There are usually flam wars between the platforms. But with your Classy way of inquiring/disagreeing Ill state my case.

Stock for stock B6 S4 is faster proven both on the track and in manufactures specs. The B6 has a 100 more Hp stock. So with the B5 you are 100hp down.

Stage 2 (cause the stage 1 seems to vary from person to person) Stage 2 a chip and Exhaust. the cost is about the same here. But stage 2 Vs stage 2 B6 S4 is faster and on a dyno will make more power..(please keep in mind there are always exceptions to the rule)

Now here is where it gets foggy. Stage 3 is ALWAYS been and is the same.
A stage 3 B5 is ko4's tuning.
Stage 3+ is ko4's tuning possibly a LWFW and cams
Stage 4 is the RS6 turbos with tuning. Now I just looked on ATP's site and didn't see the eliminators for the S4. BUT ANY thing turbo wise on a stock Manifold is a stage 4 and no more
Then stage 5 is the GT turbo kits like the VAst performance or the JDM turbo kit as they use a custom header built for direct bolt on TRUE GT turbos. Custom builds would fall in this category as well.. OK I got a little side tracked here so lets get back on corce.

Stage 3 b5 ko4's tuning. The cost for this is HUGE to make this or any of the other turbo up grades.
2400 (average price) for the turbos
2000 (once again average you might be able to find a used kit for less and some are more) for fueling
Then you have inlet pipping and bolt on hardware for the turbos 500$
If you are really looking to make the power you also need the I/C;s upgraded. The cheapest I/C I found was actually the JHM front mount. 500$

so you are at 5400$

So the stage 3 B6 S4

The NOS kit kit is 2500$ and that is the same Hp as the ko4's even if you get the long tube headers you are at 5000$ total so you are up or save 500$ even if you didn't get the I/C for the B5 you would be the same.

so if you look at things that way you can see where I'm coming from. But if you use your argument of total price of the car and mods then of course the B5 is older and cheaper

 

Glad I could help. Mine has been flooded several times

 

now one member said the NOS kit is $600 and another says $2500??

justincredible -> can you give me some more info for the nitrous setups?? meaning, looks like i need to buy a nitrous kit (which one which brand) and the nitrous plate thing. anything else?

 

You know a lot more about my car than I know about yours. I didn't even know there was a "Stage 3" B6/7. What I meant by "bang for buck" is that if you compare pricing on individual mods, the B6/B7 prices are higher. DPs are more expensive, a CB is more expensive, and for obvious reason: there are just fewer people tuning B6/7 platforms at the moment. Example: the average B5 Turboback is about $2000. Sure, you can get an SSAC for a couple hundred, but for a reputable brand like AWE or ASP, you're looking at $2k. B6/7 DPs/Catback is $2500. B6/7 boltons are just more expensive because demand is not as high.
Also, although a NOS kit may put down 400whp, is it the same as B5 STG 3 as far as daily driveability? I would equate a B6/7 SC kit with K04s for a B5 as far as having 400whp to the wheels at any given moment. For someone like me, NOS is just not practical (unless maybe I don't fully understand how the NOS kit works.)

Also here's a link to the ATP GT thread:

http://www.audizine.com/forum/showthread.php?t=277755

If the guinea pig trials work themselves out, I may be in for a GT2554 kit on stock internals.

 

You do catch many good points SOME of the parts are more expensive. But companies like Vast and JHM are building parts and not bumping the price tag just because its a B6/7 S4 so there are SOME parts that are competitive and there is a point where the B6/7 is not equipt to go past say 500whp just yet. So with the stage 3 conversation.

NOS is perfect for every day driving and dose nothing to change the driveability AT ALL. Its is always on tap you just have to activate the system and much like your tank of gas you have to fill the system every now and then.

The best part about the NOS you don't have to use it all the time its there when you want it. MOST people don't drive past 50% throttle 90% of the time. So S/C or turbo or NOS all serve the same kind of roll.

For me after looking at it there is going to be a price difference on some things. But over all the parts and cost kinda KINDA come out the same. After you install the ATP turbos (they look great thanks for the link I never saw the link) I will have the same amount of money in headers and NOS and we will have about the same power.

As for the ATP WOW that is a good deal. Although its on stock manifolds they should still do well

 

That's what a lot of the debate is about. Most people are saying the GT2554 are as big as you should go on stock manis.

 

All the people that are saying that are speaking off of pure speculation and no more then just that.

Fact of the matter is that the Gt2554 are no more then glorified KO4's and for that amount of money you would be wasting it. You would be much better off getting RS6's they are in the same league as the GT28R and have proven to make great power for less money. NOT only that but they are designed for audi (well obviously) and offer a great spool characteristic.

In the end you are going to run into some problems when try to run too much power threw the stock manifolds. Eventually the power is going to back up into the shortest runners Cylinder. But who knows what power that is achieved At

 

wow.. didnt know you could get a gt kit for that price.. and as far as gt2554 kit being as big as you want to go on stock internals, thats not true.. you could put ridiculas sized turbos on, its just how hard you push with those turbos.. just like you can push to the limit with the k04's and run almost as much as you would with the rs6's at a milder tune.. if you were to go all out with the rs6's im sure you would damage something at sometime if you ran it hard all day and all night. im sure with the gt28 kit you would be even more prone to damage if you ran them over 500 whp... but if you ran a mild tune, when you where able to build your engine and heads.. guess what.. you already have the turbos!!! you probably will see more turbo lag with a bigger turbo.. but wow.. i have enough saved up for rs6's now.. but im wondering how well these gt kits bolt right up to stock manifolds and dps?? and im sure with a mbc set low and a dyno, you could fine tune that beast to get right at 475 to 500 whp so you wouldnt blow your engine...

 

I wouldn't put the GT2554 in the same power category as K04s, they seem to fit in between K04s and RS6s at between 450-500whp on pump (ASPs GT2554 car made 486whp on 93.) The GT2554 are barely smaller than RS6s. They seem to me to be the ideal turbo for those that don't want the expense and hassle of a built motor. Not only that, I don't think RS6s even make peak power until after 7k rpm and theoretically the small GTs should spool a bit sooner than RS6s.

 

No.. rs6's much sooner than that.. peak boost is about 300 to 500 rpms higher then k04's.. the gt kit takes a little while longer to spool.. i talked to jason at jhmotorsports specifically about this info and thats the answer i got.. again.. its his r and d...not mine.. but i think his reputation is pretty good as far as that is concerned... still... a gt kit for 1000 more than what im going to spend on rs6's is pretty cool.. im sure he could work out a fueling/tuning kit as well...