Got a question about cars? (1 Viewer)

[braad]

The FWD story:

First introduced on the original mini it was an engineering revolution.

FWD is more space efficient than RWD and cheaper to produce.

The differences in terms of use though are:

FWD's have more of a tendency to understeer that is to push nose first out of a corner whereas RWDs have more of a tendency to pull the tail around and slide out backwards. This was summarised on Top Gear as understeer runs you into the tree forewards, oversteer backwards. The reason for this being that in a FWD the engine must sit ahead of the front axle which adversly affects weight balance etc etc.

This said for safety reasons (eg understeer is alot easier for the average driver to handle) almost all new cars are built to understeer.

FWD's are more likely to loose traction accelerating off the line than RWDs as when they accelerate and the car squats the drive wheels (eg the fronts) have reduced traction. Whereas when a RWD squats it increases drive wheel (eg rear wheel) traction by increasing the weight on them.

Other than that the mechanical differences mean that RWDs are generally more straightforward and thus easier for the home mechanic to work on.

Finally FWD's having the engine ahead of the front axle effect how a car has to look by essentially elongating the portion of the car past the front wheels. Some object to FWD for this alone. The get around on this is essentially the engine bay intruding on the passenger compartment. Anyone who has seen a new VW beetle up close may have noticed the huge dash this is because the engine bay is actually recessed into the passenger compartment so as to make the funky exterior styling of the beetle possible.

hate to burst your bubble, but the mini wasnt the first. It was the one that was mass-produced, successful and popular

 

[braad]

all BMWs?

the mini, before you bitch, it's a fucking BMW

oh, and FWD

 

[DaddyK]

Correct Dazy.



All small cars are (Bar the BMW 1 series).

Holden Commodore

Falcon

All BMWs are RWD.

All Mercedes except the A class


All VW's are FWD.

All subarus are ALD

All mazdas FWD

All Toyotas FWD

All mazda's? What about the mazda 929, rx2, rx3, rx4's, rx7's, there all rwd

All toyota's? What about the mr2, supra, soarer, KE10, KE20, KE30, KE55, KE70 corolla there all rear wheel drive.

Get some idea before you post eh.

 

[S13WPN]

did subaru make turbo boxers for AWD, RWD and FWD variants of liberty and impreza models?

 

[transcendent]

i think addymac meant new cars produced by those companies.

 

[SlipStream]

did subaru make turbo boxers for AWD, RWD and FWD variants of liberty and impreza models?

I don't think so.

You sure Subaru have made FWD and RWD Imprezas and Libertys?

 

[erawamai]

Get some idea before you post eh.

Current models. The soarer and such are not current models. They belong to automotive history. I thought it would abundently clear to anyone who can read that I was clearly not referring to cars outside the current model lines.

All mazda's? What about the mazda 929, rx2, rx3, rx4's, rx7's, there all rwd

Mazda 929? What decade are you living in? For the anal person who wants people to chronical every FWD and RWD car in the history of a particular brand there are three exceptions in the current Mazda linup.

The current rotary - the rx8, the new MPS which is All Wheel Drive and the mx 5 which is RWD.

But otherwise all mainstream current model consumer mazdas that make up the builk of sales are FWD. As in the 2, 3 and 6.

All toyota's? What about the mr2, supra, soarer, KE10, KE20, KE30, KE55, KE70 corolla there all rear wheel drive.

One exception to the current model range (bar workvans and etc ) is the mr2. Again, all mainstream consumer current model toyotas that make up the bulk of sales are FWD. Echo, corolla, Camry, Avalon.

 

[loquasagacious]

Suburaru globally make FWD/RWD cars but as part of market positioning subuaru australia only imports AWDs. I have no idea if RWD/FWDs of the imported models exists overseas.

 

[DaddyK]

Over here in aus yes most current models are FWD. Not Japan, they have models we will never see, current models that are rear wheel drive. You should be more specific rather than saying All toyota's are fwd.

 

[SlipStream]

Suburaru globally make FWD/RWD cars but as part of market positioning subuaru australia only imports AWDs. I have no idea if RWD/FWDs of the imported models exists overseas.

I meant the Impreza and Liberty.

 

[transcendent]

can LSDs be installed in any cars? or do they already have them? would it be useful for highway driving, everyday driving or just rally? is it better if it was for AWDs or can RWD/FWDs use them too? are there any problems with installing them, do you need a system management program to do with it?

 

[S13WPN]

I don't think so.

You sure Subaru have made FWD and RWD Imprezas and Libertys?

I dont know about RWD but I know they made NA FWD libertys and imprezas in the '90s.

can LSDs be installed in any cars? or do they already have them? would it be useful for highway driving, everyday driving or just rally? is it better if it was for AWDs or can RWD/FWDs use them too? are there any problems with installing them, do you need a system management program to do with it?

With this question can someone also tell me what welding the diff would do and how, if at all, awd's can be changed to favour the rear wheels.

 

[DaddyK]

Welding the diff up just stops all the moving cogs th at convert most of the power into one wheel, so if you weld them up power gets delivered pretty much equally to both wheels. And yes AWD cars can be converted to RWD, although i would imagine its quite an extensive conversion. Heres a clip of a WRX wagon that has been converted to rear wheel drive
http://video.google.com/videoplay?docid=-5586190858616560725&q=wrx

 

[S13WPN]

Thanks mate. lmao at that video... gold gotta love those industrial estates

 

[SlipStream]

can LSDs be installed in any cars? or do they already have them? would it be useful for highway driving, everyday driving or just rally? is it better if it was for AWDs or can RWD/FWDs use them too? are there any problems with installing them, do you need a system management program to do with it?

If it needs to turn a corner, it needs a diff. Any car that needs a diff benefit from an LSD. Originally a 4WD technology, LSDs obviously limit the amount of diff slip between the drive wheels. You can do one wheel burnouts in conventional diff cars because the diff is sending 100% of the power to one wheel. An LSD would send some power to the stationary wheel, and then you'd have heaps more traction and thus more go. LSDs are mainly useful for where you need power to both wheels: drifting, street drags, etc. LSDs are common in RWDs the most, then AWDs and the odd performance FWD has an LSD. I'm not entirely sure what is involved with installing them, but judging from the fact that they aren't a common modification, it must be fairly costly/complicated.

S13WPN: You normally buy kits to convert AWD cars to RWD, like that tool in the WRX wagon for example. I think it involves some kind of tinkering with the transfer case so it delivers 100% power to the rear wheels. I'm taking a bit of a guess though. Try Googling it.

 

[ToO LaZy ^*]

Q: what do strut bars do exactly?...

 

[SlipStream]

Q: what do strut bars do exactly?...

A car's chassis will flex under cornering, affecting a number of things such as camber, toe and bodyroll. The more rigid a chassis is, the less it will flex and basically the car will remain more composed through the corner. A strut bar/brace controls the flex between the strut towers of the wheels (front and rear), limiting (if not eliminating) variances in camber etc when the car is cornering. Strut braces also impact the attitude of the car; i.e. a car with only a rear strut brace will tend to understeer, but one with only a front strut brace will tend to oversteer. However this is most noticable on sensitive race cars with racing suspension set ups than road cars with sports or supple set ups. A strut brace on a, say, a done up Ford Laser will do jack all unless it is complemented by stiffer sway bars, suspension etc. Thus nowadays strut braces are more cosmetic on road cars than functional. When installed on road cars you'll notice an improvement in steering reaction (a little quicker point to point), but that's about it.

 

[loquasagacious]

Ok, firstly LSD.

As already mentioned the diff (short for differential for anyone who was wondering) essentially allows the drive wheels to spin at different speeds. This comes down to the power being delivered but is a much simpler way of thinking about it.

A limited slip diff (LSD) simply limits how much the wheels are allowed to spin at differing speeds eg it keeps the speed of the wheels in question closer. This makes sliding around easier to achieve and control.

A welded diff is one that can't slip at all, the wheels must always turn at the same speed. Welding is a very cheap and nasty way off accomplishing this. The end result is something like when a 4WD has the diff locked. It makes going in a straight line or driving slowly over big rocks easier however this will not make cornering very fun. Think about rolling a tube of cardboard along the floor then turning a corner with it - to do this you have to make one end turn faster than the other, otherwise it doesn't work very well.

As far as what cars have LSDs and what don't basically 'sports' cars often come with them (eg all tickford vehicles did). They are a common mod especially on the racing/drifting scene.

They are more common on RWDs because RWDs are the dominant type in the sports/race/drifting arena. Also installing one on a RWD is quite easy, usually take an afternoons work. Unbolt existing drop it out bolt in LSD clean up and you're done, just have to be careful not to damage anything.

Whereas to install one on a FWD you will usually need to remove the transmission(gearbox). This is because in a RWD it pretty much goes sequentially engine -> gearbox -> drive shaft -> diff -> rear axles -> wheels. All nice and seperate. Whereas a FWD goes engine -> transaxle -> front axles -> wheels. The transaxle entailing both the transmission and diff. So basically it's more of a hassle to get to, more of a hassle to do and compatibility issues make aftermarket LSDs harder to come by.

Converting AWD to RWD:

This pretty much depends on how the AWD is managed. eg whether it is mechanical or in some way electrical. The Adventra for instance is mechanical using a planetary centre diff (much like a 'normal' diff which controls how much power each wheel gets a centre diff controls how much power each end of the car gets eg an AWD has three diffs, front, centre and rear). Because it is mechanical like this the only way to adjust the torque split (fancy term to describe splitting the power) is to replace the diff.

On the other hand a skyline can be converted to RWD by popping a fuse, because of this for many years there have been aftermarket piggy back units that plug in and allow the driver to control the torque split in real time from the cabin. The Sti WRX has just introduced this feature as a stock feature and the MPS Mazda 6 uses similar technology to facilitate drift. I have no idea how it works really but as a heads up its out there. Converting AWD->RWD can be either tricky or easy....

Strut Braces:

This has been explained pretty well so I won't go into too much detail.

Basically when cornering a cars suspension is flexing everywhere to absorb the inertia that wants the car to keep going straight. As a result the car will most likely tip foreward towards the outside front wheel.

A strut brace or any number of other suspension components (stiffer shocks, stiffer/lower springs, coilovers, sway bars, polyurethane bushes, lower profile tyres, bigger wheels, etc, etc) all serve to stiffen the car. That is to stop the car flexing as much. To stop it absorbing as much interia. As a result the car is much more predictable and thus easy to control when cornering. The variables are reduced from every suspension component to steering and speed which are controlled by the driver.

The other aspect is that a stiffer body absorbing less inertia will exhibit more inertia. It will want to go in a straight line more, the immediate result of which being the car will like to slide more. This is great news if you like drifting.....

Reasons for strut braces: An engine swap will often introduce a more powerful engine into a car not designed to handle it. The engine alone exerts all kinds of pressures on a car and to help resist these a strut brace may be used. In fact to get an engineers certificate approving the swap, one will often be insisted upon.

Finally the popularity of strut braces: They are very easy to install, they make the car slide and they are easy to show off.

 

[lil lelu]

PSI is Pounds Per Square Inch

i've got a question
308-5L holden
302 - 5L ford
350-5.7L chev

what is the numbers for a 5L Hemi engine??
cause i am looking at a RX3 with a 5L hemi, an i just wanna find out things about that engine. how much power it can produce

there is no stock hemi 5L, so if you want that you would have to make it yourself
i have a 265 which has been bored out 60thou, which is a 273 and is 4.5L. but there is also no stock hemi 273! 330hp for a stock 265 that came in the e49 *drools*
the next size up is 5.7L which is a 350. this has 326hp (v8)

ok i know this post is hell late, but save the comments k blokes! hehe. hope i can help bowman.

 

[yenta]

I have a question: How much would
a) lowering; and
b) painting
my car cost? It's a 93 model corolla, I recently got some 17 inch wheels and so want to get it lowered and then possibly get it painted a nice metallic colour. Any rough estimates?