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sleepyhead
sleepyhead Reader
6/18/17 8:57 p.m.

so, I watched the Demuro vid, and saw the "spoiler flexing"... and {meh}

that hatch has to be pretty heavy, and (if you watch frame-by-frame) you can see that hatch's actually lifting off the gasket, which is part of the flexing. (i.e. heavy hatch with lightweight wing, means a lot of energy transferred into the wing, multiple times). Most big wings are mounted on trunks, which have a lot less inertia to them... and I was pushing on an ACR wing at OneLap (much to the owner's shagrin), and wasn't all that impressed with the upright's side-to-side strength.

And, yes, that is something to think about

Also, I think I'm seeing that the wing is rotating a little bit, which is what I suspected. I have a feeling that they've tailored the uprights to let the wing rotate "nose up" to kill the angle as speed increases. There's at least probably 3 explanations for this:
1) Mileage (reducing that AoA, reduces lift, which reduces drag, which reduces people suing them for "I'm not getting the highway miles reported on the door card" because they were doing 75mph) 2) Manufacturer Understeer (cars that understeer are 'safer')
3) Consistent Downforce ('dumping' the angle as speed builds, would mean that instead of downforce increasing as speed builds, the same downforce is available all the time... which is easier for "the general public" to be confident in how many lateral g's they can pull)

All of this is a bit of idle speculation... with only one video to go on... so, grain of salt and all. Although if I'm right about the last one... it raises the question of if the same rear wing was on the Nurburgring lap record car. I could see that going either way (let it dump angle 'cause the 'Ring has a lot of high speed stuff; or custom 'stiffer wing' for the 'Ring so there's more downforce).

JG Pasterjak
JG Pasterjak Production/Art Director
6/18/17 9:05 p.m.

Paging Stafford1500...

How much of an effect does wing deflection and vibration have on performance?

smokindav
smokindav Reader
6/18/17 9:53 p.m.

Here's the issue. There's only one rear-wheel drive small sedan (4-doors) that can be tracked as stock or near stock. The BMW 3-series (not a small car anymore).

The other options are all-wheel drive or front wheel drive. And they are:

WRX/STI A3/S3/A4 GTI Focus ST/RS Fiesta ST (too small) Civic Si/Type-R

What makes me sad is that only the (huge) BMW 3-series is rear wheel drive. Yes, I own a GTI and I like it, but I only own it so I can check it off my bucket list. I won't go front-wheel drive on my next car.

DrBoost
DrBoost MegaDork
6/19/17 6:06 a.m.
sleepyhead wrote: And, yes, that is something to think about

Wow. That really shows, in a different way, how much downFORCE properly done spoilers actually produce.
I wonder what that was like to be driving when that happened. I wonder what the driver felt.

FlightService
FlightService MegaDork
6/19/17 6:53 a.m.

So this is where Honda's engineers have been instead of working on the F1 engine....

T.J.
T.J. UltimaDork
6/19/17 7:13 a.m.

Well, the styling is, shall we say, polarizing, and the performance seems spot on with its competitors. One thing for certain is that this car is generating a lot of buzz for Honda that they haven't had in quite a while.

pinchvalve
pinchvalve MegaDork
6/19/17 7:32 a.m.

I loved my 4-gen Civic because it was so fun to drive, and that was when it was in base DX trim. Even with no power, the chassis, steering, brakes and shifter were engaging and rewarding. I have long wondered what a great Honda chassis would be like with more power, sounds like it finally happened. As soon as they come out with body kits to make it a more serious looking car and not a cartoon, I will check them out. Until then I will stick with my understated Fiesta ST.

jstein77
jstein77 UltraDork
6/19/17 8:07 a.m.

This is the first I've heard that the 7:45 Nurburgring Type R lap time was performed on R Compound tires. That explains a lot.

Robbie
Robbie UberDork
6/19/17 8:39 a.m.

Re: styling.

Where are all the "form follows function" people? This shape apparently works, and now we are all getting artsy fartsy about an engineering exercise?

I personally would love to own one. But i just bought a new house and I am about to plunk down for a new garage. Should probably let the credit card cool off before it melts.

fanfoy
fanfoy Dork
6/19/17 1:32 p.m.

In reply to JG Pasterjak:

So I'm guessing you sampled the car at the ICAR circuit? Did you guys get to drive it around the area a bit? There are truly horrible roads around there and I'm woundering how the ride was.

drdisque
drdisque HalfDork
6/19/17 1:37 p.m.
smokindav wrote: Here's the issue. There's only one rear-wheel drive small sedan (4-doors) that can be tracked as stock or near stock. The BMW 3-series (not a small car anymore). The other options are all-wheel drive or front wheel drive. And they are: WRX/STI A3/S3/A4 GTI Focus ST/RS Fiesta ST (too small) Civic Si/Type-R What makes me sad is that only the (huge) BMW 3-series is rear wheel drive. Yes, I own a GTI and I like it, but I only own it so I can check it off my bucket list. I won't go front-wheel drive on my next car.

If you consider a new 3-series "trackable" from the factory, then so is the Cadillac ATS, which is also a RWD sedan offered with 3 pedals.

JG Pasterjak
JG Pasterjak Production/Art Director
6/19/17 3:55 p.m.
fanfoy wrote: In reply to JG Pasterjak: So I'm guessing you sampled the car at the ICAR circuit? Did you guys get to drive it around the area a bit? There are truly horrible roads around there and I'm woundering how the ride was.

Yeah, we did the road drive from ICAR up to Montcalm, which is about 60 miles NW of the track. Roads were not great. Ride was fine, and everything was quiet and didn't rattle or bang over the rough stuff. Unless you lived somewhere where all the roads were dirt, I can't see ride comfort being an issue.

wearymicrobe
wearymicrobe UltraDork
6/19/17 4:04 p.m.
sleepyhead wrote: and I was pushing on an ACR wing at OneLap (much to the owner's shagrin), and wasn't all that impressed with the upright's side-to-side strength.

Huh.

I have never seen a ACR wing deflect ever on the track or in real life.

The0retical
The0retical SuperDork
6/19/17 4:19 p.m.
JG Pasterjak wrote:
drdisque wrote: I'd be more enthused if it was wearing smaller wheels. There's no reason it needs 20" wheels with the ridiculous tire size 245/30R20

Conceptually agree.

But...

Those tall wheels and the gearing combine for a 64mph second gear. That's going to be a big plus on an autocross course.

Out of straight curiosity; does the CTR have any type of throttle/fuel mapping/boost mapping logic which prevents super knock if you mat the throttle at a low RPM? Or does Honda give any assurances about the bottom end of the motor?

I know these things have an absurd markup right now but when they get around to the second or third owner I suspect you're going to see a lot of the same issues arise as with other with other hot turbocharged direct injection cars.

Also super interested in what the prospect of a turbo swap is in one of these (I know I know no impact wrenches or engine hoists on manufacturer demo day). Looking at the pictures of the motor it looks like it would be a pain to modify.

Tyler H
Tyler H UltraDork
6/19/17 4:27 p.m.

I'm willing to bet that ~300hp is about exactly as much power as this chassis can functionally put to the ground. If you added power, would it translate into better laptimes or just better dyno slips and freeway pulls?

Driven5
Driven5 Dork
6/19/17 5:16 p.m.
Tyler H wrote: I'm willing to bet that ~300hp is about exactly as much power as this chassis can functionally put to the ground. If you added power, would it translate into better laptimes or just better dyno slips and freeway pulls?

I think that probably depends to a relatively large degree on what you are planning on lapping with it. Even if it ended up being of limited benefit in your local parking lot, I bet it would at least readily accept plenty more power at 'fast' tracks like Road America, Willow Springs, etc.

Slippery
Slippery SuperDork
6/19/17 5:43 p.m.
jstein77 wrote: This is the first I've heard that the 7:45 Nurburgring Type R lap time was performed on R Compound tires. That explains a lot.

I dont think it was wearing R compound tires ... as far as I have read they where road legal tires.

Driven5
Driven5 Dork
6/19/17 6:18 p.m.

In reply to Slippery:

I think that depends somewhat on how you choose to define "R Comp" and "road legal". The simple fact seems to be that the FWD Production car 'lap record' was set on (substantially faster) tires than are actually available on the car being produced.

sleepyhead
sleepyhead Reader
6/19/17 6:37 p.m.
wearymicrobe wrote:
sleepyhead wrote: and I was pushing on an ACR wing at OneLap (much to the owner's shagrin), and wasn't all that impressed with the upright's side-to-side strength.

Huh.

I have never seen a ACR wing deflect ever on the track or in real life.

Maybe I should say "lateral deflection" under hand loads (I.e. pushing on the end plates)... mainly because of the Porsche photo above. That case was almost certainly an outlier, and possibly that failure was caused by a crosswind contribution... something I don't think many people think about. Did the Dodge engineers? Probably.

Is the ACR wing strong enough? Some evidence seems to indicates so. Is the CTR's? I'd wager the same statement applies.

But, then my background is more theoretical, or is a different application... and was more aero than structural. So I'm still getting up to snuff on the racing side of things.

Thanks for the pic, though, always like seeing people with confidence in the numbers!

JG Pasterjak
JG Pasterjak Production/Art Director
6/19/17 6:42 p.m.
jstein77 wrote: This is the first I've heard that the 7:45 Nurburgring Type R lap time was performed on R Compound tires. That explains a lot.

They were 180tw Michelin Pilot Sport Cups. So not quite R-comps, but a solid track day tire.

sleepyhead
sleepyhead Reader
6/19/17 7:05 p.m.

so, to take this discussion in another direction (away from me getting labled 'the forums grump anal aero idiot')... for $40k would you rather have a CTR or a modded and 6spd manual lsd swapped TSX wagon?

Robbie
Robbie UberDork
6/19/17 7:36 p.m.

CTR

DrBoost
DrBoost MegaDork
6/19/17 8:02 p.m.
Robbie wrote: Re: styling. Where are all the "form follows function" people? This shape apparently works, and now we are all getting artsy fartsy

Here I am.
Form follows function?
There's about 4 square feet of plastic panels that have a honeycomb pattern, to mimic an air duct. Not sure of the function.
Then there's the faux carbon fiber inside. To, uh, look lighter?
Ther there's the spoiler of dubius merit.
This is GM league stuff. Honda can actually build a heckuva power train. They can build a great chassis. They can put the two together. I'm just baffled they took this step. They don't need to rely on gimmicks to sell cars.

jstein77
jstein77 UltraDork
6/20/17 9:55 a.m.

Agree with Dr. Boost. Exactly how much rear downforce does an FWD car need?

rslifkin
rslifkin Dork
6/20/17 10:05 a.m.
jstein77 wrote: Agree with Dr. Boost. Exactly how much rear downforce does an FWD car need?

It can actually be a good bit as a guy I know learned with his autocross CRX (which ended up with a giant wing). You make the suspension a bit tail happy so the car will rotate well at lower speeds and use aero to tame it at higher speeds so it's not unstable (gradually becomes less tail happy as speed increases).

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