Drivetrain loss

[mike7570]

A 100-125 horse is a lot of power to leave out there TimeWarp. Ya know my car doesn’t weight a lot either but it sure is hard to push. I always think if I can get it to roll easier that would pick it up also.

A good stocker or class car will roll extremely easy. There is a lot of places to reduce rolling resistance from the brakes to alignment, light weight wheels and tires, gears and bearings. The stocker I’m currently building will roll easily with just one hand. (Maybe it’s because I don’t have the engine in it yet!  . )
I’ve spent time and money making sure it rolls with as little resistance as possible.

[cjshaker]

A 100-125 horse is a lot of power to leave out there TimeWarp. Ya know my car doesn’t weight a lot either but it sure is hard to push. I always think if I can get it to roll easier that would pick it up also.

That would be for the entire drivetrain. The rear end and wheel/tire combo will be eating most of that. Not to mention that full exhaust, no matter how efficient it was. You'll start going down an expensive rabbit hole when you start chasing driveline losses, like Chris alluded to. Then again, who wants to be buried with their money? 

The resistance to rolling is another matter. If a car doesn't roll easily, that translates to resistance in acceleration. Not always an easy matter to deal with. Brake drag, even if just a little, affects that pretty significantly. Residual valves on the front system and light contact of drum brakes surely wouldn't help on the strip, but they do make for a safer street car. And of course 14 lbs of pressure in big fat tires doesn't help in pushing anything.

[machoneman]

The stocker I’m currently building will roll easily with just one hand. (Maybe it’s because I don’t have the engine in it yet!  . )
I’ve spent time and money making sure it rolls with as little resistance as possible.
[/quote]

Engine less cars are always easy to push! Engine, trans, crossmember, driveshaft? Easy 750-800 lbs. Try it again one it's together and you'll see. As side note, we ran a spool in our drag car and trying to push it in a turn, forward or back, was a pain indeed. Often had to jack up the rear to make the turn into our garage. .   

[cjshaker]

The stocker I’m currently building will roll easily with just one hand. (Maybe it’s because I don’t have the engine in it yet!  . )
I’ve spent time and money making sure it rolls with as little resistance as possible.

Engine less cars are always easy to push! Engine, trans, crossmember, driveshaft? Easy 750-800 lbs. Try it again one it's together and you'll see. As side note, we ran a spool in our drag car and trying to push it in a turn, forward or back, was a pain indeed. Often had to jack up the rear to make the turn into our garage. .
[/quote]

I'm pretty sure Mike has experience with fully built cars, he's been racing for a long time. And he is correct that they should push easily when prepped for drag strip duty. Of course pushing a spool through a turn won't be easy, and like I said, a big fat squishy tire won't help, but a properly set up drag car should not push hard.

[Rory428]

Not sure how much of it was from internal friction and rotating weight, but when I had a C6 in my Fairmont, it was a fairly good piece, had all the low drag Torrington bearing thrust washers, but still had a stock steel drum. When I swapped out the C6, to a Jerico 4 speed, with no other changes to the car, the 1/4 mile numbers improved by over 5 tenths, and 6 MPH. And that was with a 8" torque convertor, and a Art Carr transbrake/reverse pattern valve body, launching at WOT at 5200 RPM. Many of the Stock and Super Stock Ford racers are using big $$$ custom built C4s behind their FEs and 429/460 engines, but some are running equally expensive C6s, that have had all the heavy internals, replaced with much lighter, MoPar 904 guts. Ritchey Pauley told me that his Pro Trans C6 was about as good as his C4 in back to back testing. As for Powerglides, several years ago, NHRA started to allow cars that were only available with 2 speed automatics, use a 3 speed. So, now , most former Powerglide Stock and S/S Chevys are running either a trick lightweight Turbo 350, or Turbo 200, instead of a trick Powerglide. The racers that I know that has switched from a 2 speed to a 3 speed, say that the lower first gear ratio, gets the car off the line much harder, and the closer ratio drops, help keep the engine in the power band.

[Gregwill16]

I did realize the C6 was a big power hog. But what doesn't completely make since to me is the muscle car era time slips. For instance, the Ford numbers showed the 68 CJ automatic cars as fast or faster than the 4 speed cars. I assume this had a lot to do with traction technology, but you would think that loss would be hard to overcome.

[mike7570]

I'm pretty sure Mike has experience with fully built cars, he's been racing for a long time. And he is correct that they should push easily when prepped for drag strip duty. Of course pushing a spool through a turn won't be easy, and like I said, a big fat squishy tire won't help, but a properly set up drag car should not push hard.

Big squishy tires? I’ve heard of big soft tires but I don’t think anyone has called them squishy. Lol
My super-gas car had 14.5x32’s and only ran 6.5lbs of air. I guess they fit the definition of squishy.
You had to plan your turns when coasting in the pits or return road, as soon as you moved the steering wheel it was like putting on the brakes. Those squishy tires would cause a lot of resistance if the rear axel isn’t mounted real straight.

[Stangman]

Mike7570 what are some of the things you do to stockers or any of your cars to get them to roll better. My motor is out and it rolls alot easier but ive seen some guys at the track and they just lean on there cars and they roll. Shit i have to really dig in to get it to roll.

[mike7570]

Since I was building a new car from scratch it was a bit easier to justify expenditures since it was already apart and needed new everything in the drive train and suspension.
My tires and rims are about as light a set as I could find (front tire/rim weighs just 17lbs ea., rear slicks/rims weigh 38lbs ea.) The 3rd member was set up professionally (I didn't do it  ) for racing and I had purchased light weight MW and Strange components including REM finished gears and ball bearing pinion support. The axle tubes received new big ends and were verified straight. There are all new wheel bearings (couldn't afford the ceramic coated versions) and new Wilwood 4 wheel disc brakes that don't drag (I'll be keeping an eye on that). The final alignment will be carefully done after all of the weight is back in the car including driver at the anticipated ride height while running down the track (not at parked ride height)
Oh, I forgot to mention very light weight synthetic gear oil. (Probably wouldn't run it in a street car)
The alignment front and back along with brake drag and weight are probably the key items. If you jack the front end up and give the wheels a spin by hand how long will they keep rotating?

[Rory428]

I did realize the C6 was a big power hog. But what doesn't completely make since to me is the muscle car era time slips. For instance, the Ford numbers showed the 68 CJ automatic cars as fast or faster than the 4 speed cars. I assume this had a lot to do with traction technology, but you would think that loss would be hard to overcome.

Keep in mind that the Cobra Jet Mustangs were fitting with F70-14 bias belted tires when new, which is smaller than my wifes 4 cylinder Toyota Corolla! Pretty touchy getting a 428 4 speed car off the line with such skinny tires, especially when so many Ford performance cars of the era didn`t have Traction Lok limited slip as standard equipment. And the horrible factory 4 speed shifters sure didn`t help either.

[cammerfe]

I changed the knob on my factory shifter as soon as I got home from the dealer after picking it up. I had to wait until friday to get a Hurst as a replacement.

KS

[Gregwill16]

I went back and reread some of the Ford internal documents Dennis posted on the CJ site and the numbers do support the C6 drivetrain losses. In SS/G class the 68 CJ stick cars (with relocated battery) were 3 tenths quicker (11.4 vs 11.7) than the automatic cars. But tests for competition in all the other classes, the stick cars were only a tenth quicker. So appears they had to figure out how to get the "extra" power to the ground in the stick cars.

[machoneman]

Off the topic but....I've always wondered what a Lenco (4-speeds, as the Pro Stocker used to use) ate up in hp compared to a 4-speed tranny. Have never seen any comparisons.

Bro' James was always able to get the crews of visiting Pro Stock cars (1972-1974 or so) to talk to him in the pits at Union Grove WI's Dragaway. Once before the finals, Glidden vs. Nicholson IIRC, one crew man (Maybe Glidden's son?) was under the car, draining all the rear end gear fluid. Then, he proceeded to drain about a pint or so from the Lenco! Said they needed that edge to reduce drag while running near identical e.t.'s. Glidden won.

This move made sense to me as just how many revolutions would a ring & pinion make in a 1/4 mile. Not many although I would not recommend this seemingly drastic move!

[Rory428]

Off the topic but....I've always wondered what a Lenco (4-speeds, as the Pro Stocker used to use) ate up in hp compared to a 4-speed tranny. Have never seen any comparisons.

Bro' James was always able to get the crews of visiting Pro Stock cars (1972-1974 or so) to talk to him in the pits at Union Grove WI's Dragaway. Once before the finals, Glidden vs. Nicholson IIRC, one crew man (Maybe Glidden's son?) was under the car, draining all the rear end gear fluid. Then, he proceeded to drain about a pint or so from the Lenco! Said they needed that edge to reduce drag while running near identical e.t.'s. Glidden won.

This move made sense to me as just how many revolutions would a ring & pinion make in a 1/4 mile. Not many although I would not recommend this seemingly drastic move!

I have a racing buddy, back in British Columbia, who races a high 8 second 67 Fairlane, and has raced it over the years with a Toploader, a Jerico 4 speed, a 5 speed Lenco, and a Liberty clutchless 5 speed. He told me that the Liberty was about 1 1/2 tenths of a second quicker in the 1/4 mile, than his Lenco. I don`t think there has been a competitive NHRA Pro Stock car using a Lenco in well over 20 years.

[cammerfe]

FWIW, back in the late '60s, Doug Nash built a Funny Car based on a Bronco. The chassis was all aluminum and he was running a small block Ford on a good dose of pop. He was likely making somewhere beyond 1500 Horsepower. I was working with John Corrunker at CorBan at the time and we were tasked with building the C4 transes that Doug was running. As I remember, the trans needed to be completely re-done after no more than a couple of passes. Every week we'd build three transmissions in order for him to be equipped through an entire weekend of competition.

Sometimes he'd try to get a third run before swapping, but it was always a bit iffy on that third go. Two passes were quite safe.

He WAS using 80 % nitro or more most of the time.

KS