Australian Belly Tank

[Rob]

It's killing me guys, what the h*ll was happening in this one?



Cheers,
Rob

[Dr Goggles]

we was trying to get some nice shots, as requested, of us's wearin' Stainless's shirts...... and looking at the shot this would be before we thought to put the bus in gear and we were doing the treadmill on the tires.....two of us with bung legs ..................it was going to end badly....no we weren't tanked......we can thank GrahaminAus for the shot above

[Rob]

Thanks Doc,

Sounds better than it looks and yep, Graham's pic. He's good on the camera but don't let him "adjust" your tent 

Cheers,
Rob

[Lynchy]

If they all ran really fast in the other direction they might find the missing 7mph.....

[Stainless1]

Great looking shirts... hope to wear one like them in Australia some day... when they get really old they make great polishing rags. 

Back in the day there used to be a large Speed Limit 1000 sign at the start line... disappeared after the 2 year shutdown 82-83.  We had the number so it was a natural....

[Dr Goggles]

All these shots were taken by bystanders when we were posing for Frank who's a real photographer, we're waiting on Frank's stuff, amongst them should be just the shot you're after Mr Steele ...last years

http://twixt-two-wheels.jalbum.net/Spirit%20of%20Sunshine/

were great...to be honest apart from a few tiny external details even I'll have trouble telling this from last years photos.

Now, I know there's a few stale half or three quarter finished ones laying around but I thought it might be time to open a fresh can of worms.....

The crew are currently "discussing" what mods we are going to make to the car , what we can afford and wht will be the most useful for the "task at hand"........getting it over 200 and beyond.

On the fast runs this year the car was putting on about 12mph per mile after the first mile , reaching a max of about 195. Now in rough terms I have been contending that if we change the final drive that the car will accelerate at rough( slightly less)ly the same rate in top but will go little further between gears thus it will be slower at the end of the first mile.....soooooo, I'm thinking for the lower rear end we are going to need just a little more power AS WELL AS the valve train mods to let her rev to 7000....otherwise although the car will still be accelerating we'll run into the small problem of the last timed mile.......

anyone?

am I right in saying that the lower numerical final drive lowers the applied torque?........

[Milwaukee Midget]

Doc -

The very first post I made on this forum brought up the very subject you're asking about -

Horse power is what makes you go fast, build it for max hp and then gear it for your max speed at close to the max hp rpm. Torque makes it easy to pull away from a stop light but doesn't give you mph
Rex

followed by

RPM baby..!....ring its neck and pick up the pieces....
kent

Given this advice from the really good guys, I'd suggest you get the tank to the dyno that your buddy had offered up a while back and see where you’re sitting on power, determine how fast you want to go, and calculate your final drive with that info.  In the lower gears, you’ll probably be able to pull past peak power (provided properly preempting percolating petroleum problems), and fall on the upswing of your power band during acceleration.

Chris

[SPARKY]

engTorque X trans ratio X Rear ratio XTire Correction= Tractive effort

the higher the RPMs and the larger rear axle number for any given speed will give you more Tractive effort--- tq being the same

[Rob]

Doc 'n Rev,

I've been pondering a thought this past day. Given your current rate of yearly improvement, you guys may well be looking at the top speed of the meet next year... certainly you will be right up there in the 4 wheelers.

Cheers,
Rob

[Dr Goggles]

Steady on there Rob flattery ain't necessarily a good thing in LSR ....fat heads have bad aero

We are engaged in debate via email as to what is the most important of the inter-related factors...the holy triangle of power/gearing/money( we are going to have a tinker with aero but on a broad scale we're happy with it).... we intend to go with a 7.5 inch rear end ala Sparky's Ratical but we have to solve the natural rev-limit that the valve train has imposed and then I suspect eek out a little bit more power to get over a taller rear end............................

this year we hoped to get into the 200's, we missed by 3&1/2 per cent.....next year we want to get into the teens......

That said it is almost time, nay IS time to re-visit some of the detail in the cab....we're going to change the gearshift lock-out so that we can use first gear..... and if time permits I might have a bit of a crack at the steering column..... the functionality in there could be a little better, we'
re going to lost the big tacho too.........One idiot light for oil pressure and a big two digit LED tach......from what I experienced on my last run that's plenty

[Stainless1]

Doc, add a little time on the dyno, it sounded like you might have been lean on top.  If you are using ram air, it is harder to simulate on the dyno but set it fat.  Then when you run it keep adding fuel till you stop going faster.  Or get one of the air/fuel thingies and be at 12.2.

[Rob]

Steady on there Rob flattery ain't necessarily a good thing in LSR ....fat heads have bad aero

Not flattery, just seriously thinking about where your car was this year and what actually held it back. If the seal hadn't died and lifters had not pumped up... you didn't lose traction or at least, not noticably so. You were running a guesstimate ECU with no dyno time so unless you were extremely lucky, you weren't at your full potential HP wise.

It wouldn't be a bad thing to get in a dyno run now as a baseline before you change anything. Then you will know how many hp you have added next year for how much speed which will help you in the future.

Cheers,
Rob

[Reverend Hedgash]

That's a very good point about the dyno and getting a baseline, Rob thanks.

I am very excited about the aero as Dr G reports that he thinks we had zero wheel slippage at top speed.

That said, it can always be better and so the plan is to improve this again by tightening seams, closing holes and smoothing this and that.

Better aero is cheap horsepower in my book.

Dik (rH+)

[wobblywalrus]

Doc and Rev, I was changing gearing, tires, and chain types in the time intervals between my baseline run and my subsequent dyno runs.  The chassis dyno we use is sensitive to this, and I could not compare the baseline and later runs to determine year-to-year horsepower changes.  It is a topic to discuss with your dyno operator.  He /she might have some recommendations. 

[Rob]

Rev,

No worries, I'm just making it up as I go along but it seems a logical idea to me. Changing rear ends and or ratios will change your rear wheel output but should still be comparable with your baseline to my mind. If you change tyres or rubber compounds, tyre to roller frictional changes will come into the equation.

Doc and Rev, I was changing gearing, tires, and chain types in the time intervals between my baseline run and my subsequent dyno runs.  The chassis dyno we use is sensitive to this, and I could not compare the baseline and later runs to determine year-to-year horsepower changes.  It is a topic to discuss with your dyno operator.  He /she might have some recommendations.  

WW,

Why wouldn't you still get a real comparison of rear wheel HP at any given point assuming the same dyno and tyres are used? Tyre change I can understand making inaccuracies.

I'm no dyno guru but I am a logical thinker with an enquiring mind.

Cheers,
Rob