The issue with how much power the Clio engine produces is the same issue engineering-wise as the issue of Clio handling.
An engineer can make a simple thing do one job well. It usually takes a more complex solution for it to be able to do all of lots of different things with conflicting requirements well.
So the simple rear suspension on a Clio can be made to handle well on a smooth road - you can even make a live axle work well in a race car that's only has to race on smooth tracks - but it needs something like the complex multi-link rear end of a Focus to be able to be engineered to work well on a range of road surfaces.
And its the same with the Clio engine. How well it does the job depends on the area under the power/torque curves. So they can tune it to higher and higher power outputs, but all that does is move the torque curve up the rev range. It doesn't increase the area under it. They could improve the area under the curve a bit with variable timing on the cams, but they don't, they only use it to cut emissions. By comparison Honda has built a more complex engineering solution with its I-VTEC engine. Two separate cam profiles and variable timing on both intake and exhaust cams means it can give near-optimum solutions for BOTH maximum torque AND maximum power for the engine size. Its smarter, it can walk AND chew gum at the same time, it can watch an exciting game on TV AND eat pretzels at the same time. That complexity increases the area under the power/torque curves compared to the simpler one-solution Clio engine. Renault could only match the Type R engine for area under the curve by building either a bigger motor - which it can't because that engine won't stretch any further - or by going to a more complex engine.
In Clio 3 form the engine had to be tuned to give 17 ps more just to capable of the same top speed despite the larger body. But because the engine was just a "hotter" version of the same simple engine that just moved the torque curve so there was less torque, and a lot less torque per tonne of bodyweight, at low speeds. So it feels gutless if you put your foot down to accelerate or overtake without first changing down.
Bizarrely, Nissan, Renault's Japanese subsidiary, had an engine comparable with the Tyre-R engine years ago. The SR20VE. Repeat, the VE. It had comparable horsepower with the Type-R (>200 bhp out of 2 litres) with great torque and torque curve. And it had great performance in the Clio 3 weight cars it was fitted to. But its too physically big to fit in a Clio.
