CA code gearbox - Crew-cab V Kombi ?

[rev-al]

Hi - Anyone have an opinion- ?
My '70 model year 1600 sp Crew cab with CA code gearbox, struggles to get over 55 mph. Just got '68 Kombi (fitted with a Type 4 CB code 1700 engine) also
with a CA code gearbox, comes alive at 55 mph - and just takes off ! It feels free and wanting to accelerate up to 70.
Question is: Why the massive difference ? With a same ratio gearbox, how is the performance/gearing so different ? Does the crew cab somehow have a lower gearing ?
Or, is it simply that the 1700 Type 4 has that much more poke ?
(Should add, both are running original fitment wheels and tyres)
Thanks
Al

 

[Trikky2]

The overall gearing of the boxes are CA - 5.375 CB - 5.857

The CB box is what was considered mountain ratios eg it was lower geared for better climbing but this reduced max cruising speed.

Type 4 1700 engined buses had the same gearing as 1600 but were quicker, because the T4 engine produces a bit more power and revs a bit more freely.

That said, if your 1600 runs out of puff at 55 then theres something wrong with it. It should reach around 70 on the flat with no headwind.

 

[rev-al]

Thanks Trikky2
Maybe I'm not pushing the 1600 hard enough _ It's a good engine - low miles dealer exchange unit. Very smooth + very quiet. I'll check the throttle cable is adjusted to allow full throttle.
In truth - I always thought it's slow top speed was deliberate because it's a crew cab and as such geared differently to drag weight for work. When the Kombi came along I had to re-think.