Modern cars have gotten to the point were 400+ horsepower is the norm for a lot of performance cars but it comes at a cost. Most of these cars are 3500-4000 lbs, a 65 Ford Galaxies weighs 3500lbs, even a 911GT3-RS is almost 3200lbs.
I've been privileged to drive many new performance cars (everything from Hellcats to aforementioned GT3-RS) and they are phenomenal but I would still trade them all for a sub 2000lb car every time. There is just something so wonderful about a lightweight car; you can get away with so much in them.
Now I'm well aware that lightweight and higher horsepower are not always mutually exclusive but most of the light cars have moderate to low power outputs
So for me I'd rather be on track with an 1800lb car with 120-150hp than anything else. An ND Miata is about as porky a car as I'd ever want.
So I'm curious what do you prefer? A lightweight low to moderate power car or are you willing to deal with the weight for more power?
On fast tracks, power/drag becomes a factor as well. You could clearly see that with my 1200 lb, 148 wheel hp Locost, it hit an aero wall at about 80 mph. Made it tough to pass people on the straights without their help at times. I agree that a light car is a boatload of fun, and I do lean towards light weight over more power. You want a car that can dance. You just have to be ready for your speed to disappear on the fast stuff.
I once had a Boxster driver hit the brakes on the straight at HPR because he realized the high grip, stock engine ND Miata that had chased him down didn't have the ability to get past after the point-by :) I thanked him later. But it's the downside of light weight, low power.
My track car is a 500 hp, 2400 lb Miata so, like the kids say,
(this will turn into a bragging thread about "I passed a million horsepower Porsche with my Hyundai Pony" or another of the same "momentum car" discussions if we're unlucky)
Keith Tanner said:
My track car is a 500 hp, 2400 lb Miata so, like the kids say,
(this will turn into a bragging thread about "I passed a million horsepower Porsche with my Hyundai Pony" or another of the same "momentum car" discussions if we're unlucky)
Disclaimer for this thread: No bragging about passing Porsches or Vettes with your gutless car. The drivers are slow (not the car) or they don't want to beat on their 150K car the way you do you old Miata or Civic.
As for lightweight and power; I get that but two things come to mind.
1. A 500hp Miata is a serious car that will bite you. My old D-sports racer would keep up with 500hp down the straights but if you got it wrong you were going to be traveling at a very high rate of speed and weren't going to have a whole lot of time to recover. In contrast my Showroom Stock NA Miata was raw fun...............you could get away with really obnoxious maneuvers without really any extra risk.
2. Consumables..............while I'm flinging that 500hp car around (or 180hp 1000lb single seater) it's eating up fuel, tires and brakes etc. I'm notoriously cheap and the extra cost takes away the fun for me.
I'm happy from my 1.6L Miata to right around 200 horsepower: BRZ, Civic Si, Integra Type R, 3.2-liter 911, etc.
Maybe it's because I don't have much track experience, but I think a lightweight, low-power car would be good fun–for a while at least.
I drive classic Minis, the epitome of "momentum cars", but if you beef it up a bit with the later model brakes, a nicely built 1275 (or even a D series Honda Vtec) they can be as much fun as basketful of puppies!
And I also say, why not both? As long as you don't get stupid with it like my friend with his 500 hp turbo charged V6 Honda Vtec mounted in the rear of a Mini Clubman did. The car was awesome quick, but would smoke the tires in any of the lower 3 gears, and sometimes in 4th.
I prefer lighter cars just on feel but I REALLY prefer lighter cars when consumable costs come into the equation.
I enjoyed my NA on track (but geez were the couple of 1.6s we went through anemic), and my friends NB. I don't think I would want Keith's level of HP. But I think a stockish weight NB with a nice tuned KA in the 210-220whp range would be about perfect for me. Gets you around the 10:1 lb/hp ratio which is plenty fast for me.
My home track Hallett, if you're running the "normal" direction a fast car will hit the braking zone at turn 1 maybe around 110 (my NA with a 1.6 would get there about 85 so all I had to do was brush the brakes to get the nose in and chuck it)..........on my R6 it was closer to 127-128 and you have to slow down more.
The fast guys on full slicks on liter bikes, are approaching Turn 1 well north of 140, and the front straight while downhill that direction, isn't particularly long.
"Adding power makes you fasten in the straights. Subtracting weight makes you faster everywhere"
"Simplify, then add lightness."
Any car which holds together for a whole race is too heavy"
Then, to finish this off:
"You won't catch me driving a race car that I have built".
All from Colin Chapman.
I used to build hot rods professionally, so I've had my share of 2000-lb builds with 1200hp. They're wicked fun, but they tend to be more wicked than fun.
My sweet spot is 300 hp/ton. Anything more than that and the car has more power than I can use. My limitation in autox isn't power, it's experience. If I run a 1-minute autox with 300hp/ton, turning up the knob to 400hp/ton in the same car won't likely reduce my lap time.
In a 11-plus second car on the strip, same thing. If I'm getting 11s with 750 hp, stepping up to 1000 would have a high risk of becoming damaged, and I'm not good enough at launches and high-speed piloting to have the extra power magically put me in the 10s
There's not question that, given the same power/weight ratio and other constraints like aero, a lightweight car will have an easier time braking, will corner faster and will be easier on consumables. The tires on that Locost would last forever, but if I swapped the same set on to a 160 hp Miata for a day I'd see noticeable increase in wear. And the high cornering speed relative to the straight line speed meant that it certainly was friendlier because you never really got going that fast and also never really had to slow down that much. On a tight track where aero wasn't a factor, it was a very large amount of fun. I never really got much of a chance to play with it on big tracks.
I did, however, get some good seat time in a turbo Exocet (240 wheel hp, 1500 lbs) at the same tracks where I was also driving the Miata (466 wheel hp, 2400 lbs). The experience wasn't really all THAT different, because they both arrived at braking zones in a bit of a hurry and the Exocet was more handicapped aerodynamically so it didn't have quite the cornering speed advantage the weight would have you think. They both had some real potential for things to go bad, but neither were the sort of car that would bite casually. The one thing the Exocet was missing was the punch, the way the higher power Miata would hit you hard when you slotted 4th. There's a lot of fun in having that big hammer. The lightweight did seem to encourage more hooliganism but I've found that is the nature of Exocets themselves.
I would not want to pay for the consumables for JG's Corvette, though.
I'm going to be accused of being part of the gold chain necklace crowd. But those big thunderboomers always get the attention.
Can Am. Trans Am, Cobra's, Corvettes, Aarrrghghhh argh argh.
Yet speed wise a Formula Ford was about the same lap speed and in a tight pack rather than spread around the whole track like the Thundrboomers are.
Anybody watch boat racing? The big unlimited boats had big crowds along the shoreline. When 4-5 boats with Allison/ Rolls Royce Merlin V12 did their racing.
Yet smaller and far more competitive class racing those crowds just disappeared.
Go big or stay at home.
Run with the big dogs or stay on the Porch
Another factor that tends to be correlated is the wheelbase of the car. Lightweight cars tend to have shorter wheelbases (just part of being smaller overall), which tends to be less stable at high speeds than longer wheelbase cars. So turning up the power on a lightweight car can have other implications.
My M3 and Miata do similar speeds over the turn 1 crest at Laguna Seca, but the M3 is MUCH more stable and confidence-inspiring doing it.
jharry3 said:
"Adding power makes you fasten in the straights. Subtracting weight makes you faster everywhere"
"Simplify, then add lightness."
Any car which holds together for a whole race is too heavy"
Then, to finish this off:
"You won't catch me driving a race car that I have built".
All from Colin Chapman.
That first claim is untrue, subtracting weight will have a diminishing effect as speeds rise. So subtracting weight will make you "faster" in the braking zones, in the corners and in the initial corner exit. But it won't make you much faster in the straights. We saw this with the Exocet when it was running a stock 1.8, it was about the same as a Spec Miata down the straight at Laguna Seca despite a roughly 850 lb weight advantage. It was quicker off the last corner, then drag took over and the cars would more or less hold station.
I'm not advocating for power above all else, just discussing some of the fallacies here. Remember, I work a Miata shop, I'm obviously a fan of small and light and friendly :)
Note that my Miata also has the optional throttle pedal that allows for any power level from 0-500 hp.
Keith Tanner said:
That first claim is untrue, subtracting weight will have a diminishing effect as speeds rise.
Yeah, this is one reason why I'm not really fond of the trend of holding up Nurburgring times as the be-all, end-all of road course performance. The HUGE straight there places a premium on horsepower, so for a given power/weight ratio the heavier cars will tend to do better at that track. The same thing is true to a lesser degree with the C&D Lightning Lap comparisons.
codrus (Forum Supporter) said:
Keith Tanner said:
That first claim is untrue, subtracting weight will have a diminishing effect as speeds rise.
Yeah, this is one reason why I'm not really fond of the trend of holding up Nurburgring times as the be-all, end-all of road course performance. The HUGE straight there places a premium on horsepower, so for a given power/weight ratio the heavier cars will tend to do better at that track. The same thing is true to a lesser degree with the C&D Lightning Lap comparisons.
Yep, I remember reading a lot of Emilio's stuff when he was still doing NASA. Basically said at certain tracks the extra weight is worth the extra power you can tune in.
That's an easy one for me, I love light weight, low horsepower cars.
1500-1800 pounds and 100-125 HP is all I need. I'm really enjoying the commuter Spark because it handles well, makes 100 HP, but it's 2250lbs. I recently put a set of small wheels on it from one of my other cars that lowered the final drive by a little more than 10% and it made the car so much more fun to drive. If I could get it under 2000lbs it would be perfect.
In reply to Keith Tanner :
It wasn't a Porsche, but I did, on my best day day, run with the V8 street stocks in my mini stock, a Hyundai Pony 
So the two fastest cars (lap time wise) I've ever driven were 94" (D-sports) & 99" (Formula Super Vee) wheelbase. Power was 175hp and 225hp respectively. Both cars were a little over 1000lbs and both cars had a decent amount of downforce.
The fastest non downforce car light I've driven was a turbo NB Miata (I think it was a MSM with mild tweeks). That was still fun but much more than that on a short wheelbase might not be fun.
I think the wheelbase may be the key to why I'm not crazy about much more then 200hp in these cars. They start getting up to speeds where the don't feel near as settled. My Formula 500 is on a 73" wheelbase; I can tell you it's not near as planted as the D-sports racer was in a 120mph corner. I think that's a combination of no downforce and short wheelbase.
Also touched on here is the fact that it's much easier to do hooligan things when your only doing 85 versus 135.
I'm going to agree with Keith that aero is the least talked about of the three major speed factors, and arguably as important as the other two. Maybe it's because street cars have limited potential to adjust or improve without making them super ugly of unsuitable for road use. For my own needs my priorities are:
- weight
- aero
- power
That said, I never really get tired of the sound or feeling of winding out a big V8.
Keith Tanner said:
Note that my Miata also has the optional throttle pedal that allows for any power level from 0-500 hp.
This is a lie..........................you know full well the power level never goes below 200 because it's to damn addicting. 
ShinnyGroove (Forum Supporter) said:
I'm going to agree with Keith that aero is the least talked about of the three major speed factors, and arguably as important as the other two. Maybe it's because street cars have limited potential to adjust or improve without making them super ugly of unsuitable for road use. For my own needs my priorities are:
- weight
- aero
- power
That said, I never really get tired of the sound or feeling of winding out a big V8.
Oddly enough while I've love driving cars with Aero (how can you not love a car that pulls 3Gs on the brakes) I really like non aero cars even more................they skate around a lot. Your SRF would be a good example of the qualities I like in a car; light moderate power on treaded tires.
In reply to Tom1200 :
Aero comes in 2 forms. There's aero for downforce and grip, and then there's aero treatment to reduce drag. Drag is the important one on a light, low power car, as drag/weight is likely more of a problem than power/weight.
In reply to rslifkin :
I think you meant power/drag :)
Old man story - we were at the Car and Driver Superfour Challenge in 2004. The course was a quarter mile drag straight into an infield road course, then up on the oval to a run to 140 mph and then a full stop. Scoring was the total overall time. We realized that the haul up to 140 was going to be a significant part of the run, so we showed up with a Miata that was as slippery as we could easily make it. Hardtop, no passenger mirror, etc. It had 400+ hp, but still, drag is a significant consumer of power in the triple digits. 2004 was in the era when F&F was in full swing, so lots of the other cars had big wings and various aero addenda that looked awesome in a magazine. By the end of the day, there was a big pile of discarded draggy aero parts piled up in the pits as everyone realized how important that 140 mph run was.
Most unfortunate car there was a Mini. The gearing on that thing had a super-tall 6th, and he couldn't hit 140 in 5th. You could hear the engine note just hold when the driver shifted to 6th and the car just kept going further and further down the straight with no discernable acceleration. We were afraid it was going to hit 140 mid-corner and have to do a massive braking event on the banking. Eeek.
One of the karts sites I follow someone was looking to rent a KZ Shifter kart for nationals ( the package to have currently is KZ) They started to post prices like $7k-$10k for a weekend, which I thought was crazy when you could rent a fast pro car in AER or WRL for less. On the otherhand the shifter kart is faster and lighter.
One point though.
Everybody talks about consumables. There are ways to control those costs.
I raced with guys who knew brand new tires were worth A little bit in lap times and accordingly raced with brand new tires in every event. So rather than have them dealing with disposing the old tires I'd give them a few drinks or buy them dinner etc. in exchange I had the cheapest tires on the track.
Brake pads the Ferodo DS 11's I used stopped production and I bought a whole crate of them at a really steep discount. I also found out that they wore like Iron the first half and the second 1/2 really got ate up. So I'd pull them out once they were 1/2 worn and offer them to other Jaguar racers.with the warning to check them before each session.
Same thing with the good racing fluids. Retail price for a few of bottles would pay for a whole case at wholesale.
Gaskets were the same deal. Buy them late in the season in bulk. In fact that works for all consumables. Get a tax license and ask for case lot prices direct from suppliers.
The other thing is buy the right car to start with. Make sure the parts in the engine are made right. Forgings instead of castings, proper sized bearings. Parts with a history of durability.
Best way to never have trouble? Have a fresh engine/trans/etc sitting in a crate ready to go. After years of it taking space in the trailer leave it home.
In fact go to every race like you're going to have to rebuild everything. Plenty of tools and equipment.
Look your competitors over before the event. Some you can dismiss just because of the short cuts taken. No dry sump for a Chevy? Let him go. He won't be running Sunday afternoon. A 3 stage pump on a big block? Same. Saginaw gearbox with no spare? Same. M22 on its 3rd race and untouched? Same.
The ones who are ready, don't try to beat them in first practice. Better to follow them and see what sort of driver they are. If they are building up to speed slowly and smoothly, those you worry about. Those you can see them edge deeper and deeper into the braking zone.
Don't get ahead of them, In fact pull into the pits for about a 1/2 lap as you work on finding your own shut off points and throttle on places. The lines that work and those that you still need to work on.
One final point, don't trash the car if you can't beat them. Know you and your cars limits.
Find someone to dice with even if it's in another class. And enjoy
