Why has no one asked what T3/T4 he has? It's like saying "I have a Porsche". Could be a 914 with 150hp or 917 with over 1000hp.

So: tell us what T3/T4 you have (compressor type/size/ratio, turbine type/size/ratio, housing type/A/R).

Looking around the shop at my 'turbo man' (TurboConcepts), I have seen T25, T3, T4 that look like they are made to power a wrist watch, to turbos bigger than tires!

Consequently, suggesting a 630cc injector (and tune) for a so called "T3/T3" may be WAY too much (wristwatch turbo) or "ok" or "880cc is just right".

I looked into T3 (turbine)/T4 (compressor) for my 1998 AEB last summer, same goals as stated here ("not going crazy, no elim (cost of turbo), no change to internals, best bang for the buck"). Here is what I thought back then:

But it looks like for the 1.8 liter Audi, target crank HP of 350:
“50” turbo, 50 trim 2.122 inducer 3.00 exducer:

Turbine 54 mm, A/R .48 (claim 250 HP for 2 liter)
Turbine 57 mm, A/R .48 (claim 300 HP for 2 liter)
Turbine 54 mm, A/R .63 (claim 350 HP for 2 liter)
Turbine 57 mm, A/R .63 (claim 400 HP for 2 liter)

Basics:
- smaller turbine faster spool
- smaller A/R more exhaust flow speed

The above are then in order of spool up time from low to high.
- The 54 mm turbine with .48 A/R will spool up the quickest, low end power, running out of flow at high rpm
- The 57 mm turbine with .63 A/R will spool up the slowest, power comes on later, but will flow well at high rpm

A Turbonetics for example T3/TO4E is rated at 150 hp (wristwatch) to 600 hp (and yes, there are supposedly AEB doing that).

Not sure how the tuners out there look at it, but I'm sure the tunes are (or should) not just take the injector size into consideration, but also the amount of air fed into the engine (duh), which certainly is a function of the turbo (hence my suggestion to find out WHAT T3 and what T4 we are talking about here).

BTW, I am currently running a "K03/K04" (to stay with the theme), using compressor wheel slightly larger than K04 and K03 like turbine wheel (housing modified, different style, clipped).



With "TAP Stage 2 - +50HP - 12 psi" chip (still haven't found out what that is, and TAP does not exist anymore?), downpipe and FMIC, I get:



Next, I will try the larger K04 housing (still hoping that it is truly 'bolt on' without the hassle of running new lines), larger turbine (K04 modified), similar compressor with the expectation to extend the high psi (say: 16 psi) all the way to 6000 rpm (but will need more fuel (maybe I can squeeze a bit more out of the stock injectors by cranking the pressure up to 5 bar; but expect lean condition at WOT and high RPM) and thinking GIAC PC16 file).

At the end, I want an
- easy to install (ideally: K03 out, Custom K04 in, no other changes)
- long lasting (K04 is SOLID)
- cheap (ideal upgrade for those who need K03 rebuild anyway)
- driveable (good midrange power)
- satisfying (not for drag racers, but fun; is 250 hp possible on the 1.8T?)
- out of the box tune, least expansive (either with FPR or injectors or both); wish GIAC would offer the PC16 at a more reasonable price.

As soon as I find a PC16 ECU (I need 8D0 907 557 P; have some stock ECU) to try, this turbo goes into the AEB to see how it is doing.

This will then also be the base for the coming 2.7T upgrade (currently looking for an Allroad with manual trans).

 

Everyone knows that so thats most likely why non of us actually ask, if he didn't post it he most likely doesnt' even know what "Trim" his turbo is. Just to clear things up, the T3/T4 setups you are talking about is called a T3/T04. Just means it is a T3 hot size and a T04 cold side. Nearly all Journal bearing turbos are T3/T04 turbos. Most common is the T3/T04E which is the turbos you posted info about in the 50 trim, 54 trim, 57 trim and 60 trim.

A T3/T04E 50 trim has a max hp rating of 420hp on a FWD car and max flow of 42 lbs/min. That flow rate is more then a GT28rs and almost as much as a GT2871r. The larger 60 trim has a max flow rate of 53 lbs/min and good to 490 whp on a FWD car. That is equal to a GT3071 flow rate.


Is it possible to make 250hp with a K04 you ask. Yes, people have made that much power with the standard K04-15 but had to push 25+psi out of it to do that. I even made 250hp with a K03 pushing only 20psi but tuned for 104-105 octane.

If you want a real hybrid K03/K04, you should have bought the FrankenTurbo. They offer kits for the 1.8t and 2.7t. I offer their products.


For the 2.7t

 

I have taken an initial look at the Frankenturbo, but not yet requested details (what wheels are they using, compressor maps). But they seem to follow a similar approach to mine.

Regarding the T3T4 on hand: I'm sure if he bought it, he can get the details from the seller. Without this information, I would hesitate to give him injector size recommendations, having seen the problems in driveability with oversized injectors (if the turbo won't flow much, the large injectors have to operate in a not so nice load cycle/frequency; the example I drove was impossible to drive at low rpm due to that).

I am sure his turbo is likely in the mentioned range (440-630cc), but its just that: guessing.

 

Mike,

Do you also have the chart for the 1.8T hybrid?
Any details on the wheels they are using?
What housings/covers? (compressor, turbine; K03 base or K04)?

 

Well 415-630cc will work for him, but which one really depends on the tuner. It isn't like he can go with a tune and then just throw in any size injector he wants. Doesn't work that way and wont work that way at all on a ndbw A4. Even the start on time for each of the injectors will be different and so is the spray pattern.

So he needs to choose a tuner/tune first and then go with the set of injectors used for that tune.


I dont think they are going to give out the info on what wheel they are actually using.

Here is the info they do give.
Compressor size: 41/51-(54)mm with high-flow profile rotor blades
Turbine size: 50/42mm with high-flow profile rotor blades
280chp rating

 

If I hear this kid say he has a "Tap +50hp - 12psi chip" one more time.....
I know your an engineer, but you over think **** constantly. When people say t3/t4, they are almost always talking about a 50 trim, unless they specify differently.
Plus I said 50trim in the beginning of the thread and no one objected, so its assumed thats what we are talking about. On this forum, the 2 common turbine housing area ratios for the 1.8's are .48 and .63.

 

No question. Tune and injector go hand in hand. And the tuner will chose the right tune for the existing turbo on hand (hopefully; unless they do the cookie cutter approach slapping the same tune/injector on anything that is a hybrid T).

So the answer to his question should be (IMHO):
- get the info on the turbo you have
- contact the usual tuners (VAST, Unitronic, GIAC, APR, etc.) and ask what tunes they have that fit the turbo, and the power goal (don't shoot for 250hp, at the very least, 300hp)
- they will respond and provide the prerequisites (injector type/size, required mods (fuel pressure, intake, IC, MAF, fuel pump, exhaust, spark plugs, etc.)

 

.63 would be the most common. The .48 is WAY too small and ends up being a huge waste of time.

TAP, hahaha. I thought their stuff was CRAP when I first saw them, most likely why they went belly up.

 

I agree with this, but he should also get as many opinions as possible first. For instance, if he calls Lavi Finkelstein at Unitronics, Lavi will tell him whatever he needs to make the sale, whether its the whole truth or not. And I'm not positive that APR or GIAC will accomadate custom tunes. I look to Eurodyne first, or a dyno tune really. I know some guys that do custom tunes with Eurodyne software.

 

Agreed TAP is crap from the past, did you see his boost plot lol? And .48's are a waste of time usually, but they wont break rods as easy and spool quicker, they have their place for some things.