Re: Launch RPM for a 4 Speed?
 

Awesome pic MR BB CHEVY!!

If you dont want to run a fuel pressure gauge make a temporary T-fitting install it as close to the carb as you can, get Autometer's copper oil pressure line, and get a small liquid filled gauage and install in on the end of the line. Run it up the cowl to the base of the windshield, under a wiper arm, or 200 mph tape it to the windshield where you can see it. Find a safe place to run through the gears, Then watch how low your fuel psi gets. You will be surprised. If you don't have always have 7psi then you aren't making hp. If you try to tune based off you plugs at the end of a run they will give you a false reading as the carb will seem lean but really there simply isn't enough fuel. No fuel means low hp = low mph.

For the launch don't worry about the other guy, when you are testing there is no prize for cutting a good light. Let the other guy leave first then watch your tach and go. Keep raising the RPM of the launch until the bog goes away. and...hold on!!

Re: Launch RPM for a 4 Speed?
 

This was my street car from the early 80's , small block , 4 speed , 5.13:1 rear . Launched around 5800 - 6000rpm

http://i203.photobucket.com/albums/a...robigger-1.jpg

Re: Launch RPM for a 4 Speed?
 

i pulled my 70 chevelle ls5 4speed out of 10 year storage to race at an abandend runway,been dumping the clutch at about 28oo,there aint nothen funner then racing a 4speed big block..https://www.youtube.com/watch?v=mKs4F9RDqrE

Re: Launch RPM for a 4 Speed?
 

There is a chance your rims are spinning on the tires. I used to have that happen before I screwed the slicks to the rims.

Re: Launch RPM for a 4 Speed?
 

After I trip the 2nd staging light I put my heel on the brake pedal and using my toes I begin to bring my rpms up to where I want to launch... then I pay attention to the tree...

Re: Launch RPM for a 4 Speed?
 

I've never tried the "heel-toe" method, but maybe I should have because I've rolled out of the lights many times..........ESPECIALLY at Broadway Bob's in Union Grove where the starting line is on a HILL. I know that track has a lot of history and people love it, but for me, it's the worst place I've ever run. I rolled back out of the staging lights THREE times before I finally kept my foot on the brake until the yellows came down, then had to HURRY back to the gas, set my launch rpm, then forget about timing the launch on the lights. By the time I was ready, the green was already on. They should have a sign in the pits saying, "line-lock required"!
I know I'll get flamed for my opinion and people will testify that they ran there with no problems, but my experience was terrible in '83.
Verne https://www.yenko.net/ubbthreads/imag...lins/frown.gif

Re: Launch RPM for a 4 Speed?
 

My first vote would be to throw on a historically correct Hurst Link Lok, but the other option is set the e-brake just enough to prevent the roll and creep through the prestage lights to light the stagine ones.

Re: Launch RPM for a 4 Speed?
 

GREAT advice. https://www.yenko.net/ubbthreads/imag...s/confused.gif Your right hand is on the shifter; your left hand is on the e-brake release handle; your right foot is on the gas; your left foot is on the clutch. Who's steering the car? https://www.yenko.net/ubbthreads/imag...s/rolleyes.gif

Re: Launch RPM for a 4 Speed?
 

You have a chin don't you? https://www.yenko.net/ubbthreads/imag...lins/smile.gif

Re: Launch RPM for a 4 Speed?
 

Verne I have had the same problem... way too much to do and way too little time to do it in!
To me the heel toe method is the easiest way... as soon as you roll to the gas you are naturally releasing the brake from your heel...