hi all im new to the forum but not new to datsuns!
just wondering if any one thinks a donut LPG tank in the spare Tyre well in a datsun 1600 will upset the handeling?
being a donut tank, it the well, the weight sits very low. let me know what you think thanks

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owned- 10- 1600's. 1-180b. 2- 260z's. 1- 240Z. 1- 280zx. 3- bluebirds. sss n14, r32,r33,r34 ,s14 200sx, MY09 WRX, 2-gq patrols NISSAN FOR LIFE!!!
Build Thread: http://ozdat.com/forum/viewtopic.php?f= ... 6&start=15

i thought about this when i was looking into lpg systems, given that it is going to be much lower than the original fuel tank it may improve handling you would think.

what i am not sure of is how much fuel can you get into a donut that sits in the 1600 wheel well, i am guessing bugger all.

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FOR SALE 1600 FIBREGLASS PARTS

Not sure on how much it will actually effect the handling but another thing to think about is it sit further away from the C.G. so slightly better roll characteristics however slightly less steering response?? If you are concerned about it why dont you just put a normal gas tank where your current fuel tank is?

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My garage:
180b sedan daily (needs some TLC)
180B sss (under restoration)
180b Wagon daily
http://ozdat.com/forum/viewtopic.php?f= ... 9&start=30

this i did 9 years ago, didnt get to drive it propaly (no reg) - i did it because i was super charging a 1600. i finally got this 1600 back with all the gear in it and i want to turbo it this time its 61L water capacity and 50L gas fits nice, had to bash the well a little bit on the back

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owned- 10- 1600's. 1-180b. 2- 260z's. 1- 240Z. 1- 280zx. 3- bluebirds. sss n14, r32,r33,r34 ,s14 200sx, MY09 WRX, 2-gq patrols NISSAN FOR LIFE!!!
Build Thread: http://ozdat.com/forum/viewtopic.php?f= ... 6&start=15

It'll be fine.
You're adding weight up front with the turbo gear, etc. so some extra at the back will balance it, and your fuel tank is lower than a stock one. I'd put the battery in the boot, too. It'll give you more room to run plumbing in the engine bay and you can put the battery either where the stock tank sat or behind the left rear wheel arch (where mine is. My LPG cylinder is where the stock fuel tank was).

Only just found this thread- what are your plans engine wise?

I don't think you understand, its not weight that is the problem. it is weight past the back axles that is the problem.

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I know that moving mass away from the centre of gravity increases the polar moment of inertia (which can be good or bad, depending on your planned use for the car). And lowering mass lowers the CoG.

Without doing all the calculations to try to determine the difference made by changing the fuel tanks, I did think about my reply and reasoned that if your car handles fine with a standard tank full of fuel and a spare wheel and jack in the wheel well, plus a toolbox and/or battery in the boot (and Datsuns usually do) then removing the standard tank and replacing the spare wheel & jack with an LPG cylinder won't make a huge difference. Having 14 kilos of tools and my battery in the boot of my Datsun (both behind the axle line) makes such a small difference to the handling you wouldn't really notice on the street. Sure, I have heavier than standard springs and shocks, but most Datsuns do these days. I bet Drifta1600 will make sure his supension is improved to handle his planned power increase.

Am I missing something Spandex (always happy to learn something new )?

A quick drive of the car in question will reveal if there is a problem.... but if there is you'd normally fix it with springs and shocks, not by changing fuel tank. The only reason my LPG cylinder is in the stock tank's location is because I think that's the safest place for a fuel tank.... and because like Jetdat I didn't know you could get a toroidal tank with that much capacity.

Cheers!

The donut tank should hold 45 lts of LPG, the same as the B10 tank in the R30 Skyline.

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1984 R30 LPG 206rwkw with 563Nm torque
2009 Aprilia Dorsodouro
1996 Suzuki GSXR 750

Personally Id get a cheap stainless tank of 72litres from a wreckers before its too late
as they are getting rare now and weigh less than halve a normal tank. big difference
when you weigh the 2 its like day and night. Dattos should be kept as light as possible.

Put it in place of a normal tank and no probs on balance. I dont like the donut ones
they are super heavy, maybe closer to 80-100 kilos full?

stainless tanks by law where allowed as long as they are inside vehicle.

I wanted one of these in my 1200 but couldn't find one small enough easily. Went with a 50lt useable gas one where stock one sat. LPG installer says safer there than wheel well of a Datsun too lol.

Yes would be good lower than stock tank but better where stock tank is than further past the rest axle line. My car feels better balanced with gas tank in rear than was with petrol tank... Even under track braking felt rear could do with a little more back there to stop that lifting under braking feeling.
Battery in rear now- will see how it goes next time out

I found altering the brake balance (fitted rear disc brakes & adjusted brake bias) significantly reduced front end dive under hard braking, too.

For the extra expense of the LPG conversion why not spend a little more and inject instead? You'll be much happier with the end result. And you won't be breaking any laws when you work on it. A lot of guys use a R31 skyline fuel tank to keep costs down. If you run out of fuel you can use a Jerry can. LPG you're stuffed.

There's a few blokes I've met that after spending a heap getting the LPG right regret not going fuel injection instead. But once you outlay all the cash with lpg you will be stuck with it. It'll be a massive loss on the product and twice the job to repair your mistake.

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Some people play hard to get... I play hard to want!

With the new gas vapour technology available now, you can get more HP and economy from it than from comparable petrol systems. The cost however is hard to justify. You would be looking at around $5k for such a system. My 2c worth.

If I was to do my Skyline again, I would not hesitate to spend the money on one of these systems.

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1984 R30 LPG 206rwkw with 563Nm torque
2009 Aprilia Dorsodouro
1996 Suzuki GSXR 750

That's a heap of torque in your sig!!!! I'd skip vapour go straight lpg injection.... Ultimate in tune ability

(I do not want to hijack this thread)
But yeah, it makes a truckload of torque. Not bad for an old style Impco system.......

As mentioned, if I was to do my old girl up now, I would go with gas vapour injection. Liquid injection has still not proven itself reliable enough. (Most issues come with manufacturers wanting to run dual fuel thru the same injector and it will not work)

Just put new mixer and converter on and it now pushes over 575Nm of torque on Eastside Automotive dyno. Pretty happy!

Back to the original thread: any weight past the rear or front axle, is going to effect handling. If you had an out and out competetive race car, then yes any change is going to be potentially detrimental. On a weekend warrior........not so much. Lowering the C of G is going to help more than the cumulative effect of having some more weight behind the rear axle. Just do not want it to give more creedence to lift off oversteer!

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1984 R30 LPG 206rwkw with 563Nm torque
2009 Aprilia Dorsodouro
1996 Suzuki GSXR 750