This is not a quality or performance comparison. We are only looking at the prices of each kit, what are the turbo options offered and what parts are included in the kit.
Laurent Motors offer a wide variety of big turbo kits for the 1.8T. They list “Stage 1, 2 and 3” kits, the difference between the kits, from what I can tell is the amount of parts included. For example the Stage 3 kit includes injectors whereas the Stage 1 and Stage 2 kits do not.
Each “Stage” of turbo kit is offered with a range of turbo sizes from unbranded journal type turbos which they say are good up to 400bhp to genuine Garrett turbos, the largest being a GT3076R turbo. All kits appear to use the same cast iron manifold and have the basics things needs to get the plumbing on the car eg oil feed lines, downpipe, intercooler (with universal piping)
Like Laurent Motors, Qualitec appear to be focusing on the best possible price. Their “Complete VAG 1.8T turbo kit” looks to have more or less everything needed to get up and running including downpipe, MAF sensor housing, fuel pump and injectors and the price is almost the same as the Laurent Motors Stage 3 kit. The turbo options include non branded 2860 type turbos as well as genuine Garrett GT2860RS turbos. Like Laurent, the Garrett turbo option increases the price of the kit by around 25%.
Something that Qualitec should be commended for is the the level of information they have on their website regarding tuning the 1.8T motor. They also sell the parts in the kits separately which is super useful if you are piecing together your own turbo kit. If I had to chose between Laurent Motors and Qualitec I’d lean towards Qualitec because of the information they share with the 1.8T community.
A K04-064 turbo kit, unfortunately Much Boost do not specify exactly what in included in the kit. For this reason it is impossible to form an opinion regarding the price.
Much more expensive than the offerings from Laurent and Qualitec while turbo options looks to be the same. It is not clear to me why the CTS price is more than Qualitec & Laurent.
Bartek offer 2 kits which use Garrett turbos (they do not offer non branded turbos). It is not clear from their website if the manifold they use is the same as that used by Qualitec. The price of the Bartek kit is around 25% more than the Laurent/Qualitec kits but looks to include less parts. Granted, the parts that are included in the Bartek kit look to be of the highest quality.
Like Bartek, Turbo Zentrum only offer genuine Garrett turbos in their kit specifically the GT2871R which is one of our choice turbos for the 1.8T (see the 1.8T big turbo selection guide). The price is in the ball park of the Qualitec and Laurent turbo kits but costs a bit more and does not include an intercooler.
Turbo Zentrum also offer a K04-064 turbo kit although it is focused on getting the turbo mounted to the engine and lubricated. It does not included injectors, exhaust piping, fuel pump etc.
eBay – 1.8T Big Turbo Kit
eBay turbos have a bad reputation which I am not sure is deserved. After sales support is probably limited and the quality of the components is not know, at least if the parts are unbranded.
Having said all that, if these factors are not a problem for you there are a number of kits on offer on eBay and at the time of writing all of the sellers are located in the USA.
You can also find 1.8T intercooler kits on ebay
Aliexpress – K04-064
Products listed on Aliexpress can have the same reputation as those on eBay. Having said that, if you trust the products on Aliexpress to give good value for the money there are K04-064 turbos to be found. But you will need to source all of the ancillary parts, like cylinder head mount adapter, oil lines, water lines, hoses, to mount it to your 1.8T separately. Here is a cheap K04-064 which I have no idea of the quality.
You can find a ton of information on the K04-064 turbo swap here.
1.8T Big Turbo Kit – General Information
If you have be doing any research into 1.8T tuning you have probably come across the website 18t-tuning but in case you haven’t you can find it here. This website is an absolute gold mine.
I mentioned it already but Qualitec also include a wealth of information on their website.