Car & Driver Comparison Test Review: Veloster N vs. GTI vs. BRZ vs. GR86

[PulsarBeeerz]

Originally Posted by TommyW

Theres a video by the guys that do the Everyday Driver series and he had an FRS and did header and tune and then FI later. He said it was a bigger improvement from stock to header and tune than from header and tune to FI. Regardless of numbers which are all over the place, The header and tune really woke the car up

Not quite, there were two different cars in that video. The SC'd car was putting out a whopping 199whp vs 176whp from the channel owner. Having gone from stock to header/tune then E85 and finally SC'd on 93. FI is the biggest gain felt just like all the dyno show..

[Dzmitry]

Originally Posted by ZDan

Again, trap speed is not strongly dependent on tires, particularly for a 14 lb/hp street car on street tires. But if you want same vs. same...
On the same tires (215/40-18 Pilot Sport 4), the new cars tested 7mph faster and 0.9s/1.0s quicker in the 1/4 vs. 2018 BRZ tS.
https://www.caranddriver.com/reviews...-drive-review/
https://www.caranddriver.com/reviews...-gti-compared/

This is a strong point, though I wouldn't say same vs. same exactly considering that all the aero on the tS (particularly the wing) slows the car down in a straight. I certainly can't argue this very far as you would have far great experience than me on this subject in terms of tires and how they may affect your quarter mile times or trap speed. I would expect an improvement with better grip based on many videos I have watched and discussions I have read, but I don't know how much of a difference this may be. Obviously there are also many other factors, as you have stated as well.

[PulsarBeeerz]

Originally Posted by Dzmitry

More like there aren't any gen1's with the setup I have going out to the dragstrip and bringing a professional driver with them that gets a few runs in and pulls off a time around that.

I can bring a couple of examples in that don't stray my point from the truth very far.

Fully stock BRZ with ONLY E85 pulls off 14.35 @ nearly 99 mph
https://www.delicioustuning.com/Stoc..._Breaks_200whp
Yes I'm aware that is why I said what I said.lol .4ths and 2mph slower than a stock Gen 2.


Header back BRZ with E85 pulls off 13.58 @ 100 mph on Hoosier slicks and 4.56 FD. A shorter FD makes a difference in the 1/4 times despite the back and forth this forum has about them.

I know neither of these fit the bill for your particular case. But that is exactly the problem - no one is going out there to make that case and publishing it. You get whatever information you may find from random people that go out and give it a shot with random modifications, tunes, and tires. You will never get the consistent answer you are looking for.

But I'll agree on one thing. I do hope gen2 is at least a LITTLE quicker than my gen1. But from the racing videos I have watched so far and the data that's out there, I am not so sure yet. Gen2s are pulling on FBO 210+whp K20 civics, that wasn't a thing before.

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[Dzmitry]

Originally Posted by PulsarBeeerz

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Again, I see your point, but it's just not fully conclusive enough yet to say which will be faster IMO. Showing me a modified car race such as this civic tells me nothing as I have no clue how good this tune is, whether this dyno was high reading or low reading, what weight it's at, etc... So telling me "that wasn't a thing before" tells me nothing as it's a very specific comparison to make. Not sure that there are videos of fully tuned up gen1's vs a 210 whp k20 civic that we can compare to. I prefer comparisons that we know true numbers to. Gen1 header+e85 twins have plenty of videos smoking stock WRX's by a wide margin including from a dig, and staying even with a stock STI from a roll. These can also be dictated as poor comparisons because AWD vs RWD and weight definitely plays a big role as well.

Like I said, there has already been a video posted by CSG Mike trying to outpace a stock BRZ on a long straight, and it just wasn't happening, at least not very quickly. So it'll be interesting to see some real lap data on track comparing a fully tuned up gen1 to a stock gen2, if such data will ever come to exist.

[ZDan]

Originally Posted by Dzmitry

This is a strong point, though I wouldn't say same vs. same exactly considering that all the aero on the tS (particularly the wing) slows the car down in a straight.

That wing isn't hurting it much, but if you want some more evidence, the tS on Pilot Sport 4 posted both 0-60mph and 1/4-mile one tenth slower than a '17 on Primacies.
https://www.caranddriver.com/reviews...l-test-review/
https://www.caranddriver.com/reviews...-drive-review/
The tS PS4 tires didn't even help it get to 60mph quicker vs. Primacies. In fact it's the same 0.1s behind at 60mph and at the 1/4-mile.
At higher speeds, the added drag of the wing of course will come into play. But if there's already a 0.1s time deficit at 60mph, I think it's pretty safe to conclude that the PS4 tires don't really help straight-line acceleration vs. Primacies. Worth noting that PS4 are not optimized for dragstrip launches but more for handling performance.

I would expect an improvement with better grip based on many videos I have watched and discussions I have read, but I don't know how much of a difference this may be. Obviously there are also many other factors, as you have stated as well.

With stickier dragstrip-optimized tires that can give much better 0-60-foot tims, you'll see much bigger changes in ET than in trap speed.

That drag run you reference where an E85 car ran 100mph at 13.58 on Hoosiers, you can tell that the ET vs. trap speed aren't "normal" due to the much grippier tires. On "normal" street tires, 100mph trap speed would be about 14.0s. Put that car on either Primacies or PS4 tires, and I would bet it hits ~99mph at ~14.1. I.e., much slower time but nearly same mph.

[timurrrr]

Originally Posted by Dzmitry

I would expect an improvement with better grip based on many videos I have watched and discussions I have read, but I don't know how much of a difference this may be.

We're not talking about Teslas and supercars here.
Cars that are doing 0–60 in 2's and 3's are traction limited for a long time, and a 10% change in traction (ballpark for Primacy vs PS4) does account for up to 10% difference in acceleration rates for a significant chunk of the 0–60 or quarter mile.

Even with 2.4 engines, BRZ/86/FRS cars have so little power (relative to Tesla/supercars) that they are power limited all the time, unless you first accumulate excess energy in the flywheel and then do a clutch dump / clutch slip. At least I've never seen them spinning rear wheels in 1st gear in a straight line in dry without utilizing the flywheel energy.

Assuming the initial flywheel-to-kinetic-energy conversion takes less than a second on these cars, the 10% difference in traction gives us less than 0.1s of difference.

Originally Posted by Dzmitry

So it'll be interesting to see some real lap data on track comparing a fully tuned up gen1 to a stock gen2, if such data will ever come to exist.

As soon as I get my 2022 and go to a track day, I'll definitely compare the data against my 2017's with basic bolt-ons.

I will also compare my '22 data with someone who has a 4-2-1 catless header and a few more power mods (not sure about E85) if I get his permission.

[EAGLE5]

Originally Posted by timurrrr

We're not talking about Teslas and supercars here.
Cars that are doing 0–60 in 2's and 3's are traction limited for a long time, and a 10% change in traction (ballpark for Primacy vs PS4) does account for up to 10% difference in acceleration rates for a significant chunk of the 0–60 or quarter mile.

Er ma gerd. I was telling people the same thing on a BMW forum, except I was arguing that despite the bigger wheels being heavier, their larger footprint and stickier tires should lead to better acceleration to 60 and in the 1/4. The i4 M50 is a 530+ HP 3.6 second to 60 car. I know, it's not a 2.9, but all you gotta do is stomp.

[Dzmitry]

Originally Posted by timurrrr

We're not talking about Teslas and supercars here.
Cars that are doing 0–60 in 2's and 3's are traction limited for a long time, and a 10% change in traction (ballpark for Primacy vs PS4) does account for up to 10% difference in acceleration rates for a significant chunk of the 0–60 or quarter mile.

See I thought with the twins, even at low power, the launch is everything when it comes to 0-60 and quarter mile times. I could be wrong, and it seems like I am obviously not treading towards winning this

I just figured that's why there's such a large variation for people with 0-60 times (anywhere between high 5's to 8's) because it's a struggle to get the perfect launch with the right amount of grip on the tires. So based on that, I assumed grippier tires get a better launch, obviously with skill involved as well. Guess this isn't exactly that simple.

[ZDan]

Originally Posted by Dzmitry

See I thought with the twins, even at low power, the launch is everything when it comes to 0-60 and quarter mile times. I could be wrong, and it seems like I am obviously not treading towards winning this

This is why it is MUCH more reliable to go by 1/4-mile *trap speed* rather than 0-60 or 1/4-mile *times* when trying to compare power/weight of different cars. The trap speed is going to be fairly consistent, while elapsed time will vary quite a lot between street tires on a "normal" tarmac surface vs. drag-tires on a sticky dragstrip launch pad with traction compound.

Again, referring to your referenced 13.58 run at 100mph, that's just never going to happen for a nose-heavy FR car on normal street tires on a non-traction-compounded surface. That time doesn't tell us much about that car's power/weight vs. a stock car on normal tarmac (whether on Primacies or PS4). However the trap speed does give us a clue...

It's important to keep as much as possible similar between tests. Which is why I always quote Car and Driver tests, because they have a consistent procedure and are testing totally stock cars. Their *trap speeds* are a pretty reliable way to judge a car's power/weight, particularly comparing cars that are very similar like gen1 and gen2.

[wizee]

Originally Posted by Dzmitry

See I thought with the twins, even at low power, the launch is everything when it comes to 0-60 and quarter mile times. I could be wrong, and it seems like I am obviously not treading towards winning this

I just figured that's why there's such a large variation for people with 0-60 times (anywhere between high 5's to 8's) because it's a struggle to get the perfect launch with the right amount of grip on the tires. So based on that, I assumed grippier tires get a better launch, obviously with skill involved as well. Guess this isn't exactly that simple.

You can roast the rear tires in first gear in the new car, and even the old car could break the rear tires loose. On a manual transmission car, 0-30 mph times are more a test of driver skill and traction than the car’s performance. However, in second gear and up, you’re limited by engine power rather than driver skill or tires.

That said, the new car has a 6 mph increase in trap speed (101 mph vs. 95 mph), which is a decent improvement given that trap speed is roughly proportional to the [s]square[/s] cube root of power to weight ratio. More significantly, it has around 35% more torque at 4000 RPM, which makes a huge improvement in everyday performance. In a quarter mile race, you can stay above the torque dip of the old car, so the trap speed difference, while significant, isn’t quite as huge. However, in everyday driving, acceleration is done in the 3000-4500 RPM range where the old car falls flat, and the new car has almost 30% more torque on average.

Keeping in mind that you’re using around 25-35% of the old car’s torque to maintain speed in fifth or sixth gear highway cruising, the mid range torque increase becomes even more accentuated as a 50% or more increase in mid range highway acceleration. Try accelerating from 65-80 mph in fifth gear - the difference between the old and new cars would feel massive.

[ZDan]

Originally Posted by wizee

That said, the new car has a 6 mph increase in trap speed, which is a decent improvement given that trap speed is roughly proportional to the square root of power to weight ratio.

Not the square root, the cube root!
101mph vs. 95mph in the quarter implies (101/95)^3 = 1.20x, or 20% more power.

[wizee]

Originally Posted by ZDan

Not the square root, the cube root!
101mph vs. 95mph in the quarter implies (101/95)^3 = 1.20x, or 20% more power.

Ah yes, I screwed up the derivation in my mind. Speed after a fixed amount of time is proportional to square root of power. Speed after a fixed amount of distance is proportional to the cube root of power.

[Yoshoobaroo]

So a 20% increase lines up with the dyno whp differences as well. Seems pretty cut and dry that the new cars are making 20% more power at the wheels than the 2013s. Functionally it’s a 240hp car underrated to 228.

When all roads lead to Rome, the shoe fits and it quacks like a duck or something like that.

[Robertw]

I liked the part in this thread where a stickered on rear spoiler is adding drag and impacting 1/4 times or speed. I've been off forums for a little bit, and man I missed them.