac bars help eliminate wheel hop right? I don't seem to have that problem. I am planning to narrow a 9" and build a coilover suspension this winter. I will most likely use ladder bars. I don't want to put a lot into this stock rear end setup. If you watch the video on the bottom of the first page its kind of neat to watch the M/T lettering on the tire when I launch. The tire doesn't spin at all :)

1Bad62Pro/Street 07-21-2009 10:23 PM

Re: Drag radials or slicks
 
I am going to use The Ladder Bar with Floaters and Leaf Springs in my application on my truck.
http://67-72chevytrucks.com/vboard/s....php?p=3420591
I like the Triangulated 4 Links, but will just stick with the plan for now since I wont be Drag Racing! My dad will be helping with that since he just started his buisness. I will be posting Pics of the progression as we go!
http://z3.invisionfree.com/Shadyside...showtopic=9105


How Ladder Bars Work:
http://www.competitionplus.com/2004_...s/chassis5.jpg
The Ladder Bar is a more sophisticated traction device because it serves as an extremely rigid, bridge-type truss that locates the rear axle housing directly to the chassis. With the axle housing held firmly in place, the torque applied to the differential is now transferred immediately through the Ladder Bars and into the chassis. By using the Ladder Bar to carry power to the chassis, the front end reacts by rising. As the front of the car travels upward, rapid weight transfer is created which "plants" the rear tires and propels the car forward.

Housing Floaters Eliminate Suspension Bind:
http://www.competitionplus.com/2004_...s/chassis6.jpg
When using ladder bars with a leaf spring rear suspension, the axle housing cannot be rigidly attached to the springs. If it were, severe binding of the rear suspension would occur because the Ladder Bar and the leaf spring both travel in separate competing arcs. By allowing the housing to rotate and glide on the leaf spring, the Floating Housing Mount eliminates the bind and allows the Ladder Bars to work the way they were designed.

Key Performance Benefits of a Ladder Bar or Fourlink Suspension

Substantially improved traction control over existing suspension.
Helps eliminate wheel hop, chassis "squat", and other adverse launch characteristics.
Potential to shorten 60 ft. times through additional suspension adjustability even if car currently hooks well.

Which one is best for my application? Selecting a fourlink or ladder bar suspension

Benefits of a FOURLINK:
The improved suspension adjustability is the greatest benefit and can shorten quarter mile times, or more specifically, 60 ft. times through fine tuning of the instant center to yield an optimal percentage of rise for varying track or traction conditions. They are well suited for short wheelbase cars that have minimal clearance from the rear axle centerline to the drivers seat. They are also well suited for Street Rod and Pro Street applications where uneven road surfaces are encountered which can be compensated for by running the bars in a parallel fashion.

Benefits of LADDER BARS:
A Ladder Bar suspension is a substantial improvement over a stock suspension that may utilize a pair of leaf springs or trailing arms and helps eliminate spring wrap-up on leaf spring equipped cars. It is quite easy to install and maintain, and typically requires fewer floorboard modifications. Adjusting a pair of ladder bars is quite easy due to the fact that there are only adjustment holes at the front of the bar. The remaining adjustment is in the lower portion of the bars and is for returning the pinion angle to its correct position at 1 to 2 degrees nose down in relation to the driveshaft.
Still Uncertain?

Maybe this will help. If your primary concern is to go drag racing and achieve the best possible 60 ft. times and possibly run te only adjustment holes at the front of the bar. The remaining adjustment is in the lower portion of the bars and is for returning the pinion angle to its correct position at 1 to 2 degrees nose down in relation to the driveshaft.
http://67-72chevytrucks.com/vboard/a...1&d=1228321620
http://67-72chevytrucks.com/vboard/a...1&d=1228321620
http://67-72chevytrucks.com/vboard/a...1&d=1228321774
http://67-72chevytrucks.com/vboard/a...1&d=1228322151
http://67-72chevytrucks.com/vboard/a...1&d=1228087389
http://67-72chevytrucks.com/vboard/s...d.php?t=315664

Gearz - Ladder Bar System (Season 2 Episode 5)
http://www.gearztv.com/showdetails.php?episode=33


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