GTI 6 Inlet Manifold in 1.8

[C.A.R.]

Basically just got the textbook response from Ruan above.

I've owned -
A 1.8 which I converted to GTi6 manifolds myself
A 1.8 Cab which was already converted, I turned it back to standard

In short, the pro's are-
Massively improved throttle response (this is due to the larger TB)
Noise (epic)
Looks more bling-er?

Con's -
Ruined MPG.
Flat spot at low RPM
Confused ECU, can cause EML to illuminate (more so on later cars especially)

The Cab 1.8 also had GTi6 cams. These made the car virtually no different to drive until you got near the rev-limiter. It would shove a little bit more power out but without the ability to raise the rev-limiter it was pointless.

If you have a 1.8 16v you have already got a great engine. Good, smooth powerband and incredibly reliable (bar a couple of sensors...) If I owned one today I'd add a stainless cat-back and a cone or panel filter and have done with it, as they are sweet-as-a-nut when standard. Once you can afford insurance, the cheapest thing to do is upgrade to a GTi6. Unless you can afford aftermarket management (£300+) and have access to someone or software that can map your car accurately.