VF30 AutoX tactics..

[Brad B.]

I don't want to get into a debate over whether or not the VF30 is a good upgrade for AutoX racers. I think everyone pretty much agrees that the stock turbo is better due to its lower lag. For me, the street benefits of the VF30 I'll get everyday I drive the car outweigh the increased lag I'll experience for the few events I'll enter.

That being said, does anyone have any tips? Should I try to run some courses in 1st gear so I'll be under boost? Or will the engine braking upset the balance of my car as I lift off throttle? Should I ride the clutch a bit to keep the RPMs up?

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[Scooby Freak]

You just have to practice the timing. With my car (stock drivetrain) there is still a significant turbo lag. You need to know when to get on the gas. I will go full throttle well before the apex of the turn, even before I unwind the steering wheel. So that boost comes on right where you need it.

As for 1st gear, I wasn't able to shave any time by downshifting or keeping it in first longer.

-jeff

[afpdl]

Yeah just work on getting on the gas way way before you actually need it.

[gotsol]

left foot breaking

[jmott]

add a bigger engine to it

[chudlo]

Anti-lag system?












Sorry, had to say it.

[MNbiker]

Originally posted by gotsol
left foot breaking

Is that where your left foot accidentally slips off the clutch while trying to shift, and your tranny BREAKS?

[wrrrx]

Actually- all of that is good advice!
Getting used to the how long it will take for spoolup on an AutoX course will come mostly from experience. So, enter as many as you can!
Also- I dunno which AutoX class you're in, but if you run a UTEC you can indeed run the anti-lag option. Yes, yes "it's hard the turbo" blah blah- but it's only for a short time, so who cares?
(And, hey- if it blows up- what a great excuse for a new turbo! )
Left foot braking should help a LOT!! Only problem is doing it- I keep meaning to, but in the "heat of battle", I continually forget...
Someday I'll get it right...

Russ R

[LOLSTi]

Originally posted by MNbiker
Is that where your left foot accidentally slips off the clutch while trying to shift, and your tranny BREAKS?

that was great.

[dorao]

I know exactly what you mean about auto-xing your 'street-fun' vehicle. I had a stg4 WRX w/ a vf34 in SM and I wasn't very competitive, especially on the tighter courses.

Does you wrx actually go into first? Mine would grind like crazy if I wasn't going slower than 5mph....
What I tried to do is be smoother and maintain speed through corners so I could get into boost sooner. I have been practicing left foot braking to try to make the transitions smoother... I have been getting better at trail braking as well.

Anyway, I really don't care if I am competitive with the others in my class as much... I just go out there and do the best I can w/ what I have and most importantly, just have fun! I'm starting to get used to my new STi and having a blast .

Good luck!
Masuo

[MK19_]

I have yet to run my V7 STi w/ its' VF30 in an auto-x this year... I am also in SM and I know this will be challenging. At least my first event is at Grissom (sticky, big, wide open and fast!)

[mykrrrr]

I LFB during autoX.

I think it helps me out more to settle the car than keeping the turbo spooled but it's my first year @ autoX and my first year w/a turbo car.

My autoX skool instructor couldn't believe that I LFB'd @ skool and still can't believe I do it now.

-mykr.

[rex n effect]

Originally posted by MNbiker
Is that where your left foot accidentally slips off the clutch while trying to shift, and your tranny BREAKS?

Nah,
It's when you stick your left foot out the door under the front tire while driving in reverse. Left foot breaking.

[Brad B.]

I tried to LFB the other day and was surprised how easily the brakes can out power the engine. But more than that, it was really hard hitthing the brake and not the clutch becaues the WRX pedals are so close to one another. Practice practice!

[mc2racing]

Originally posted by Brad B.
I tried to LFB the other day and was surprised how easily the brakes can out power the engine. But more than that, it was really hard hitthing the brake and not the clutch becaues the WRX pedals are so close to one another. Practice practice!

I've heard it said that if you want to use left foot braking to beat your competition, you just need to convince your competitors that they need to be left foot braking.

Seriously though, I've heard guys talk about getting on the gas sooner to get the turbo on boost at the right time. However, consider the traction circle. If you are cornering at the limit of the tires, any additional application of the gas, even of it's at an rpm that doesn't build significant boost or power, will upset that balance. IMO, if you can get on the gas sooner, you aren't going through the corner fast enough.

Try increasing your cornering speeds (easy enough to write, a little harder to do), that will increase your rpm and make the turbo available a little sooner. This may not get you on boost much faster, but it will increase your cornering speeds, which is (argueably) the most important factor in getting good times on an autocross run.

[afpdl]

Originally posted by mc2racing
Seriously though, I've heard guys talk about getting on the gas sooner to get the turbo on boost at the right time. However, consider the traction circle. If you are cornering at the limit of the tires, any additional application of the gas, even of it's at an rpm that doesn't build significant boost or power, will upset that balance. IMO, if you can get on the gas sooner, you aren't going through the corner fast enough.

Its not for constant radius turns, its for turns that the entrance speed is much lower then the exit speed. With a vf30 you will often be way out of the power band. So instead of holding steady through the increasing radius, floor it.

[Templar]

Geez, VF30s must be terrible. I race with an 18g and I have no problems at all.

Remember, that even though the bigger turbo may only be making 10 psi at 3000, where the stocker is making 15. The power difference between the two is minimal. It just feels slower because you haven't hit that point where the turbo really kicks in and knocks you back in the seat.

Edit: Oh, I hit 1 bar by 3300 in second gear.

[jmott]

Originally posted by Templar
Geez, VF30s must be terrible. I race with an 18g and I have no problems at all.

Remember, that even though the bigger turbo may only be making 10 psi at 3000, where the stocker is making 15. The power difference between the two is minimal. It just feels slower because you haven't hit that point where the turbo really kicks in and knocks you back in the seat.

Edit: Oh, I hit 1 bar by 3300 in second gear.

no problems at all?

what is your pax rank and out of how many people?


also, lag is not just "how much boost do I make at this rpm" but how quickly that boost gets built when you get on the gas.

a camaro will make all 350horsepower INSTANTLY if you want it too.

a big turbo wrx may take a tenth of a second.

and that is a big deal.

[Templar]

Originally posted by jmott
no problems at all?

what is your pax rank and out of how many people?


also, lag is not just "how much boost do I make at this rpm" but how quickly that boost gets built when you get on the gas.

a camaro will make all 350horsepower INSTANTLY if you want it too.

a big turbo wrx may take a tenth of a second.

and that is a big deal.

Well, first off, if you could see most of the lots we are forced to run on around here, you would understand why our local club doesn't utilize pax for anything. The longest course we have had in the last two years was just under 40 seconds average time. With the fast cars running in the 35-37 second range. When courses are that short, Pax doesn't work correctly.

Second, If you factored in pax I would have always ranked in the top three or four cars in the last two years (but that doesn't matter since I was racing with a TD04 last year, and the bigger turbo this year. This is out of anywhere from 65-90 cars.

Yes, we do understand that a naturally aspirated car will put its power down sooner. Would I be faster with less turbo lag...Yes. Am I faster with the 18g making 75-90 more horsepower 250 rpm later than the 13g. Hell yes. The point I was making is that with equal drivers (of good skill levels, not novices) a properly tuned VF30 equipped (or any of the moderately sized turbos) car should waste a properly tuned stock turbo equipped car at autocross.

[mc2racing]

Originally posted by afpdl
Its not for constant radius turns, its for turns that the entrance speed is much lower then the exit speed. With a vf30 you will often be way out of the power band. So instead of holding steady through the increasing radius, floor it.

No doubt. Of course, this is where our ability to discuss this further in this forum ends. Way too many variables in the details of each corner on an autocross course to hash out the details of each one.

In summary, here's what we've basically come up with. Keep corner speed as high as possible. Get on gas as soon as possible. How's that for earth-shattering?