View Single Post
Old January 16th 2013, 10:51
Sandeep's Avatar
Sandeep Sandeep is offline
Join Date: Aug 2002
Location: Brampton, Ontario, Canada
Posts: 1,795
Realistic top speed and tire choice for circuit driving

Hi All,

I'm looking for some suggestions on a realistic top speed for circuit driving along with some tire suggestions as I need to replace my ~ 10 yr old Pirelli P Zeros.

Car information:

1974 standard beetle body with no aero mods, 2" wider rear fenders, 1.5" wider front fenders

Coilover rear suspension, QA1 double adjustable dampers with 400 lb/in springs, 5 bar kafer brace, stock steel rear arms, no torsion bars. 24mm whiteline adjustable sway bar, new bushings throughout.

Lowered adjustable front suspension, hybrid spindles (VDub Engineering), new bushings, additional camber adjusters, 22mm whiteline adjustable sway bar.

18 x 10 rear wheels, 18 x 8.5 front wheels, 993T front calipers with 322x32mm rotors, 944T front calipers on rear with 309x28mm rotors

2413cc T4 Turbo (80mmx98mm) GT3076R turbo, max rpm ~6300, max boost ~ 20 psi. Hoping for ~ 350 FWHP

Porsche G50/01 gearbox, stock, Tilton double clutch setup with custom flywheel.

My local track would be Mosport Raceway ... now renamed and the Porsche 930's (stock) are hitting 140 mph / 225 kph on the back straight before needing to brake.

From old you tube videos (in a controlled environment ) the beetle with turbo 2.0 / 901 gearbox hits 200 kph from a standing start in ~ 13 seconds and did the quarter mile in ~ 12 secs at ~ 118 mph.


1. Is it realistic to drive up to a top speed of ~ 150 mph / 240 kph in a beetle with a kamie front spoiler and remmele style rear spoiler ? Not a constant top speed for a long duration ? I think it may be as I've been up to 200 kph with the car feeling stable with no jittery tendancies. Can I add 40 kph more ?

2. Old data was with a turbo 2.0 T4 and Porsche 901 gearbox. New gearbox is a g50/01 with 3.44 R/P and 0.89 5th gear. Old tire size was 235/35/18 front and 265/35/18 rear. Not a big selection in 235/35/18 now but looking at Michelin Pilot Super Sport in 245/35/18 (similar dia as old tire @ ~ 24.6) and 285/30/18 Pilot super sport rear (up from 265/35/18, but slightly smaller diameter)

This would give ~ 60 mph in second gear @ ~ 5800 rpm, 100 mph in 4th @ 5300 rpm, and ~ 150 mph @ 6200 rpm which would seem to be within the car's capabilities

Any comments from the group who's had their bugs on a circuit ? I don't plan on doing any autocrosses and only limited drag racing with the Pilot Super Sports.

Thanks !

Reply With Quote