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Discussion Starter · #1 ·
Guys,

In straight line racing, how much does keeping your side windows open on your car affect your acceleration or top speed?

I'm trying to figure out why when I raced the Hayabusa this past Saturday, in race one, I started reeling him in at 4th gear and at the top of 4th gear put the bike to the rear of my car, but then on the 2nd run, I didn't start reeling him in until well into 5th gear.

At first I thought it might be because my car was fresh the first run and realtively cool. But now I remember that I ran the first run with my windows totally up. Could that have made such a huge difference, or do you think it was something else?

He does get a slightly better jump the 2nd race, but the time to reel him in in the long run was VASTLY different.

-Manny
 

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Re: >>> WIND DRAG WHEN RACING WITH WINDOWS OPEN - TORQUEMONSTER? <<<

Roll up your windows - its not hurting you much but its really not helping either.

Take off your splitter - that probably costing you at least half a car length against the bikes. If you had a completely stock body it would be worth a car length in my opinion. Pimped out aero body parts look cool and can offer a more stable car at speed. But they do this at the cost of adding drag and slowing the car down a bit.

Your bread and butter gear in a roll on race is 4th gear. In the video it sounds like you are short shifting well below 6000 rpm when going into 5th gear. Your rate of acceleration will fall off quite a bit once you go into 5th. So stay in 4th to at least 6000 before shifting.

Also, running those bikes back to back like that will heat soak your intercooler. Get a water injection kit like the other SC guys are running and I bet that will give you more consistent power from run to run.

Fold your mirrors in next time. Also, it looks like your car is running the stock suspension. Lower that sucker, it will help for high speed stuff.

Have fun, be safe and keep the videos coming!
 

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Re: >>> WIND DRAG WHEN RACING WITH WINDOWS OPEN - TORQUEMONSTER? <<<

I agree with John 100%. I would also add that the rear wing has got to be costing you a little too.
 

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Discussion Starter · #4 ·
Re: >>> WIND DRAG WHEN RACING WITH WINDOWS OPEN - TORQUEMONSTER? <<<

I've got methanol injection and an intercooler. The car ran well within operating temps, but no doubt everything was heat soaked.
 

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Re: >>> WIND DRAG WHEN RACING WITH WINDOWS OPEN - TORQUEMONSTER? <<<

Many C-Can you tell me who makes the meth\water inj system?
Thanks
 

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Re: >>> WIND DRAG WHEN RACING WITH WINDOWS OPEN - TORQUEMONSTER? <<<

Agree, agree, and agree again.

Dump the aero stuff (splitter/wing), roll up windows, lower the car, fold mirrors, don't short shift fourth.

Here's some ideas, but I'm no expert:

- Lose any extra weight in car if possible (no passenger).
- I think cool weather will help you more than them, as long as you still can get traction.
- I would think over-inflating the tires would reduce rolling resistance. What psi, I have no idea. Don't want to lose traction or pose a health risk (blowout), so check with the pro's.
- Make sure your tires/rims are perfectly balanced.
- Light weight rims may help a tinny-bit.
- Skinnies in the front will help with weight and aero, but you probably don't want to run them on the street.
 

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Re: >>> WIND DRAG WHEN RACING WITH WINDOWS OPEN - TORQUEMONSTER? <<<

Manny, don't run anyone when heat soaked.. If I were you, after the 2nd run, I would have let the car sit for 15 minutes to cool down like the guys at the track do.That along what was said above will DEFINATELY help you out. YOur windows up will cut drag down, put your mirrors in and lower it. If you really , which it sounds like you are, after the bikes. YANK THAT F'ING splitter off, it cant' take you more than 1/2 hour....


If you're out to race them, go for the kill and not to be killed. Also yank your air filter, that will help you more than ANYTHING..trust me.

Gerald
 

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Re: >>> WIND DRAG WHEN RACING WITH WINDOWS OPEN - TORQUEMONSTER? <<<

Manny - next time you are out and have a chance to dial up over 100mph - wind down your window and stick a hand out.

YOu'll be amazed how much force is against your hand - feeling like a brake on the car - which it is, except the car has so much power it doesn't really notice.

Mutliply that by many times and that is what your wing is doing - pulling your car back as you get faster.

It looks great - but for high speed straight line work - will cost quite a few mph.

Also - what John said. Windows down equalize pressure but at a cost of lots more drag. I'd keep them up as John suggests. I'd also agree with John about losing a car length with the extra drag - and the faster you go the worse it'll get.
 

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Discussion Starter · #9 ·
Re: >>> WIND DRAG WHEN RACING WITH WINDOWS OPEN - TORQUEMONSTER? <<<

The Gen 2 GTS's have built in equalizers, right? How fast can you go without danger of popping a side or rear window? I assume my autoform body kit didnt change any of that.

-M
 

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Re: >>> WIND DRAG WHEN RACING WITH WINDOWS OPEN - TORQUEMONSTER? <<<

I think aerodynamics come into play at terminal speeds, less so under with acceleration under 175. At the speeds we were running it may have some effect, but I think aerodynamic aspect in these contests is minimal.

That being said, by all means remove whatever you like from the car for the next encounter.
 

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Re: >>> WIND DRAG WHEN RACING WITH WINDOWS OPEN - TORQUEMONSTER? <<<

Funny, I was going to mention your windows being down when I saw the video with your passenger obviously taking video out the open window what with the wind noise and all. I would think open windows would have some effect and dragging your speed down. Kind of like having an open parachute out the back of the car but to a much smaller degree.
 

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Re: >>> WIND DRAG WHEN RACING WITH WINDOWS OPEN - TORQUEMONSTER? <<<

I think you can beat that second bike with the things mentioned above. I would also bring a few bags of ice to cool down the intake.

THe most important thing I heard from the video is your shift from 4th to 5th, you have to run that sucker to redline then shift fast into 5th. That makes a huge difference. Ol' johnny boy is right about that. 5th gear is so tall that you got to bring those rpms up so you hit some peak power sooner.
 

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Re: &gt;&gt;&gt; WIND DRAG WHEN RACING WITH WINDOWS OPEN - TORQUEMONSTER? &lt;&lt;&lt;

you didn't race him sideways, did you? /images/graemlins/smiles
 

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Discussion Starter · #14 ·
Re: &gt;&gt;&gt; WIND DRAG WHEN RACING WITH WINDOWS OPEN - TORQUEMONSTER? &lt;&lt;&lt;

SUPRAVIPERGTS said:
you didn't race him sideways, did you? /images/graemlins/smiles
Huh?
 

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Re: &gt;&gt;&gt; WIND DRAG WHEN RACING WITH WINDOWS OPEN - TORQUEMONSTER? &lt;&lt;&lt;

Manny_C said:
SUPRAVIPERGTS said:
you didn't race him sideways, did you? /images/graemlins/smiles
Huh?
Manny, thats a good point..I was actually surprised that you didn't have an issue with excess wheel spin.

Were you in 2nd gear when you began the race ?? Do you have any problems hitting the rev limiter in 1st and 2nd gear under WOT ?

:cheers:

JEff
 

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Re: >>> WIND DRAG WHEN RACING WITH WINDOWS OPEN - TORQUEMONSTER? <<<

Manny , keeping that aero stuff on the car is like the bikers not tucking when racing..and then some.

On my busa if I would go from a tuck and then upright my mph would drop instantly 2mph!! That's a car length. Imagine what a splitter and wing would do. No matter WHAT speed you're at, it will make a difference. Espcially when you accelerating in 3,4 and 5th gears.

I guess maybe there was something wrong with my bike after a full Ti Force Exhaust, Power Commander w/ Map, K & N I only pulled 157RWHP, corrected.
I'm sure that bike has more? Small box and big box mod? Pair valve removed, sucker / flap removed, veloctiy stacks removed. All that makes a pretty big difference on the top end as I'm sure FullTilt would agree. /images/graemlins/smiles I CANNOT see a bike with a pipe on it pulling that hard. Perhaps your heatsoak was a factor too.

BTW, the cops have your IP. They are subeono'ing (sp?) your ISP.. /images/graemlins/laughing.gif /images/graemlins/laughing.gif

G
 

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Discussion Starter · #17 ·
Re: &gt;&gt;&gt; WIND DRAG WHEN RACING WITH WINDOWS OPEN - TORQUEMONSTER? &lt;&lt;&lt;

Yellow Fever said:
Manny_C said:
SUPRAVIPERGTS said:
you didn't race him sideways, did you? /images/graemlins/smiles
Huh?
Manny, thats a good point..I was actually surprised that you didn't have an issue with excess wheel spin.

Were you in 2nd gear when you began the race ?? Do you have any problems hitting the rev limiter in 1st and 2nd gear under WOT ?

:cheers:

JEff
I had no wheel spin issues. When it is warm outside and the tires are warm, my car will not spin in 2nd gear from a roll -- at least it hasn't happened yet. Maybe accelerating from 1st to 2nd might induce spin since the car is slows down for a second and then wham, mass gas again. Kind of like me accelerating up to 2nd gear, letting off the gas and then mashing it -- but I didnt do that. I got up to a certain speed in 2nd gear, held the speed and then mashed the pedal and it just took off. I also don't have the HP/Torque curve that you are going to have with your turbo. I want to talk to some turbo guys that drive their cars on the street to see if they can mash the pedal in 2nd gear at all, or if it is just spin city. Me personally, I didn't want to have to ease into the throttle in 2nd gear (and maybe even 3rd gear), which is why I don't drive around on sport pilots.

-M
 

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Discussion Starter · #18 ·
Re: >>> WIND DRAG WHEN RACING WITH WINDOWS OPEN - TORQUEMONSTER? <<<

Gerald said:
Manny , keeping that aero stuff on the car is like the bikers not tucking when racing..and then some.

On my busa if I would go from a tuck and then upright my mph would drop instantly 2mph!! That's a car length. Imagine what a splitter and wing would do. No matter WHAT speed you're at, it will make a difference. Espcially when you accelerating in 3,4 and 5th gears.

I guess maybe there was something wrong with my bike after a full Ti Force Exhaust, Power Commander w/ Map, K & N I only pulled 157RWHP, corrected.
I'm sure that bike has more? Small box and big box mod? Pair valve removed, sucker / flap removed, veloctiy stacks removed. All that makes a pretty big difference on the top end as I'm sure FullTilt would agree. /images/graemlins/smiles I CANNOT see a bike with a pipe on it pulling that hard. Perhaps your heatsoak was a factor too.

BTW, the cops have your IP. They are subeono'ing (sp?) your ISP.. /images/graemlins/laughing.gif /images/graemlins/laughing.gif

G
I proved that my car can do what I thought it could do against a bike, so I am happy enough. I'm not so much into having to beat somebody that I am willing to remove my splitter and all that stuff. I'll just need to make more horsepower in the future to compensate /images/graemlins/smiles

Seriously, I bought this car based on looks - I really liked how unique it was. Next I wanted it faster than stock. I got both of those things, so I am happy.

I did tell Gar (the copper Hayabusa that pulled me in race 4) that I would run him again on a 1st run basis since he lives close to me. I'd like to see how much, if any, heat soaking had to do with the difference between race 1 and race 4.

Oh yeah, I have to take FullTilt on a ride too, at least once, as he didn't get to last time.

-Manny
 

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Discussion Starter · #20 ·
Re: >>> WIND DRAG WHEN RACING WITH WINDOWS OPEN - TORQUEMONSTER? <<<

Jeff -- Negative. If they were, I would also get 19 inch HRE's.
 
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