Perspective audi owner here. My neighbor has a 2001 s4 for sale and i was looking for a new car to make some serious power with. I have seen many turbo upgrades for this model such as a gt2871r upgrad vthat is said to make 800 hp. Is it even possible to have a b5 s4 with 800hp? That is my target goal but i do not know what supporting mods are needed and what upgraded internals are needed. Is there a step by step guide for making that much power with an s4 in this site? I would have a performance shop do all the tuning. Any help would be appreciated!

 

800whp is hard to get with most twin turbo setups on these cars. in the least youre gonna have to bore and stroke to 3.0 and go with 2.8 or 2.4 heads, with 2.8 cams, full valvetrain upgrade, dual fuel pumps w/surge tank, 1000+cc injectors, turbo kit(gt2871r or higher), wastegates, custom down pipes/exhaust or dumptubes, etc. even with the gt28, in whatever variation, or the tial 770 kit, its a struggle to hit 800.

There is also a single turbo kit from 034. this allows for a very wide range of ridiculous turbos. think diesel truck turbo upgrade big. there are already a couple people hitting high horsepower numbers. 800 is very acheivable on this setup.

the third common option is the legendary turbo VR6 swap. requires a ton of fab work. tons of horse power. i think they use either the 2.8 or 3.2 vr6 engines to build.

this should help you out way more than i can:

B5 S4/RS4 Projects & Builds

 

 

sick vid, but thats a 1.8t.

 

Not to argue, but it's not a 1.8t. It has 6 cylinders. Stop the video at 5:05 exactly and you'll see all 6 spark plug wires

 

These guys got pretty damn close, and it's probably one of the sexiest B5S4s ever...

 

good call. didnt see that. i guess its a turbo'd vr6 swap.

the mrc s4 is runing k24 porsche turbos(i think). no one on this side of the pond tunes for them. i'm pretty sure theyre above the 800hp point. this car was actually stolen and trashed. they ended up parting it out. sad.

800whp is definitely doable with a vr6 swap or single turbo build on e85 w/meth/nitrous. i feel the 770s and most of the lower level gt28's wont get you there without pushing them right to the edge of their performance.

 

If i bought the car I would prefer to keep a twin turbo setup. I will look into the vr6 swap but i would rather use the original motor. Would a bigger turbo like a gt35 work to get my goal? Upgrading almost everything about the engine is not a problem for me but if it really is that difficult i could settle with 700whp. I did see one build where someone made over 1000 horsepower with an built original motor and two large garret turbos. Not sure which ones but at least gt35 or bigger. I realize that i can get any amount of horsepower with enough money and time but i want to be able to drive this car on the street and frequently.

 

x2 gt35 would more than likely do it, but you wont be able to fit them in the stock locations. in that case the single turbo kit would be a better idea. the plumbing would be way more simple.

loba motorsports, in Germany, has a 750hp kit. i think its a modified tial 770 kit. not many places carry there products yet, but there are a couple cars running there products. RSworx, in new jersey, is building a loba based car. high quality parts for sure.

loba shop car:
LOBA Motorsport - LO750 Audi S4 B5 "HULK" - Projects

i really dont see 700-800whp being daily drivable.

 

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