Diff ratio for Phillip Island

[Scando]

Hi guys

 

I'm just wondering if my diff ratio is going to be suitable for PI.  I'm running 255/40 17's, a 3.7 diff, and at Symmons Plains I'm pulling roughly 230km/h at 6000rpm at the end of the straight.  Everybody tells me to expect to pull a fair bit more speed down the straight at PI than Symmons.  I've got my limiter at 6300 which should give me a maximum of around 240.  Do you think this will be enough?  I'd be interested to hear what other people run there (obviously ratios will change massively depending on engine, wheel size, etc.)

 

Thanks

Shane

[C.A.R.]

I'd be taking a 3.54 with you...

[zr240]

I used to run a 3.7 with 16x10 285 tyres (dunlop slicks) with about 250-280hp motor.  There is only one 240z that I know of that did quicker times than me which is Tom Cantwells car but Im not sure what diff he ran.

 

hope that helps

 

Its a great track and you are going to love it! Maybe there will be another zed quicker than mine after you run there

 

Ash

[Scando]

Thanks guys, I've got a welded R180 3.54 that I was running last year at Symmons with the 15's so I think I'll take that and the moustache bar to fit it just incase.

 

Don't think I'll be going under your time Ash.  I was comparing times the other day trying to work out roughly where I'll be and I saw you did a 1:47.  Man that is quick for a n/a Z!  I know slicks make a fair difference but still, to be almost on the Improved Production lap record and a second quicker than the Nc lap record with a lot less power than those guys is very impressive 

 

I just can't wait to drive the track 

[dat2kman]

usually run a 4.375 at Eastern Ck/Qld Raceway/Lakeside/winton,/morgan park and sandown but for PI and Mt Panorama I run a 4.111

running Group S spec 195/60x14 rubber, 0.83 fifth gear and 7500 rpm max

whats that work out to kmh wise??

with 4.1,  I reckon max speed approx 230kmh, and with 4.3 220kmh

The entry into turn 1 at PI and Easterncreek at these sort of speeds has the car floating, and driver holding breath and puckered additional centre seat grip in full fluctuation, especially when there's another two or three cars right next to you doing the same thing.

[C.A.R.]

and driver holding breath and puckered additional centre seat grip in full fluctuation

Farkin LOLZ! Nice one Choclate man!

[Scando]

Thanks for the info Jason.  Sounds like I'll definately be taking the 3.54 just incase.

[Zedman240®]

I think that's why my lap times suck at PI; I don't take that first turn at those speeds! hahaha I think I can make up those 8 seconds there alone. Alot of the zeds that sprint there usually have 3.9/4.1's. 3.53 might be a bit high specially at Honda corner and exiting Lukey Heights...But with your monster torque there Shane, it should be fine!

[Scando]

Alot of the zeds that sprint there usually have 3.9/4.1's. 3.53 might be a bit high specially at Honda corner and exiting Lukey Heights...But with your monster torque there Shane, it should be fine!

 

My max power is only at 5,000rpm so I don't have the revs to play with that most Z's do.  Any idea what sort of speed you cary through Honda and the bottom of Lukey Heights?  Normally as long as I can carry about 80-90 through a corner it'll get onto boost and pull fine in 3rd.  Think I need to get onto Youtube and watch some in-car vids 

[zr240]

I had to go back to second in honda and then short shift into 3rd just on the exit to settle the car.

 

(240z box std ratios with 3.7 diff)

 

ash

[RB30X]

You need to get a camera for your car like Zedman has to show your laps etc from different parts of the car.

 

One of my favourite track vids from when I was a VL nut is this VLT in NZ with an auto of all things.

 

http://ozdat.com/membersites/lurch/Vids/HSVSUX_one_lap.mpeg

 

or the page can be found here: http://ozdat.com/membersites/lurch/hsvsux.html

 

Click on him doing the lap of pukekohe.

[620Z]

3.7 should do it.

[C.A.R.]

Hahaha... Brent is a popular man

[Scando]

I can't view that at the moment cause I'm at work but I'll have a look another time.

 

Got myself one of these:

http://www.goprocamera.com/index.php?area=2&productid=30

 

Got this footage from the last round but I still need to get the sound working properly:

 

Thanks for all the info here guys.  From what you guys have said in this thread I've decided to put the 3.5 in before I leave and take the 3.7 as a spare.  The 3.5 is a weldy but it only makes it understeer through very tight corners, since PI is mainly sweepers it should be fine.