[brainsboy]

Ok, so what do I do? New convertor, or will I end up with the same problem, with bands? Change to a C-6? I have been having some band problems seems I have to tighten them alot or I get a 2-3 flare. Or just dont worry about the slip?

[red65mustang]

I defer to the tranny guru's cause you are at the upper torque and HP limit for what a "normal" C-4 was designed for....

post a new thread question in the transmission/drive train section with all the info

I know C-4's can be built to handle 600hp (when you turn on the nitrous!).....

trust you saw my add on..."Type F" only fluid in a C-4 for less slippage

[BOBCRMAN@aol.com]

Your low MPH is probably because you let off the gas at the finish line.

The Mph clocks are tripped before the win/lose light (finish line), then the car must travel after the win/lose light to click them off. To determine mph. The mph is calculated from the time between the clocks set before and after the line..

IF you decelerate at the finish line you will get a slow mph. If you drive the car the extra sixty ft. your mph. will rise substantially.

[brainsboy]

Gosh, how embarrassing if thats what it is, but you may be right, I was letting off the gas just as I hit the Poles that show the Times. Im going back this saturday so we will find out.

[BOBCRMAN@aol.com]

Thats why it's the ET that counts. The MPH will vary with the driving style. Unless you are making BIG horsepower on the high end and driving thru...

I used to run a 10.30 car, usually hard on the brakes in the lights. This gives very irratic Mph readings.

[red65mustang]

I'm embarrased (and laughing) also....Bob Corman definitely can be correct!

but if he's not...one fix to consider (I still defer to the tranny guru's) thats part of most hipo C4 builds is to machine the third gear pressure plate to allow 5 clutch disks instead of 4

[engineczar]

Those are some funky numbers your getting. I think he'd have to be all over the brakes to lose 20+ mph at the finish line. 6400 rpm's with a 28" tall tire and 3.89 gears is 137mph. Think about it, one of my customers cars runs 10.20's at 131mph with 1.41 60' times. If you're going 10.70's with a 1.43 60' (both slower) and still hitting 137 mph (much faster) before the finish line the momentum alone and just letting off the gas wouldn't scrub off 20+mph. I'd say Red's thinking about converter or tranny slipping is much more plausable.

[IanRiordan]

As you say, the convertor could be an issue. If your track doesn't have an uphill braking area then find a long road (obviously not public) and at 3/4 throttle in top jump on the gas. With one eye on the road, see if the tacho jumps rather than climbs. If it does so above stall speed look at the trans, below - convertor. Not foolproof but a good place to start.

[brainsboy]

Geeez guys do I ever feel stupid.... Think I found the problem...

I was going a few steps bigger on the jets when my annoying buddy was playing inside with the radio, I figured as long as he is there I'll use him, so I told him to stomp the gas to the floor, with the motor not running of course...so I looked down the carb.... the secondarys were only barely cracking open at full throttle, then I thought holy crap that means I was running 10.7's on almost primary's alone...

The track last week and this week has some crappy event going on, so I will get to run again next weekend.. I cant wait!!!!!

thanks for all the help

[NAIRB]

Originally Posted by brainsboy

Geeez guys do I ever feel stupid.... Think I found the problem...

I was going a few steps bigger on the jets when my annoying buddy was playing inside with the radio, I figured as long as he is there I'll use him, so I told him to stomp the gas to the floor, with the motor not running of course...so I looked down the carb.... the secondarys were only barely cracking open at full throttle, then I thought holy crap that means I was running 10.7's on almost primary's alone...

The track last week and this week has some crappy event going on, so I will get to run again next weekend.. I cant wait!!!!!

thanks for all the help

If that's the case, watch out coming out of the hole next time. You ran some good times with an unintentional throttle stop. Mash the pedal through the floor next time!

[red65mustang]

WHOO, STOP!....test the secondaries WITH the motor running unless you have mechanical secondaries linkage

My $.02 worth....leave the carb alone (for now), test and tune only one thing (tranny slippage) at a time or you will end up with a can of worms

[brainsboy]

It is mechanical secondarys

..... the linkage was too loose

[xntrik]

Originally Posted by BOBCRMAN@aol.com

Your low MPH is probably because you let off the gas at the finish line.

The Mph clocks are tripped before the win/lose light (finish line), then the car must travel after the win/lose light to click them off. To determine mph. The mph is calculated from the time between the clocks set before and after the line..

IF you decelerate at the finish line you will get a slow mph. If you drive the car the extra sixty ft. your mph. will rise substantially.

The old timing method measured the speed in the last 66 feet to the line and another 66 feet past the line....and many kept their foot on it as long as possible... with the increasing velocities of many cars, the shut down areas were starting to seem a little short.... so....

In recent years the rules have changed and only the last 66 ft of the quarter is used for mph.... the finish line IS the finish line.

Renegade tracks might still be using the old methods...

[brainsboy]

It was the throttle cable, with it fixed I got


10.25 @ 125mph

[BillyShope]

Right at 340 horses at the rear wheels, by my estimation. Not bad!