Shave 2 seconds off your 1/4 mile times for free

BuddTX

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I do something along the same line . . .

I just put super unleaded in, and put a couple of more PSI's in my tires . . .same result /ubbthreads/images/graemlins/naughty.gif
 

iddibhai

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more psi? that would help in autocross, but drag? anyway, funniest thing i read in a LONG time! got any more? thanks!
 

Gimpy00Wang

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Re: Shave 2 seconds off your 1/4 mile times for fr

More psi...hehehe. I'd typically drop 2-3psi when I went to the track. Island Dragway. BuddTX used to live right by there! /ubbthreads/images/graemlins/smile.gif Anyway, it's a really funny post. I enjoyed it a LOT!

- G!mpy
 

Unicorn

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Re: Shave 2 seconds off your 1/4 mile times for fr

It actually does make sense in one respect. A higher pressure reduces the amount of force needed to get and keep the tire rolling. I'm sure that there is a real term for this, but I'm tired. /ubbthreads/images/graemlins/smile.gif Of course it also reduces friction, so your tires might be more likely to spin out, especially the rear, and that would just slow you down.
 

SilverFox

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Re: Shave 2 seconds off your 1/4 mile times for fr

Hello Unicorn,

You are in my home town. Send me an email.

Tom

By the way, if you are going to go up a grade in octane, don't forget to advance the timing a little too.
 

V8TOYTRUCK

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Re: Shave 2 seconds off your 1/4 mile times for fr

When my friends go race, they inflate it to max psi in the rear for less rolling resistance. They also change the camber so edge of the tire is touching the ground. Of course this is only for the back tire. In the front they have a fat Mickey Thompson slick ( Fat for imports at least ) connected to superlight Bogart drag wheels. Those same friends run 12.6 N/A in a 1.8L motor
 

Gimpy00Wang

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Re: Shave 2 seconds off your 1/4 mile times for fr

Yeah, I have a few friends that consistantly hit mid 12's. They all have something different. One is an S10 with a small block worked over, another is an ITR NA with Toda everything (way too much $$$ there /ubbthreads/images/graemlins/smile.gif ), SC TA WS6 (pure evil), and a Talon with tons of work. The WS6 was hitting low 11's last year, but I think he wrecked it. The Talon is a deamon. His best time was 10.79 at Island. Great thing is...he still has A/C, stereo, and full interior.

Oh, my car? It's just a '00 Si. My best time was 14.52 at Island, but I've since removed most of my mods in exchange for $$$ and better fuel economy! 8^) Now it's pretty close to stock speed-wise.

- G!mpy

[ QUOTE ]
V8TOYOTATRK said:
When my friends go race, they inflate it to max psi in the rear for less rolling resistance. They also change the camber so edge of the tire is touching the ground. Of course this is only for the back tire. In the front they have a fat Mickey Thompson slick ( Fat for imports at least ) connected to superlight Bogart drag wheels. Those same friends run 12.6 N/A in a 1.8L motor

[/ QUOTE ]
 

NeonLights

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Re: Shave 2 seconds off your 1/4 mile times for fr

When I go to the drag strip with either one of my Dodge Neons, I usually overinflate the rear tires for less rolling resistance, and underinflate the fronts for better traction. I usually start out around 25 psi front and 40 psi rear, and go from there.

I got my DOHC Neon down into the 14's a couple years ago, that was just with a few bolt-ons and some weight reduction (nothing nearly as drastic as the car in the SCC article though). I have since added a full roll cage which was over 100 lbs, but have also bumped up the power a little more. The car is really built more for autocrossing and open track events, so it isn't optimized for the drag strip. The -2.5° camber I run in front can't help traction off the line much at the drag strip.

-Keith
 

iddibhai

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Re: Shave 2 seconds off your 1/4 mile times for fr

OK, i was thinking less psi on drive wheel to get larger contact patch, but the higher psi on the nondriven axle makes sense, reduce rolling resistance.
 

Unicorn

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Re: Shave 2 seconds off your 1/4 mile times for fr

Rolling resistance! That's the term I was trying to think of. It's the same reason that a street car should have it's tires inflated to the max to increase fuel economy. Not much, but every little bit helps.
That's what happens when you spend too much time online instead of in bed.
 

Wolfen

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Re: Shave 2 seconds off your 1/4 mile times for fr

Car Craft or Hot Rod Magazine did that to a Cadillac, maybe in 1982-83. Quite awhile ago. /ubbthreads/images/graemlins/smile.gif
 

Skyline

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Re: Shave 2 seconds off your 1/4 mile times for fr

LOL, that was pretty funny. Needless to say, I won't be doing that to my car! /ubbthreads/images/graemlins/blush.gif
 

iddibhai

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Re: Shave 2 seconds off your 1/4 mile times for fr

unicorn, you mean inflate the tire to the max indicated pressure stamped on the sidewall? gee, that could get harsh... the sidewall max is, to my knowledge, the max pressure the tire can hold--it's there since the same tire may be used on a wide range of vehicles with different weights and payloads; the heaver vehicles will need to use the higher pressure, but just inflating to max would really make a harsh ride, with not much gained in MPG i would think. sure the factory spec is a compromise in terms of handling/safety/ride/wear, generally speaking (this is talkin about family cars, not sporty or niche vehicles). i tend to run a couple psi over spec on some cars, mainly to get a bit more handling at the expense of a tiny amount of noise and ride compliance.
 

NeonLights

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Re: Shave 2 seconds off your 1/4 mile times for fr

A lot of the question of how much to (over)inflate your tires has to do with your tolerance for NVH (Noise, Vibration, Harshness). For two of my cars the recommended tire pressure is 32 psi, but for some of the tires I use, the max psi on the tire sidewall is as high as 45 psi. Around town I typically run 36-38 psi, and on trips I will go as high as 40 psi to minimize rolling resistance. Won't make a huge difference, especially if you are running wide or sticky tires already, but every little bit helps. You also want to be careful with overinflation because it could lead to uneven tire wear. If you overinflate your tires and after awhile notice the middle of the trewad is wearing a little faster than the outsides, drop the psi down a little to even things out.

-Keith
 

iddibhai

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Re: Shave 2 seconds off your 1/4 mile times for fr

true.. our camry calls for 29 all round for general use, 32 for towing and 35 for extended high speed use where permitted /ubbthreads/images/graemlins/wink.gif I run 36-38f, 32r; higher in the front because it wears out the shoulder otherwise (used to be 4cyl camrys had all same psi, v6 had a few pounds extra up front; now it's all the same), and a little high on the rear to get better handling w/o losing so much contact patch that i have to worry about snap oversteer /ubbthreads/images/graemlins/smile.gif. the odyssey calls 36 all round, and we run it 38f36r since beyond that it gets harsh. bmw seems to have a good idea (well the car is well balanced to start with) 29f 32r, and it works out just fine as far as ride/handling goes.
 
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