Author Topic: Getting ready for Bonneville(rebuild)  (Read 1892862 times)

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Offline Freud

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Re: Getting ready for Bonneville(rebuild)
« Reply #1995 on: March 02, 2014, 03:16:25 PM »
Years ago, I think it was when the L88 Corvette came out, Slick Gardner gained 20 MPH by removing the

tires that came on the car and used B'ville rubber. He didn't lack courage....just traction and stability.

His last runs were around 180 as I recall.

Now I can't even remember where I put my Social Security Card.

FREUD
« Last Edit: March 02, 2014, 03:21:55 PM by Freud »
Since '63

Offline manta22

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Re: Getting ready for Bonneville(rebuild)
« Reply #1996 on: March 02, 2014, 03:25:45 PM »
Rex;

There are lots of variables that come into play regarding tires at Bonneville. I haven't finished my car yet so I can't speak from first- hand experience but I can point out a few other cases that may be germane.

Sports racing cars routinely ran 240mph- 250mph at Le Mans and at Spa- their tire widths were enormous. I suspect the difference you found might be influenced by differences in rolling resistance, actual rolling radius at speed (how much tire growth was there?), rubber durometer, and the tread pattern. Wide slicks might not hook up well due to the thin layer of loose salt that exists on the surface most of the time. Under those circumstances a tread pattern might help but narrow LSR tires exhibit a greater pressure on the salt surface (lbs per sq inch) and may have better traction due to crushing the loose salt layer. I doubt that there is one choice with an advantage under all circumstances.

This is just my idle speculation- Goodyear may have actual test data somewhere.

I had an opportunity to talk to factory tire engineers from Dunlop and Pirelli at a Superbike Championship at Laguna Seca some years ago. They were very skeptical of narrow LSR tires' lateral stability and thought that, all else being equal, a wide tire should give better handling even at high speed. I'm reasonably sure those engineers had no LSR experience so how much credence their opinions had is uncertain.

One thing is for certain-- some measure of F & R down force will be necessary for both traction and stability.

Regards, Neil  Tucson, AZ
Regards, Neil  Tucson, AZ

Offline wheelrdealer

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Re: Getting ready for Bonneville(rebuild)
« Reply #1997 on: March 02, 2014, 04:56:01 PM »
Years ago, I think it was when the L88 Corvette came out, Slick Gardner gained 20 MPH by removing the

tires that came on the car and used B'ville rubber. He didn't lack courage....just traction and stability.

His last runs were around 180 as I recall.

Now I can't even remember where I put my Social Security Card.

FREUD


That's ok Doc, you remember the really important stuff.

BR
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ECTA    Maxton D/CBGALT Record Holder 166.715

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Offline Captthundarr

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Re: Getting ready for Bonneville(rebuild)
« Reply #1998 on: March 02, 2014, 11:39:09 PM »
OH No not wide tires!!!!!!!!!

Sorry folks, I made the comment toguein cheek. there was some discussion a ways back in this tread about some folks giving thes guys some greif about using wide tires... :-D
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Offline bvillercr

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Re: Getting ready for Bonneville(rebuild)
« Reply #1999 on: March 03, 2014, 10:05:34 AM »
The last year we ran we changed many things in our suspension set up.  That combined with a wet course was an uncomfortable and unpredictable handling car.   We will be making some changes for this year, with that said how many cars do you know of that has gone 294 in the 3?  Not many cars that's for sure, we just happen to run wide tires. :-D

Offline jl222

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Re: Getting ready for Bonneville(rebuild)
« Reply #2000 on: March 03, 2014, 09:03:27 PM »
OH No not wide tires!!!!!!!!!

From someone that has tried both wide Goodyears and narrow Goodyears back to back, we could not make the wide tires work on the 3838 Corvette. From what I understand, if the salt was drier and not like it was during the 2013 Speedweek, the wide tires would have worked MUCH better. The crazy thing was how much more traction the wide tires had at the lower speeds such as less than 240mph. The first time I ran it through first and second and even third gear, I was really exited because she was hooked up! Then a strange phenomenon happened where the tire seem to start floating on the salt and had trouble getting the car past 250mph. Switched to the skinnys and immediately went 276mph.
From what I can figure out, you almost need to have both types of tires with you when you go to the salt. This can allow you to squeak out a couple of decent runs together even if conditions are not so good. It's not like most of us can come back the following week when conditions are better, we have to deal with whatever Mother Nature hands us. When we went 276mph this year, the conditions were not good at all but that run did qualify 12mph over existing record. What I'm really trying to say is that the salt is almost never good anymore so we all need to figure better ways to deal with it instead of saying "Oh well, salt sucks this year, maybe next year will be better".
One more thing and I will quit rambling, the salt got so much better as Soeedweek went on that if most of the racers would have just stuck it out to the end of the week instead of booking out there, they would of had some descent salt to run on.
I for one still have a lot to learn about salt conditions but if I has a car that could fit both kinds of tires, I would take both kinds if tires especially since the wide tires are relatively inexpensive. I thank John and Troy for turning me on to the wide tires. Besides, they look SOOOOO much cooler!

  Rob when you posted  about your wide tire problems on the vette my computer had gone out.

  At the time there were fotos posted showing where the wide tires rubbed on the fender wells. I thought that might be causing a problem
with the handling.

            JL222

Offline jl222

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Re: Getting ready for Bonneville(rebuild)
« Reply #2001 on: March 03, 2014, 09:34:58 PM »
The last year we ran we changed many things in our suspension set up.  That combined with a wet course was an uncomfortable and unpredictable handling car.   We will be making some changes for this year, with that said how many cars do you know of that has gone 294 in the 3?  Not many cars that's for sure, we just happen to run wide tires. :-D

  Also the run before, were I shut off at the start of the 3, we were 9 mph faster in the 2nd mile from the start than on the 294 run.

  Just measured the wear holes in our new tires they vary some but most are .130 thou, then measured our old 222 tires that have several runs on them at .125 thou.

   Picked up my misplaced Crank from magnafluxer, and rods and pistons were shipped Friday :cheers:

                 JL222

   

Offline robfrey

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Re: Getting ready for Bonneville(rebuild)
« Reply #2002 on: March 03, 2014, 10:16:49 PM »
Tire rubbing was only a problem early on.which we fixed.  I made 7 runs with wide tires trying to get then to work. I think it was just the wrong salt.
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Offline jl222

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Re: Getting ready for Bonneville(rebuild)
« Reply #2003 on: March 04, 2014, 02:59:23 AM »
Tire rubbing was only a problem early on.which we fixed.  I made 7 runs with wide tires trying to get then to work. I think it was just the wrong salt.

  Rob what air pressure were you using?

      JL222

Offline robfrey

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Re: Getting ready for Bonneville(rebuild)
« Reply #2004 on: March 04, 2014, 08:57:43 PM »
52 psi
496 BGS
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Offline jl222

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Re: Getting ready for Bonneville(rebuild)
« Reply #2005 on: March 04, 2014, 09:33:25 PM »
52 psi

  Year that's just 2 psi more than what we usually run, but we did have 45 psi one time and ran 288 with an exit speed of 279
with no problems.

                  JL222

Offline jl222

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Re: Getting ready for Bonneville(rebuild)
« Reply #2006 on: March 06, 2014, 12:10:43 AM »
 
  Got the crank back Monday, yesterday FEDX delivered the rods and pistons and UPS dropped off longer studs for rear axles. For 2012 we tried wheels with more offset to narrow the tread width thinking there would be less leverage on the chassis and some other changes, As I've said before it felt like I would spin out at any time and the car usually feels glued in and stable at speed.
 So ordered a 1 inch spacer for 5/8 holes and longer Mark Williams studs to get wheels back to normal. Problem is that these wheel studs have a shoulder that fit the wheels that are just a bit bigger than 5/8 and would not fit through spacer :roll:
 Lucky that we have International Hardware a great place, that had a 45/64th drill bit. 47 bucks :-o as much as the spacers :-P

     JL222
 
   

 

Offline Milwaukee Midget

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Re: Getting ready for Bonneville(rebuild)
« Reply #2007 on: March 06, 2014, 12:42:53 AM »
Lucky that we have International Hardware a great place, that had a 45/64th drill bit. 47 bucks :-o as much as the spacers :-P

     JL222
 

Ouch.

First iteration of my engine, the cam was a regrind, and they bunged up the threads.

I've got no further use for the 5/8 fine die I had to buy to chase 'em out.

I'll keep it, knowing full well that when I croak, it will have not been used since 2010.  It will wind up in a box at the estate auction with a UNI-SYNC carb flow gauge, a spoke wrench and a Gunson Colortune, and the only reason they will have gotten $5.00 for the whole lot is because there was a Reddy Kilowatt patch from the Eastern Iowa Rural Electric Cooperative in the box.

What can you do?  :|
"Problems are almost always a sign of progress."  Harold Bettes
Well, I guess we're making a LOT of progress . . .  :roll:

Offline Buickguy3

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Re: Getting ready for Bonneville(rebuild)
« Reply #2008 on: March 06, 2014, 11:40:58 AM »
    And the buyer will say: WTF was that old guy doing with this stuff?
  Doug  :cheers: :cheers: :cheers:
I keep going faster and faster and I don't know why. All I have to do is live and die.
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Offline Elmo Rodge

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Re: Getting ready for Bonneville(rebuild)
« Reply #2009 on: March 06, 2014, 12:02:28 PM »
    And the buyer will say: WTF was that old guy doing with this stuff?
  Doug  :cheers: :cheers: :cheers:
When they see all the Whitworth stuff they'll say "Oh. He was one of those.  :roll::cheers: Wayno