Going Racing Friday....Need some pointers

[mikemustang289]

Its been about 6 months and this will only be my 4th time out. Last time out I ran 14.5@96 and only got 4 runs in that night, that was my first time on slicks. Since then I have changed some suspenstion stuff and built a new motor.

Car is a 68 Mustang coupe: No AC/PS/PB
306 roller
AFR 185's
Jay Allen Cam ~219/226 .550 114 lsa
9.2:1 CR
RPM Intake
650 DP Carb
Full MSD ~36 degrees total
1 5/8 Longtubes
2 1/4 exhaust
T5z Trans
4.30 Gears and Locker
26x10.5x15 e.t. streets
Cal-tracs and front 90/10 Drag shocks

Last time out my best run was my final run and I believe that was at 14psi in the tires and the launch was probably at 2000 rpm (didn't have a tach)

I do have a tach and shiftlight now but one other thing I am waiting on is a line-lock which I won't have this time out. Last time would not burnout for ***** partially due to the 4 wheel drums but it kept getting sideways on me.
I also plan to install a 100 shot within the next few months.

If anyone has any advice as to what RPM I should launch, where to shift (light is programable), how much tire pressure to run, best setting on the Cal-tracs etc... I am also debating on dropping the exhaust as it might be a restriction.

I know burnouts will still be a problem but I will be back out a few more times before the end of the year with a line-lock.

 

[dennis112]

Its been about 6 months and this will only be my 4th time out. Last time out I ran 14.5@96 and only got 4 runs in that night, that was my first time on slicks. Since then I have changed some suspenstion stuff and built a new motor.

Car is a 68 Mustang coupe: No AC/PS/PB
306 roller
AFR 185's
Jay Allen Cam ~219/226 .550 114 lsa
9.2:1 CR
RPM Intake
650 DP Carb
Full MSD ~36 degrees total
1 5/8 Longtubes
2 1/4 exhaust
T5z Trans
4.30 Gears and Locker
26x10.5x15 e.t. streets
Cal-tracs and front 90/10 Drag shocks

Last time out my best run was my final run and I believe that was at 14psi in the tires and the launch was probably at 2000 rpm (didn't have a tach)

I do have a tach and shiftlight now but one other thing I am waiting on is a line-lock which I won't have this time out. Last time would not burnout for ***** partially due to the 4 wheel drums but it kept getting sideways on me.
I also plan to install a 100 shot within the next few months.

If anyone has any advice as to what RPM I should launch, where to shift (light is programable), how much tire pressure to run, best setting on the Cal-tracs etc... I am also debating on dropping the exhaust as it might be a restriction.

I know burnouts will still be a problem but I will be back out a few more times before the end of the year with a line-lock.

Sounds like a nice build.

14lbs on the ET's should work fine.

Set the Caltracs on the lower hole and add a turn of preload to both sides. Try launching at 3K and see if it spins excessively or hooks up. If it hooks up, try 4K. If it spins alot, try 2K. Hopefully your rearend is capable. Some spin off the line is acceptable. Watch your 60's and see what the car likes.

I would probably shoot for 6-6200rpm shifts my first time out to see how it goes. More than likely it will like a little more though-maybe 6500+. Shifts will probably happen faster than you can imagine with the 4:30 gears and the 5 speed.

Do your burnouts in second gear with the rear tires wet. Try to get maybe 5 seconds of burnout before going to stage. The line loc will help once you get it installed.

It is best to do one change at a time and test it over maybe 3 runs and then decide if the change was worthwhile before making a second change.

I wouldn't mess with the exhaust this time out unless you are always going to do it at the track. You probably have lots of other things to iron out first.

 

[washMO66]

like Dennis said leave the exhaust for now as it will effect your AF mixture and you might have to re-jet. Maybe later down the road it will net you another .10 and some MPH and you get your combo dialed in. it's all a matter of trial and error and it takes time to get your set up to be ultimatley effective...

Seeing that you are running a three pedal car you can adjust your launches as you see fit, with the power you are most likely making I would think you would be able to get up in your sweet spot (4200 to 5000RPM) on the launch and still not blow off the tires at 14 PSI. As far as the PSI you will have to just go by trial and error. at 14PSI if your hooking you will net more MPH at the big end rather than at a lower PSI.

Shift points is dependant on your build, I'm too lazy to look up your cam specs etc but where does you car make peak HP? SHift somewhere in the neighborhood of 10% higher than you peak HP - For me I am making peak HP around 5800 to 5900 so i shift at 6500RPM..... All builds are different, do your homework and or experiment to see what nets the best times...

Burn out? If you have rear drums crank them out a few settings to save you pads a little. You should be able to pop off the clutch in second and get that foot on the brake quick to get some heat in. For me on ET streets they needed a little more heat than my Hoosier Drag slicks to hook close to as good... I used ET streets for one season and then went to the Hoosier Drag slick in a 26X9.0X15 and the tread width is just as wide as the ET streets but a better tread compound (they will last longer at the track as well. As a matter of fact UPS just dropped me two by my door yesterday (and if I ever work all the little bugs out of this thing I may actually get to use them this year).

A few things, have fun and drive it hard.......

 

[mikemustang289]

thanks for the replys, the peak HP is 5900 and torqe at 4300 according to the cam. I will leave the exhaust on for now as well.

What about driving to the street on the e.t. streets? Round trip to my track is about 60 miles. I'm considering just driving on the e.t. streets which are d.o.t. approved and then bringing an air compressor to fill them up before I leave. Last time I brought them in the trunk and it was a hassle.

Is tire wear something to be concerned about in a 60 mile trip? I don't want to ruin the tires.

 

[washMO66]

you'll be fine driving them to and fro, I have ran my ET streets all summer and they are just now going away. And I drive my car hard when I do drive it....