In my experience, don't bother with the GTi6 inlet.
The management is extremely fussy on these engines and doesn't take well to the upgraded inlet - more notably the much bigger throttle body which is about twice as big. I have a photo of them side-by-side somewhere. Without an expensive aftermarket engine management system the ECU will run the car rich with the GTi inlet and you can have some dodgey running issues. It's a half-day job to fit one if you've not done it before, but the gains aren't worth it. It sounds good and looks good and vastly improves throttle response, but my experiences from two different 1.8 engines is that the MPG and driveability suffers. If you want to do it you need to retain the old injectors else it will run VERY rich, you may also want to look at what Dan86 tried with the adapter plate using the original throttle body, but in my opinion this is just mitigating a bigger problem instead of improving the engine, since one of the biggest advantages of the new intake is the increased response, which is lessened by putting a restrictive throttle body on.
GTi6 camshafts again, not worth it, these 'come on song' too late in the rev range and you can't take full advantage of them in a 1.8 engine as the rev-limiter is lower than that of a GTi. It will run nice and smoothly (contrary to some sources) if timed up correctly, but it's only worth doing if you can raise the rev-limiter... (which I think Dan86 did)
Exhaust manifold from a GTi6 does give positive gains however and I think it's worth doing. You'll need a full system though, cat/downpipe, mid section and backbox. It would pay to upgrade to an aftermarket system. Installing the manifold is a b*tch of a job, it's a case of either tilting the engine forward on it's lower mount (at the risk of damaging the radiator) or dropping the subframe down. Whereas a diesel will benefit from having as fewer silencers a 1.8 is really sensitive to having a straight-through system and you will lose a lot of low-down torque as a result. It may sound epic, spit flames and increase top-end power by a tiny amount, but it makes the car a pig to drive.
IMO, keep it relatively standard, induction cone (they sound really good on these) and if you haven't the space/time to do the GTi6 exhaust manifold just upgrade to a nice stainless system for a bit of noise.
EDIT; Regarding brakes, the GTi6 upgrade is well worth it, as they have a much better contact patch on the larger diameter discs (288mm vs 266).
You have a late-model XS so probably already have the 23.8mm Brake Master Cylinder, but it's worth checking as earlier 1.8s had a 22.2mm MC and this is not sufficient enough, whilst it has enough clamping force the pedal becomes really spongey, so if it has a 22 on it, that will need upgrading too.
You'll need calipers, discs and pads, I think the standard fluid hoses just about reach but it would be wise to replace these too.
The management is extremely fussy on these engines and doesn't take well to the upgraded inlet - more notably the much bigger throttle body which is about twice as big. I have a photo of them side-by-side somewhere. Without an expensive aftermarket engine management system the ECU will run the car rich with the GTi inlet and you can have some dodgey running issues. It's a half-day job to fit one if you've not done it before, but the gains aren't worth it. It sounds good and looks good and vastly improves throttle response, but my experiences from two different 1.8 engines is that the MPG and driveability suffers. If you want to do it you need to retain the old injectors else it will run VERY rich, you may also want to look at what Dan86 tried with the adapter plate using the original throttle body, but in my opinion this is just mitigating a bigger problem instead of improving the engine, since one of the biggest advantages of the new intake is the increased response, which is lessened by putting a restrictive throttle body on.
GTi6 camshafts again, not worth it, these 'come on song' too late in the rev range and you can't take full advantage of them in a 1.8 engine as the rev-limiter is lower than that of a GTi. It will run nice and smoothly (contrary to some sources) if timed up correctly, but it's only worth doing if you can raise the rev-limiter... (which I think Dan86 did)
Exhaust manifold from a GTi6 does give positive gains however and I think it's worth doing. You'll need a full system though, cat/downpipe, mid section and backbox. It would pay to upgrade to an aftermarket system. Installing the manifold is a b*tch of a job, it's a case of either tilting the engine forward on it's lower mount (at the risk of damaging the radiator) or dropping the subframe down. Whereas a diesel will benefit from having as fewer silencers a 1.8 is really sensitive to having a straight-through system and you will lose a lot of low-down torque as a result. It may sound epic, spit flames and increase top-end power by a tiny amount, but it makes the car a pig to drive.
IMO, keep it relatively standard, induction cone (they sound really good on these) and if you haven't the space/time to do the GTi6 exhaust manifold just upgrade to a nice stainless system for a bit of noise.
EDIT; Regarding brakes, the GTi6 upgrade is well worth it, as they have a much better contact patch on the larger diameter discs (288mm vs 266).
You have a late-model XS so probably already have the 23.8mm Brake Master Cylinder, but it's worth checking as earlier 1.8s had a 22.2mm MC and this is not sufficient enough, whilst it has enough clamping force the pedal becomes really spongey, so if it has a 22 on it, that will need upgrading too.
You'll need calipers, discs and pads, I think the standard fluid hoses just about reach but it would be wise to replace these too.
Disclaimer: The above is not to be taken to heart and is probably a joke, grow up you big girl.
![[Image: Sig500x130.png]](http://i430.photobucket.com/albums/qq25/chris_rx71/Sig500x130.png)