60' questions.
- Thread starter 2themax2
- Start date
The height of the tire changes but the circumference is still the same. I don't see how it affects gear ratio.
I don't worry about circumference, I worry about the radius of the center of the axle to the track. Try pushing a rear axle with a lower psi tire on one side and see what happens. Overall circumference is close to the same but radius from axle to the ground is not, making the ratio different thus pulling the axle in a circle. Just my opinion.
Interesting, I will have to experiment with my air pressures more next time I get to the track. I was always told to run the rears less than the front, usually was only a few pounds difference though...
I usually run my rears close to the fronts but I'm curious if I deflated both my back tires and drove straight if the tires would bind up.
I run 28 front and 18 rear on my cheaters and it launches smooth every time. Not saying it is right but it works for me
This past weekend I tried 20r 25f with 420s and the front end still danced around pretty hard. Tried 32 all around weeks ago. Same thing, pretty hard hopping.
10pounds is about all I can get before it really gets hairy. Sleeves and DHD brace. T bolts out and it have 2" drop shackles in the rear.
At Irwindale I ran a 7.7 with 28 psi up front and 32 out back. I have 22s though and my ranchos set at 9.. But on a non prepped track I can cut 7.9 full weight with 42 psi on all 4 corners and my ranchos have to be set at 5 in the rear. Next race day I'm going to try to lower my tire pressure to 34 out back and see if I can get a 7.8
So far I'm very happy because I can hit 7.9 all day on a no prep track
Traction bars out back
What's your set up? I pretty consistently run 7.6 @88 -89 Just can't get the 60' to make up some time on the big end.
Caltracs, ranchos, overloads removed, 3" lowering shackles, and that's it for suspension.
I usually cut 1.8 60' the 7.7 was with a 1.7 60' which isn't bad considering I just have a billet 75 and stock fueling.
Maybe this will work? I cant figure this thing out
http://vid342.photobucket.com/albums/o406/yamaha537/truck/IMG_3096 1.mp4
hopefully the video uploaded. Just to give a prospective on whats going on maybe
http://vid342.photobucket.com/albums/o406/yamaha537/truck/IMG_3096 1.mp4
hopefully the video uploaded. Just to give a prospective on whats going on maybe
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I ran toyo proxes st1's for a long time. This is with a full kryptonite front end, rancho 9000's, cal trac's, and spring clamps. I could never cut a consistent 60 foot to save my life. Tried all sorts of tire pressures. So I finally got a deal on some drag radials and read up on caltrac tuning and I can now cut a low 1.6 every time in my 7500lb whale. If I could get my converter to stall a little higher it would go high 1.5's
I run my pressures equal between the front and the rear. The caltracs are setup up with an 1/8th inch or so of space between the pin and the leaf with the bar in the top hole. I also no longer run spring clamps. Ever since running this way, the truck leaves dead consistent unless the track is total crap.
I run my pressures equal between the front and the rear. The caltracs are setup up with an 1/8th inch or so of space between the pin and the leaf with the bar in the top hole. I also no longer run spring clamps. Ever since running this way, the truck leaves dead consistent unless the track is total crap.
I might throw stock wheels on the truck this weekend and try again. I think maybe the big offset on my 20s are pulling the front end around a bit. Not sure if anyone can see it in the video but it squats pretty hard and that's when the front wheels start to toe in and out
Sorry to the OP I'm not trying to jack your thread. Just gathering information to help us both hopefully.
Sorry to the OP I'm not trying to jack your thread. Just gathering information to help us both hopefully.
