Advantage of going rear wheel drive on a high hp application if any?
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Offense comes from your wording which was/still is pretty condescending.
I fail to see how 80# equates to significantly better braking and corner entry, can feel more nimble but unless you've changed the steering ratio I'd dont see how you achieve better turn in or how it equates to faster cornering. You can still steer the car off throttle on turn in, a bit differently, but same result. You can get on the gas sooner and harder so not seeing the acceleration gain, this is where I see my gain on gt3's, from the apex out and its huge.
Likely you deal with higher speed corners and probably have some aero advantage.
I commented my experience in this thread because like the OP I read on here that rwd was so much better, which I didn't find to be true, for a modified street car that is tracked exactly as its street driven.
My recommondation was the first step should be a LSD. Easy to remove the center drive shaft and experiment after, but rwd without LSD is pretty pointless with any kind of power upgrade.
I fail to see how 80# equates to significantly better braking and corner entry, can feel more nimble but unless you've changed the steering ratio I'd dont see how you achieve better turn in or how it equates to faster cornering. You can still steer the car off throttle on turn in, a bit differently, but same result. You can get on the gas sooner and harder so not seeing the acceleration gain, this is where I see my gain on gt3's, from the apex out and its huge.
Likely you deal with higher speed corners and probably have some aero advantage.
I commented my experience in this thread because like the OP I read on here that rwd was so much better, which I didn't find to be true, for a modified street car that is tracked exactly as its street driven.
My recommondation was the first step should be a LSD. Easy to remove the center drive shaft and experiment after, but rwd without LSD is pretty pointless with any kind of power upgrade.
Please take no offense, I simply think it's good for readers to know where to pick their data for their decisions. A guy asking if RWD conversion is for him or not should not be guided by forum myths and should know during what circumstances something was better or worse.
In your case, I'd say AWD is better. You have traction problems and you proved that in your case you were a lot faster with AWD but with adding a LSD. Respect to that!
In my case which is different, it was not like this. I run a sporty street tire (treadwear 140) with only 515 hp so I have almost no traction problems whatsoever which means I need more speed everywhere else and that comes with later braking, faster cornering and bit better accel from carrying less weight/inertia, and it helps the balance of the car.
If OP has 650 hp and street tires (as a matter of saying don't hang on to the exact hp number), he might have to keep his car AWD.
If he's an avid track driver who is used to running alright tires but a little new to the 996TT and asking is RWD conversion good or bad, I say he might want to toss the front diff and install a LSD.
Forum myths are entertaining. For a while.
In your case, I'd say AWD is better. You have traction problems and you proved that in your case you were a lot faster with AWD but with adding a LSD. Respect to that!
In my case which is different, it was not like this. I run a sporty street tire (treadwear 140) with only 515 hp so I have almost no traction problems whatsoever which means I need more speed everywhere else and that comes with later braking, faster cornering and bit better accel from carrying less weight/inertia, and it helps the balance of the car.
If OP has 650 hp and street tires (as a matter of saying don't hang on to the exact hp number), he might have to keep his car AWD.
If he's an avid track driver who is used to running alright tires but a little new to the 996TT and asking is RWD conversion good or bad, I say he might want to toss the front diff and install a LSD.
Forum myths are entertaining. For a while.
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80 lbs is appr 2 percent of the TT.
In braking and cornering the equivalent of 4 percent due to physics. Same for accel. Corresponds to 11hp on a 500hp car.
W/o traction problem means the car at limit can corner 2-4 percent faster. Say 60mph turn it's a couple of mph.
On a track w half time in turns, say 90 sec lap turns are 45 sec. Count low 2-4 percent it's 0.9 sec. That's not counting 2-4 percent later braking (on 300 ft braking equals 10 ft later braking to get to same entry speed - but we can go a couple mph faster so we can brake even later than that). Then exit speed carries down the entire straight after and car will accel like having 11hp more only from weight loss. Gains from removing the rotating mass adds further.
It's quick and dirty but very very revealing even though it's not clear to see unless you really analyze it.
80 lbs is simply massive if you can lose it without getting traction problems. There is a reason pro race teams fight tooth to nail w organizers to reduce just 20lbs from the regulated minimum weight.
As mentioned by everyone it all needs to be re-evaluated if there are traction issues in case of for example a overpowered tire setup or rain, snow or dirt.
In braking and cornering the equivalent of 4 percent due to physics. Same for accel. Corresponds to 11hp on a 500hp car.
W/o traction problem means the car at limit can corner 2-4 percent faster. Say 60mph turn it's a couple of mph.
On a track w half time in turns, say 90 sec lap turns are 45 sec. Count low 2-4 percent it's 0.9 sec. That's not counting 2-4 percent later braking (on 300 ft braking equals 10 ft later braking to get to same entry speed - but we can go a couple mph faster so we can brake even later than that). Then exit speed carries down the entire straight after and car will accel like having 11hp more only from weight loss. Gains from removing the rotating mass adds further.
It's quick and dirty but very very revealing even though it's not clear to see unless you really analyze it.
80 lbs is simply massive if you can lose it without getting traction problems. There is a reason pro race teams fight tooth to nail w organizers to reduce just 20lbs from the regulated minimum weight.
As mentioned by everyone it all needs to be re-evaluated if there are traction issues in case of for example a overpowered tire setup or rain, snow or dirt.
Offense comes from your wording which was/still is pretty condescending.
I fail to see how 80# equates to significantly better braking and corner entry, can feel more nimble but unless you've changed the steering ratio I'd dont see how you achieve better turn in or how it equates to faster cornering. You can still steer the car off throttle on turn in, a bit differently, but same result. You can get on the gas sooner and harder so not seeing the acceleration gain, this is where I see my gain on gt3's, from the apex out and its huge.
Likely you deal with higher speed corners and probably have some aero advantage.
I commented my experience in this thread because like the OP I read on here that rwd was so much better, which I didn't find to be true, for a modified street car that is tracked exactly as its street driven.
My recommondation was the first step should be a LSD. Easy to remove the center drive shaft and experiment after, but rwd without LSD is pretty pointless with any kind of power upgrade.
I fail to see how 80# equates to significantly better braking and corner entry, can feel more nimble but unless you've changed the steering ratio I'd dont see how you achieve better turn in or how it equates to faster cornering. You can still steer the car off throttle on turn in, a bit differently, but same result. You can get on the gas sooner and harder so not seeing the acceleration gain, this is where I see my gain on gt3's, from the apex out and its huge.
Likely you deal with higher speed corners and probably have some aero advantage.
I commented my experience in this thread because like the OP I read on here that rwd was so much better, which I didn't find to be true, for a modified street car that is tracked exactly as its street driven.
My recommondation was the first step should be a LSD. Easy to remove the center drive shaft and experiment after, but rwd without LSD is pretty pointless with any kind of power upgrade.
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anyone who says that going RWD will SIGNIFICANTLY impact traction is absolutely not speaking the truth.
ive been rwd for 3 or 4 years now.
and ive said it before, I BEAT THE **** out of my car. constant sliding, slamming gas in mid turn.. all the wrong things to do.. and the car is absolutely planted.
you guys either have bad tires, a bad alignment, or absolutely no ***** whatsoever.
ive been rwd for 3 or 4 years now.
and ive said it before, I BEAT THE **** out of my car. constant sliding, slamming gas in mid turn.. all the wrong things to do.. and the car is absolutely planted.
you guys either have bad tires, a bad alignment, or absolutely no ***** whatsoever.
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for the record, there are NO advantages to our "AWD". NONE in the rain, NONE in the snow.
i challenge ANY k24 AWD car to step up to my car.... if i lose a race to an awd k24 car, i'll go back to awd.
we can race in the rain, on sand, we can race around a big circle.
a RWD turbo is superior than its AWD (red headed stepchild) counterpart.
i challenge ANY k24 AWD car to step up to my car.... if i lose a race to an awd k24 car, i'll go back to awd.
we can race in the rain, on sand, we can race around a big circle.
a RWD turbo is superior than its AWD (red headed stepchild) counterpart.
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for the record, there are NO advantages to our "AWD". NONE in the rain, NONE in the snow.
i challenge ANY k24 AWD car to step up to my car.... if i lose a race to an awd k24 car, i'll go back to awd.
we can race in the rain, on sand, we can race around a big circle.
a RWD turbo is superior than its AWD (red headed stepchild) counterpart.
i challenge ANY k24 AWD car to step up to my car.... if i lose a race to an awd k24 car, i'll go back to awd.
we can race in the rain, on sand, we can race around a big circle.
a RWD turbo is superior than its AWD (red headed stepchild) counterpart.
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no LSD. absolutley not necessary.
my car has 500 rwhp. that it. and more torque.
just an FYI, a lot of the fast porsche guys don't have an LSD (or didnt have one when they did monster runs).
back when tim had 800rwhp, he was rwd, open diff.
eddie bello's car runs a factory open diff.
we don't need lsd's. just good tires and an alignment.
LSD's are for guys that know how to drive a rwd 996tt, and make childsplay out of it.. an LSD is a reward for them.
im not there yet.
anytime i do a burnout, or launch the car really hard, i get 2 lines of rubber , not 1.
my car has 500 rwhp. that it. and more torque.
just an FYI, a lot of the fast porsche guys don't have an LSD (or didnt have one when they did monster runs).
back when tim had 800rwhp, he was rwd, open diff.
eddie bello's car runs a factory open diff.
we don't need lsd's. just good tires and an alignment.
LSD's are for guys that know how to drive a rwd 996tt, and make childsplay out of it.. an LSD is a reward for them.
im not there yet.
anytime i do a burnout, or launch the car really hard, i get 2 lines of rubber , not 1.
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Joined: Jul 2010
Posts: 4,848
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no LSD. absolutley not necessary.
my car has 500 rwhp. that it. and more torque.
just an FYI, a lot of the fast porsche guys don't have an LSD (or didnt have one when they did monster runs).
back when tim had 800rwhp, he was rwd, open diff.
eddie bello's car runs a factory open diff.
we don't need lsd's. just good tires and an alignment.
LSD's are for guys that know how to drive a rwd 996tt, and make childsplay out of it.. an LSD is a reward for them.
im not there yet.
anytime i do a burnout, or launch the car really hard, i get 2 lines of rubber , not 1.
my car has 500 rwhp. that it. and more torque.
just an FYI, a lot of the fast porsche guys don't have an LSD (or didnt have one when they did monster runs).
back when tim had 800rwhp, he was rwd, open diff.
eddie bello's car runs a factory open diff.
we don't need lsd's. just good tires and an alignment.
LSD's are for guys that know how to drive a rwd 996tt, and make childsplay out of it.. an LSD is a reward for them.
im not there yet.
anytime i do a burnout, or launch the car really hard, i get 2 lines of rubber , not 1.
Last edited by pwdrhound; Aug 14, 2012 at 11:19 AM.
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one of the great mysteries of the world
There are guys in here that run over 800 whp with no problem. And I have heard of people with much less have problems. It probably comes down to how good and easy you are on the drive train. Clutch drops with sticky tires is a good way to kill any drive train.
John, I totally agree with you that LSD is a must in most situations, but you have to be a good driver. The car is much more squirrely now than it was before. For you it will not be a problem. For someone who does not know their car it will.
Steve is also right, there are many people who don't run an lsd and love it. Car seems to hook up well in a straight line without it.
Steve, Id say you were 90% correct. My car with K24s and AWD at the time would spin the wheels in 4th at 130-140mph without the LSD (Dennis and a few other members here have witnessed this).
After the LSD, there was no way the wheels would spin. I had attributed this to tires but swapped them out for better ones and still have the same results.
After reading a couple other 6spd threads, there is more to an LSD than straight line traction such as advantages in turns as well as breaking but I would agree that most are not in the power range to realize any difference in straight line acceleration. I cant explain Eddie Bello's or anyone elses experiences, just my own.
After the LSD, there was no way the wheels would spin. I had attributed this to tires but swapped them out for better ones and still have the same results.
After reading a couple other 6spd threads, there is more to an LSD than straight line traction such as advantages in turns as well as breaking but I would agree that most are not in the power range to realize any difference in straight line acceleration. I cant explain Eddie Bello's or anyone elses experiences, just my own.
no LSD. absolutley not necessary.
my car has 500 rwhp. that it. and more torque.
just an FYI, a lot of the fast porsche guys don't have an LSD (or didnt have one when they did monster runs).
back when tim had 800rwhp, he was rwd, open diff.
eddie bello's car runs a factory open diff.
we don't need lsd's. just good tires and an alignment.
LSD's are for guys that know how to drive a rwd 996tt, and make childsplay out of it.. an LSD is a reward for them.
im not there yet.
anytime i do a burnout, or launch the car really hard, i get 2 lines of rubber , not 1.
my car has 500 rwhp. that it. and more torque.
just an FYI, a lot of the fast porsche guys don't have an LSD (or didnt have one when they did monster runs).
back when tim had 800rwhp, he was rwd, open diff.
eddie bello's car runs a factory open diff.
we don't need lsd's. just good tires and an alignment.
LSD's are for guys that know how to drive a rwd 996tt, and make childsplay out of it.. an LSD is a reward for them.
im not there yet.
anytime i do a burnout, or launch the car really hard, i get 2 lines of rubber , not 1.
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Posts: 8,930
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Sounds like you who have 2WD problems are running bald crappy tires or waaay more power than I have.
I have RWD with flashed K24 turbos at 1.1 bar. At that level there is no way to break traction unless I jam it and dump the clutch in first gear, then I will have wheel spin for some 20-30 yards if I milk it. Alt if I corner at the limit and then mindlessly mash the throttle - but do that in 4WD and you will push out of the turn so just a preference if you want to make the turn a little loose or go off with a push.
My tires are Hankook RS2 or Hankook RS3 depends on wheel size, both are sporty street tires.
Car in 2WD is A LOT faster bc it's lighter (no diff) and has less inertia losses. Anywhere the road or track starts to turn the car in RWD handles a lot better, it doesn't change the balance on you as a driver back and forth. The 4WD car will be a little dot in the mirror after a couple of turns, unless rain. I took appr 3.5 sec of the laptime at Buttonwillow going 2WD because balance finally wasn't shifting all the time, and I was quicker down every straight thanks to not having to drag the front diff weight around.
However I'd like to add that at 700hp and up AWD would start to make a bit more sense.
I have RWD with flashed K24 turbos at 1.1 bar. At that level there is no way to break traction unless I jam it and dump the clutch in first gear, then I will have wheel spin for some 20-30 yards if I milk it. Alt if I corner at the limit and then mindlessly mash the throttle - but do that in 4WD and you will push out of the turn so just a preference if you want to make the turn a little loose or go off with a push.
My tires are Hankook RS2 or Hankook RS3 depends on wheel size, both are sporty street tires.
Car in 2WD is A LOT faster bc it's lighter (no diff) and has less inertia losses. Anywhere the road or track starts to turn the car in RWD handles a lot better, it doesn't change the balance on you as a driver back and forth. The 4WD car will be a little dot in the mirror after a couple of turns, unless rain. I took appr 3.5 sec of the laptime at Buttonwillow going 2WD because balance finally wasn't shifting all the time, and I was quicker down every straight thanks to not having to drag the front diff weight around.
However I'd like to add that at 700hp and up AWD would start to make a bit more sense.
On flat tracks they are close, on tracks with lots of elevation changes or moisture, AWD is faster. Yes even the weak Porsche AWD, especially with lots of HP. You just can't put the same power down in RWD on corner exit.
There is a sliding scale as to which is faster. There is no way RWD is faster on street tires. The stickier the tires get vs hp, the more rwd has an advantage. AWD is just REALLY hard to tune and needs all the fancy suspension bits to tune out the understeer.
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Only way I see getting that much improvement from awd to rwd is if he went non LSD awd to LSD rwd, then I'd buy that.
Think of the awd in these cars with LSD as rwd with better traction.
I run my car with the full RSS tarmac series setup and kw clubsports and a within factory spec alignment. Also run 255/35-19 front tires, understeering isnt an issue at all.
Think of the awd in these cars with LSD as rwd with better traction.
I run my car with the full RSS tarmac series setup and kw clubsports and a within factory spec alignment. Also run 255/35-19 front tires, understeering isnt an issue at all.
I respect your opinion but 3.5 secs from AWD to RWD? Highly disagree.
On flat tracks they are close, on tracks with lots of elevation changes or moisture, AWD is faster. Yes even the weak Porsche AWD, especially with lots of HP. You just can't put the same power down in RWD on corner exit.
There is a sliding scale as to which is faster. There is no way RWD is faster on street tires. The stickier the tires get vs hp, the more rwd has an advantage. AWD is just REALLY hard to tune and needs all the fancy suspension bits to tune out the understeer.
On flat tracks they are close, on tracks with lots of elevation changes or moisture, AWD is faster. Yes even the weak Porsche AWD, especially with lots of HP. You just can't put the same power down in RWD on corner exit.
There is a sliding scale as to which is faster. There is no way RWD is faster on street tires. The stickier the tires get vs hp, the more rwd has an advantage. AWD is just REALLY hard to tune and needs all the fancy suspension bits to tune out the understeer.
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Only way I see getting that much improvement from awd to rwd is if he went non LSD awd to LSD rwd, then I'd buy that.
Think of the awd in these cars with LSD as rwd with better traction.
I run my car with the full RSS tarmac series setup and kw clubsports and a within factory spec alignment. Also run 255/35-19 front tires, understeering isnt an issue at all.
Think of the awd in these cars with LSD as rwd with better traction.
I run my car with the full RSS tarmac series setup and kw clubsports and a within factory spec alignment. Also run 255/35-19 front tires, understeering isnt an issue at all.
Still not possible to get 3-3.5 seconds IMO unless the AWD setup was not tuned or tuned horribly.
It's give and take, AWD will sacrifice some mid corner speed, but make up for it with extra traction everywhere, even RWD with LSD doesn't have more traction.
I've done back to back testing (with no other changes but RWD and some weight reduction) and the 996 TT with RWD was about .5 slower with no LSD but almost 200 lbs lighter with sticker tires vs worn ones. All factors considered (tires, LSD, extra 120 lbs over rwd removal weight), the times are roughly even with an advantage to the AWD. Test was done on slicks.
A sticker set of slicks where you have enough traction to floor it almost everywhere in RWD is where there is no AWD advantage. But the less traction available, the more AWD is advantageous.
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