zagaone

I will be doing a half mile event on Sunday on a nearby closed facility. Purpose being finding the car with the highest top speed at the end of 1/2 mile. No timing will be taken just top speed. I was wondering what else to do to improve my chances:

1. Bigger diameter/lightest wheel/tyre combo that I own. Will use Yokohama Advan Neova AD08 295/35/18 on Kinesis very light wheels. Also have BBS on 295/30/18 Hoosiers(They are thinner and smaller diam. than the Yoko. Thinner 245 front.

2. Car as light as posssible. Right now at 2,900lbs. (It is a street car with a/c and full interior except for a racing seat).

3. Racing tape around the body gap.

4. Won't take out the outside rear view mirrors or any body panel. To much work disconecting wires. This is a fun event not professional stuff.

Anything else that might help improve top speed?

I heard people saying than in this kind of event a drop clutch launch is not that important. What is the best launch method to improve top speed at the end of 1/2 mile?

The car is a 3.2lt 16v/variocam with 550 rwhp at 16.5psi; 6spd stock 968 tranny with lsd.

Comments or ideas welcome

Angel

toddk911

40-45+ psi in the tires.

racerxrick

even though it's a half mile it's still basically a drag race though only MPH matters. If the Hoosiers are softer with better "hook" then go with them as you won't waist a bunch of time spinning. The others have a little more diameter though you won't hit high gear/red line in the 1/2 mile distance anyway.

Try to get a decent launch and then max redline each gear and keep the peddle down! I'm sure you'll get into 5th which should be one to one...hold her there and let it rev

Oh yeah (and this is most important)...provide results AND pics next week for all of us on Rennlist!

Good luck and have fun!!

Raceboy

Any predictions?
Ok, I'll be the 1st one. With the specs you provided 260-265 kph (around 160-163 mph).

As for suggestions, like toddk911 said, 40 psi pressure to the wheels and no, traction has little importance on top speed events. Just rev to the redline and don't miss a gear.
If you have to wait in line for your turn, bring some dry ice to cool the intercooler so it will be cold already on first few hundred metres.

86 951 Driver

I would think with 550 HP that it will go a lot faster than 160 MPH.

Ben951S

Yeah really, I would imagine breaking 175mph...

zagaone

I have never run the car on the 1/4 mile so I have no idea what 1/2 mile will do. I do know that down the 3/8mile straight on track days it is impressive but different since the car is already at speed before hitting the straight. I do hit 5 gear easily on the straight at track day and shift to 6 for a little before braking for a low speed chicane. Rev limiter is set at 7K but I usually shift at 6.5-6.8K.

What is the powertrain loss on our cars? What will 550rwhp means at the flywheel. I believe 650hp should be close. 15% loss at this hp level?. Torque curve is pretty flat and peak at 483 ft-lb.

It should be interesting. Bunch of GT-R; Vipers; ZR-1; Ferraris; Lambos; 997 GT-3RS and Turbos are registered. Even a MB SLS will be there.

zagaone

I just recently saw in you tube a Hennessey Ford GT with 1500hp do 232mph in the mile and in that same run the Vbox indicated it did 191mph in the 1/2 mile. But that was with more than double my car hp. So 160 might seem reasonable, even though its gearing must be longer to attain the 232mph with 6spd tranny(I believe that is what a Ford GT has) and don't know the GT car weight.

piperporsche180944

My best trap in the 1/4 mile at 15lbs (with mods listed in sig) was 111mph.

You have a LOT more hp. Id assume you would be around 130mph in the 1/4, 168 in the 1/2.

racerxrick

should be fun...the only reason I mentioned traction was in regards to the power your making! Damn I'm sure your spinning the tires hittin' third gear!!!

2bridges

my bet is about 156mph best pass assuming it is an honest 550 rwhp

I always find it entertaining the opinions of those that have never run such an event.
not frownin but 175 BAWWWAHAHAHAHHAAHAHAAA - not even in the ballpark, no way, no how

George D

Ease out in 1st till redline. If you have traction in 2nd just shift up within your powerband. Sounds like fun. Good luck

333pg333

Definitely get some video!

elargentino

If your engine truely makes 550 rwhp and this is not speculation, you need to make sure your alignment and all you aero equipment is in order.
Especially since you say you have not been on the 1/4 and you say your powerband is flat.
You will be going fast, be carefull.

Remember....they're ALL fun events until someone flips their car 20 times.

Raceboy

You should attend few top speed events before you make such statements

Markus951 500 rwhp 951 hit 265 kph on 1 km distance (slightly more than 1/2 mile) which is 165 mph. With extra 50 rwhp you should be close on 1/8 mile.

Just for reference, my 250hp/320 Nm turbocharged euro 924 did 200 kph on 1 km distance and stock Evo 10 did exactly the same result. Stock 951 S did 188 kph on the same event