To the best of my knowledge, the AAB engine in the Audi 90 has 90 horsepower, while the T4 has 78. What's the difference?
Can I also increase the horsepower of my T4 AAB to 90 hp by using "a few other parts"?
Are you sure that the person in the Audi is also named ABB?
To the best of my knowledge, all T4 engines have reduced power output compared to their similar counterparts in passenger cars.
The 1.9 TD engine has 68 horsepower instead of 75.
VR6 has 140 horsepower instead of 174.
The 2.0 gasoline engine also has fewer [features/components/etc.].
The motors are designed differently because of their different purpose, which is to push a cabinet wall through the wind.
I don't think it's something that can be achieved with just a few parts.
Oh, whether it's 4-5 horsepower or not depends on the number of modifications... and what those modifications might cost, or where you can get them.
My T4 is a camper van with a kerb weight of approximately 2.2 tons, RHD, with an added high roof (2.65 meters) and a rear bike rack, so you can use every horsepower.
"Because of the high roof, the translation is actually too long, so it rarely reaches its maximum speed."