DescentBB

It's time to take my 210 horsepower 2004 Jeep Liberty Renegate out to the drag strip. My friends and I all decied to take our cars (two '92 4runners, '04 Liberty, '04 Titan, '67 Mustang, '82 (I think) Trans Am, '93 Camaro, '95 Trans Am) out to the drag strip and do one or two runs, just for fun and to test out the times. However, (obviously), I've never done this before. What kind of things should I know about in advance? How does it work? Do you have to pay per race, per hour, or at all? Is there a "free race" time or do you have to be entered into some kind of ladder to race? Will this completely destroy my car and I shouldn't do it?

I think normally you reserve some track time. But it can vary.

Have fun.

Working the engine out once in a while is good since it will loosen up the carbon build up inside the engine and keep the rings around the pistons moving and carbon free. The worst that can happen is your transmission breaking but thats only if it has alot of miles on it (200,000+)

Yeah I only have 30k on it or so. Should I use premium fuel/does it matter at all, and if I do, should I run it near-dry before I fill 'er?

And thanks

DO NOT run your tank near-dry! This can cause the flakey residues which sit on the bottom of your tank to get sucked into the fuel system. In general, the conventional wisdom is never to never allow your tank to get below 10% full.

Nitrofox125 wrote:Yeah I only have 30k on it or so. Should I use premium fuel/does it matter at all, and if I do, should I run it near-dry before I fill 'er?

And thanks

I'd just stick with what ever fuel you're using now. Raising your octane points isn't going to make your car any faster. This might sound a little odd but taking out your spare tire, and running only half a tank of gas might give you a little bit more pick up but not by much.

Do whatever you can to remove any excess weight like spare tire, back seat, etc will help. Also, keep the amount of fuel as low as reasonably possible. IE, don't make the passes with a full tank. Each gallon of gas is about 8 lbs or so. Good luck and have fun.

Actually higher octane is better for the engine if you didnt know that already.

That's what I was thinking, if I'm already giving the engine a little purge, why not do it with a little cleaner gas? Heh, if I can afford it...

Thanks for the tip to not run it dry, though I'm afraid it's too late for that twice now Just a few weeks ago I coasted into the gas station in Neutral, go me.

But thanks everyone for the tips, I'll post pics and times when I get back from it!

And higher octane can cause engine knocking if you an't careful.

Behemoth: The only reason that you would need higher-octane gas is if your car was detonating or pinging. Thats it. If your car runs fine on 87 then theres absolutely no reason to pay more for a higher octane, since it doesnt give your car any more power or clean it better (certain chains might add special detergents but you'd need to use their gas for more than just a few 1/4-mile passes).

TRFX: Having too high of an octane rating wont hurt your engine... o_O You're thinking of an octane rating that is too low.

Actually it DOES make the engine run cleaner, my dad was a mechanic and he says that all the time.

Behemoth,
Higher octane does not make a motor run "cleaner". The *only* purpose for higher octane is detonation resistance. Some fuel manufacturers do add chemical cleaners that work, but it has nothing to do with octane rating.

Fill it up with Race Gas

Ok, some things need to be cleared up:

What is Octane? It is a rating which says how much pressure/heat needs to be applied to your fuel before it ignites without a spark. The higher it is, the more resistance it has for pressure and heat. So even if an engine works on an 87, there can be times where the engine is really hot and the building pressure causes the fuel to ignite before the spark is generated. Because of this not only your efficiency but your peformance goes down. It may not be audible, but it happens.

There are cars out there that requre premium and it says so on the dash, especially cars with superchargers in them. There is a reason for that. Some of these car's computers pull ignition timing from the engine. Therefore if you use lower octane fuel your performance and efficiency will not be where its supposed to. I have felt a difference on a Bonneville and a Taurus (although the latter is just a rust-bucket put-put car now). It has nothing to do with "clean" or "dirty" fuel, it has to do with how that fuel is ignited.

So which octane should you put into your tank? The best way is for you to do a trial-and-error yourself and see firsthand yourself which fuel gives you better efficiency and not have to loose power.

Of course, none of this means squat if you are getting gas from a lousy supplier that poorly refines/filters ect its fuel. You can have 93 octane and still have lousy efficiency if the gas is bad than if you went from a good fuel that was 87 octane. Companies such as BP, Mobile, and Phillips 66 tend to have good quality gas, especially BP so I would fill up at those stations.

So to re-cap, higher octane does not "add" any more performance than the engine is designed to output, and nether is a lower octane "dirtier" than the higher. How pure the gas is depends on the supplier. But lower octane may lower performance and make your car inefficient because of how the fuel is ignited. How true this is depends on how the engine is built, and like I said you will have to try it out for yourself. But the noted performance and efficiency I get using higher octane in my cars isnt because I got someone behind me pushing thats for sure...

I never said the fuel itself was "dirty" at all i said the engine runs cleaner with higher octane, you can argue all you want i was just offering advice.
Also it would definatly be wise to lessen as much weight as possible as someone stated earlier. Less weight = Faster acceleration.

Dude I wasn't arguing I was just giving some insight to Nitrofox.

But I dont believe it will make a difference how clean the engine will run if the octane is higher unless it comes from a clean supplier. Can you explain?

The engine will always perform better (no matter how slight of an increase it is) if its running clean.

Vindicator wrote: TRFX: Having too high of an octane rating wont hurt your engine... o_O You're thinking of an octane rating that is too low.

My mistake I had it backwards. But are you sure about that only becasue heard if you go to far over it can hurt engine performance over time. I'm only going by what I read some years ago after doing some research on high octane and octane boosters.

Behemoth wrote:The engine will always perform better (no matter how slight of an increase it is) if its running clean.

Right. The question is, does "higher octane" = "clean"? Or are they unrelated? TW seems to think they're not related, while you seem to think they are. Do either of you have a more authoritative source?

Yeah just run 87 octane in that Liberty, a higher octane would be of no help and to high of an octane could hurt performance.

Check your air filter, make sure it's clean.
Making it as light as possable is good advice.
Inflate you tires to the maximum cold pressure ( do this when the tires are cold ).
Keep you windows up when racing and your AC off
If the fuel filter is easy to get to, change it.
Check spark plugs and wires, make sure they're in good condition.

But the most important thing of all is to HAVE FUN!!

#1 Octane

http://en.wikipedia.org/wiki/Octane

#2 Octane and pinging

http://en.wikipedia.org/wiki/Engine_knocking

Basically, Top Wop is right. The higher the octane rate the more uniformly the combustion takes place in the cylinder. As follows from the 2nd article, engines with higher compression rates/operation temperatures will need higher octane rated fuel to prevent the pinging described in article #2. The downside of this is that putting more expensive fuel into your engine than it actually needs is a waste of money: If the combustion process is already perfect you cannot make it better. It is however wrong that a higher octane number can damage your engine.

I'd rather try some high performance oil (for engine and gear), or additives. Such stuff can increase engine performance by 3% (sometimes even more), which is more than it sounds.

P.S: I doubt that there is "dirty" and "clean" fuel in terms of stuff that simply should not be in it (or be filtered out of it) depending on the brand.