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Technical Gassers

Discussion in 'The Hokey Ass Message Board' started by Boneyard51, Mar 4, 2022.

  1. Boneyard51
    Joined: Dec 10, 2017
    Posts: 5,916

    Boneyard51
    Member

    Could we have a discussion here on the details of the gasser drag cars? I have always had a problem understanding why those cars are jacked way up in the front end, and in my opinion catching way more air. Also putting a straight axle under them that can’t save much weight , if any, and bringing in the dreaded straight axle wobble to play! Then the straight axle , jacked up , requires the rear to be raised, somewhat causing the whole car to higher and top heavy making it harder to control!
    Any thoughts?

    PS: I do like the looks of them!




    Bones
     
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  2. Motorwrxs
    Joined: Aug 15, 2021
    Posts: 239

    Motorwrxs
    ALLIANCE MEMBER

    I have learned since joining the HAMB that not all gassers had a straight axle…
     
  3. greybeard360
    Joined: Feb 28, 2008
    Posts: 2,011

    greybeard360
    Member

    It was all done in an effort to get more weight transfer to the rear wheels. The old slicks back then were barely an improvement over street tires so they did what they could to get the weight to the rear of the car on the launch. And no, not all gassers had sraight axles. On some cars it probably did take a little weight off of the front but not a lot. Once the wrinkle wall slicks came on the scene the front ends started getting lower and aerodynamics improved as well as driveability.
     
  4. At some point there was the 24 inch to crank center height rule.
     

  5. Bob Lowry
    Joined: Jan 19, 2020
    Posts: 1,108

    Bob Lowry

    Yep, the thinking back in the late 50's and 60's was that when you were coming off the line, it
    was a waste of horsepower and e.t. to have the front end lift up when taking off. Racers basically
    had solid front end suspension, lifted as high as feasible to eliminate lost time and power. Once
    one guy did it and he won, everyone else copied him, thinking it was an advantage. Here is my
    street '40 Chevy which I did the same thing to......
    pumpkin (2).jpg
     
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  6. Mike VV
    Joined: Sep 28, 2010
    Posts: 2,709

    Mike VV
    Member
    from SoCal

    Really, these answers are, well...

    Basically what greybeard said..!
    Take a look at the AA/FA's too ! Nice and high in the air...same problem. Way too much power for the ties of the era.

    The tires at the time, were NOT the tires of today. They did NOT have the traction that the tires of today have.
    The other half of this answer is 8th grade physics. With the front up in the air, the more weight is put onto the rear tires, helping to force the tires into the ground. They when the clutch is let out, "physics" again, the car want's to stand still, the tires want the car to move forward. So, again, more weight is forced onto the rear tires...remember that physic's thing.

    As tires got better, both the engines and car height came down from their nosebleed altitude to the nice low heights we have today. The cars are low, the engine crank centerlines are low, the tire's provide pretty good traction.

    So there you go. just more power than the tires could handle, and the desire to go "quick" and fast.

    Mike
     
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  7. What was considered fast in the 60's isn't that fast by today's standards, so another reason today's logic doesn't work to understand yesterday's designs.
     
  8. seb fontana
    Joined: Sep 1, 2005
    Posts: 7,717

    seb fontana
    Member
    from ct

    They didn't treat the tracks back then either. I'd rather have an axle than some of the factory independent geometry night mares that happened at extreme suspension travel.
     
  9. TA DAD
    Joined: Mar 2, 2014
    Posts: 794

    TA DAD
    Member
    from NC

    I don't know but I would think as seb fontana pointed out a straight axle would eliminate alignment issues. Especially the toe changes that happen as the front end rises. Just a thought.
     
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  10. ramblin dan
    Joined: Apr 16, 2018
    Posts: 3,060

    ramblin dan

    My understanding it had to do with weight distribution to the rear of the car. Kinda like the same reason you would move the engine back or move the rear end up. 145.jpg
     
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  11. THE FRENCHTOWN FLYER
    Joined: Jun 6, 2007
    Posts: 4,489

    THE FRENCHTOWN FLYER
    Member
    from FRENCHTOWN

    seb touched on the other overlooked part of the equation.
    Track prep back then often meant little more than sweeping the broken parts off the track. Nowdays if you walk across the starting line at most tracks you're likely to step right out of your shoes due to the "glue" they put down.

    I built my avatar car 20 years ago using 12 x 32 slicks. Last year I looked at the car and said, "Why am I still using tires designed for the tracks 20 years ago?" Track prep has evolved since then. I changed from 12 x 32s to 10.5 x 28s and picked up .05 in the sixty and .10 in the eighth.
     
  12. 1971BB427
    Joined: Mar 6, 2010
    Posts: 7,676

    1971BB427
    Member
    from Oregon

    A lot of what was true for Gas Class cars in the late 50's and early 60's doesn't apply to mid 60's and later gassers. And it's also been exaggerated by some people building gassers in recent years.
    A lot of what was done to make those early gassers hook up, did also make them less aerodynamic, but the price to pay for better traction was accepted by the guys wanting to go faster. Once development of slicks made huge increases in traction the vast majority of car frontends came down to make them more aerodynamic.
    Solid front axles were far more common in the upper class, or of course with cars that were older and came with solid axles from the factory. But in the lower classes it wasn't as much of a problem to hook up the less powerful cars, so many didn't raise the frontend, or swap in a solid axle.
    Very few cars back in the early days were jacked up in the rear much, if at all. Guys had no qualms about cutting the rear fenders to allow larger tires to clear, unlike today's builders who want to preserve body panels and end up creating "street freaks" not gassers.
    Solid axles don't mean your car will automatically have death wobble, or handling issues. Of course any car raised too high will tend to feel top heavy. But a solid axle isn't to blame. It's simply the fault of some builder wanting to make a car that screams "look at me". I've owned and built gasser type cars since the 60's, long before the latest craze to resurrect the theme. I love that they're so popular these days, but hate to see the cartoon versions that misrepresent the era, and confuse new guys into thinking what they see is correct.
     
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  13. corncobcoupe
    Joined: May 26, 2001
    Posts: 6,278

    corncobcoupe
    SUPER MODERATOR
    Staff Member

    Couple of pics of my old 37 Plymouth.....

    Chucky built Vanilla Shake

    37 PLYMOUTH GASSER 2.jpg

    37 PLYMOUTH GASSER 1.jpg
     
  14. DDDenny
    Joined: Feb 6, 2015
    Posts: 16,723

    DDDenny
    Member
    from oregon

  15. Boneyard51
    Joined: Dec 10, 2017
    Posts: 5,916

    Boneyard51
    Member

    Very good information! Makes sense! I am aware that not all straight axles have the “ death wobble” but most all vehicles that have the death wobble are straight axles! I have dealt with this problem since about 1962. I can’t tell you the umber of axles I have fixed over the years that were “ unfixable”. I guess that is why it seems strange to put a straight axle under a race car to me.
    Again thanks for the info!






    Bones
     
  16. Sky Six
    Joined: Mar 15, 2018
    Posts: 3,190

    Sky Six
    Member
    from Arizona

  17. last I checked there still is. ^^^^^

    Its funny the jacked up car deal only lasted a couple of years in the pro ranks and if you look into NHRA rules it happened after our respected cut off rule. Well sort of some of us think that our cutoff is '64 and others think that it is '65. The rules changed in '65 allowing cars to be lifted for traction advantage.

    The demise of the lifted gasser was bigger trap speeds. The cars that were winning were taking advantage of slip streaming and not catching much air on the big end.

    That said "gassers" should run on gas too. But that is also an argument that many rationalize.

    That said a well designed "gasser" is a good look. In my world it is one of those things that falls under sublime or ridiculous.
     
  18. tire compounds back in the 60's weren't as sticky as now, so any advantage to get more weight on the rear tires helped traction.
    I've always liked the gasser stance as long as it wasn't extreme,...here's my 37 street car with the "look" I liked...
    37 coupe 5-10 016.jpg 37 coupe 5-10 014.jpg
     
  19. uncleandy 65
    Joined: Jan 14, 2013
    Posts: 4,049

    uncleandy 65
    Member

    Back in the 60's there was a saying, If I have to explain, you won't understand.
     
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  20. seb fontana
    Joined: Sep 1, 2005
    Posts: 7,717

    seb fontana
    Member
    from ct

    51 New Pics 014.jpg 20220812_183410.jpg
     
    Last edited: Nov 5, 2022
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  21. 6sally6
    Joined: Feb 16, 2014
    Posts: 2,051

    6sally6
    Member

    It was also thought that a high center of gravity aided weight transfer hence.....jack'em sky high(front & rear) and you increase weight transfer!
    The straight axle was a little lighter than IFS and the springs got the nose waaay up!
    "slicks" were a traction joke back then (compared to todays) so..
    max weight transfer and rosin dust/danc'in dust/Dixie dust made the launch area "more sticky" than typical no-prep starting line.
    It was also a REAL crowd pleaser....spread'in-the-dust. Only the 'big guys' went through the ritual!
    Ronnie Sox/Dyno Don/Gene Cromer were great at it!
    Then came the altered-wheel base...then the "funny car"...and so on.
    Anyway.....it was later learned the weight transfer 'happened' on NON-jacked up gassers too so the aero craze took place.
    progress..........I guess.
    I still get that 'funny-feel'in' when I see a nose high gasser launching.
    (SEGA races is full of those gassers BTW)
    6sally6
     
  22. choptop40
    Joined: Dec 23, 2009
    Posts: 4,507

    choptop40
    Member

    Vanilla Shake is perfect !!! Even in White..
     
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  23. 6t5frlane
    Joined: Dec 8, 2004
    Posts: 2,387

    6t5frlane
    Member
    from New York

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  24. Sky Six
    Joined: Mar 15, 2018
    Posts: 3,190

    Sky Six
    Member
    from Arizona

    With the proper engine setback.
    15632691367_659b87bdd7_c.jpg 15632042649_c8035c3131_c.jpg
     
  25. Sky Six
    Joined: Mar 15, 2018
    Posts: 3,190

    Sky Six
    Member
    from Arizona

  26. Sky Six
    Joined: Mar 15, 2018
    Posts: 3,190

    Sky Six
    Member
    from Arizona

    Another with the proper engine set back.
    485632441_9968c7a2dd_c.jpg 485610007_e2b70085d0_c.jpg
     
  27. Sky Six
    Joined: Mar 15, 2018
    Posts: 3,190

    Sky Six
    Member
    from Arizona

  28. 1971BB427
    Joined: Mar 6, 2010
    Posts: 7,676

    1971BB427
    Member
    from Oregon

    As to weight reduction, it depends on how the axle is installed, and what axle is used. A tube axle will usually be a little lighter than a donor I bema style. And the weight savings can be a lot if the swap includes stubbing the frame rails from the firewall forward.
    Most independent front suspensions use huge crossmembers and beefy frame rails to include all the mounting points for upper/lower A arms. So removing all the control arms and brackets is one way to do a straight axle, but doubt you'll save any weight. Cut the entire frame rails off, and replace with box tubing, and you'll definitely reduce the weight, and also get a cleaner look.
    Here's a before picture of the front suspension and crossmember setup on my '39 Chev coupe:
    [​IMG]

    After removing all the front suspension I have one round tube at the front frame rails added, and the rest is the donor axle and springs. A good amount lighter.:
    [​IMG]

    I had one straight axle with handling, and death wobble issues. It was my first one I put under my '57 Chevy in 1968, and I was totally clueless. I knew nothing about toe in, kingpin angles, drag links, or sizing tierods for this work. Car was all over the road, and had crazy handling issues.
    I visited an old guy who had an alignment shop and did a lot of old pickups with beam axles. Told him what my issues were, and he walked out and did a few quick checks on my axle, and laughed. But he quickly told me where I'd gone wrong, and sold me some spring shims to correct kingpin angles. I went home and made all the changes he suggested in a few hours, and headed out for a test drive. Car drove great, and I went back to thank him for his help. After that I stopped by often, and occasionally helped him if he needed a 2nd hand on anything.
    I never have had a case of death wobble, bump steer, or any handling issues since. I've done too many solid axle swaps to count since, and never had anyone bring one back to tell me it had handling issues. If the old trucks drove great, there's absolutely no reason a solid axle swapped into a car shouldn't drive just as good.
     
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  29. Sky Six
    Joined: Mar 15, 2018
    Posts: 3,190

    Sky Six
    Member
    from Arizona

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