SCCA SportsCar Mag: "Is Lighter Better" (regarding rallycross)

Chiming in to agree that the article is bogus. I was waiting for someone else to start the thread.

Here's what the article could have said and saved a lot of space: 'Drivers of light cars haven't consistently won at the National Championship.'

BTW, if you want to see good rallycross content in Sportscar, write it. Obviously they'll take almost anything (except the GLDiv Challenge recap I submitted last year). This is one of the pictures that was submitted with it, because the 2nd best part of rallycross after the driving is the pictures.

Knurled wrote:

irish44j wrote: I expect you to show up at nationals this year in a Lincoln Town Car. You would be a lock to win by a mile with all that weight, power, and long wheelbase resulting in so much general rallycross awesomeness. I mean, it'll zip around the course so fast that the other competitors will probably just give up and go home. Also make sure to carry a full load of passengers (preferably in business suits) and their luggage to improve your victory margin.

SR was traditionally won in Detroit by someone in a Crown Vic. I am still ****this**** close to running an E36 M3 in SR, and BMWs are kinda like Town Cars, lots of leather and cracked interior plastic.

well there you go. We'll see you at nationals next year in a crown vic, then, to prove your theory? Yes?

In reply to irish44j:

So that means you are actually going to nationals?

After re-reading the article one thing that really stood out for me was that the author mentioned that in his quest to make his car better a weight reduction resulted in a ride height that he called "too high". To remedy that, he said he had to switch to coilovers but there wasn't any detail past that. That makes me wonder if his real problem was putting in a suspension that was too firm or didn't have enough suspension travel.

Upon further review, you could wrap that whole article up with

• Better drivers will turn better times
• Tires are very important
• Consistency matters more when every run counts than when you just need one hero run
• Predictable handling characteristics help to turn better times

None of those things should be any surprise and pretty much apply to any form of racing.

EvanB wrote: In reply to irish44j: So that means you are actually going to nationals?

It's always a possibility next year. This year was a definite no-go due to tons of other expenses (weddings far from home, primarily). We'll see how next year plays out in terms of scheduling and finances.

We do have NE Divisional Challenge here at our home venue this year. And, as luck would have it, I will be at a good friend's wedding during the first day of it. Someone else will be driving my car instead to go for the divisional title (another experienced e30 rallycrosser whose track e30 I road race with), and I'll just run the 2nd day for fun.

In reply to irish44j:

Jim?

bluej wrote: In reply to irish44j: Jim?

Yep. Figured it's a fair trade considering I've put over a dozen track hours on his car :)

irish44j wrote: well there you go. We'll see you at nationals next year in a crown vic, then, to prove your theory? Yes?

My "theory" is just that weight reduction is generally not a huge benefit because you're screwing up the sprung/unsprung weight ratio. A 'Vic has really heavy suspension and so there'd be no benefit.

IMO the ideal weight is around 2500lb or so. Yeah, I know - this is quite a bit lighter than my RX-7, but my car also LAUGHS at rough stuff despite and possibly because of the solid axle. Despite because it's not quite so good sometimes, but when under power it's like the tires are tractor-beamed to the ground. And you should always be under power.

Now, let's do a better comparison - let's compare GC vs. GD Imprezas. I choose these because the GD is significantly larger and heavier while using more or less the same suspension as the GC. Note LARGER. That extra bit of width and length makes them more of a pain in the ass to navigate courses. It can be the difference between straight-shotting a section and having to slow down a little and make a couple arcs. But as far as handling rough things goes? GD owns the GC. But the GC is still pretty durn good because there still isn't that much in the way of unsprung weight since the Subaru suspensions are so simple. So the roughness advantage is GD but the GC will be able to hold its own on tighter sections because of its greater nimbleness.

If/when my GTI ever makes it to rallycross, I'll be putting a large focus on reducing unsprung weight. This I feel is one of the huge benefits of the twist beam rear suspension, since most of the suspension's weight is concentric with the pivot so there's very little unsprung weight in the rear. The front is the same control arm and strut that everyone elses uses but, gosh, does a car that only makes 200hp really need those large vented disks? 9.4" solid rotors are a bunch lighter, and Strange rotors weigh like three pounds each and they get used on 150mph drag cars.

Heck, even if I DO do the 350hp monster engine because of some innate desire to replace transmissions more often than I change my socks, I don't think big brakes are really necessary for rallycross.

Knurled wrote:

irish44j wrote: well there you go. We'll see you at nationals next year in a crown vic, then, to prove your theory? Yes?

My "theory" is just that weight reduction is generally not a huge benefit because you're screwing up the sprung/unsprung weight ratio. A 'Vic has really heavy suspension and so there'd be no benefit. IMO the ideal weight is around 2500lb or so. Yeah, I know - this is quite a bit lighter than my RX-7, but my car also LAUGHS at rough stuff despite and possibly because of the solid axle. Despite because it's not quite so good sometimes, but when under power it's like the tires are tractor-beamed to the ground. And you should always be under power. Now, let's do a better comparison - let's compare GC vs. GD Imprezas. I choose these because the GD is significantly larger and heavier while using more or less the same suspension as the GC. Note LARGER. That extra bit of width and length makes them more of a pain in the ass to navigate courses. It can be the difference between straight-shotting a section and having to slow down a little and make a couple arcs. But as far as handling rough things goes? GD owns the GC. But the GC is still pretty durn good because there still isn't that much in the way of unsprung weight since the Subaru suspensions are so simple. So the roughness advantage is GD but the GC will be able to hold its own on tighter sections because of its greater nimbleness.

I'd keep arguing, but trying to prove an intangible (like "how well a car handles bumpy terrain based simply on its weight") is pointless. If you have telemetry of equally-equipped GC and GDs on the exact same patch of bumpy surface showing that the GD is faster, please show us. Otherwise, that claim is akin to the butt dyno after you put an intake on your car. How a car "feels" in terms of smoothness on terrain is not (necessarily) indicative of how fast it is actually going in that section. We can argue til the cows come home on this point, but neither of us has facts to back it up, and even if we did they would only apply to one specific car - what if a GC was heavier than a GD, but had a shorter wheelbase - who wins then? (for instance).

I also notice now you're saying now that "weight reduction is not a HUGE benefit," rather than it being "NO benefit." Well, nobody here has argued that dropping a couple hundred pounds is a panacea that would instantly make a car a class winner. And weight savings won't outweigh (no pun intended) driver skill, or other more substantial mods (like LSD, good tires, etc). Ever. But that wasn't the argument. The article stated that weight reduction was essentially NO benefit (except in slippery conditions). That was the bone of contention here.

I will agree with you about reduction of unsprung weight being a good thing. The e30 already has low unsprung, and is on 14" wheels, and with standard brakes. I can't do a lot more to reduce it but I'm always looking for ways.....I don't think weight reduction has to be mutually exclusive to unsprung to be effective. Or so my butt dyno says..........

If you're on standard brakes, there's some savings to be found. We pulled 6.5 lbs of unsprung weight off each front wheel of the NC Miata by changing the calipers to a Wilwood Dynapro.

Of course a lighter car will be faster. Simple physics. But if you handicap the car whilst removing weight by not taking care of the suspension, then you're a bit of an idiot and you could very well lose time. I like the suggestion to add weight to a fast car and see what happens.

irish44j wrote: I also notice now you're saying now that "weight reduction is not a HUGE benefit," rather than it being "NO benefit."

I'm talking about gutting a car, apparently you're talking about going from a 2700lb car to a 4800lb one

Like anything (even, he gritted his teeth and admitted, horsepower), there is a curve not a slope. You can go far enough in either direction to see detriment. The contention is not the fact that the curve exists, but rather where the peak is and why it is there.

I've seen enough ultralight cars look absolutely horrendous on course to not want to contemplate trying to build a 1800lb car. I've also seen Warren (and codrivers cough Brianne Corn cough) dominate MA with his PA-legal car enough times to believe that a heavy car is not really a hindrance at the pointy end of the curve either. So when you see stripped 323GTXs look downright pathetic and sand rails unable to safely navigate a course because of how uncontrollable they are, and then you see some fat pig of an Evo set times that are almost embarassing, what conclusions would you make?

I also note that Warren has lightweight wheels, is running smallish tires and NOT the 17cm WRC-size tires that seem to be popular with the Subaru crowd, and has Wilwoods. Brakes is free in Prepared you know.

I'm in MR, so everything is free. Now if only it was free in a monetary sense.

I'm certainly not suggesting some crazy 1800lb car with all panels drilled, and a bare aluminum race seat, and no dashboard, and trunk cut out, etc etc. You have me wrong there. I agree there can be "too light." There are very light cars that would be just silly for rallycross, just like there are heavy cars that would be silly. Then again, I've seen audis and subies and e30s and MR2s look downright pathetic at events too.

What I'm talking about is that taking (for instance) an e30 and taking out the heavy backseats. taking out the sunroof (which is weight up high, right where you don't want it). And (though I haven't done it), removing bumpers which are heavy and and in absolutely the wrong place for weight on the car. I keep them since my car is street-legal. Taking out 45lbs of power window motors and stuff. Things that are reasonable and reversible. Not swiss-cheesing of a car to get it into kart weight. Reducing weight to take advantage of the car's balance and to maximize its limited engine power.

Comparing a 323GTX and an Evo isn't really fair as they are generationally different in capability. It would be like comparing a 323GTX on course with a 1960s Mustang.

Maybe I approach things from a more RWD-centric viewpoint. An Evo or STi can compensate for their weight by pure power, advanced AWD systems, and great geometry. In the RWD classes you know most of us are running a bunch of 1980s-1990ss cars that are reasonably similar in performance. Cars like the BRZ are what are going to take over the RWD classes once they are cheap enough to trash in rallycross, no question. Not because they're heavier, but because they're better in almost every respect than an e30 or e36 or RX-7. The same reason that new cars generally dominate every other motorsport out there where they're allowed to. Hell, anyone remember the Honda Odyssey vs. (some old sportscar) comparo? Right now is prime time for RWD cheap cars because most newer RWD cars are not suited to rallycross, or the ones that are are still too expensive to make them widely affordable to rallycrossers. That's gonna change in the not too distant future I think.

And sure, the lightness equation differs if you have a 300hp AWD car that is fast with a full load of passengers, as compared to a 120hp e30 or Miata or Civic which is substantially more......er.....strapped for power. Again, I'm speaking of 2WD classes primarily because that's where the light cars tend to live.

I don't think the "subie crowd" at rallycross runs 17" wheels to be cool (for the most part). IN most cases you have to to clear brakes (my WRX can only fit a very few 16s, maybe). Guys who use these cars for DD and trackday duties aren't going to put tiny brakes on just for rallycross, that's not reasonable for most people. Most of them are just using stock wheels because they're cheap and readily available secondhand. Would be great if we could all afford some Braid wheels, for sure...

Brakes and all kinds of other things are "free" in regulations, sure. But in a budget-oriented motorsport, not a lot of people want to drop thousands of dollars on brake kids or ultra-lightweight wheels or whatever. Hell, most of us in this region run secondhand rally tires because it's hard to swing $1k per season for fresh ones. So yeah, there are plenty of other ways to make a car faster. But the one thing they all have in common (aside from improving your driving), is that they cost money. Weight reduction is free in the monetary sense, so it's obviously going to be popular in a budget-oriented motorsport.

Were I Ken Block with unlimited budget, or Warren....yeah, I'd have all kinds of neat stuff on the car. But I'm not. I have a $500k mortgage, payments on our street cars, and 2 kids. Buying a lightweight brake kit doesn't make financial sense. Nor does dropping $1k on wheels that are 2lbs lighter than my stock 14s.

In any case, this weekend if I'm either way ahead or way behind coming into the second day, I may take a few runs with my car at "normal" and then do interspersed runs with, say, my set of street tires strapped in the back seat area (~150lbs) and see how that goes. More out of personal curiosity, since assuming the weight slows the car down, you won't believe me anyhow

For what it is worth, you can easily get a Golf under 1800lb. I think my GTI is there right now in mostly stock trim, and if you told me that ZB's MkIII was 1700lb, I wouldn't doubt it.

This also meshes with something else I was thinking of. Why FWD is so ridiculously good at rallycross and why FWD seems to be immune to the weight issue. Quite simply, I think it's down to this: In FWD the rear end almost does not matter. As long as you have enough steering to keep the front tires pointed to where you want to go, you will go there. So as far as the rear end is concerned, it can be as light as it wants and bounce and kick all over the place, who cares? And at the front, those same dynamics mean you're not going to kick the nose around much either, you get tirespin in rough stuff and this keeps you from being kicked around too much.

Now, here's what I need to test this theory. I need an AWD car that weighs as little as an empty Golf, and enough raw horsepower to be able to spin all four tires at will at 60mph.

For science!

(hmm, there's no Delta S4s on Craigslist right now.)

FWD cars tend to have the majority of their weight over the drive wheels. RWD cars don't unless they're 911s or MR2s. Traction!

I swear classic Mini road racers would replace the rear wheels with casters if they were allowed. They're just there to hold the back of the car up.

Can't comment intelligently on the rallycross thing (or anything else for that matter ) but I will point out that in the offroad motorcycle world lighter is always better when combined with proper suspension setup.

And the best rider will still win.

Keith Tanner wrote: FWD cars tend to have the majority of their weight over the drive wheels. RWD cars don't unless they're 911s or MR2s. Traction!

What if you're accelerating hard enough to carry a front tire? Roll the water around in the cup, Takumi-kun!

Late to this game, as usual. But glad to see I'm not the only one that read the article and went "Huh?"

It's the "road hugging weight" concept all over again

I have done some rallycross across most regions east of the Mississippi. I ran in Stock All Wheel Drive.

One point I must make is that there was a guy in Detroit region in a Panther body that only did rallycross for fun but he was terribly FAST! He was one of those guys that if he got focused on competition instead of fun that he would probably get several National Championships. Only mod was tires!

The point has been made regarding the article that basically the guy didn't put the proper suspension on his newly lightened chassis. I agree with that. My experience testing with a lightened car was that the balance was thrown off so I stayed in Stock instead of going to PA or MA class. Either would need more money than I had for suspension and other mods.

Specifically the lightened weight resulted in the car's rear stepping out too swiftly and less predictably. Then on the brakes I just couldn't get the modulation control I had with stock weight. Needed some proper suspension to make it come together.

Side note: I quit rallycross due to my two events in the DC area rallycross. They were way too rough for stock cars. At one event three guys left after walking the course and 2 cars including mine got stuck on track where they forced you to drive between a tree stump and large rock through a mud bog. Just zero fun. Organizers response was "Move up to PA. Or just go around and take the off course penalty."

I hope it is better now Irish!

Advan046 wrote: I have done some rallycross across most regions east of the Mississippi. I ran in Stock All Wheel Drive. One point I must make is that there was a guy in Detroit region in a Panther body that only did rallycross for fun but he was terribly FAST! He was one of those guys that if he got focused on competition instead of fun that he would probably get several National Championships. Only mod was tires! The point has been made regarding the article that basically the guy didn't put the proper suspension on his newly lightened chassis. I agree with that. My experience testing with a lightened car was that the balance was thrown off so I stayed in Stock instead of going to PA or MA class. Either would need more money than I had for suspension and other mods. Specifically the lightened weight resulted in the car's rear stepping out too swiftly and less predictably. Then on the brakes I just couldn't get the modulation control I had with stock weight. Needed some proper suspension to make it come together. Side note: I quit rallycross due to my two events in the DC area rallycross. They were way too rough for stock cars. At one event three guys left after walking the course and 2 cars including mine got stuck on track where they forced you to drive between a tree stump and large rock through a mud bog. Just zero fun. Organizers response was "Move up to PA. Or just go around and take the off course penalty." I hope it is better now Irish!

That must have been a long time ago. I've been with WDCR for 3 seasons and have never seen stuff like that, and never heard of anyone arriving and leaving. What venue was this at??

Those conditions would never fly with the current leadership. At Summit we used to beg them to LET us put the course through big muddy puddles, but they pretty much never did, lol. I'm in RWD class and I've never seen any RWD cars get stuck anywhere in 3 seasons at various venues.

Our new venue in Frostburg is kind of rough on cars (compared to super-smooth SUmmit Point, at least), but after 4 events there I think we've only had 2 casualties that ended a car's day: a 1980s Dodge Daytona who broke one of his ancient stock wheels, and today Nick's 1980s 5-series, which somehow lost the c-clip on his rear bilstein and the whole spring seat dropped so he had to call it a day (which may or may not have been the course's fault).

My car did almost 60 runs this weekend (30 for me, 25+ for Nick) on what I consider to be a fairly rough course, and my only damage was that my half-worn rear rally tires are now slicks due to some heavy feet and lots of powersliding :)

You should come out to one of our events now, I think you'll find that things have probably changed a good bit since you had that experience. There's a lot more focus on keeping the cars safe and minimizing "hard hits" on the course (though it is rallycross, so you are gonna bottom out and hit ruts no matter what)....

In reply to irish44j:

I don't have horsepower so I added lightness, thats the only way I can stay competitive against people in my class. 911, bridged rx7, supercharged/turbo miatas.

Also in mud or ice I prefer light car with big heavy wheels/tires.

Not a data point but I used to run against a guy with a 98 Impreza and I was running a 97 Legacy Outback. Same transmission, drivetrain, etc., etc., but I have the 2.5L (he has the 2.2L) and I am approx. 465 lbs heavier by curb weight. Both of us are running rally tires. In our classing we are both Class 3 (NA, AWD).

He hands me my ass by about 10 sec on a 2 minute run. I would take a lighter car any day.

I was also routinely beat by most of the Class 1 cars (NA, FWD). Many of them were extensively lightened. Some also ran snows vs. rally tires and got away with it due to the light weight. The lighter snow tires really helped vs. the much heavier rally tires.

Many heavier AWD cars de-beaded snows with alarming regularity.

if you do some testing by adding weight, I guess by the arguments made in this thread you will also have to change suspension settings...