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.