Road racing advantage?

[suicidal2af]

Preface: I haven't slept in about 26 hours, and I'm tired and bored and was doing a lot of thinking.

Everybody(for the most part) likes the 2gb eclipses better than the 2ga. However, delving into the technical manuals, the 2ga has a Cd of .28, whereas the 2gb has a Cd of .29...

Assuming a road racing course with lots of highspeed sections and wide sweeping turns, how much of an advantage would you see from a 2ga? I plan on doing mainly autocross and roadracing, and while the aesthetics of the 2gb are a little nicer, is the more aerodynamic shape of the 2ga really enough of an advantage to warrant staying with it?

 

[Catbox_95]

I don't know the technical calculation to figure it, but I would imagine that a .01 drag coefficient difference is worth about 3 HP at 100 mph.

 

[suicidal2af]

I don't know the technical calculation to figure it, but I would imagine that a .01 drag coefficient difference is worth about 3 HP at 100 mph.

While I don't know for sure, I seem to think that at 100+mph, it's going to make at least a little bigger difference than that, possibly even at lower speeds. Otherwise, why would manufacturers spend so much time and money getting that number as low as possible? Look at the Prius...that has a .26 and had millions in R&D to get it to that number for optimum gas mileage. But, my theory is just a theory. I was kind of hoping someone like jtoby or Dennis Grant would pop in here and leave their 2 cents.

 

[2-0turbo]

Preface: I haven't slept in about 26 hours, and I'm tired and bored and was doing a lot of thinking.

Everybody(for the most part) likes the 2gb eclipses better than the 2ga. However, delving into the technical manuals, the 2ga has a Cd of .28, whereas the 2gb has a Cd of .29...

Assuming a road racing course with lots of highspeed sections and wide sweeping turns, how much of an advantage would you see from a 2ga? I plan on doing mainly autocross and roadracing, and while the aesthetics of the 2gb are a little nicer, is the more aerodynamic shape of the 2ga really enough of an advantage to warrant staying with it?

I think by roadracing you mean trackdays? No, it won't make a difference. Stick with what you've got if that is what you like. Certainly don't change over 0.01 Cd number. I've got to assume you've not done any track days? Try a few out. You'll soon learn that Cd of 0.01 or even 50 HP is NOT going to make much difference. Go out there and have fun. You are not racing anyway--you are learning how to drive your car quickly, precisely and safely.

EDIT: Grammar

 

[Catbox_95]

I think by roadracing you mean trackdays? No, it won't make a difference. Stick with what you've got if that is what you like. Certainly don't change over 0.01 Cd number. I've got to assume you've not done any track days? Try a few out. You'll soon learn that Cd of 0.01 or even 50 HP is NOT going to make much difference. Go out there and have fun. You are not racing anyway--you are learning how to drive your car quickly, precisely and safely.

EDIT: Grammar

Yeah, I agree with him. If you were one of the best drivers in the world, then it might be time to contemplate over 0.01 drag coefficient. I'll bet good drivers in slow cars can easily outrun bad drivers in fast cars.

 

[2-0turbo]

I'll bet good drivers in slow cars can easily outrun bad drivers in fast cars.

Bingo! I'd call myself an average driver--nothing more. But, when I can run down a ZR1 Corvette on the roadcourse with an automatic, 4-cylinder Hertz rental Toyota Solara on street rubber, this statement takes on new meaning.... In the Vette driver's defense, it was sticky Potenza street rubber and not the all-season steely-stockers Hertz issued me.

 

[Catbox_95]

.... In the Vette driver's defense, it was sticky Potenza street rubber and not the all-season steely-stockers Hertz issued me.

I love it!

So, you go and rent a car and autocross it? Why wasn't I notified about this, and why in the hell didn't I think of it!

 

[suicidal2af]

Yeah, I agree with him. If you were one of the best drivers in the world, then it might be time to contemplate over 0.01 drag coefficient. I'll bet good drivers in slow cars can easily outrun bad drivers in fast cars.

We're not talking different drivers though. The same driver given cars that handle identically will see a difference, theoretically, between 2 cars with different Cd's. I'm not asking if me with a 2Ga will run down joebob with a 2Gb -- I'm asking that if given the same and/or equal drivers on a fairly highspeed course, will there be a discernable difference?

 

[pneumo]

I'm guessing the reason the 2Gb has higher drag coefficient is because they added the baskethandle on the rear deck. It's common to see higher drag from aero add-ons. I wonder if the 2Gb wing creates much downforce?

 

[Defiant]

This is the first mention I've run across that the 2G's Cd was higher than the 1G's.

But I dunno..... a big ol' wallowy 2G on a road course.... I'm tired just from picturing it.

 

[2-0turbo]

I love it!

So, you go and rent a car and autocross it? Why wasn't I notified about this, and why in the hell didn't I think of it!

Well, yes and yes. I have rented a Mazda6 and autocrossed it with a buddy on a couple of occasions (very nice handling car BTW). The specific case I'm referring to above, I rented a car and took it to the track, as in the roadcourse (VIR). You just have to keep in mind if you wreck the car, you are screwed. Your personal insurance is not going to cover you and the rental insurance sure as hell is not going to cover you. But, if you have signed up for an event, paid your money which is non-refundable and then you blow your motor in your DSM, you have to find alternate transportation. It did better than you'd think and I got my track time in. I actually learned a lot since it was a low HP "momentum" car. You really had to concentrate on not over-braking for the corners and keeping your speed up because blistering acceleration was just not there at the exit.

 

[suicidal2af]

This is the first mention I've run across that the 2G's Cd was higher than the 1G's.

But I dunno..... a big ol' wallowy 2G on a road course.... I'm tired just from picturing it.

2G is lower than 1G. But 2gb is higher than 2ga.

Actually, the basket handle probably has less to do with it than you think. Neither of the spoilers serve any aerodynamic purpose -- they're purely there for aesthetics. The difference is mostly the front bumper, with the 2ga having more of a teardrop shape and the 2gb having a larger frontal surface area, which also happens to be flat(and thereby less aerodynamic). The sideskirts also probably pay a role -- according to the 95 technical manual, the 2ga sideskirts actually serve an aerodynamic role...they promote the venturi effect. The 2gb skirts are just there to look pretty.

 

[MrPikolo]

This is the first mention I've run across that the 2G's Cd was higher than the 1G's.

But I dunno..... a big ol' wallowy 2G on a road course.... I'm tired just from picturing it.

I belive the 1g CD is around .33

 

[DG-FNR]

A 260 peak HP, FWD, 1.8m2 frontal area, CD of 0.29, minimal downforce car at Laguna Seca is looking at a laptime of 1:34.78 if driven perfectly.

Same car, change CD to 0.28 gives a laptime of 1:34.73

0.05 seconds quicker.

DG

 

[suicidal2af]

A 260 peak HP, FWD, 1.8m2 frontal area, CD of 0.29, minimal downforce car at Laguna Seca is looking at a laptime of 1:34.78 if driven perfectly.

Same car, change CD to 0.28 gives a laptime of 1:34.73

0.05 seconds quicker.

DG

Thanks Dennis, that's exactly the kind of answer I was looking for.

On a semi-related note, how much of a difference would it make to have a solid underbody?

 

[Revolution]

I would personally think that having a solid undergarment for the front bumper area would do wonders for the turbulant air that gets trapped underneath the car. In regards to the 2ga and 2gb dc I personally think the 2ga has a better rear bumper , wich can add as much drag as an ill placed spoiler.

I dont like the eclipse rear ends and would prefer a talons back side anyday for these reasons, and even then we can still learn from asian tuners wich have been using under spoilers for the rear bumpers for awhile now wich promots a flat surface where the turbulant air cant be trapped hence aidding the unwanted drag away from the car.

Check out the cosmetic section of tuners at the end of march, I will be posting up some picks of my theorys and how I've incorpereated them into my custom bodykit.

Aswell as everything else on my car, but then again maybe some one can host them for me, I think every one on tuners even DG-FNR would like what I have done ,but then again I wont let the cat out of the bagg as of yet.

 

[Greg Collier]

Preface: I haven't slept in about 26 hours, and I'm tired and bored and was doing a lot of thinking.

Everybody(for the most part) likes the 2gb eclipses better than the 2ga. However, delving into the technical manuals, the 2ga has a Cd of .28, whereas the 2gb has a Cd of .29...

Assuming a road racing course with lots of highspeed sections and wide sweeping turns, how much of an advantage would you see from a 2ga? I plan on doing mainly autocross and roadracing, and while the aesthetics of the 2gb are a little nicer, is the more aerodynamic shape of the 2ga really enough of an advantage to warrant staying with it?

Get as much seat time as you can. All else will follow.

 

[Revolution]

2G is lower than 1G. But 2gb is higher than 2ga.

Actually, the basket handle probably has less to do with it than you think. Neither of the spoilers serve any aerodynamic purpose -- they're purely there for aesthetics. The difference is mostly the front bumper, with the 2ga having more of a teardrop shape and the 2gb having a larger frontal surface area, which also happens to be flat(and thereby less aerodynamic). The sideskirts also probably pay a role -- according to the 95 technical manual, the 2ga sideskirts actually serve an aerodynamic role...they promote the venturi effect. The 2gb skirts are just there to look pretty.

Quick question how does the venturi affect the aerodynamics of our cars ? Does it pull or scavange tha air thats passing underneath it? Is that what the 2ga's sideskirts promote?


venturi affect

a constriction in a tube designed to cause a pressure drop when aliquid or gas flows through it

a restricted air inlet in a carburetor that produces a drop in pressure, causing fuel vapor to be drawn out of the carburetor bowl


Again some one pls explain As im familiar with certain aerodynamic terms but my google isnt showing me anything new. How does this affect our cars?

 

[suicidal2af]

Quick question how does the venturi affect the aerodynamics of our cars ? Does it pull or scavange tha air thats passing underneath it? Is that what the 2ga's sideskirts promote?


venturi affect

a constriction in a tube designed to cause a pressure drop when aliquid or gas flows through it

a restricted air inlet in a carburetor that produces a drop in pressure, causing fuel vapor to be drawn out of the carburetor bowl


Again some one pls explain As im familiar with certain aerodynamic terms but my google isnt showing me anything new. How does this affect our cars?

To be honest, I don't know. All I know is that the technical manual specifically says that the skirts were designed to promote the venturi effect.

 

[Defiant]

All I know is that the technical manual specifically says that the skirts were designed to promote the venturi effect.

Yeh. Amazing how those advertising wonks..... oh, sorry, tech manual wonks can write a tale, isn't it?

I'm very curious how/who/what determined what a "perfect lap" at Laguna Seca's supposed to be. The idea that any two laps would be within 5/10 of a second is.... suspect.

 

[1LE]

But I dunno..... a big ol' wallowy 2G on a road course.... I'm tired just from picturing it.

Hmmm, mine doesn't wallow around on the road course. Does quite well I think Sure, it's no MR2/NSX/Esprit, but it does real well for basically being a grocery getter/chick car.

 

[Defiant]

Actually, the basket handle probably has less to do with it than you think. Neither of the spoilers serve any aerodynamic purpose -- they're purely there for aesthetics.

I wonder. I noticed while gassing up the other night, the tapered trail the dew had left on the top of the trunklid, behind the thumbnail spoiler... where's my masking tape and yarn tufts....

 

[Greg Collier]

Have you gotten any sleep yet?