haha i think you just need to swap the turbo to a k04 and learn from there and u can move on when your done with it

 

why would you need twin K04s on a 1.8 liter engine? you can get 450 crank hp on a single turbo with off the shelf parts and tune. theres nothing special about it and its been done many times before. do you know what a compressor map is? go read some and figure out which would work for what you are trying to accomplish.

would i like to see someone go out and design a badass dual turbo setup? sure. but there is no reason to run two turbos in series unless the larger one is something like a GT42 or larger being fed by a smaller turbo like a 28rs or 2871. and that is way more power then you are looking for. and at that point, you might as just get a single twin scroll turbo or spool it with nitrous if thats what you are looking for. dual k03/4's is a waste of time unless you have a S4.

well hes talking about a widebody conversion, so im guessing that changing the clutch wouldnt be a big deal. that is- if the project ever progresses past this thread.

 

What mod should I do first?

Okay, so you just got your A4 and you want to start modding it. Which mods should you buy first? The absolute first thing you should do is a chip. By far it offers the most bang for the buck. Expect to pay around $500 for a good one + labor and tax. With this $500 you will be getting roughly 40-50 hp and 60-80 ft/lbs of tq. When you get a chip you will also have to upgrade the DV (diverter valve). The stock ones in the car are plastic and crappy and will not be able to handle the added boost the chip provides. You don't NEED to change it at the same time but there's no telling when the stock one will blow and its best to just do it at the same time. Next mods, you can get are intake (although the stock airbox is very efficient, and anything aftermarket is mainly for the cool sound), test pipe/hfc, exhaust, turbo inlet pipe, water/meth injection, and nitrous. You can do other mods that don’t add power like snub mount, short shifter, and suspension. What you do after that is entirely up to how far you want to take the car and how deep your pockets are. If you want to know what brands are available, keep reading.


Which Turbo should I get? Another guide I made that goes more in depth into this- https://www.audiforums.com/m_816714/tm.htm

K04- easiest and most reliable replacement turbo. It is a direct bolt on replacement. You don't need to replace anything but it is strongly recommended that you get new programming. The most popular is GIAC and with it you will also need a 5 bar FPR. GIAC also offers 3 aggressive files PC-16 for Pre '00, J31 for '00, and Hammer for '01. They are each different but all require an adjustable FPR, bigger injectors, fmic, and you will most likely need a new clutch soon after. If you have a B6 or B7 A4 the k04 is a pointless upgrade. You will only gain a 5-10 hp because of the k03s. It has a 1mm bigger wheel shaft, and more aggressively angled fins on the compressor wheel so it can hold more boost more efficiently. A big injector file for the k03 will put out almost the same numbers as a k04 setup. k04 will max out around 250hp

Elims- The cheapest and easiest BT setups. They eliminate the need for a new exhaust manifold and testpipe like full turbo setups require. The gt2x is only oil-cooled and has a not so good reputation, but it is the cheapest. The gtrs is a good choice. Lots more power than a k03/k04 yet has very little lag. Another choice is the 71r Elim. It has the same housing as the gtrs but a larger comressor wheel. Because of this it has slightly more lag but produces more power. With each of the elims you will need bigger injectors, software, fmic or water/meth, intake, MAF, FPR, and a clutch would be a good idea too. It's also recommended you get a braided oil return line cause the stock one is a pain to get it. GTRS will max out around 300hp. 2871r elim will max out around 350hp.

GT28RS- You will need to get a new exhaust manifold due to the different flange, the stock one would most likely crack and rob it horsepower anyways. You also need a new testpipe/cat or you could just get a new flange welded on. You will also need a 3" VR6 MAF, custom intake, 3" turbo inlet pipe, 2.75"-3" exhaust, FMIC, bigger injectors (660 or 440 usually depending on the software), walboro 225lph fuel pump, stage 3 or higher clutch, adjustable fpr, and oil and coolant lines. And new mounts (all of them engine, tranny, differential, snub),a bigger oil cooler, new suspension, and bigger brakes are good ideas as well but not required. Cost will vary depending on what you have done to your car already. For a stock A4 expect a shop to charge you 7 grand, if you can do it yourself it'll cost around 4 grand for everything. It will max out around 350hp.

T3S60- This turbo is very simular to the gt28rs but unlike the rs, it is a journal bearing turbo. It spools a little slower than the 28rs while making simular numbers. The cost of this turbo is also about 1/2 of the 28rs

GT2871R- Pretty much the same as the GT28RS only with a bigger 71mm compressor wheel. .63/.64 A/R is the faster spooling one. It should be fully spooled ~3600RPM. The .82/.86 A/R has a bit more lag, full boost right around 4KRPM, but it produces more top end power. With the .86 A/R you will need the same mods as the gt28rs, but with the .64 A/R you will need that plus new forged connecting rods if your planning on running it past 20psi. Most AEB guys go with Scat rods, and all others use Integrated Engineering rods w/ 19mm wrist pins (unless you swap in 20mm pistons). Some people dispute whether or not you need new rods with the .86 A/R but there are some guys using stock rods and haven't run into a problem...yet. And you'll also want a stage 4 clutch. 2871r will max out around 500hp

GT3071R- Bigger turbine than the 2871r. The .63 A/R spools ~4KRPM and produces more power than the 2871r .86 A/R. There is also a .82 A/R on the 3071r which hit full boost around 4500RPM. You'll want a stage 4 or 5 clutch and new rods for both these turbos. It will max out around 600hp.

GT3076R- Uses the gt30 turbine wheel and a 76mm compressor wheel and spools the same as a 3071 maybe 100rpms later. Also where the 3071r tops out at just over 400whp, this turbo is efficent enough to reach 500whp with a proper tune and upgrades. On pump and low boost (22-24psi), expect to see just ~400whp and mid 300tq depending on mods. Popular with guys who bore their engine out to 2.0L to put down sick numbers.

GT3082R/GT3040r- A combination of the gt30 turbine wheel and the same 82mm compressor wheel found on the gt35r and gt40r. It is a decent turbo that is capable of high 500whp and will spool between the 3076 and gt35r.

GT3582R- The big daddy turbo. Good for 700hp+ and 10 sec 1/4 miles. Spool is expected about 47-4800 on a .63. This turbo is known to surge on stock displacement so a anti surge housing is a good idea along with a AEB head and/or stroker engine.

T3/T4- Turbo's that use a t3 turbine and a t4 compressor. These come in so many sizes and variations its ridiculous. They can produce anywhere from 300 to 700+ hp depending on the turbo and your setup. The only one that really should be used is the 50trim. It is the most effient of the 50,57 and 60 trim turbos. Unlike the gt turbos, these use old technology with journal bearings. This gives the turbo slower spool but is more gradual. This also makes it easier on the rods to where higher hp numbers can be achieved on a stock engine. The only other drawback is that the turbo doesnt respool as fast as a dbb turbo. But on the brighter side, these turbos can be had for a mear $575-625 depending on where you shop. Also the lag can be decreased by using a .48 housing or a .63 housing for more top end. A 50trim will spool just past 4k and is capable of making 350whp easy.

There are others as well, but these are the popular choices.

 

there are not any "dual turbo" 1.8ts that i know of, there are plenty of big turbo 1.8ts.
the stickys are at the top of the page with the word sticky beside them. read threw them.
just out of curiousity, whats your budget lol. a full oem widebody is $$$$$ same with a 450hp turbo setup.

 

I figured that out . . . at least I can do the mechanical stuff, its da parts and body work I have to worry about . . . smh

 

your looking at 10k easily to do all that which means your gonna spend more than what the car is worth

 

I hear you ghost but I want an oddball car, just not as much power as ur talking about . . . I cant find a dual-turbo 1.8 on the internet, neither, and I've read the newbie guide countless times since I joined this site . . and I'm willing to spend that much on this car, if I wasn't, I'd be looking like a bonafide *** right now . . . Where can I find separate compressor map for available turbos?

 

well you can do the dual turbo its just gonna be alot of tunning but it can be done i would love to see it done it will deffently be differnt or you can do the 4.2l swap

 

Simple dual-turbo question for you - HTF are you going to fit two turbos in there? How would you even fit a divorced exhaust manifold in there, even without turbos? And finally, on an engine that size, putting two turbos in there is flat-out dumb. The displacement of the engine is enough to spool even a moderately sized turbo like a 71 elim respectably and make goid power, as ghost was alluding to. Try and put two turbos in there, even kO3 or T22 turbos (very little ones), and having 0.9L to spin each of them up, you're gonna gain almost nothing, and are more likely to lose significantly vs an elim. Two smoking hot turbos crammed in there (unlikely to fit but for argument's sake we can pretend) mean so much baking residual heat that you are likely to heatsoak virtually everything, for the prospect of wheezing two tiny turbos up to boosting RPM. A stock KO3 falls off up high, so two of them, each spooled by half the engine, will also fall off.

That's all in discussion of a twin setup. A sequential would suffer differently but would deal with all the same heat and space compromises, to an even greater degree.

The reason you've never seen more than one turbo on a 1.8L engine? It's a bad idea. Better results are able to be realized with off the shelf parts that can be bolted on, for way less money than trying to custom-fab, fit, and tune a dual setup to make the same, or less, power.

 

4.2L swap? A8 engine?