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Where am I losing power

K

Kooter

Member
I have never had a car that could do a burnout. So two years ago I made up my mind to give my 66 vert with a 289/C4 the power to do so. I currently living in Japan with the car in storage in Iowa. Last year I took leave and flew home and installed trick flow heads with ford racing roller rockers, a comp cam and lifters. I ran out of money so I kept the stock 4bl intake and carb. After all of that it still couldn't do it. So this year when I flew home I swapped out the intake and carb with a Edelbrock performer intake and 1405 carb. I also upgraded the ignition to MSD. The car also has 2 1/4" dual exhaust. I figured all of this would give me more then enough power to spin the tire. Where am I losing power or what else can I do?
 
Your engine should be producing more than enough torque to "spin your tire". That is provided the engine work was done properly. Timing set correctly and the carb adjusted well. It doesn't take much to break loose a peg-leg. If you are running the stock exhaust manifolds you're not doing all the new parts any favors. An engine is basically an air pump and those things are choking off the airflow potential of the new heads and cam combo.

I would also look at the rest of the drivetrain. Your trans could use a bit of a looser converter (I assume you are running stock) and your stock rear gear isn't doing you any favors in terms of a harder launch.
 
I am sure the car can be tuned more. The initial timing is set at 12 degrees and the carb was tuned to make the car idle good. These steps were done with the help of my neighbor who is a mechanic.

I forgot to add in the earlier post that I have tri y headers installed.

As far as my technique goes I tried to do a burnout in all three gears and also power breaking. However the car is far from sluggish. It will throw you back in the seat and go from zero to 100 in nothing flat.

Could the stock tranny be sucking up that much power?
 
This doesn't make sense. My first thoughts were transmission and/or gear ratio. "Throw you back in the seat and go from 0-100 in nothing flat" suggests you have plenty of power/torque. Maybe a combo of the rear gear and rear brakes being adjusted too tight? Have you tried a rolling start with the wheel turned? Can it break loose attempting a doughnut?
 
What are the rear gears? That may be part of the problem if they are 2.80.

If you are trying to spin them from a standing start, do you immediately "mash it" or do a "quick accelleration?"

If you are absolutely, positively itching to spin 'em, drive around and come up to a clear intersection with no one around, slow to about 10 mph, drop the trans into 1st, you'll feel it downshift and the RPM's should go up, take a good, quick, hard 90 degree RIGHT turn and 1/2 way into the turn, punch it really good, 1/2 way throttle at least and maybe more as needed. You WILL light 'em up and the backend WILL start to come around, so BE CAREFULL, countersteer as needed, and watch out for the rev's so it does not spin up too high. Have fun.


---
Disclaimer: the above actions are intended to be performed on a racetrack, under adult supervision only. :lol
 
"blue65coupe" said:
He should still be able to powerbrake a 2.80.
Click to expand...
That's what I'm thinking. Hold the brakes, floor it...if you don't get a smoke show, something is *wrong*. I can do a successful brakestand in a 150hp minivan...
 
"blue65coupe" said:
He should still be able to powerbrake a 2.80.
Click to expand...

I'm no expert, but I've heard powerbraking is really bad/hard on the trans, powerbraking overheats it, but again, this is just what I recall being told.
 
Object is to get the tires to break loose quickly. (That's also why you'll see some "rolling start powerbrakes". Get a little weight transfer to the front and it's that much easier.) If they don't break loose then you risk the tranny. I'm still wondering about the rear brake adjustment. It doesn't take much to pb a rear-wheel drive vehicle with a light rear end and street tires.
 
The rear end gears are 3.00. I could spin it around if I was turning around at a intersection. I tried to power brake but the car would push through it. The car did have a full tank of gas as well. When I would try a burnout I would floor it. I did try to do a few rolling burnouts as well. I know that I need to work on my technique for doing burnouts. I just did not think it would be this difficult.

Thanks for all of your input. I now have something to research for the next year until I can make it back home.
 
Find an old rear wheel drive car in Japan and work on your burnout.....or borrow the Commanders car and go for a spin....lol
 
I've got a 289 with a summit carb and stealth manifold but otherwise stock engine, C4 with the 2.79 open diff. From a stop, it will smoke the right tire - with the open diff, left is just along for the ride. So, even with the 2.79, he should be able to break them loose - unless he's got some huge rubber in back. IIRC, mine are 205s (been a while since it moved).

What tires do you have back there?
 
MY old 66 I had in college would not break them loose either. It had a new 289 with a decent cam, headers, MSD and all the normal bolt ons. I think my problem was with the C4's converter not being close to what I needed and the tall rear gears. If I had a small amount of dirt on the road or moving slowly it would squeal the tires but not from a stand still. I guess I really did not need the traction bars I had on there did I. :lol
 
Throw some soapy water down and get the tires wet first. Get the technique down and then go to dry pavement.
 
I think Dave's video is a key, he has a manual trans so he can "dump" the clutch. The stock converter and possibly the surface you were on may be holding you back. I have a 2.8 gear in my 67 right now (I got avg 16 mpg on the HRPT!) and the 429 will break loose the right rear easily on "smooth" asphalt with a stock converter. I have found some concrete and rough asphalt where the car will grab and go rather than spin and other surfaces where I can breath on the gas pedal and both tires break loose. When I switch to the 3.73's or 4.11's I can hardly drive the car. In fact I have ordered some 17x9.5" rims and 275/40/17 tires to help with that. Anyway, find a well worn surface, smooth slick asphalt and it will probably light 'em up. Also a high stall speed converter will help but remember they slip all the time below their rated stall speed and will get hot. Heat destroys auto transmissions. You may want to install a lower gear to keep the rpm's up above the stall speed at highway speeds (lower gear will multiply torque as well and help). But be careful what you wish for, the thing may be fun to mess around with but tricky to drive aggressively without spinning out. Like I said, I went back to the 2.8 in mine for drivability...
 
i think it's the tune....i have a similar combo, and just this weekend got it tuned to where i can drive w/out problems.
302 crate, airgap manifold, 625 demon, tri-y headers...i can scratch the rear right in a straight line, no problem, and that's with a 2.79 open diff.
drove friday and saturday and i could chirp off the line w/o hesitation. i'm no expert but i have experienced over the last month what a poor tune can
do to your performance. even when you think it's right, it's got more room to go. try again.
*** just checked and my tires are 195/75-14.....pretty easy to spin *** but i'd still check the tune or trans
 
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