Hi, Does this sound like a reasonable job with reasonable brands / parts? The thing is i don't know what should be replaced to make an engine stronger and work well together along with brands and what is actually decent enough to trust? The basic spec i have been given is: APX engine but changed to VVT Maxspeed forged conrods King race big end bearings Hastings piston rings Victor Reinz head bolts Bosch 550cc fuel injectors Audi R8 coilpack ECS hybrid sump conversion kit Any feedback on this would be gratefully received Michael
Hi, thanks for your reply. It’s on a standard KO4 and I’m told it’s currently running 250bhp which to be honest i would be happy with. Not aiming for massive power particularly without a diff.
Generally a standard engine is good for 300bhp. The k03 and k04 are ‘spikey’ though so prob good peace of mind to fit forged rods. You won’t need 550cc injectors with the k04. Is this a built engine with turbo that you are looking to buy?
It’s in a car and running etc already. I guess it won’t hurt to have the large injectors?? With the spec listed what would be achievable power with the KO4 and then with a larger turbo? I believe the current issue is the intercooler holding it back.
The bigger injectors will just give more overhead for future tuning, no harm. I'd say on the K04 you are probably looking at 250-260bhp. Is it mapped already? The intercooler and exhaust will definitely hold any additional tuning back due to heat soak and flow through the exhaust. The k03/k04 generate a good bit of heat as is, especially when tuned further than intended. With a larger turbo, pick a bhp number! There is no limit, but keep in mind it's not just about peak bhp numbers. You could stick a massive turbo on there and make 500bhp, but that would just be peak power with no power down low. It would make it a pig to drive on the street. The question should always be what's the intended use of the car, and how driveable it needs to be, and then pick a turbo to suit. A common upgrade on these is the Garret GT28 turbo. This should make anywhere from 350-400bhp with plenty of torque low end to boot. Revo do an off the shelf map for GT2871 and 550cc injectors. Just keep in mind the added costs as well, intercooler, exhaust, clutch, engine mounts etc.
