Hi
Since i've had a tacho in my car i've started to wonder if my car (71 type 3) has the wrong gearbox in it.
According to the tacho my car is turning about 3800-3900 rpm at 70mph.
Is this right? My mechanic thinks its a bit high..
I've been in another type 3 (early swing axle) and that apparantly does 100mph easily.. whereas mine sounds like its really straining at 80!

[ Edited on 30-4-2007 by jo_tas ]

yours seems about right, my type 3, 64 square; sits on 100k at about 3200 rpm, according to the speedo, and rev counter..

and according to a copy of a "wheels road test" printed in scientific publication, No 47..

top gear mph per 1000 prm = 19.7 mph. and cruising at 83 mph, was revving at 4300

so to do100 mph, the motor would be revving at 5076 rpm, if all is standard??

mmmm there are a few threads about this but here is a new one
my bug was about 2800 - 2900 at 60 mph
and i think about 3300 - 3400 at 70
not sure now as it has been of the road for some time
and it has irs

Hmm.. still sounds like mine is a bit high..

First of all 100MPH = 160km/h, I don't know of any stock engined type 3 which easily does 160km/h. (Except downhill with a tail wind)
Now for the facts. According to the Intereurope workshop manual at 4000RPM in 4th gear you should be doing 127kph (79MPH). The gear ratios in swinger and IRS transmissions are virtually identical.

So your numbers sound pretty right.

My auto fasty is doing just below 3000RPM at 80km/h

Are your wheels standard size? Wheel OD will effect the RMP/km ratio.

If you have 195/65 x 15" tires, you should be doing about 3600 rpm at 70 mph.
If you have 195/65 x 14" tires, you should be doing about 3750 rpm at 70 mph.

All Type 3 vehicles have a diff ratio of 4.125:1. Earlier Bugs had a diff ratio of 4.375:1.

Speed is, as above, given at around 19.7 or 19.8/1000 RPM with standard wheels.

The VW 1500S 8.5:1 compression engine vehicle manual states maximum speed of 84 mph.

The Poms of the 60s had reports of the S doing 100 mph on the M1, presumably with a strong northerly wind if they were heading south!!

Anything better than that with a standard 1600 engine would indicate an inacurate tacho, speedo or both. The speedos on type 3s are known to wear the input spindle bearing which puts the magnet too close to the needle cone resulting in some incredible speeds.

DH



[ Edited on 30/4/2007 by 1500S ]

Well i've been in that 100mph notch.. the engine looks standard externally, but no one knows what's inside it.. but it goes really well!!
I run the 195/65 R15's on my notch.
And driving again last night i think its more like 4000rpm at 70mph..
*Shrug*
The plan is to put a 2litre type 4 and an Lbug gearbox in her later anyway..

The fastest my 65 standard notch could do was 95mph with my foot to the boards until crosswinds made the experience a bit hairy. My guess is that it was max revving (assumed as I have no tacho fitted) which would be about in the vicinity of 4500rpm+. This was done with my original stock standard engine of 1500cc and running a single carb.
- Adam

Single carb 1500 notch, flat strap at about 78 mph but you must have a sister speedo to the one I had in a 1964 1500N. Checked out with others vehicles (in 1967) and found error of near 10 mph. Problem was the worn input to speedo.

Check with satnav and you may find a more reliable readout.

DH

hey jo,
if you ran taller tyres you would be running more after what your chasin..
like a 195 15 but you would lose stability around corners thats for sure..
from the other comments it sounds about right hey..

Heres mine at 108 ish kph. 3200rpm with a single side plate Super Beetle IRS box. 15in wheels with 205 / 60.

Speedo is pretty much correct. Checked against speedo check points on the Hume hyway. Tacho is correct for engine.

[ Edited on 1-5-2007 by Grey 57 ]