Outer Limits 4x4 Board

roc70y wrote:I think Ruff runs different ratios front and rear, the front wheels spinning quicker than the back.

No basically its a bit of a illusion, its mainly due to the amount of wheel spin he produces. Because the front drive shaft is slightly longer than the rear it allows for the front to spin a little faster! He also runs a Centre bearing on the front shaft, this reduces alot of friction and allows the front to rotate easier/faster. It doesn't usually pose to much of an issue until he runs in reverse. Because the front shaft is so long it takes ages for it to change direction so sometimes his front wheels will be going the opposite direction to his rear, unless hes going forward! He could balance this out by running reverse cut Cv gears, they should allow faster rotation (and they are heaps stronger).

POS wrote:

roc70y wrote:I think Ruff runs different ratios front and rear, the front wheels spinning quicker than the back.

No basically its a bit of a illusion, its mainly due to the amount of wheel spin he produces. Because the front drive shaft is slightly longer than the rear it allows for the front to spin a little faster! He also runs a Centre bearing on the front shaft, this reduces alot of friction and allows the front to rotate easier/faster. It doesn't usually pose to much of an issue until he runs in reverse. Because the front shaft is so long it takes ages for it to change direction so sometimes his front wheels will be going the opposite direction to his rear, unless hes going forward! He could balance this out by running reverse cut Cv gears, they should allow faster rotation (and they are heaps stronger).

Hu

RUFF wrote:

POS wrote:

roc70y wrote:I think Ruff runs different ratios front and rear, the front wheels spinning quicker than the back.

No basically its a bit of a illusion, its mainly due to the amount of wheel spin he produces. Because the front drive shaft is slightly longer than the rear it allows for the front to spin a little faster! He also runs a Centre bearing on the front shaft, this reduces alot of friction and allows the front to rotate easier/faster. It doesn't usually pose to much of an issue until he runs in reverse. Because the front shaft is so long it takes ages for it to change direction so sometimes his front wheels will be going the opposite direction to his rear, unless hes going forward! He could balance this out by running reverse cut Cv gears, they should allow faster rotation (and they are heaps stronger).

Hu

Maybe he should use more viscosity in the rear then

All fun aside , we Did experiment with a 3.7 rear and a 3,9 front in a
Zook many years ago ,
The theory behind it was to make the zook a better uphill performer-
Idea = Front wheels Turning at a slightly slower speed when confronted with a vertical or near vertical obstical eg steps,

Result i think it did step better , it didn,t turn as well (rear pushing very slightly did make a difference) And to make it turn better you couldn,t throw it in two wheel drive in a hurry there was just to much bind to get it out of four wheel drive .
Today most people are looking at front rear disconect's, run different ratio,s and these items will be useless the bind effect will make it impossible to release the shafts.

IMO the only place for different ratios is if your choices of diffs don,t make matching front rear Ratio,s , and in this case do your maths to the last mm to get your front or rear tires to make the difference up .

Larry.

POS wrote:

roc70y wrote:I think Ruff runs different ratios front and rear, the front wheels spinning quicker than the back.

No basically its a bit of a illusion, its mainly due to the amount of wheel spin he produces. Because the front drive shaft is slightly longer than the rear it allows for the front to spin a little faster! He also runs a Centre bearing on the front shaft, this reduces alot of friction and allows the front to rotate easier/faster. It doesn't usually pose to much of an issue until he runs in reverse. Because the front shaft is so long it takes ages for it to change direction so sometimes his front wheels will be going the opposite direction to his rear, unless hes going forward! He could balance this out by running reverse cut Cv gears, they should allow faster rotation (and they are heaps stronger).

MAN YOU MUST HAVE HAD A BORING DAY AT THE BANK!

POS wrote:

roc70y wrote:I think Ruff runs different ratios front and rear, the front wheels spinning quicker than the back.

No basically its a bit of a illusion, its mainly due to the amount of wheel spin he produces. Because the front drive shaft is slightly longer than the rear it allows for the front to spin a little faster! He also runs a Centre bearing on the front shaft, this reduces alot of friction and allows the front to rotate easier/faster. It doesn't usually pose to much of an issue until he runs in reverse. Because the front shaft is so long it takes ages for it to change direction so sometimes his front wheels will be going the opposite direction to his rear, unless hes going forward! He could balance this out by running reverse cut Cv gears, they should allow faster rotation (and they are heaps stronger).

best tech post evaaaar

i thought i'd trow this in as to what i'm doing.

the "Renesis" engine is out of the new RX8 Mazdas.

The RENESIS generates an estimated 250 horsepower at 8500 RPM, with a torque peak of 162 lb-ft coming at about 7500 RPM. Roughly 90% of this torque is available at 3000 RPM, however, giving the RENESIS a very flat torque curve and very linear power delivery. An approximate engine torque/power curve derived from information found at a European website is attached below.
Compared to the twin-turbo 13B in the third-generation RX-7s, the new RENESIS engine has a large number of improvements. One of the largest changes, besides the lack of turbo-chargers, is a new port layout with larger exhaust ports on the side housing instead of the peripheral housing. The design and placement of these ports improves the performance of the engine by removing the overlap between the intake and exhaust phases present in earlier Mazda rotary engines. The design of these ports also improves emissions by allowing unburned hydrocarbons near the walls of the engine to be carried over into the next combustion cycle. In addition, Mazda also claims to have improved fuel efficiency about 30% at idle, and wardsautoworld.com posted at article estimating around-town mileage of about 23 MPG. This is in contrast to the 18 MPG the RX7 got from its 13B powerplant. Despite these changes and having no turbo-chargers, Mazda estimates, as stated above, that the RENESIS will generate a peak of 250 HP, as much as the twin-turbocharged 13B in the third generation RX-7.




That'll do for my buggy!

and with programable fuel injection, we can play with where the power / torque comes in.

how much is the renisis engine worth chris? i thought it'd be big $$$'s seeing as they're still so new?

i'm about to hit a local guy up for a package deal of new and old stuff, the new engine will still bolt up to an older (non electronic) auto box.
I'm also hassling some old rotary contacts down in Sydney for parts too.

Engine and auto, with all sensors etc should come in under $3000.
then got to modify some stuff, so i can run the aftermarket ECU.

Chris

roc70y wrote:i'm about to hit a local guy up for a package deal of new and old stuff, the new engine will still bolt up to an older (non electronic) auto box.
I'm also hassling some old rotary contacts down in Sydney for parts too.

Engine and auto, with all sensors etc should come in under $3000.
then got to modify some stuff, so i can run the aftermarket ECU.

Chris

Hey Chris

Just make sure that your aftermarket comp. will run this motor.
A mate has just put a Series 8 motor into his car and Microtech computers cannot support this motor. He is working on a solution!

Also 'had' some rotary parts you would have been welcome too. They were given to the above mention party

I.M.P.O.S.E wrote:

roc70y wrote:i'm about to hit a local guy up for a package deal of new and old stuff, the new engine will still bolt up to an older (non electronic) auto box.
I'm also hassling some old rotary contacts down in Sydney for parts too.

Engine and auto, with all sensors etc should come in under $3000.
then got to modify some stuff, so i can run the aftermarket ECU.

Chris

Hey Chris

Just make sure that your aftermarket comp. will run this motor.
A mate has just put a Series 8 motor into his car and Microtech computers cannot support this motor. He is working on a solution!

Also 'had' some rotary parts you would have been welcome too. They were given to the above mention party

already on it!
a mate in Sydney is a MoTeC distributor and they have these engines sorted.

Chris

Cool as! Just checkin before you get as far as he did! All it need was the wiring!

Damn I am already scared of this thing, can't wait to see it going.

As for the running differestn gears long tailshafts and reverse cut cv's post.

YOU HAVE TO STOP DRINKING AND TYPING

That was the most imaginative piece of tech talk I have ever seen.

Hooked up with the Motec guy today. Very cool stuff!
Chris

Stuff running it backwards and crap

follow the lead of the Jeep Hurricane and have 2 engines



http://www.detnews.com/2005/autosinsider/0501/10/A01-55058.htm

AussieCJ7 wrote:Stuff running it backwards and crap

follow the lead of the Jeep Hurricane and have 2 engines



http://www.detnews.com/2005/autosinsider/0501/10/A01-55058.htm

that would be cool, if i were a millionaire, but unfortunately ,i'm not and that car also doesnt comply to WE Rock rules.

Chris