I have narrowed it down to either going with a KO4 or with GT 25 turbo upgrade and was just woundering if there is anyone on this forum that has run the GT 25 upgrade? It's seems that everything that I have read says that the K04 max out at about 400 whp and that you can get more HP out of the GT 25 in the long run and fast spool up is this correct? If anyone has any other sugestions I am up for anything right now.

 

definately a few more ponies out of the GT25s, not much lag at all. but about 3 times the price tag

 

http://videos.streetfire.net/video/6...udi_113175.htm

 

i personally have ko4 on my s4 and have dyno sheets that show me cuming in around 456whp 489tq i have heard this thing about ko4 maxing out at 400whp i highly disagree

 

Have you ever looked at a compressor map of a K04? They are rated at about 220chp a turbo. The dyno you were on was clearly a high reading dyno.

At the end of the day a GT car is going to make bigger numbers than a K04 or hybrid car. Plain and simple.

 

There is a lot of uncertainty in those numbers. Just because it says 220chp per turbo doesn't mean that is the max, that is the mean on a confidence interval from both experimental and theoretical sets of data. GT's will make bigger numbers, no doubt...

 

put it this way. If you want to go over 400WHP and spend more money, get the GT's. But, if you want to be around 400WHP and not spend more money get the k04's.

 

GT2554Rs are nice because theyre still a smaller turbo so they will spool pretty good. Besides more power they are also ball bearing, use external wastegates, and come with new manifolds, downpipes, and inlets. All advantages over K04's. Youll either use a FMIC or something like ER smics, and replace the connecting rods and bearings for relyability, a new clutch is a must and a JHM or stasis tranny rebuild should be in order. All tuning is custom based on who is near you. If your spending this kind of money your also going to put a big break kit on it so you can match that acceleration with stopping power. All in all your going to end up with a more extensively modified car that is probably more relyable. The parts themselves have many benefits over a K04 car.

You could pretty much do whatever you wanted to a K04 car for the price of a GT car and it would be no slouch, stasis close ratio rebuild, Rs4 cams, water/meth, good parts all around. Just a couple years ago k04's were the best thing since sliced bread... theyre expensive and not the best technology but because of the rs4 they fit right on. They will still make it a whole new car just not as over the top as GT's

 

i would still say my idea or you can put it this way also. If you want a track car and have money get the gt25's but if you want more of a daily driver (with massive power) get the k04's as they are much more common.

 

GT > K04 in every aspect. The turbos themselves are even cheaper, you just spend more in the long run because theres more parts to replace.