MK Turbo Kit Drop-In Upgrade
 

Hey guys, I want to find a drop-in upgrade for the MK Turbo Kit. The quality of the kit is VERY good, but the turbo itself leaves something to be desired. It's reliable and hasn't given me any issues, but it tends to spool very late and doesn't provide much air. I want to upgrade to a GT2871R, but the standard turbine housing is a T25, which would mean that I'd have to change both the turbo manifold and the downpipe.

ATP Turbo sells a GT2871R with their own custom turbine housing that features a 0.63 A/R, a T3 inlet and a T3 Ford outlet, which is the same profile as the MK Turbo kit. I believe I may be able to simply drop this turbo into place without any fitment issues. I would like to add that it's a 56 trim compressor wheel, whereas the MK kit is a 50 trim.

My concern, and the reason for creating this thread, is spool performance. I know the 2871R can provide the air for the power I want, but would the increase in the turbine housing size cause a significant drawback on boost threshold? There's another thread where a standard 2871R hit the full boost of 15 PSI by 3700 RPM. By contrast, I'm barely hitting 14 PSI at 5000 RPM on the MK turbo.

Would having the T3 housing cause my spool point to be more like 3900 or 4000? If so, that's acceptable. If you think it might move my boost threshold to 4500 RPM, I would consider that unacceptable and worthy of changing the manifold and downpipe.

I think you have a problem if you're spooling at 5k. Most MK kits I've seen spool way better. Maybe your flapper doesn't fully shut or something

Nope, adjusted all that. It's shut.

I do have a problem with the engine, it's got low compression, but still 5k is crazy

I looked at other dyno maps and it confirms the boost at 5k. The boost just gradually builds between 4k and 5k.

Like it STARTS spooling earlier, but it doesn't get to target boost pressure until 5k.

I saw a dyno graph of a GT2871R and it was FULL BOOST 15 PSI at 3700 RPM.

2871r isn't as cool as you seem to think it is. I dont know if you're living in 2008 or something, but by today's standards it neither makes good power nor does it spool fast. if you're gonna make a jump, you should jump to something proper like gtx or efr. and the mk setups I've tuned wake up well before 5k so again I think you have a problem, or maybe just got a defective turbo, who knows. Or maybe bad motor, or tune, or........
https://cimg2.ibsrv.net/gimg/www.mia...b9acadbada.jpg
https://cimg4.ibsrv.net/gimg/www.mia...b7a9bd84c0.jpg

Actually I do have a bad motor, here are compression numbers

70
110
130
160

NB2 VVT motor, 115,000 miles

Previous owner ran it with a failing stock fuel pump and killed it with lean running.

I have a new built motor coming soon!

I believe the GT2871R will get me what I want at a relatively low cost, but if I can upgrade to something significantly better and more modern for a small premium, I'm interested! Tell me more!

Maybe a GTX2867 Gen2?

Oh! ATP also sells a GTX2860R Gen2 drop in with a T3 Ford housing!

Maybe I should get that instead? Only a few hundred bucks more!

Maybe you should fix your motor first? That's the problem, not the turbo.

Putting a bigger turbo on will only make the boost come in even later, there might be more power, but it will be later in the RPM, not the result you're looking for. But if you just want to spend money, go ahead.

Already got a built motor being built by the builder, just waiting on the builder to finish building the build.

The 28 series isn't necessarily that much bigger, but it's more so that I can take advantage of newer technology and advancements in airflow, bearing, and spool. The turbo that's included with the MK kit is this tiny Chinese journal bearing turbo, I'd prefer to get a modern ball bearing turbo in there.

I figured the GT2871R would be pretty cool, but modern turbos seem to have made huge strides over stuff from 2008 now that I'm REALLY looking deep into it. GT2871R is like $1100, I could spend $200 more and get modern stuff? I'm in.

You're completely missing the whole point of MKturbo. I'm done here

What's the problem?

You shouldn't change anything until you change the engine.

With compression numbers like that a huge amount of exhaust energy that should be powering the turbine is being lost into the crankcase so your spool and power suck.

Additionally, a large portion of the air charge being generated by the compressor is being squeezed past your failed rings without generating any power.

TL;DR : Don't blame the turbo when you are running on 3 cylinders. Yeah, it's gonna really suck until you fix it.

Also shoot me an email. If you are going to decide to drop ballar money on a new Garrett, I would rather you drop that money on an EFR and we get you a slightly different manifold and down pipe.

Also Here is a link to a 2860 that drops in. I have one customer running it. For $200-$250 more you can get a 6258 and those will out perform any Garrett on the market.

I have a built motor getting dropped in soon. I'm not changing the turbo immediately, but rather changing it a bit further down the road after I do suspension and brakes. The most it seems I can get out of the MK turbo is ~250 HP, but since I have a built engine eventually I'd like to run 300 HP or more, and that's why I want to upgrade to a modern turbo.

Also check out this thread for more info on how to hit 350whp with just a $250 turbo.

Yeah, there are guys doing a lot more than 300 on that same turbo. Like I said you judge it incorrectly.

Well, I'll see what it does on a dyno once the new motor is dropped in. I'm trying to go for quick spool, great transient response, and lots of area under the curve. Maybe I can save myself the $1500 if the turbo performs the way I want it to!

I would get the new motor installed and broken in. Then get EBC working with the turbo I shipped. Then once you max it out look to upgrade.

EBC is working and correctly configured, just need the motor then!

Like has been said 100x already.
Get the good engine in, then judge and change stuff if you still feel it's needed.

upgrading stuff on a cooked engine is like breaking your leg and then expecting a new pair of shoes to make you run faster.
Might help a little, but you should probably work on the busted leg getting fixed first.

Well among other things, having a more efficient turbo would not only help spool and capable peak power, but would also put less heat into the air that it's producing

So if you have one turbo that produces 20 psi at 70% efficiency and another turbo that produces 20 psi at 80% efficiency (let's assume same volumetric airflow), the second turbo will not only flow a greater mass of air (denser), but will also be cooler, possibly allowing you to avoid knock OR push the ignition timing advance a little further.

Considering I'm planning on using this turbo to turn laps around tracks in Florida heat, it'd help!

BUT IF I CAN SAVE $1500 AND STILL GET WHAT I NEED THAT'S ALSO NICE, NOMSAYIN.

Also guys, either way I came here to ask a specific question, the additional information and advice is AWESOME and I appreciate it, but it deviates from the information I seek:

Would having a T3 Ford housing on a T2-framed small turbo significantly negatively affect spool and transient response in a noticeable way? Or would I be better off changing the manifold and using a T2 flange with a T2-framed turbo?

Right now your turbo ain't spooling shit, BECAUSE YOUR MOTOR IS FUCKED!

Judge the turbo and upgrade as necessary after you put the new motor in.

The current turbo might not be the best, sure, a GTX will probably be better. But you could put a magical fantasy turbo on there, insta spool, plus massive flow, with zero heat, but your engine will run it like crap, BECAUSE YOUR MOTOR IS FUCKED!

We're trying to get you to see a point here. Go back and read every reply, see if you can pick up on it.

WOW THANK YOU FOR NOT ANSWERING MY QUESTION

Please, tell me more about how my motor is in a worn state and is in need of replacement, which is already on the way, and repeat off-topic information already stated in previous posts that I've already read!

this is the dumbest thread ive seen in a minute. congratulations.

Agreed.

I came to this thread with the goal of asking a specific question regarding the relationship between boost threshold/transient response and flange size in relation to the frame of the turbo.

I didn't come here asking about my engine.
I didn't come asking about how capable the turbo is on the MK Turbo Kit.
I didn't come asking whether or not I have a problem with my tune or a defective turbo

I did not ask ANY question other than "how would the response be using a T3 Ford turbine housing from ATP on a GT28-framed turbo compared to the standard Garrett housing?"

ANY reply that isn't an answer to that question is off-topic and doesn't contribute anything towards achieving that goal.

Yes, I am aware of the problems with my engine. Yes, I am aware that once the new engine is in, the MK turbo may respond in the manner that I am expecting. Yes, I am fully aware of everything that has been stated in this thread. I have not gained any new knowledge in this thread. At all.

I see this may not be the right place to get an answer to this question, so I will seek this information elsewhere.

I am going to give you a clue.

This place works different than you think. The answer you seek is most likely that it won't make any difference. Nobody wants to state this because "most likely" doesn't mean shit. We aren't going to tell you what we aren't sure about, if we happen to feel like spoon feeding you at all.
The real answer is get your new motor in, get your swapped t3 housing Garrett, show us some logs and stop whining. Then you will know for sure, we will probably still be skeptical tho, especially after this thread. Maybe if a few other folks do the same we would answer with more confidence in the future.

That is how this place works.

It will be different, probably. I don't think anyone here has experience with running that combo, because it sounds really stupid. Try it and report back.

:bowrofl:

See! :rofl:

COOL, THANKS FOR STAYING ON-TOPIC

See guys, how hard was that?

All I want to do is see if I can do a drop-in turbo upgrade on the MK kit, changing only the turbo and nothing else. Easy.

Whelp, if nobody's tried it yet, I'll give it a shot and see where it goes. I like the idea of buying the MK turbo kit to get your foot into the forced induction door, and then being able to upgrade later on when you're ready, like a "Stage 2" kind of thing.

And hey, if nobody's tried it yet and nobody's sure about it, that's fine too! Just say it! There's entirely no need to add a dozen off-topic replies before getting to the actual information. Maybe there's someone else out there looking for the same info and they'll stumble upon this thread and have to wade through a bunch of non-answers before getting the info.

Every other kid in the world will "try it and report back". Like maybe one out of every thousand actually does. So pardon us for not even a little bit believing or caring.
You asked really dumb questions and skipped really important info, and then when we were nice enough to answer you didn't like it cause it wasn't what you wanted to hear.
If you don't want to be dismissed as a dreamer then go buy stuff and test stuff and report back. Bench racing and napkin math gets old.

If it helps, I'm strongly considering doing a Turbo II trans and diff upgrade. Possibly even next week since the motor is coming out and all that stuff is happening. Hopefully machine shop will have motor done next week, as promised :)