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1manwolfpack
1manwolfpack New Reader
12/19/11 10:00 p.m.

Ok, I am not trying to start an argument about FWD vs. RWD but I'm curious to hear from people with FWD track driving experience. All of the real driving experience I have has been with RWD and while I see the obvious weight transfer and tire benefits I also understand why people race FWD cars and have seen some very fast ones.

So, what do you do to adjust your driving for a FWD car on track vs. a RWD car?

turboswede
turboswede SuperDork
12/19/11 11:34 p.m.

Learn to left foot brake to reduce understeer (by getting the rear loose) and maintain momentum because most FWD cars spin the inside front tire on corner exit.

If the FWD car has a LSD or a welded diff, then it becomes more of a point and shoot (more so with the welded diff) driving style.

Of course each car is different so like any race car, you get to play with various settings and driving styles to find the one that works the "best" for the situation.

SVTF
SVTF Reader
12/20/11 8:31 a.m.

I track a Focus SVT, which is one of the better handling FWD cars, but most FWD can be made to handle well with the right suspension goodies. The Focus will rotate even without trail braking, and really gives up very little in the corners to the high-dollar RWD on the track.

In my mind, the racing line is the same whether FWD or RWD, and the objective is to manage tire adhesion and weight transfer for max grip (using all of it). The SVT can spin the inside front tire on slow sharp corners, but in a momentum car with mild torque it really isn't an issue. The main differences I've experienced is that RWD can get rotation on corner exit with throttle, but FWD is more forgiving if you screw up somewhere on track. Both are fun when driven in anger. That said, I would not like to drive a high-horsepower, light-weight FWD.

One FWD "adjustment" is to overcome the impulse to come out of the throttle if you are about to spin. That one has been tough for me to learn.

carguy123
carguy123 SuperDork
12/20/11 9:38 a.m.

slow in, fast out

When you are in a RWD following a FWD you realize just how slow they must enter the corners when compared to a RWD. But they can get on the gas (need to get on the gas?) earlier.

DaveEstey
DaveEstey Dork
12/20/11 10:28 a.m.

I spent the last season racing a 415whp Integra. Slow in. Feather the throttle in and wait for the turbo to rip the slicks loose, then feather some more. The car responded more to throttle lift than left foot braking.

My Miata on the other hand, come in fast, lift to induce oversteer, back on the throttle early and away you go.

Raced an SM Subaru STI at the end of the season and it's the same as FWD only left-foot braking is more effective. However, that car would NOT tolerate being over driven at all.

RossD
RossD SuperDork
12/20/11 10:31 a.m.

I took a vehicle dynamics class in college and we learned this little diagram (I hope I'm remembering it correctly). It's useful in understanding the different forces acting on both front and rears tires of any vehicle (awd,fwd,rwd).

Cone_Junky
Cone_Junky HalfDork
12/20/11 11:24 a.m.

I had a FWD GTI with a quaife for years. With R-comps that thing was a point and shoot monster. Could rotate on momentum alone, easily induced with trail braking. I ended up being pretty competitive in my local SM class.

Fast forward 2 years and I'm struggling with my new RWD toy. I was much faster in my FWD for sure. But that's lack of skill/experience/r-comps, not the drive wheels

Taiden
Taiden Dork
12/20/11 11:31 a.m.

Ahh the circle of truth

Dashpot
Dashpot Reader
12/20/11 12:19 p.m.

I've run similar powered F & RWD cars in TT's & track days for while now. I found snap oversteer situations (fluid on track, etc) to be the toughest to adjust to when switching back & forth. After running RWD for for years my instinct was to go to neutral throttle when suddenly sideways in the front driver. First time it took what seemed like a minute to make the conscious decision to get back on the gas. Full lock, soon to be backwards, stomped on it and all was good again. Quite a different response than RWD.

bigbens6
bigbens6 Reader
12/20/11 12:44 p.m.
RossD wrote: I took a vehicle dynamics class in college and we learned this little diagram (I hope I'm remembering it correctly). It's useful in understanding the different forces acting on both front and rears tires of any vehicle (awd,fwd,rwd).

I think it is important though to note that once weight has transferred the from braking, accelerating or turning that grip circle is going to be different for each of the 4 tires. Understanding that is also important because the jobs your tasking your tires to do and how you manipulate them changes from FWD to RWD to AWD

carguy123
carguy123 SuperDork
12/20/11 1:09 p.m.
Dashpot wrote: I've run similar powered F & RWD cars in TT's & track days for while now. I found snap oversteer situations (fluid on track, etc) to be the toughest to adjust to when switching back & forth. After running RWD for for years my instinct was to go to neutral throttle when suddenly sideways in the front driver. First time it took what seemed like a minute to make the conscious decision to get back on the gas. Full lock, soon to be backwards, stomped on it and all was good again. Quite a different response than RWD.

Truer words have never been spoken. When your body's reaction patterns are FWD or RWD changing the drive wheels takes quite a lot because you are fighting the automatic reactions of your body.

RossD
RossD SuperDork
12/20/11 1:40 p.m.

In reply to bigbens6:

Good point.

Gearheadotaku
Gearheadotaku Dork
12/20/11 3:44 p.m.

Then there's the whole mid / rear engine thing to really berkley with everything you've learned....

Knurled
Knurled Dork
12/20/11 7:39 p.m.
SVTF wrote: One FWD "adjustment" is to overcome the impulse to come out of the throttle if you are about to spin. That one has been tough for me to learn.

To be fair, lifting is a pretty bad idea in a RWD, too.

EdenPrime
EdenPrime Reader
12/20/11 8:01 p.m.
1manwolfpack wrote: Ok, I am not trying to start an argument about FWD vs. RWD but I'm curious to hear from people with FWD track driving experience. All of the real driving experience I have has been with RWD and while I see the obvious weight transfer and tire benefits I also understand why people race FWD cars and have seen some very fast ones. So, what do you do to adjust your driving for a FWD car on track vs. a RWD car?

FWD invites understeer and torquesteer. I personally have only dealt with understeer. I use a technique Keiichi Tsuchiya demonstrated; when entering a corner, graze the inside rumble strips with the inside tires-- it disrupts that understeer enough to get you through the corner well. Not to mention you can use the E-brake if you're that good (which i'm not).

Using that rumble strip technique in a RWD car can disrupt it and send it sideways, though. But it also helps AWD vehicles, too. Also sucks if your track has tall/harsh rumble strips.

I also use the technique in Forza.

Also, like carguy123 said, Slow-In--Fast-Out works well, too.

1manwolfpack
1manwolfpack New Reader
12/20/11 10:02 p.m.

A lot of good info guys. And RossD, I am familiar with the traction circle. I have a pretty good understanding of vehicle dynamics, but of course there is always much more to learn. I knew the obvious things like lift off oversteer but I guess the main changes would be throttle and brake inputs.

I'm not going to be tracking a FWD immediately but its good to get some input from those with experience. I want to get a track car sometime in the near future and have primarily been pondering the typical RWD contenders such as Miata, E30, E36, MR2 etc. but there are many deals to be had for FWD cars.

1manwolfpack
1manwolfpack New Reader
12/20/11 10:03 p.m.

And I have been reading on GRM enough to know the answer is always Miata but I am pretty tall.

friedgreencorrado
friedgreencorrado SuperDork
12/20/11 11:26 p.m.
carguy123 wrote:
Dashpot wrote: I've run similar powered F & RWD cars in TT's & track days for while now. I found snap oversteer situations (fluid on track, etc) to be the toughest to adjust to when switching back & forth. After running RWD for for years my instinct was to go to neutral throttle when suddenly sideways in the front driver. First time it took what seemed like a minute to make the conscious decision to get back on the gas. Full lock, soon to be backwards, stomped on it and all was good again. Quite a different response than RWD.

Truer words have never been spoken. When your body's reaction patterns are FWD or RWD changing the drive wheels takes quite a lot because you are fighting the automatic reactions of your body.

Only thing I disagree with is the term "automatic". IMO, when it comes to learning how to drive quickly, nothing is automatic. If you're changing from RWD to FWD, it's time to learn something different. Seat time, seat time, seat time.

EDIT: Sorry carguy! I misread your post. You were already talking about switching back & forth on short notice, weren't you. Yeah, that takes a bit of work.

DILYSI Dave
DILYSI Dave SuperDork
12/21/11 7:16 a.m.

Techniques - The big one is that throttle can save you in places with FWD where it will smack you with RWD.

Setup - I will typically set up a FWD car to be more loose. Toss it in to the corner on entry, let the oversteer help you through the turn, and then throttle out. A RWD, I want the rear to be more planted.

pinchvalve
pinchvalve SuperDork
12/21/11 7:54 a.m.

It's funny to read the "brake early for FWD" comments because my very limited track time in a FWD had me out-braking most of the other cars on the track. I think it had more to do with the fact that my Civic weighed a lot less than the Mustangs and Camaros I was out there with, and I had better brakes. I could brake much, much later than them and carry much more speed through the corners. (Of course, once we hit the straightaway they would blast past me.)

iceracer
iceracer SuperDork
12/21/11 5:33 p.m.

A stiff rear sway bar helps alot. I never had much problem with braking, I would keep going deeper until I found the point of no return coming up. Then I backed of a little. Braking hard and turning do not work too well. Almost lost it a Lime Rock entering the uphill. Then I remembered to get on the throttle.

Keith
Keith SuperDork
12/21/11 8:50 p.m.

My fwd track experience is in my classic Mini. The technique there is to enter the corner too quickly, turn in, nail the throttle and watch the laws of physics shatter as you laugh like an idiot.

thunderzy
thunderzy Reader
12/21/11 9:50 p.m.
Keith wrote: My fwd track experience is in my classic Mini. The technique there is to enter the corner too quickly, turn in, nail the throttle and watch the laws of physics shatter as you laugh like an idiot.

Yesssssss

DaewooOfDeath
DaewooOfDeath HalfDork
12/21/11 9:52 p.m.
pinchvalve wrote: It's funny to read the "brake early for FWD" comments because my very limited track time in a FWD had me out-braking most of the other cars on the track. I think it had more to do with the fact that my Civic weighed a lot less than the Mustangs and Camaros I was out there with, and I had better brakes. I could brake much, much later than them and carry much more speed through the corners. (Of course, once we hit the straightaway they would blast past me.)

This has been my experience as well. In FWD cars oversteer is easy to control and understeer is hard to get rid of. If the car oversteers on trail-braking it makes sense to carry that oversteer into the corner.

I do a lot of the stuff people have mentioned before, like hitting rumble strips, giving mild Scandinavian flicks and using trail throttle. On a lower powered car you can also get on the power just as early as in a RWD car (and with less risk if you overdo it).

That said, I don' think there's a universal technique to driving a FWD car and handling on the brakes is the biggest reason. Some cars - from my experience 92 Integra, my Daewoo before suspension mods, 86 Honda Accord, Ford ZX2, Kia Morning - really liked trail braking. This encouraged a "stick it in DEEEEEEEP" driving style.

Other cars - my Daewoo after the suspension mods, 88 Civic, 99 Ford Taurus - just plow if you try to corner while hard on the brakes. Because of this, I try to get the braking done in a straight line (or with a Scandinavian flick) and get back on the power as soon as possible.

As awful as it is to watch, this style, with lots of small, sharp inputs, really seems to work with some FWD/AWD cars.

http://www.youtube.com/watch?v=GrYuvrD2Wgo

friedgreencorrado
friedgreencorrado SuperDork
12/22/11 1:00 a.m.

You've probably read everyone else's replies..consider that there's one simple idea running through most of them.

Get the rear to rotate. Whether it's momentum, or left-foot braking, or whatever else, you've got to get the thing to rotate without the throttle. You can get a FWD car to rotate with the throttle, but you have to lift & punch, instead of just teasing the throttle like a RWD car. Kills the driveline if you do it too often, and kills your momentum in the first place. Get the car to rotate on its own, so that you don't have to force it to do so through your input.

I drove VWs in SCCA Improved Touring, what we did was simply stiffen up the rear suspension so much that when the car was loaded in a corner, the inside rear wheel would come off the ground. Losing that traction would make the car rotate. Of course, those cars all had solid beam rear axles, I don't know what it would take to do the same trick to a FWD car with an independent rear suspension.

EDIT: Buy Jack Doo's book. It's old..but still has a nugget or two about the basics.
http://www.amazon.com/Front-Wheel-Driving-High-Performance-Advantage/dp/0879382988

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