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I'm trying to cheat

KPoole9008

New Member
I have a rearend from a 2000 GMC Jimmy 2 wheel drive with a 3:08 ratio. I want to have more of a "holeshot" when first taking off. I am looking at changing the ratio to a 3:42 {a 3:73 is too low} but am wondering if I can accomplish the same thing by going to a shorter tire. The tire size on the rear is 275/60/15. They are 27 inches tall. Can I get away with going with a shorter tire and if so how tall?
 
To go from a 27" tire with 3.08 diff to a smaller tire equivalent to a 3:42 diff.......3.08 / 3.42 x 27 = 24.3.
 
If you get to short a tire your car will suffer from "funny stanceitus" and any performance gain will be over ridden. (IMHO)
 
To go from a 27" tire with 3.08 diff to a smaller tire equivalent to a 3:42 diff.......3.08 / 3.42 x 27 = 24.3.


if your gonna have to buy some biggies of another size and rims....do as Ron suggested....drop the coin for a good used Doug Nash 5 or a OD automatic. Or just gear it so it'll run and drop in a seperate OD unit....if ya got the room....
 
"I'm trying to cheat." I thought you might be talking about drag racing....

I never thought of it as cheating (inch counter or delay box in a street bike) I always thought of it as.. advancing the sport - like traction control on pro-stock Harleys. NHRA = No Harley Rules Anticipated.

Oops, off topic huh?
 
"I'm trying to cheat." I thought you might be talking about drag racing....

I never thought of it as cheating (inch counter or delay box in a street bike) I always thought of it as.. advancing the sport - like traction control on pro-stock Harleys. NHRA = No Harley Rules Anticipated.

Oops, off topic huh?


Haha....here before too long theres a couple of NHRA types thats just gotta give me a hard time.....I'm gonna use that one on them. They have a tendency of getting really pissed at me when I try to give them a hard time.
The Inspectors can be total jerks, usually....they're ok, but sometimes....
 
"I'm trying to cheat." I thought you might be talking about drag racing....
Several years back, a heavily-backed NHRA Pro Stock team got caught with their pants down around their nitrous, errrr, I mean around their knees. A favorite saying of one of that team's owners was, "It's not cheating until you get caught."

Some of the stories I could tell about the Oxide brothers, Propylene and Nitrous, and their effects on enhancing the performance of an NHRA Pro Stocker... Some stories need to be left untold, although changing anyone's name would be a waste of time, since nobody was innocent. :wolf:

Twenty years ago this very weekend, we were at the NHRA World Finals. A pal from that area was running E/ED with inline, 6-cylinder Nissan motors and he hurt his last good piece. So, we shipped one of our V-6 motors to him, so he could run D/ED. We were looking at possibly switching to that class and figured we could learn a bit from the venture. After the second round, both cars were looking pretty smart and one of the NHRA tech guys came down on us like white on rice. The car we were running was a bit flaky and we had the fuel tank mounted ahead of the foot box. According to NHRA rules, from the point to where the fuel lines entered the footbox, to the point where they exited under the seat, they were enclosed inside an aluminum channel, that fastened to the floor with Dzus buttons. And I say lines, because we ran a Mallory fuel system that used a return line to dump excess fuel back to the tank. Someone didn't care for the way we seemed to be punching out competitors with both cars, so NHRA descended on us with evil in their eye. "Someone" felt there were too many fuel lines on our car, so we were either cooling the fuel (illegally), or we were introducing something to the fuel. The complaints on the other car were too numerous to mention, but they had both of us removing body panels and I had to expose all the fuel lines on our car. I found it rather interesting when that same "someone" won Comp at the U.S. Nationals, a year or two later. "Someone's" car suddenly picked up almost 3 tenths in the final round and was mysteriously allowed to bypass both the scales and fuel check on his way to the winner's circle. "Someone" had a very large and very well-known sponsor at the time, said sponsor spending trainloads of cash sponsoring cars in nearly every category.

There is an end to that story at Pomona. The second car took out the well-sponsored car and we ended up running him in the semis. We didn't want to cheapen a possible win by making him stay at the trailer, so we agreed to race. Some idiot :suicide: made a bad clutch call on our car and it shook itself out of the groove in 3rd gear. We figured all was not lost, because the second car was still fast enough to win the race. One of the slags on that team took it upon himself to take some air out of the rear tires (not understanding our V-6 stuff needed to spin the tires a touch to keep from tugging the motor too low). It meant a red light in the final and that was the day I was beat twice at the same race. I could go on to tell the story about the well-known Top Fuel chassis builder who had <cough, cough> "borrowed" a golf cart from the NHRA corral and had backed it all the way to our trailer after the race, to enjoy a few cold ones. He ended up backing around our trailer to leave, backed into a light pole, turned the cart on its side, dumping him and the widow of another chassis builder onto the ground, causing himself a massive head wound. But that story, complete with my being questioned by the Pomona PD is best left for another time. :angel:
 
Someone didn't care for the way we seemed to be punching out competitors with both cars, so NHRA descended on us with evil in their eye. "Someone" felt there were too many fuel lines on our car, so we were either cooling the fuel (illegally), or we were introducing something to the fuel. The complaints on the other car were too numerous to mention, but they had both of us removing body panels and I had to expose all the fuel lines on our car. I found it rather interesting when that same "someone" won Comp at the U.S. Nationals, a year or two later. "Someone's" car suddenly picked up almost 3 tenths in the final round and was mysteriously allowed to bypass both the scales and fuel check on his way to the winner's circle. "Someone" had a very large and very well-known sponsor at the time, said sponsor spending trainloads of cash sponsoring cars in nearly every category.

Yea Mike, thats one of the reasons why they ought to make it mandatory for the 'thugs' in the NHRA and AHRA to have 'personalitily' reviews....
While I'm a extremely creative typa builder....I look upon the rulebook as not exactly what it says, but, what it doesn't say. I've been known to mount this thing ahead of that thing to give a little advantage, or this instead of that. If I'm gonna be accused of being illegal until proven legal....I'm gonna have some fun doing it and be a splinter in their side. I'm kinda glad to say I've been one of the most protested builders because of the crap the officials do to the good folks.
They tell me 'you can't do that!' My answer? 'WHY, it ain't in your dawm rulebook....lets race!'
The Best on was using chassis flex to help accelerate to forward imputus! Ha! That one stuck in their craw! And sliding stuff so the torque reactions can help the chassis load the tires? Oh, that ws a good one....HeHe.... thank god I'll be retired, again , in a few years and all I'll do is deal with hotrods....and my own private customers in racing....
 
Thanks for all the help. I went to the recycle [ junk ] yard and bought a complete rearend with disc brake calipers, rotors, emergency brake cables,etc from a 1998 Chevy Blazer 4x4. It is a 3:42 ratio. I got a deal on it for $150.00.
 
Thanks for all the help. I went to the recycle [ junk ] yard and bought a complete rearend with disc brake calipers, rotors, emergency brake cables,etc from a 1998 Chevy Blazer 4x4. It is a 3:42 ratio. I got a deal on it for $150.00.

Might want to double check that ratio, most 4x4 came with 3.73's. If it was a ZR2 model its defiantly 3.73.
 
With a light bucket and a good powerful motor, lets say a hot 327 on up to a 388, 3.23's or 3.55's would be the ticket because they have to power to pull agianst that tall of a gear and a medium tire size.
3.73's are good for the same motors, maybe just a little lesser motor, pulling agianst a tall tire. A REALLY TALL tire will take 3.90's, maybe 4.11's....but as light as these cars are, you don't need any lower gears, cause your not lauching a 3800 pound car from a standstill.
When your setting your car up, you need to take into consideration the whole car, power of the motor, your trans., your cars weight, and your TIRE SIZE when you go shopping for that rear gear.
There's alot of charts or wheel type calculators where you can plug your info....and get really close 1st time out.
To have your cake and eat it too....the ticket is to go like Ron said....4.11's and the overdrive.
A good strong 388 with a powerglide and 3.55's with some tall sprint cars tires....you'd smoke just about anything on the street except for maybe some severe streetfreaks pushing upwards of 800 horses....
Remember, Mike, Ted and I have said the power to weight ratio is supreme....for the utmost in performance....it is.
 
Might want to double check that ratio, most 4x4 came with 3.73's. If it was a ZR2 model its defiantly 3.73.
I counted the teeth on the ring and pinion gears before I bought the rearend. There are 12 teeth on the pinion gear and 41 on the ring gear. That comes up to a 3:42. I know you are correct in saying most 4x4 Blazers have a 3:73 ratio. I was lucky to find the 3:42 I wanted.
 
I counted the teeth on the ring and pinion gears before I bought the rearend. There are 12 teeth on the pinion gear and 41 on the ring gear. That comes up to a 3:42. I know you are correct in saying most 4x4 Blazers have a 3:73 ratio. I was lucky to find the 3:42 I wanted.

If you have a good strong motor, wide tires even the tall 15's.....you'll have a good clean takeoff. Tire spin will be proportional to how hard you mash on the go pedal! Remember....your not pushing a whole lotta weight!
 

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