Only Porsche, huh?

Enzo
F430
599
Z06
Elise
Exige
M3
M6
CCR
CCX
S7
Zonda F
Vantage
Viper
SLR
Ford GT
RUF-RT12 (converted to RWD by RUF) I assume you believe RUF doesn't know what they're doing either?

Shall I continue?

Exactly. RWD is better in every way. I'm glad we agree on that point.

I realize that your car is faster AWD...and it's only because you failed to set it up properly.

As far as whether you keep it AWD or not doesn't matter to me in the least. But posting incorrect information to other forum members *does* matter to me.

You don't have to be an engineeer to understand basic physics. Less weight and less drivetrain loss, with a proper suspension setup and good tires = better acceleration, handling and braking.

And each time you post it, I'll remind everyone that it was your fault. Not the fault of the RWD conversion. That's my prerogative as well.

I do...

Had you simply stated that *in your personal experience*, your car was slower..while admitting that you did not do basic things like remove the entire front diff, install and properly setup a proper suspension, and install an LSD...that would have been great. I wouldn't have said a word.

But what you've been doing instead is proclaiming as it were a fact (when it's not) that RWD is bad, it makes all cars slower, and that you essentially are the only one smart enought to realize it. You also have it in your sig like you are on some strange mission.

The honest truth is Des, as much as I like you, I got tired of reading it over and over...so I decided to finally call you on it.

 

That's the way to do it right there.

Kevin is saying that in his experience, he *prefers* AWD. I wouldn't argue that, nor would I even want to to try. That's his opinion and I respect it.

He isn't trying to convince everyone on the forum that RWD makes every car slower and that it's "badd...mmmmmkkayy"..especially if he hadn't setup his car properly prior to forming that opinion.

 

My point in bringing up Rear Engine was to show that it is beneficial to have 4 wheels turning under acceleration because of the Rear Engine weight bias. For traction, yes you want the weight of the car to be in the rear where the power is being used, but for acceleration there is less resistance on the front of the car so power there is used more effectively in a Rear Engine format.

I'm not being close minded, I have admitted that my thoughts are just a theory, you and scott are the ones trying to tell me was car wasnt slower when I have PROOF of it. You can come up with all the reasons you want but without adding LSD and removing parts of the car other than the shaft, my car is faster in AWD, that is a fact, not a assumption. In fact I'll make another point that will blow your mind about the acceleration, I managed to acheive a higher top speed (165) on the same straight in RWD than I did in AWD (157) , why? So a simpleton would say, "the RWD has to be faster since you got a higher top speed right? NO! For 2 reasons. #1 My exit speed in the RWD was faster therefore I was able to attain more speed on the top end by starting off faster (if you know road racing (OR PHYSICS) you know what this means) #2 I went deeper into the next turn before braking giving myself a longer period on the gas (because I had better tires and better brake pads, and also knew the car better (AND PHYSICS) ). I understeered so bad exiting that same turn that I couldnt even get on the gas for almost a half second later w/ AWD on street tires, but tires wont make THAT big of a difference in max acceleration which my lap timer records as well and my max accleration g's were about .2 higher with AWD, so let me see what your next argument is?

 

What size tires were you running? What exact sizes..both front and rear? I have an idea what was possibly happening...

 

Oops my bad I meant Rear Engine, you knew that, opportunist though huh? You get confused typing RWD vs RE so many times, that was a typo.

My tires are Hoosier R3S03 245 front 305 rear.

My point is that given the same stuff the AWD is faster, setup is irrelevant when it includes additional mods to make the RWD go faster (i.e. LSD)

Properly set up suspension? meaning what exactly that would affect acceleration, Actually I take that back, I had the car setup for RWD, I had the whole alignment done, camber done, toe done, suspension settings changed. I dont know what else there is other than corner balance which I did not have done. When I ran AWD I had coilovers and alignment and that was it.

Well you and I are just gonna have to duke it out because I will be the voice of reason around here that doesnt just say "hey gut your tranny because it's less weight and more power to rear wheels even though the tranny was designed as AWD and the car too".

And if you look back the only thing I have posted is that MY car is faster w/ AWD, appearantly not the case with everyone but still the case for me no less. I am a proponent of AWD for the Turbo and wont change that opinion, you're just gonna have to get used to someone who doesnt just say so because everyone else does, because I'm not the one. Other than this topic, all is good as far as I'm concerned. What buddies dont argue over something at some point. I dont mind being called, but as my wife says I'm pretty stubborn, but I dont change my mind without concrete evidence that can refute my beleifs.


So I will provide evidence to anyone who wants to see it, go to traqmate.com and download traqview (free trial version, not really a trial) or if you have it I'll send you the data I'm seeing, you can see accel vs distance/time graphs, max accel, max decel, and the laps I'm reffering to. If you find something wrong with my assessment, I'll gladly say I'm wrong and it will be the end of the story, but it is evidence to me, CONCRETE.

 

245/35/18 and 305/30/18?

Also, do you drive on the track with PSM on or off?

Yes, a properly setup suspension is primarily for handling...but absolutely will have a positive effect on acceleration and braking as well.[/quote]


And you'll be wrong each and every time too. That's not called "reason"...that called putting out disinformation.

You'll have to get used to someone that will continually and publicly blame you for the problems you had, since they were truly your fault for not setting your car up properly.

 

According to who, you? So the car wasnt designed as AWD then? Oh I thought it was, my bad.



Well Scott at this point you are completely wrong because there are lots of people on this board who dont want to do the whole drivetrain mod and ask about just removing the input shaft.

You are still being vague about what I did wrong, not removing the drivetrain? what's the difference in me removing 70 lbs from there as oppsed to from somewhere else, the AWD would still be faster.

Meanwhile I continue to offer proof and you continue to make assertive assumptions based on nothing, sorry but you have done nothing to prove your point, I put the evidence in your face and no amount of suspension setup is going to make that much of a difference in acceleration, look for yourself. When you provide me some objective data to prove your ASSUMPTIONS, then you can call me wrong, but until then all I hear is blah blah blah. blah blah blah. This is no longer about my word against yours because frankly who cares, show me something. Or hush

 

That's not what I was saying you were wrong about. I was saying you were wrong about the below:

Attention to detail, my friend.

I'm wrong about what? That just removing the input shaft is not a *proper* RWD conversion? I'm actually 100% right about that. It's not a proper RWD conversion. My opinion is that if you're not going to do it right, you shouldn't do it at all.

I have already found 3 things you did wrong (failed to remove all components, failed to properly set up suspension, failed to install LSD)...who knows how many more there were?

The tire size I asked you about might have caused a problem as well. If you were running 305/30/18's and 245/40/18's you have a 1/2" diameter differential between your front and rear tires which can cause problems with your PSM and ABS if your front half-shafts and differential is still in place. For all I know, your PSM was going crazy on the straights.

Honestly, it's hard to decipher exactly what went wrong since you butchered the conversion process so badly.

You haven't shown us anything, Des. No proof whatsoever. All you are doing is making erroneous claims based off what you "think* may have happened; "My turn-ins were faster, my top speed was greater..but RWD still made me slower."

Hmmm....let me see. Should I believe Des, who admittedly half-assed his RWD conversion...or should I believe the laws of physics?

That sure is a difficult choice.

 

I agree, I didnt do a complete conjversion, but WHAT SUSPENSION SETUP???, my car is set up for road racing and the settings dont change much from rwd to awd in novice setups.


I agree I didnt do the full conversion, wanted to try basic way first and you can explain to me how an LSD helps acceleration when traction isnt an issue also tell me how much removing the diff helps other than weight. If you cant do that I still call b.s..

No PSM lights except in the sweepers.

I have demonstrated how physics work to support my claims, you have said nothing other than it affect drivetrain loss, where is the science in that?

Based on whay I think may have happend? That is LOL-able, not only me driving the car, but watching the car exiting turns faster on the lap timer software is not proof?

Again Scott I challenge you to provide some evidence to challenge me other than off base assumptions purely based on power transfer and leaving out the large MAJORITY of physics that accompanies.

 

From high school physics classes...F=uN. Or, the force required to push an object sideways along the ground (like spinning the tires) = the coefficient of friction between the two objects (road condition and tire compound) times the Normal force downwards (weight on the axles). So, according to that equation, tire width and the number of tires just always cancels out of the equation because if you had the acceleration ability to unload the front end, there is no driving force there. And with AWD, you're adding that much inertia to the driveline that you're just dampening the acceleration force to the point that it just can't accelerate that fast and tends not to spin. The front end on the 911 has only a 10% transfer anyhow.

Also, on front engines cars...you're transmitting the torque through the chassis vs. directly to the tires like in a 996TT. Front-engined, RWD cars have the engine bolted to the frame, and the rear end bolted to the frame, then the driveshaft going between them utilizing the frame to resist that torque. So, upon applying that torque, the chassis twists and tends to unload one of the tires (even though it already had very little weight on it due to the engine being in the front). So, that tire spins, upsets the chassis, then the other one gets going.

Now, on the other had, the Porsche uses a transaxle. All the torque is transmitted through the transaxle, and the output of this is the axles. So, the only resistive force required by the chassis is the tires spinning forwards which will tend to rotate the rear of the engine downwards into the mounts and the trans upwards which will tend to lift the nose of the car and apply more weight to the rear tires (which looking at the F=uN equation is ideal). This applies more traction to the rear and will propel the car forwards with no tweaking/twisting of the chassis.

This explains why the GT2 and GT3 are able to launch so damn hard out of the hole with only RWD.

Add to that less weight (52 lbs on the driveshaft alone)...and less drivetrain loss...which puts more power to the ground.



Now...how about you provide some *proof* that you being slower in the straights wasn't caused by something you either failed to do, or did wrong when doing the conversion.

Maybe your failure to remove the front differential and half-shafts caused enough parasitic drag that it overcame the weight benefit of removing the front driveshaft...thus making acceleration worse than if had you left AWD in place?

The fact that you didn't do the conversion correctly, leaves far too many questions unanswered...thus the burden that a *proper* RWD conversion makes a car slower lies with you. Since you did not perform a *proper* RWD conversion, you really don't have a valid argument at all.

The fact is, other than something done wrong with the conversion, RWD will not make a car slower. It's not possible.

But I guess instead of trying to figure out the actual reasons, you simply default to the easiest conclusion "RWD is bad...mmkkay". Out of sheer stubborness, I think you've completely closed your mind off to any other possible causes of what happened.

Out of everyone that has converted to RWD, you're the only one that has had a problem with *slower* acceleration. Not only that, but you seem to think your car can break the rules of physics.


Brilliant.

 

As I have said MANY times before, traction is irrelevant because the tires were not spinning, in eiter case. Nice to try though.

Quote:

Originally Posted by divexxtreme

Also, on front engines cars...you're transmitting the torque through the chassis vs. directly to the tires like in a 996TT. Front-engined, RWD cars have the engine bolted to the frame, and the rear end bolted to the frame, then the driveshaft going between them utilizing the frame to resist that torque. So, upon applying that torque, the chassis twists and tends to unload one of the tires (even though it already had very little weight on it due to the engine being in the front). So, that tire spins, upsets the chassis, then the other one gets going.

Of non affect as well, maybe this is something you wouldnt know unless you drive road courses but power can only exceed traction coefficient up to a certain speed with sticky tires and since the car was already in motion and I'm a good enough driver to know when to hit the gas, there is neither a great enough force to unload any of the tires under acceleration nor exceed traction, therefore traction and unloading, pointless.

Quote:

Originally Posted by divexxtreme

Now, on the other had, the Porsche uses a transaxle. All the torque is transmitted through the transaxle, and the output of this is the axles. So, the only resistive force required by the chassis is the tires spinning forwards which will tend to rotate the rear of the engine downwards into the mounts and the trans upwards which will tend to lift the nose of the car and apply more weight to the rear tires (which looking at the F=uN equation is ideal). This applies more traction to the rear and will propel the car forwards with no tweaking/twisting of the chassis.

Not ideal for acceleration sans traciton. Force vs Resistance on the rear wheels is not ideal unless traction is a factor which I have repeatedly said it's not (and for the purpose of the debate, it's better that way, no excuses) . Ideally (with plenty of traction) there is no weight transfer, because of a bodies resistance to said motion based on its weight in relation to gravity. The motor is turning, components moving tranny shifting, but there is only ONE part (well 2 or 4 RWD or AWD) where the power is being used to get the car going. While rolling we know that the resistance of the body is less, but the weight transfer that occurs under accleration is only adding more resistance to rear wheels, resistance in this case = weight which is beneficial for traction but nothing else.

Quote:

Originally Posted by divexxtreme

This explains why the GT2 and GT3 are able to launch so damn hard out of the hole with only RWD.

Quote:

Originally Posted by divexxtreme

Add to that less weight (52 lbs on the driveshaft alone)...and less drivetrain loss...which puts more power to the ground.

is everything you say related to drag racing, is this where the poorly setup suspension comes from? because I can bet my suspension setup is closer to a GT2 or GT3 than yours is if it's set up for drag. Weight transfer is unavoidable but downforce thorugh use of wings, etc is more ideal in road racing conditions as opposed to soft springs setups used for drag because it keeps the car balanced, which isnt used as much in drag racing. You wouldnt take a road racing setup to the drag strip and vice versa, there is nothing wrong with my suspension setup, and has never been.

Quote:

Originally Posted by divexxtreme

Now...how about you provide some *proof* that you being slower in the straights wasn't caused by something you either failed to do, or did wrong when doing the conversion.

Quote:

Originally Posted by divexxtreme

Maybe your failure to remove the front differential and half-shafts caused enough parasitic drag that it overcame the weight benefit of removing the front driveshaft...thus making acceleration worse than if had you left AWD in place?

The fact that you didn't do the conversion correctly, leaves far too many questions unanswered...thus the burden that a *proper* RWD conversion makes a car slower lies with you. Since you did not perform a *proper* RWD conversion, you really don't have a valid argument at all.

The fact is, other than something done wrong with the conversion, RWD will not make a car slower. It's not possible.

But I guess instead of trying to figure out the actual reasons, you simply default to the easiest conclusion "RWD is bad...mmkkay". Out of sheer stubborness, I think you've completely closed your mind off to any other possible causes of what happened.

Out of everyone that has converted to RWD, you're the only one that has had a problem with *slower* acceleration. Not only that, but you seem to think your car can break the rules of physics.


Brilliant.

What type of drag are you talking about, aero dynamice drag? That whole portion of car is covered, so I dont think it changed the aero too much. I guess if I change to racing seats it will change the aero too huh, will I be faster with the windows down with the racing seats? So you are telling me a LSD would make me faster on a 60-130 run? Hell to the NAW, LSD doesnt do jack but help provide traction, it doesnt add power. And since I was already rolling in both cases it took traction out of the equation and nullifies your argument. So let me list the points you have brought up that are meaningless.

Traction- check
Unloading tires- check
Drag - check
Suspension - check

So I'm sorry but your argument isnt enough to show me that my car would be equal under rolling conditions with the RWD other than lost weight which is only relevant if I couldnt lose it somewhere else and even then, still a big gap.

I'm proud of you dusting off your old school book but you didnt say anything but that for traction reasons it's better to have RWD, which it's not (AWD has always been better for traction, which really eats your point. And that lift makes the power to the front wheels ineffective, yeah maybe if your at a stop in which case the AWD is still better. I'm not the only one who hasnt like the RWD, there is another who has posted in this thread as well as others I have seen while trying to figure out if I wanted to do it or not.


LOL driver, yeah ok, I like doing something that takes an abundant amount of skill as opposed to 60-130's therefore exceeds the normal realm of thinking and elminates some factors which you seem to be stuck on, all my runs were done at the same speed, in the exact same place, same car, same driver, the only difference was tires and drivetrain.

 

You commented earlier why AWD is better in a straight line. I just proved why you were wrong.

Quote:

Not ideal for acceleration sans traciton. Force vs Resistance on the rear wheels is not ideal unless traction is a factor which I have repeatedly said it's not (and for the purpose of the debate, it's better that way, no excuses) . Ideally (with plenty of traction) there is no weight transfer, because of a bodies resistance to said motion based on its weight in relation to gravity. The motor is turning, components moving tranny shifting, but there is only ONE part (well 2 or 4 RWD or AWD) where the power is being used to get the car going. While rolling we know that the resistance of the body is less, but the weight transfer that occurs under accleration is only adding more resistance to rear wheels, resistance in this case = weight which is beneficial for traction but nothing else.

Resistance?! So weight transfer resulting in increased traction is bad because of added resistance? LOL..the weight of the car isn't increasing! You are simply giving the tires more friction to grab. It's not like you're putting a 18-wheeler on top of the car. You are simply getting existing weight to transfer to the rear of the car. This is a GOOD thing, Des. Not a bad one. Sheesh....

Quote:

is everything you say related to drag racing, is this where the poorly setup suspension comes from? because I can bet my suspension setup is closer to a GT2 or GT3 than yours is if it's set up for drag. Weight transfer is unavoidable but downforce thorugh use of wings, etc is more ideal in road racing conditions as opposed to soft springs setups used for drag because it keeps the car balanced, which isnt used as much in drag racing. You wouldnt take a road racing setup to the drag strip and vice versa, there is nothing wrong with my suspension setup, and has never been.

Earlier, you said said that your car turns-in quicker, and has more top speed..but was still slower (amazingly convenient for your argument). That means that you're implying your car is slower during acceleration in a straight line. Just like drag racing. Therefore, we will talk about what makes a car slower or faster in a straight-line.

Traction, weight transfer, power to the ground, weight, gearing and aerodynamics all effect a car's ability to accelerate.

Gearing and aero didnt change, so we don't need to discuss those. Weight was reduced...drivetrain loss was reduced (well, in your case it may not have been)...you said you didn't have traction issues..so what does that leave us with?

Either your failure to remove the front diff and half shafts added more drivetrain loss than when the car was turning the front wheels on its own in AWD...or something else is wrong is wrong with your car, or your driving. Period.

No matter how hard you try, Des...you can not argue away the physical effects of gravity (weight) and friction (parasitic drag from drivetrain components).

You even posted earlier:

That is completely and totally wrong. Just the fact that you are posting some of these comments makes me honestly wonder what the heck you're thinking.

AND reduced parasitic drag...had you actually done the RWD conversion properly. A stock TT will put down 340 or so to all four wheels. That same car will put down 360 in a RWD configuration. What exactly do not understand about this factual concept?

Unless you're in mud or snow...RWD in a rear-engined car gives you just as much traction as AWD. Since we are talking about a track that does not have mud or snow, my point is was perfectly correct. We have 60' times posted on this forum that prove that.

Yes, others have indeed stated that "they didnt like it". But you are the *only* one that I've ever seen that honestly seems to believe it defies the laws of physics and makes the cars "slower"...which it absolutely does not, can not, and will not. Ever.

And the fact that you hindered the car by doing a half-*** RWD conversion. You seem to keep forgetting that key point.

Try as you might, you really have no argument here. You did not perform the conversion properly, therefore any data that you have is skewed and/or totally innacurrate.

 

Des,

I'm done. Someone I highly respect just PM'd me to let me know that you'll never get it...so there's really no point in me continuing to try. I believe he's right.

Take care, man.

 

Heavy,because you did not remove the diff when you did the conversion you still have the front axles connected to the diff,so when the front wheels are turning they are turning all the little gears,shafts,and bearings through the diff fluid..........may not seem like much but every bit helps......espescially on a timed course.Also the car would need to be properly corner balanced and be running a LSD to be effective in RWD.There also would be a driver learning curve......one could not expect to go out on the first lap and cut a faster lap because the car would behave differently than before.

Hey Scott, maybe we should start a new thread so that we don't hijack the OP thread........I don't think it is gonna end anytime soon LOL.

 

You took the words right out of my mouth. Agreed to disagree. Feel free to see evidence at any time.