Hi all, Own a 99 Mk4 GTi Turbo running an AGU, and if someone would be kind enough, I would like to find out more about the engine and tuning side. The car is used as a daily and I fully intend to keep it that way, however I want more reliable power to use on track days etc. I don't want the car to "rely" on just a remap for obvious reasons, just shoving loads of extra boost and leaving it to blow doesn't appeal to me. I have been told the AGU unit is quite a strong unit in itself, and I dont want the cost of a rebulid, the engine is in good health with a full VW history. I have been looking at turbo options and was wondering if a k04 is a direct replacement part? I know this would work well with a remap, and currently have the car booked in for a clutch and flywheel upgrade. My questions are as follows really; Is the k04 a direct replacement? (any other suggestions here?) Will the k04 include the acuator, or will i need an aftermarket part? Can any other VW offer better braking options? I want to run the standard 16's with decent tyres (I believe the current set up is 288mm) I dont really want to reaplce the front bumper (thinking fmic here) are any other options available (charge cooler - if there would be room?) The car does have climate control. Will any modification be required for the oil system? Better Oil cooler etc? Sorry for all the questions, and i apologise if these have been asked before, i am just after some decent power, which can tick all the boxes for what i am asking the car to do. Thank you to anyone who reads this essay and can provide some help!
First question is how much power and torque you want. Second question is how much money do you want to spend. You can reliably remap that engine to 190bhp without any problems. The bottom end will stand up to 300 ft/lb of torque, so even if you throw a K04 at it, you'll not get beyond 270bhp and about 290 ft/lb. To fit a K04, you need to replace the exhaust manifold and downpipe. If you buy a complete turbo unit, it should come with the actuator. Forge Motorsport do a replacement, adjustable one. You can go to 310mm disks under 16" wheels, depending on the after-market calipers you're using. Your option is to go to Mk4 R32 brakes (the calipers bolt straight on to the carriers), but you'll need 18" wheels. If you're fitting a charge-cooler, you'll still need to fit a radiator for it, so, if you want to keep your costs down, just fit a FMIC - you'll just need to cut away behind the bumper, again, depending on which FMIC you go for. If it was me with that car, I'd get it remapped and fit a full Milltek with the hi-flow sports cat - that'll give you about 220bhp and 240 ft/lb. You won't have any reliability problems with that set-up. Companies like www.revotechnik.com www.amdtechnik.com or www.autops.co.uk can help you - AutoPS are closest to you in Brackley. HTH
There's not really too much of an issue with running your chipped K03 turbo, if it does fail they're bugger all to replace. If you're worried about the turbo reliability at hicher boost you'll be in the same boat with a K04 as both the K03 & 4 are designed to run approx 7psi boost. K04's cost more if they go as they're in demand. Like our Southern friend Mook said just get a remap, filter, exhaust, DV and FMIC and you'll be happy and still have a daily drivable and reliable car.
there is a ko4 turbo which is a direct replacement but its another type of the ko3s turbo, depends wot sort of power you are looking for? its called the ko4-001 turbo which is apparently slightly better dan the ko3s but if u want the proper one you will want the ko4-023 which is off the audi s3 and tt and also the cupra r but will need other bits to go with it!
Thanks all for the advice so far. To be honest I am not chasing "figures" as such. 200+ would be nice, but as long as its easy to drive and as fun as it is now, that all that matters to be to be honest. I will concentrate on the suspension set up to make the most of it, which I am fine with to be honest, no point having all the power if you cant use it.
well do like all the other guys say... 220-230 bhp will b a gud daily drive plus u get the fun part aswell
