Went drag racing for the first time tonight and had alot of fun but I am kind of disapointed in my numbers.
My car is a 02 z28 6-speed convertible. I ran a best of 14.391 my best trap speed of the night was only 101 mph? My 60 ft times averaged about 2.4 with one 2.2.
The weather was about 97 deg and about 80% hum.
Rear tire pressure was set to 30psi and I would leave the line at about 2500rpm.
Am I doing something wrong? Was it the weather? I was hoping for high to mid 13 second runs traping about 105 or better?
Thank you for your time and consideration any advice would be most welcome.

 

Is the car stock? Considering the weather and your 60' I'd say those times are about right. 6 speeds are tough to 60' in on radial tires and the driver has alot to do with it. It takes practice to say the least.

 

30 psi for rear tires is pretty high, you could have gotten better 60 foot times with lower pressure. I wouldn't worry too much about the low 14s in 100 degree weather with 80% humidity. Your trap speed definitely should have been higher though.

 

Sounds exactly like what happened to me last night. It was my first time out to w/ my car. It was about 90 deg. and my best time was 14.1@101 w/ a 2.4 60'. I have a 00' M6 SS w/ lid and cutout. The clutch is going though so that could be another reason why my times were so bad.

 

Heat has alot to do with it. I raced my car with no cool down time, right off the interstate. I then waited an hour for it to cool down and my time was a 1/2 second better.

 

LS1's don't run worse when hot, in fact dynos show an increase once they're a little "hot". I can hot lap at the track and it has no detrimental effects on my times vs. letting it cool for 20 minutes. The weather is definitely not helping you out though...that's what it's like here too. High humidity and outside temps slows you down vs. low humidity and low air temp.

 

No, LS1's don't run worse when THEY are hot as ~200* is optimum.....but they do run worse (like any internal combustion engine) when the AIR is hot. That's the killer.

You need to practice practice practice and aim for 2.0's at the 60' mark. You'd be amazed how much power 97* air takes away. Keep practicing and see what happens with a good launch and cool, crisp fall air.

 

The hot air and humidity kill good elapsed times. Another factor in your times is the fact that it was your first time to the track. You can't expect to run your best on your first attempt. It takes a lot of practice in drag racing. The casual observer will tell you that it looks easy, but in reality it really isn't as easy as it looks....espcially if you're serious about improving your times. To me, it's the elapsed time that is important. The big MPH is nice, but it's really not that important.

 

your loosing .2-.3 just cause its 95*+ out and your leaving alot on the table with the 2.4 60' times It is said that ever .10 in the 60' you drop .2 in the 1/4. Personally i think its more like .15 for every .10 you drop in the 60' So in good weather and better traction you would drop a full second off your times.... What is your location, that also has alot to do with what you will run caus if your in the desert your always going to run slower than someone like me at sea level and cool temps...

 

I am sorry, I have alot of exp. with LS1's as well as LT1's. But your time is just about right.... given the conditions. I am going to break this down into sections to explain each one the best that I can. If I miss something, please add it in.

The Car:'02 FBody 6 speed Convertable- Well the 1st issue is that it is a convertible and you have added weight to the car over a hardtop car (in stock trim). Your MPH trap speed is a weight to hp ratio! The issue I have always seen with a 6 speed is that consistant launches are near impossible (i said nearly). Getting used to have the car hooks up is key. Given the engine mods and suspension (if at any) you need to get your car's rpm to the point where it bogs or spins. Find the sweet spot. But long story short 2.0-2.5 60's is normal for a fairly stock 6 speed LS1 with a AVERAGE driver.

Before I forget, was with regard to Tire PSI, its not optimal to have high rear tire PSI, but it isnt good to have it too low. This is a radial, and having it a good range of pressue will help it NOT spin, but later on down the back half of the track your not losing MPH due to a under inflated tire riding on its side walls.

In reality if you can dead hook with 35 psi in the back you will do better than the same car that hooks on 25 psi becuase you (35psi guy) should be out mph the guy with 25 psi. Generally put the fronts up to 45-50 psi and the rear to 27psi. Then run the car, if you need a few more out of the rear then do so, but if dont need that little, add more.

Just make sure you write down on the time slip how the car was set up and what were the conditions, did you spin, or did you bog, did you miss a shift, was the air cold, was it warm, etc etc. Track your progress!!!

Engine Temp: Some car are effected while others are not. FOR the most part LS1's dont seem to be effected by hot lapping. But the reason why that is you guys have a Composite (plastic) intake manifold that does not asorb as much heat as a LT1 aluminum intake manifold. Neither has coolant running through them but LT1's heat soak and we cant cool them off. Ice is the best solution but as soon as you start the engine, it immediately heat soaks again. But for LS1's heat soaking in the block and cyl heads is normal because your engine coolant regulates that. Your only worry would be pre-ignition(detonation) but in stock form that should NEVER be an issue.

Outside Air Temp: Fact is, HEAT KILLS. What every racer (from imports to domestic) wants is COLD AIR, the colder the air is, the less the oxygen molecules expand. You want the most dense air (oxygen) and fuel mixture. Fuel is what makes combustion happen, fuel makes the power happen. But having a denser charge of oxygen will make more power given if the fuel req. was the same. I know its kinda confusing but just remember, the colder the air, the more power you will make than if the air was hotter. Humidity works the same way, water molecules are taking up space where oxygen molecules could be sitting and thats bad too.

Getting the Density Altitude from someone who has a meter or someone at the tower will help you figure out where you stand. For example you run 14.2XX at 101 where it has a Static altitude (your actual elevation) but then the DA for that time of day was 4000 feet, well I will bet money on it. That the same car in a lower DA (maybe 300) will show signs of improvement. Thats why people run fastes in places like E-town and Atco becuase their DA on average is REALLY low. ALso great track prep