[rkaslyfox]

Disappointing night at the track

I'm the weak link :huh:
507rwhp/490rwtq

my best run:
rt-.414
60'-1.822
330-5.129
1/8-7.820
mph-94.84

Had a very difficult time trying to launch, also at high rpm it's very difficult to get in and out of gears.

Video-http://www.youtube.com/watch?v=LgpOxnQR5lQ

 

[BigMikeyT88]

Your times will improve by the next outing, what was your rear tire pressure?, looks like you would be running an 11.6-7 with those 1/8th mile times.

 

[rkaslyfox]

Your times will improve by the next outing, what was your rear tire pressure?, looks like you would be running an 11.6-7 with those 1/8th mile times.

my rear tire pressure was 28 psi. . . .I'm not sure whether I should be powershifting or lifting off the throttle?!

 

[The Punisher]

In a drag racing situation I would be power shifting.But I don't have experience drag racing a six speed C5.

 

[BigMikeyT88]

my rear tire pressure was 28 psi. . . .I'm not sure whether I should be powershifting or lifting off the throttle?!

28 psi is just like stock tire pressure, lower it down to 20 heat them up real good and then try launching you should have better 60', I don't powershift some say do it some don't, I like to come back from the track with a working tranny :thumbsup:

 

[iburke]

My take on power shifting (shifting with accelerator to the floor). With high horse power cars you will get three things(besides the obvious broken parts), you will put the engine in to the revlimiters, you will shock the engine and drivetrain when the clutch locks up, and when the rear wheels lose traction(street tires) the traction control will kick in and slow them down or if no traction control you could lose control of the car. The 1/10 of a sec you are off the gas shifting the engine will lose about 2000 rpm which if you are geared right will put you in the power band and with a smooth roll on the throttle you will not lose traction and will have max acceleration....this does not apply to drag cars with slicks or high traction tire, and beefed up drive trains. A trick a lot of motorcycle riders use is to put a kill switch on the bike you then apply pressure to the shifter then you actually turn the engine off and back on again this removes the stress on the shifter allowing it to actually shift as fast as you can toggle a push button switch.

Now if I don't get flamed to bad by the experts...If any one can show me the error in my thinking I am open to their input.

Dang did I say all that.:laughing:

 

[rkaslyfox]

My take on power shifting (shifting with accelerator to the floor). With high horse power cars you will get three things(besides the obvious broken parts), you will put the engine in to the revlimiters, you will shock the engine and drivetrain when the clutch locks up, and when the rear wheels lose traction(street tires) the traction control will kick in and slow them down or if no traction control you could lose control of the car. The 1/10 of a sec you are off the gas shifting the engine will lose about 2000 rpm which if you are geared right will put you in the power band and with a smooth roll on the throttle you will not lose traction and will have max acceleration....this does not apply to drag cars with slicks or high traction tire, and beefed up drive trains. A trick a lot of motorcycle riders use is to put a kill switch on the bike you then apply pressure to the shifter then you actually turn the engine off and back on again this removes the stress on the shifter allowing it to actually shift as fast as you can toggle a push button switch.

Now if I don't get flamed to bad by the experts...If any one can show me the error in my thinking I am open to their input.

Dang did I say all that.:laughing:

Interesting points. . . .For me an extra 1/10 here or there is not worth the extra $ for repair!

 

[Patrick]

That 1/8th MPH is huge man. Huge....

 

[itchynackers]

I'd say your off at least 5mph on the 1/8 trap with your power. Huge it's not.

 

[Patrick]

I'd say your off at least 5mph on the 1/8 trap with your power. Huge it's not.

94 mph is plenty huge.

He had a pretty good 60' time so I doubt he's going to be able to see 99mph ever in the 1/8th on the same tires.

 

[AK's Z06]

My take on power shifting (shifting with accelerator to the floor). With high horse power cars you will get three things(besides the obvious broken parts), you will put the engine in to the revlimiters, you will shock the engine and drivetrain when the clutch locks up, and when the rear wheels lose traction(street tires) the traction control will kick in and slow them down or if no traction control you could lose control of the car. The 1/10 of a sec you are off the gas shifting the engine will lose about 2000 rpm which if you are geared right will put you in the power band and with a smooth roll on the throttle you will not lose traction and will have max acceleration....this does not apply to drag cars with slicks or high traction tire, and beefed up drive trains. A trick a lot of motorcycle riders use is to put a kill switch on the bike you then apply pressure to the shifter then you actually turn the engine off and back on again this removes the stress on the shifter allowing it to actually shift as fast as you can toggle a push button switch.

Now if I don't get flamed to bad by the experts...If any one can show me the error in my thinking I am open to their input.

Dang did I say all that.:laughing:

:agree: Why power shift at all? Get you 60' time down a smidge, it's all in the launch.:thumbsup:

 

[itchynackers]

94 mph is plenty huge.

He had a pretty good 60' time so I doubt he's going to be able to see 99mph ever in the 1/8th on the same tires.

Just goes to show you... Tires don't have too much to do with trap speed (assuming you don't spin too much) sticky or not. Even with F1's and a 2.1' 60 foot, I was able to trap 127 (99 in 1/8), and thats "only" with 507rwhp. He definitely should trap higher, unless it was 105 degrees out.

 

[Patrick]

Just goes to show you... Tires don't have too much to do with trap speed (assuming you don't spin too much) sticky or not.

Absolutely wrong.

Beyond track prep his tires have a lot to do with trap speed as it's a variable of the launch, which is a major variable contributing to both ET and MPH.

Even with F1's and a 2.1' 60 foot, I was able to trap 127 (99 in 1/8), and thats "only" with 507rwhp.

Did you ask him what his rear gear ratio is, tire height... his shift points... or seen his dyno chart? You don't have the right variables to compare.

He definitely should trap higher, unless it was 105 degrees out.

Sure, air temp is a variable... but altitude, barometer and humidity are the big players outside the car.

Any experienced drag racer knows that Best ET and best trap speed are generally attained separately.

You hook hard, you'll have a lower trap speed.

You slip a bit and get a little wheel spin you lose some ET but pick up MPH.

 

[itchynackers]

If you pick up mph with a spin launch, then why is his so low? All you have to do is compare similar powered car 1/8 speeds to his. I've seen lots, and his is off, simple. Off too much for gearing to have that much of an effect. I'd challenge you to go and find a 500rwhp car that traps that low, regardless of the other factors.

 

[rkaslyfox]

Did you ask him what his rear gear ratio is, tire height... his shift points... or seen his dyno chart? You don't have the right variables to compare.

Stock 3.42 rear gear ratio, 25.4 tire diameter, shifting out of 1st gear at 5000 rpms (due to not having drill mod done!), shifting out of second at 6400 rpms, and very long delay getting into 3rd becuase of difficult high rpm shifting!

Here's the dyno sheet:

This run was during a very humid evening!

All I know is the car has low 7 sec. power with 95-100 traps

 

[Patrick]

If you pick up mph with a spin launch, then why is his so low?

He never said he spun the tires.

 

[rkaslyfox]

He never said he spun the tires.

I didn't spin. . . . .launched at 2000 rpms, anything higher resulted in wheel hop (mostly due to my inability to smoothly come off this stage 3 clutch)

 

[itchynackers]

Well I guess I'm going to keep getting outvoted here. My only response can be... just keep thinking that 94mph in the 1/8 is good (for 500rwhp) when its not. I'm certainly no "experienced" drag racer, however have managed to consistently run 99 in the 1/8 with 60 less rwtq. Good luck...