Where to Shift RPM wise at the track?

[xtweakerx]

Engine: 4.6L
GMS Driveshaft Loops
Hurst Line-Locks
5 Speed Transmission
Ford 4:10 Rear-end Gears
Brenspeed SCT2 Tune 93 Octane
Steeda Under Drive Pullies
C&L "Racer" Cold Air Intake
Steeda Upper & Lower Control Arms
M&H 275/50R17 Drag Radials
Pypes Off-Road H-Pipe
Flowmaster Axle-back Exhaust


I have been shifting at 6200. Lend me your thoughts.


Disappointed with my last time out at the track however it was god awful humidity 80% plus and temps 77&higher and also the first time back in the car racing in 6months at a new track plus i was testing out different tire pressures.


But i ran back to back 13.23 @ 104 w/ 1.90 and best of the night 1.87.



i plugged my values into Density Altitude calculator and it said 12.99 corrected whatever that means.. ; ) Hell im gonna go race this saturday should be great weather so ill try again, should i shift higher than 6200?

 

[NotQuik]

was wondering this as well...going tomorrow for first time with a tune and didnt know if i should still shift at 6200 or bumpit to 6400

 

[xtweakerx]

yup thats wut im thinkin maybe 6400 *shrug*

 

[xtweakerx]

also wondering if the brenspeed tune is holding me back and if i get bama chips race tune *shrug* i kno evenually down the road i want a real dyno custom dune done by this local guy but its PRICEY!!

 

[ArtQ]

6400 should work good, especially if you're speed shifting. Raise your launch RPM, and slip the clutch on launch to get the 60' down. The better you get at the lauch the more you can add rpm.

 

[US-1]

I'm thinking that with the 28" tire and 4.10's you could go 6400 or 6500 on the shift point. Don't fart around with tire pressures. Set them at 18 or 20 psi and work on your launch. What rpm are you using at the starting line?

The "corrected" reading from your calculator could be showing you what the car would run at sea level with that same humidity and barometric pressure. What is the correction factor of that calculator?

 

[xtweakerx]

i used this site: http://www.modulardepot.com/density.php

i plugged in my track alt which is like 23 feet above sea level and that days weather values along w/ my e.t

I'll be going this saturday outlook on weather this saturday is much better than the last time i went showing low 70's w/ mid 60% humd. last time it was high 77+ and 80+ humd.


Ok yeah from that night im pretty set at 19-20psi seemed best for me when i went lower it didnt help at all.


I was leaving around 4 to 4500 rpm's , trying to practice with my foot to not over rev and watch my RPM on my tach to see where im leaving at, i think im gonna try 5,000 rpms to launch too.

I will change my shift point from 6200 to 6400 and give that a whirl as well.

Yeah The taller tire must be droppin my 4:10's down to what 4.00's or 390's?

thx for the input

 

[ArtQ]

The correction shows what the car would have done based on standard day conditions which is Sea level, 60 degrees at 29.92.

 

[US-1]

Says right there on the calculator that it corrects for sea level. Good luck.

 

[xtweakerx]

i used this site: http://www.modulardepot.com/density.php

i plugged in my track alt which is like 23 feet above sea level and that days weather values along w/ my e.t

I'll be going this saturday outlook on weather this saturday is much better than the last time i went showing low 70's w/ mid 40% humd(forecasted). last time it was high 77+ and 80%+ humd.


Ok yeah from that night im pretty set at 19-20psi seemed best for me when i went lower it didnt help at all.


I was leaving around 4 to 4500 rpm's , trying to practice with my foot to not over rev and watch my RPM on my tach to see where im leaving at, i think im gonna try 5,000 rpms to launch too.

I will change my shift point from 6200 to 6400 and give that a whirl as well.

Yeah The taller tire must be droppin my 4:10's down to what 4.00's or 390's?

thx for the input

 

[NotQuik]

heading out to "moroso" good luck man, i'm hoping for some good numbers tomorrow night with the 3.31s lol

 

[xtweakerx]

heading out to "moroso" good luck man, i'm hoping for some good numbers tomorrow night with the 3.31s lol

bad ass, im going Saturday for the Mustang Bracket Race, let me know if u wind up going saturday. let me know how it goes for u on Wednesday night. should be nice with this cold front we got recently

 

[hdmlnium]

I am running 4:10's with a 5-speed stick car and I leave at about 2200 rpm's slipping it then go full throttle. I was shifting my stock motor at about 6500 and now that I have a built motor I am shifting at 6800..
I hope that helps some..

Bill

 

[GERMANSHEPERD]

I am running 4:10's with a 5-speed stick car and I leave at about 2200 rpm's slipping it then go full throttle. I was shifting my stock motor at about 6500 and now that I have a built motor I am shifting at 6800..
I hope that helps some..

Bill

what cams are you running?

 

[hdmlnium]

what cams are you running?

I am running the Comp stage 2's now..

Bill