Author Topic: Australian Belly Tank  (Read 3165546 times)

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Offline Stainless1

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Re: Australian Belly Tank
« Reply #4350 on: March 11, 2014, 10:37:23 AM »
Doc G, lets talk about shift points and the runs in a little more detail...
Did the car rev and pull to 6300 in all the gears except hi?  Sounds like you were fighting the engine a little?  Do you think it would pull the gear is it was running right? 
Wait, let me get a beer.... ok we are ready for the long explanation...  :cheers:
Stainless
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Offline Sumner

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Re: Australian Belly Tank
« Reply #4351 on: March 11, 2014, 11:06:20 AM »
Since you only have 2.41, 2.28 and 2.14's to choose from and can't change transmission ratios I'd for sure go with the 2.28's until you run out of gear with those or the 2.41's if a different cam and higher rpms are a possibility (probably better rods and valve-train are required for that though). 

I think we already had this discussion a ways back...

http://www.landracing.com/forum/index.php/topic,862.4185.html

Above 200 the HP needed is going to really start jumping and I feel the 2.14's are just not going to work until you put a turbo on that motor  :-D  :cheers:,

Sum

Offline Milwaukee Midget

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Re: Australian Belly Tank
« Reply #4352 on: March 11, 2014, 05:33:13 PM »
Here's a quick analysis from what I was able to glean from Mark's spread sheet and Doc's info, and incorporating Sumner's spread sheet.

w/2.14s @5285 we’re at 204
Spread sheet says 5307=205

5285/5307=.9959
204/205=.9951

We’re talking .08% difference, so we can eliminate any slip in the drivetrain, and reasonably assume any other numbers we generate should be accurate.

The Purple line was the power band used in 4th with 2.14s.

The Australian Non-Lucas Electronic Yellow line was the power band used in 4th with 2.41s.



In short, you spent less time in the area where the power was hanging out.

What IS good news is that by hitting the wall with NO WHEEL SLIP, we can take the HP figure at that RPM and calculate your drag coefficient.

 :cheers:


"Problems are almost always a sign of progress."  Harold Bettes
Well, I guess we're making a LOT of progress . . .  :roll:

Offline Dr Goggles

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Re: Australian Belly Tank
« Reply #4353 on: March 11, 2014, 07:33:19 PM »
You're all saying what I am thinking, yes,yes,yes and yes. No new info here.

What I am struggling with is making posts stick ,I have lost four and it is annoying me.

Edit: hooray! This one stuck.
« Last Edit: March 11, 2014, 07:35:06 PM by Dr Goggles »
Few understand what I'm trying to do but they vastly outnumber those who understand why...................

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Current Australian E/GL record holder at 215.041mph

THE LUCKIEST MAN IN SLOW BUSINESS.

Offline Sumner

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Re: Australian Belly Tank
« Reply #4354 on: March 11, 2014, 09:23:27 PM »
If the engine was running the same I just think you threw too tall a gear at it and it wouldn't pull it as your HP was too low at the lower rpms.

I have the same problem with my truck.  Runs right up to 122 in 3rd.  Go into overdrive and it will take it a mile to get to 130+ since the rpms dropped below 4000 and I"m out of the power band,

Sum

Offline Dr Goggles

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Re: Australian Belly Tank
« Reply #4355 on: March 11, 2014, 09:51:49 PM »
Had it not broken down with the 2.28 in it we would have had a much better idea of where we were at,Que sera....or should it be OK Sara?
« Last Edit: March 11, 2014, 09:53:51 PM by Dr Goggles »
Few understand what I'm trying to do but they vastly outnumber those who understand why...................

http://thespiritofsunshine.blogspot.com/

Current Australian E/GL record holder at 215.041mph

THE LUCKIEST MAN IN SLOW BUSINESS.

Offline Dr Goggles

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Re: Australian Belly Tank
« Reply #4356 on: March 11, 2014, 10:12:45 PM »

That's 21% less than a linear relationship.

speed/drag ain't a linear relationship is it.
Few understand what I'm trying to do but they vastly outnumber those who understand why...................

http://thespiritofsunshine.blogspot.com/

Current Australian E/GL record holder at 215.041mph

THE LUCKIEST MAN IN SLOW BUSINESS.

Offline wobblywalrus

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Re: Australian Belly Tank
« Reply #4357 on: March 11, 2014, 11:29:31 PM »
It seems like the 2.28 ratio is best at this time based on what is posted.  It is time to move to taller gearing when the engine can pull around 6,300 to 6,500 with 2.28. 

Offline Reverend Hedgash

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Re: Australian Belly Tank
« Reply #4358 on: March 12, 2014, 03:13:35 AM »
Thanks for all the info everyone. Something no-one has mentioned is rolling resistance. With the softer salt I would imagine this would have a big affect on potential top speed. As a bicycle rider, I have noticed how if my tyres are even slightly flat I need a different gear to get up the local hill due to the extra rolling resistance.

It seems everyone was having lower speeds because of this and so we should not forget to factor this in.

Rev H+

Offline maj

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Re: Australian Belly Tank
« Reply #4359 on: March 12, 2014, 03:57:19 AM »
Yep i was hearing a few comments from the bike guys that the first measured mile was like you put the brakes on ,

Offline grumm441

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Re: Australian Belly Tank
« Reply #4360 on: March 12, 2014, 04:18:23 AM »
You know it was fine when I ran in the van
First mile     100.053
Second mile 100.053
Third Mile    100.054

Oh and that's kilometers  per
Ok, it's not that fast but at least I know my speedo is accurate   8-)
G
Chief Motorcycle Steward Dry Lakes Racers Australia Inc
Spirit of Sunshine Bellytank Lakester
https://www.dlra.org.au/rulebook.htm

Offline Dr Goggles

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Re: Australian Belly Tank
« Reply #4361 on: March 12, 2014, 06:41:18 PM »
Squirmy is how I would describe the track, it felt like driving into a few inches of water at times. The tank is about as easy a drive as you'd get I reckon,you can feel any movement and because it's so stiff there is no strain and release sensation. This year was the first time I've used first off the line and it stepped out a bit but it just snaps back . Yes, I think the track was slow both because of the poor traction and higher rolling resistance.
Few understand what I'm trying to do but they vastly outnumber those who understand why...................

http://thespiritofsunshine.blogspot.com/

Current Australian E/GL record holder at 215.041mph

THE LUCKIEST MAN IN SLOW BUSINESS.

Offline grumm441

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Re: Australian Belly Tank
« Reply #4362 on: March 13, 2014, 10:54:59 PM »
Thanx Grumm. It is however not 'til next Friday.  :cheers: Wayno

Hey Wayno
Happy birthday
G
Chief Motorcycle Steward Dry Lakes Racers Australia Inc
Spirit of Sunshine Bellytank Lakester
https://www.dlra.org.au/rulebook.htm

Offline Milwaukee Midget

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Re: Australian Belly Tank
« Reply #4363 on: March 14, 2014, 01:15:44 AM »
Thanx Grumm. It is however not 'til next Friday.  :cheers: Wayno

Hey Wayno
Happy birthday
G

I went out and bought myself something for your birthday . . .



Thanks for providing the excuse.

Bring harps in August.

Happy Birthday, Wayno! :cheers:
"Problems are almost always a sign of progress."  Harold Bettes
Well, I guess we're making a LOT of progress . . .  :roll:

Offline Dr Goggles

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Re: Australian Belly Tank
« Reply #4364 on: March 14, 2014, 02:10:42 AM »
Excuse my ignorance,but,what is it?
Few understand what I'm trying to do but they vastly outnumber those who understand why...................

http://thespiritofsunshine.blogspot.com/

Current Australian E/GL record holder at 215.041mph

THE LUCKIEST MAN IN SLOW BUSINESS.