62 Chevrolet, STILL No Traction
 

I am very much afraid to even bring this up... actually stalling for a week now.

Car is back together.
I did EVERYTHING I was told to do... including spending every last cent I will ever see, on chassis related components that are permissible in Stock.
Moroso front springs
Loose, firm control arm bushings
Thousands of dollars in QA1 adjustable drag race shocks
MANY thousands of dollars in state-of-the-art wheels and tires
MORE thousands of dollars on light weight disc brake components
( already had the 2.83 Jerico, aluminum flywheel, aluminum soft lok clutch )

I also relocated the upper control arm at the housing, about 2 1/4" upward.

The difference ?
At least now, I don't have to let off the gas pedal in first gear. Engine actually hovers at around 6200 RPM, until the car catches up.

So, I started scouring the Internet, looking for a couple good diagrams and brief, direct pointers, as to where a person needs to have the "instant centre", yadda yadda.
What I found, is that like everything else about this hobby... that elusive information, will cost $100 - $200 ???????????????!!!!!!!!!!!!!!!!!!!!!!!
IE, books, programs, ect.

My problem appears to be that the rear tires aren't receiving the neccessary intial "hit".
Yesreday, I did a full series of measurements. Here's what I came up with:
( it's a factory "4 link" )
Distances from ground:

lower mount at housing... 8.75"
Upper mount at housing... 19.75"
Lower mount at frame... 12.125"
Upper mount at frame... 19"
Rear rocker to ground... 12"
Front rocker to ground... 9.5"

Lower control arm length... 23.75"
Upper control arm length... 13.75"
The lower mount at housing, is located approximately 1 1/2" behind the centre of the drive axle. The upper, 4.5" behind.

Car has 119" wheelbase.
Weight distribution is 50/50
Total weight, with me, is 3750 pounds

Rear tires are 29.5" X 9" M/T "stick" compound... front actuall effective diameter 27".

From my calculations, the point of intersect of the two "imaginary" lines extending forward of the two rear control arms, is located: 53.5" ahead of rear axle centre line... 16" from the ground.

SURELY this is enough info ???!!!

Can someone PLEASE advise me as to what might be wrong, and where it should be ?
( please PLEASE don't ask things like shock settings... I understand enough to have them adjusted for lift, ect. ! Tire pressures have been moved from 13 - 19 pounds )

I just don't get. EVERYBODY else gets traction...
I get laughed at
( can you tell I'm at my wit's end with this thing ? ! )

Re: 62 Chevrolet, STILL No Traction
 

Stupid question but how did you set up the clutch or adjust it?

Re: 62 Chevrolet, STILL No Traction
 

DAMN !
forgot to add that into my "please don't ask" list !

slips alot low RPM... especially cold. Never get any kind of "shock" feeling from it.
Has good centrifugal... no slippage at tp end in high gear.

What I failed to mention, is that I am releasing the clutch at about 5000 ( 7000 RPM engine ).

Re: 62 Chevrolet, STILL No Traction
 

Contrary to thoughts, you could be getting too much "hit " on the tires. Need to know if the car squats, Balls up tires, if you tried uping pressure, lowering pressure? Result of pressure. Have you experimented with Rpm you leave? Dick Butler

Re: 62 Chevrolet, STILL No Traction
 

Here is another foolish question. What is the rim width for your slicks?

Re: 62 Chevrolet, STILL No Traction
 

I guess I should have asked what is the base pressure or static preload and what if any cetrifugal weight is added? Clarify what RPM you are leaving at.

Re: 62 Chevrolet, STILL No Traction
 

HOLY !
I appreciate the replies, guys

in reverse order:
Dick...
Takes the tires off with a 3500-4000 RPM launch ( peak torque is at 4700 ). Should be able to leave at 6000... like everyone else
As stated, moved pressure from 13-19 pounds ( lower is REALLY REALLY dumb )
Tires seem to be wearing VERY smooth ( my old ones peeled up the tread badly )
I am completely alone, so no one to view. No sensation of "up" or "down" from the rear of the car.

Mark...
rims are American Racing Pro Series Trackstar, 15 X 10 / 5" back spacing.

Glen...
actual measured "pressure" has not been calculated ( this doesn't mean... "NO WONDER.... YOU'RE AN IDIOT" !... it means this clutch setup is very much common sense. A person can feel the slippage on engagement... the "torue converter" philosophy )
There are 11 full "turns" of the adjuster bolts, from nothing to max.
This is set 4 1/2 "in".
Counter weight... I'll go weigh what I put in there...
Since retarding the cam 4 degrees, the lower end torque has dimminished some.
Can't really launch below 3000 ( would be freakin' ridiculous anyhow... car has "super duper" slicks for crying out loud ! ).

Re: 62 Chevrolet, STILL No Traction
 

Are you testing at the track or on the street?

Re: 62 Chevrolet, STILL No Traction
 

Does Higher pressure make any effect on 60? Are you on good track. None of this will matter if not at track though.Also an awful lot of first gear I think on a 10 tire. especially when starting out. Dick
Try a trans with a lower first and see what happens Maybe you are just so far up on power, torque at this point you need to creep up on this kind of ratio making one or two adjustments at a time. If the tail drops try Air bag on Rt. Helps with rotational movement and picking up rt tire.Its like preload for SS cars or ladder cars...Are you allowed the Bolt on Comp ladder bars? They really helped my heavy chevelle wagon. Made it press the tires down instead of lifting the slicks up(SQUAT)

Re: 62 Chevrolet, STILL No Traction
 

Steve, yes, everyone seems to think the track is best.
One thing that I have confirmed for absolute certainty, is that the only place this car EVER spun more than on good, clean, new highway pavement... was on a prairie track, concrete "launch pad".
A little video in Saskatoon, with the old slicks:
http://www.youtube.com/watch?v=8M2L2g8n7u8
Granted, that spinning completely through first and second, was a little extreme ( usually only goes an additional 20 feet in second ). If I remember correctly, the 60 ft was a 1.78 that time. So far, the track performance has proven to be a joke, largely due to the fact that the traction is always so poor.

Dick, I'm told that I'm WAY off on 1st gear in the trans. Saying I should have 3.08 or even 3.22.

Tires seem to "plant" dead-on even left/right ( has slight weight jacking in RR spring )
Car goes straight as an arrow.

No traction device permitted, which has a front mounting point ahead of the factory lower control arm mount.

Still can't seem to find the info on the 4 link, which indicates the optimum geometry for effective initial planting of the tires, resulting in weight transfer, which should perpetuate itself. PLEASE don't tell me the "every car is different" story !
At this point, I'm not looking to tune the chassis in order to go from a 1.50 60 ft, to a 1.49 !
I'm trying to go from 1.75 to 1.50. I don't think this discrepency is due to being out half a pound on tire pressure, or the like. It's a BAD problem, from a very fundamental error in design. Just need to know the "rules" !

Re: 62 Chevrolet, STILL No Traction
 

On a good track by someone elses performance changing tire pressure UP 3 or 4 lbs stabilizes tire wall. This fights distortion or wrapping up the surface of the slick. With no one to observe for you the 60 ft time change if present can give hints about whether you are TOO high on instant center or ..... Sounds too High off hand for me. I think it would like more like 6 or 8 inchs. Get an observer to watch or film the rear tire on dropping clutch. My money is on TOO much attempted % rise. Dick

Re: 62 Chevrolet, STILL No Traction
 

http://aolsearch.aol.com/aol/search?...lover&ie=UTF-8

Here is a link that will give you a page of choices on Instant Center for free.

Re: 62 Chevrolet, STILL No Traction
 

Maybe you find something usefull here.
http://home.earthlink.net/~whshope/

Leffe

Re: 62 Chevrolet, STILL No Traction
 

I don't know what you mean by 5000 (7000 RPM engine)??

Do you use a 2 step to set your leave RPM??

Do use a very light weight flywheel to cut down on inertia??

Maybe at a 7000 RPM leave you have all of your centrifugal assist in??

Bob

Re: 62 Chevrolet, STILL No Traction
 

Oldtimer, that DID go to a list of links. None of them seem to address the what is desireable as a drag racing application.

Not bad there, Leif... but again, no practical diagrams indicating the desired geometry.

As mentioned earlier, Bob... aluminum flywheel ( 11 pound ), aluminum McLeod 10.5" "hat"
What do I mean ?
exactly THAT !
It's a 7000 RPM engine, that makes NO power below 3000, with horsepower peak at around 6700-6800.
With this 7000 RPM engine, I can release the clutch as low as 3500, and still blow the tires right off.
Two step ?
that's a dance, isn't it ? !
Need my "shoes" on the ground before I'll bother to try dancing !

oh... the centrifugal weight that I added.... 8 grams, on each of the 3 release fingers.

Here's a link to a VERY rough sketch that I did up, after I took a whole series of very acturate dimensions:
http://www.bruneauperformance.ca/62b...eometry900.jpg

Bottom picture is exactly as the car is right now.
Upper picture is after my proposed lowering the rear 1 1/2 inches.
The 63" dimension, is a result of lowering the front loer control arm mount at the frame ( not permitted ).

Re: 62 Chevrolet, STILL No Traction
 

If you got no help use a tripod for the camera. Must be able to see what's going on.

Re: 62 Chevrolet, STILL No Traction
 

"A person can feel the slippage on engagement... the "torue converter" philosophy "

What do you mean " a person can feel the slippage on engagement" ?

Re: 62 Chevrolet, STILL No Traction
 

Here's that clutch slipping, Jeff:
http://www.bruneauperformance.ca/wat...tstock409.html
can't explain the tires though ? ? ?
and p l e a s e... no more about the "track is God's ground"... time and TIME again, it aint.
but seriously...

Low RPM, high RPM... ?
If this thing planted the tires AT ALL, it would shut the engine off if I tried to dump it at 3000.
Like I mentioned earlier, there is absolutely NO slippage in high gear.
Yes, I do use the clutch to shift ( doesn't the rule book say you have to ! )

The video above, is an old one, with the old tires ( they were relatively new at the time ).
Isn't quite THAT bad anymore. Like I mentioned, rather than bouncing off the rev limiter, and having to "back pedal"... at least now, the limited traction I have, keeps the engine from flaring up like the car's on ice.

You're right, I doubt the lower 1st gear is the miracle cure ( like... not )...
I just wish somebody could tell me where this rear control arm geometry should fall ?

Re: 62 Chevrolet, STILL No Traction
 

Make sure the lower link connecting the rear end to the frame is running down in the front at least 2 degrees. Park the car on a level surface and step back and look at it visually first. the bottom bar must run at a down angle ( lower in the front ) in relationship to the rocker panel. If it is running up it will not hook up even on the best track with new tires. You may need to adjust the ride height to correct this problem if it exists. Had the same problem with my super stocker.

Mike

Re: 62 Chevrolet, STILL No Traction
 

that bears repeating
all said
THAT is exactly what I am experiencing... no traction, no matter WHERE the tire pressure is !

Mike, it would be basically impossible to make the lower control arm rake "down", while even remotely staying within the rules.
By lowering the car though, I can get a lot closer... and the upper arms will provide that snap down ( up on the body ) on the axle housing when it tries to rotate back under engagement.

Thank YOU, Mike !

Re: 62 Chevrolet, STILL No Traction
 

Aubrey ... heres my .02 from what I have learned from my car ..67 Camaro F/S .. you have seen it in the Hat before . You stated :
"There are 11 full "turns" of the adjuster bolts, from nothing to max.
This is set 4 1/2 "in". .... if you have 11 turns available , and are 4 1/2 in from full out (which is max pressure) then that is leaving you at 6.5 turns "out" from base ... which is probably too much . That static pressure, along with counter weight pressure is more than likely contributing to blowing the tires off ... In my car , with 6 turns (out)in the clutch I can 60' in the 1.55-1.57 range and spin the tires on the gear change. With 2.5-3 turns "out" I can 60' in the 1.48-1.51 range and the gear changes are a little smoother ... so-to-speak.
There is a fine line between "going fast" and "going rounds" as any stick racer will tell ... Rob Youngblood has too much of my money for "freshening jobs" .. but thats a different story.
Tire pressure .... in my car (3215 lbs.) leaving at 6200-6800 I can get away with as little as 10.5 lbs .. but 12.0 seems to be the best. Some of those B/S 396 cars can run low pressure and get away with it .. so you should be able to get down there without running on the rims.
my best advice to you would be to buy a Autometer Ultimate II tach that will give you data about driveshaft speed and engine RPM. At least that way you can visualize when, and for how long the tires are spinning, or not spinning.
If you are going to be at Medicine Hat , stop by the trailer and I can show you the data I've collected with my tach... show you the difference of a 1.50 60' verses a 1.59 60'.

Mike

Re: 62 Chevrolet, STILL No Traction
 

You will have to make some adjustments to the attachment at the rear end housing and the frame to get the proper geometry. there is no way the car will work in its present set up.You might be able to put a band aid on it by slipping the clutch. but that will create excess heat and the clutch will fail prematurely and the car will be inconsistent. Lower the ride height and extend the lower brackets on the rear end housing as much as you think you can get away with. Fabricate them to look as stock as possible. This is definatley your problem.

Mike

Re: 62 Chevrolet, STILL No Traction
 

I agree with Mike wholeheartedly. When I first read your post, the difference in measurements of the upper and lower bars jumped out at me. The upper bar is almost flat and the lower bar is pointed "uphill", so to speak. You will never make that work. The lower bar needs to be at least parallel to the ground, preferably pointed "downhill" from the axle like Mike said. The upper bar should be pointing downhill a lot.

You may need some work with the clutch settings, too. You have been given some good suggestions in the other posts, so I won't add anything else.

Once you get past these two areas, you will find some improved ET performance with lower trans gears. Be thinking in the range of 3.15 - 2.00 - 1.40 for the weight you are carrying. ET will be made in the first 330 feet; from that point on you are mainly carrying the weight.

Good luck and don't get discouraged! You have such a neat car and I applaud you for the resolve to crank it up!

Re: 62 Chevrolet, STILL No Traction
 

This is TREMENDOUS, guys !!
All the replies, covered EVERYTHING
I''ve got a new fuel pump / system coming in on Tuesday ( actaully dropped to zero fuel pressure at top of 1st and 2nd gear ! ).
During this time, I'll "adjust" the rear springs in order to get the rear ride height where it should be.

oh... Mike.... that was YOUR car ?????!!!!!!!
Got some photos of THAT one !
clutch pedal forever !

Re: 62 Chevrolet, STILL No Traction
 

What is your pinion angle set at and what kind of bushings are you useing ?

Here's another web site that might help some

http://www.baselinesuspensions.com/index.htm

Re: 62 Chevrolet, STILL No Traction
 

That was informative, Bud... informed me that ALL the factory mounting bracketes on the rear housing and the frame, are quite simply, fundamentally, in the wrong location !
Both upper and lower re BEHIND the axle centre... apparently counter-productive.

May have more of a problem than I thought.

Re: 62 Chevrolet, STILL No Traction
 

Mike and Dwight, are you saying she needs to lower her IC and move it back? According to Baseline Suspensions, a higher and farther forward IC tends to plant the rear tires harder and lift the nose. Why would that be bad?

Re: 62 Chevrolet, STILL No Traction
 

May be some useful info here.... http://home.earthlink.net/~whshope/index.html

(((Sorry Leif (Andersson). Just saw your post. My bad)))

Re: 62 Chevrolet, STILL No Traction
 

I bracket race a factory 4 link car, (Malibu) all bushings in the rear bars are solid except the upper housing bushings, pinion angle is critical, I MUST have at least 4 degrees negative, runs best at 4 1/2 degrees. Now how you measure pinion angle is a subject for much debate, but I measure relative to the ground and frame (at ride height) plane.
I feel like what makes the rear suspension work is the "allowed" pinion rotation of the upper bushings at the housing.
I get probably 4"+ of separation at the rear axle, or plant on the tires, however you want to look at it.
Atlas non-gas shocks on the rear, QA1's on the front.
My setup is the old Southside Machine deal, the lower bars point "up" at an insane angle due to being located low on the axle housing. Upper bars are near level.
Your long wheelbase is a bit of a conundrum, in my opinion, although your weight bias is much more favorable than mine. (1660 frt / 1440 rr empty)

The M/T "stick" 29.5x9 tires are the absolute WORST tires I've ever run on my car, I usually run only Goodyear D-4A Radials (at 16-16 1/2 psi) for warm tracks. (6303's)
I'd think that a stiff sidewall or radial slick would be the ticket for you.

1.37 to 1.39 short times at any track with decent air, 1.40-1.41 when the HP is low.
Of course, it's an automatic, 2.10 low ratio TH-400 with 5200 stall off the t-brake and 3600 two-step, but the "hit" is fairly solid. Had no trouble with the 2.48 low ratio though, just made the car feel better with the 2.10 ratio. 4.11 rear gears.

I will agree with others that some quality video of your car is mandatory to study what is really happening. Nothing like a frame by frame playback to see things you never thought of.

Don't think you'll ever see the potential of your car until you can stand it on the rear tires at launch.

Re: 62 Chevrolet, STILL No Traction
 

Nova man,

you can raise the IC in the car as long as you dont make the bottom bar run uphill in the front. You need about 2 degrees down angle and 2 degrees pinion angle. pinion angle is the difference between the angle of the driveshaft to angle of the pinion shaft. If you have rubber bushings in your link bars you will need more pinion angle. You should install solid bushings.

Mike

Re: 62 Chevrolet, STILL No Traction
 

aubrey, just put driveline into your daily driver (60 nomad) and it will hook :)

suggest air bag in passenger spring to absorb twist... and everything else these guys said

jack mccarthy

dont understand, my wagon hooks in a car wash

Re: 62 Chevrolet, STILL No Traction
 

HEEE HEEE !... no doubt, Jack !
Don't have the 60 anymore though... wouldn't meet Stock anyhow.
But THIS would... I've owned it since 1985..
63 Canadian Pontiac Parisienne Safari... factory 409 4 speed... and meets Stock PERFECTLY !
http://www.bruneauperformance.ca/my6...ksaskrr720.jpg

http://www.bruneauperformance.ca/my6...side640big.jpg

http://www.bruneauperformance.ca/my6...nteriorfrt.jpg

Re: 62 Chevrolet, STILL No Traction
 

Is there ballast in the rear of the car?
Are you using a sway bar?

If Alf was still in business, He'd get you to hook!
Guaranteed!

Re: 62 Chevrolet, STILL No Traction
 

"pinion angle is the difference between the angle of the driveshaft to angle of the pinion shaft."


Sorry, THAT is DRIVELINE ANGLE, and has NOTHING to do with how the rear suspension will work.

It's been run through the wringer many times, and even DAVE MORGAN HISSELF corrected his "bible" in regards to pinion angle, what it is, what it does, and how to measure it.

Check the IHRA magazine that he used to have his articles in, and NO, I am not going to go back and dig out the issue again, it was late 2001 or 2002.

He never corrected the "Doorslammers" book in it's late reprints though......


Google pinion angle.......then hold on.

You leaf spring car guys KNOW!

I've added a photo of my car as my avatar, you might notice that it seems to be hooking well.

Re: 62 Chevrolet, STILL No Traction
 

Yes, I agree, if Alf ( I DID speak to him about this a couple years ago ) had ever worked with a 60-64 Chevrolet, I'm sure he WOULD have found the answers !

No sway bar.... about 40 pounds under the rear of the package tray, 4" back from the centre line of the axle, about 8" above the top of the tire.


admittedly... NOW I am REALLY messed up on pinion angle !

Re: 62 Chevrolet, STILL No Traction
 

That would be a no-no...

Re: 62 Chevrolet, STILL No Traction
 

OK Jeff, I'll bite...
What's a "no no" ? !

I used to have about 60 pounds bolted inside the rear crossmember, behind the bumper.
Got big flack for THAT. Told to put it directly over the rear axle, as high as practical.
This weight is "adjustable", on a weight bar, which is bolted to brackets that are welded to the frame.

oh... about weight to "fit" the class ?
 

Took the car to the scale finally.
No ballast, 4 gallons of fuel, with me in the car...
NOW it sort of makes sense...
1930 / 1740... 3670
For C Stock, my minimum weight over the scale would be 3635
For D Stock, ...... 3828

I'm 20 something pounds over weight... should I go on a diet, and run with no ballast in C ?!!!
Or, should accept my "middle age spread", add 150 pounds of stratigically placed weight to the car, and run in D ?

I know the ballast would make it launch better, but I always like the speed out the back door... and the car is heavy enough... lighter is easier on chassis parts.

Guees my question could be, can a car hook properly, with the front / rear weight distribution that this car has as is ?

( oh, the reason for my arror in my previous weight info, is that I forgot that last time I had weighed the car, that weight bar was in the rear bumper )

Re: 62 Chevrolet, STILL No Traction
 

General Regulation 4:2 - Ballast.
Ballast not allowed above rear tire. :(

Re: 62 Chevrolet, STILL No Traction
 

I see...
is that a specific rule just for me... to help gaurantee that this piece of $#%& NEVER hooks up ?!!!!!!

NEVER saw that. I've been over the rule book some 3,687,521 times...
never saw that.

So... WHERE does a person put ballast in a car that won't get initial traction ?
In front of the radiator ?

got the towel in my right hand, raised over my head... I'm ready.... get'n close !