Savington

iTrader: (31)

This guy's timing is impeccable.

https://www.miataturbo.net/showthrea...339#post669339

GrahamC

iTrader: (4)

With respect Sav ... are you serious? From what I can see you're comparing a built 1.6 with a built 1.9 w/VVT??

So a 19% increase in displacement = how much more torque?? No ****.

Unless I'm missing something, to quote you with reference to the F1 6 puck clutch; WTF? Seriously ...

Savington

iTrader: (31)

I went through the two lists and identified the actual differences.

Railz has: crank work, ported 1.6 head, Chinabay 2870, stock intake manifold, MS2
I have: VVT, 1.8, no crank work, no head work, Garrett GT2871R, Honda IM, AEM EMS

So your argument is that the increase in displacement (which is a little less than 17%, by the way, and that assumes that his motor is stock bore which it likely isn't), the stock VVT head (vs his Rebello-worked 1.6 head), and the ECU change is worth 100ft.lbs at 4000rpm?

There are two explanations available for this:
a) Either the turbo has inferior flow/efficiency characteristics at low RPM which produces poor low-end torque, or..
b) 1.6 motors are DRASTICALLY inferior to 1.8 motors

Which one do you think it is? (hint: the motors are different, but not that different.)

GrahamC

iTrader: (4)

I'm saying two set ups are too different to point the blame entirely at the feet of the churbo. There are so many contributing factors to be conclusive.

I think it's pretty well known that the quality control of these units is more than a little questionable as well. Some people are seeing good numbers, the others aren't.

In order for this comparison to be worth a damn is for the same car running the genuine vs directly comparable chinacharger at the same boost, on the same day on the same dyno.

18psi

iTrader: (76)

Apparently its far less stupid to compare a ported 1.6L to a vvt 1.9L with a bunch of different **** with the only thing in common being that they both run e85 and both came out of a miata.

LOL

I'd do the test myself if someone with a flanged 2871 let me borrow it for a couple days

Savington

iTrader: (31)

Too different? What are all of these factors, guys? The intake manifold makes no difference at that RPM, I have a dyno chart to prove that. The fuel is the same, the exhaust manifold is the same. If your argument is that the setups are different, you need to back that up, because I don't think they are all that different. It's displacement and the head - the differences are quantifiable, there are comparisons out there detailing the gains that should be seen from VVT heads and 1.6>1.8 swaps, and the difference we're talking about is larger than that.

Link me to the good numbers, because I sure as hell haven't seen them.

We're not talking about chump change, here - we're talking about 100ft.lbs of torque at 4000rpm.

JayL

iTrader: (12)

As much as I would like to believe that the chinachargers are complete garbage, I still think it deserves a proper test. Someone like myself (when I had a turbo car) or Savington have spent a lot of time on the small details that most people overlook when doing their build. These small details are what win races and decide who's going to be on the podium or who's going to be watching me stand on the podium. I just can't see someone taking that same attention to detail if they are going to cheap out on one of the most important components of the build. Sure I believe there's going to be a difference between the turbos, but I don't think it's going to be as big as people would think. Obviously we aren't going to see a true comparison from the cheap seats, so until we see someone with a setup like Savington install a chinacharger we won't have any proper data to do a comparison.

When people start building cars for second place, I'll become a believer.

fmowry

iTrader: (8)

c) Tune.


And a combination of a, b, and c.

Hell, seeing the other cars with stock turbos (Suby, DSM) that I've owned/seen pick up a ton of HP and TQ (especially in the midrange where railz car is falling short) with a better tune on a bone stock car, I can certainly see where maybe railz tune is inferior to yours.

That said, I do believe that a) is a contributor.

If you jump in the wayback machine and look at the old threads in the turbo section of M.net with Link powered FMIIs vs Shiv and his similar hardware Tec II equipped car and then Markp running his Haltech, you could see the obvious differences in power in cars with virtually the exact same hardware on bone stock motors, yet with superior engine management and tuning. Not saying the MSII railz runs is inferior to the AEM, but well, it is.

I've also watched a lot of professional tuners go for that high peak number and neglect the midrange. I don't know railz tuner and he could have a spot on tune, but it's really hard to tell. His thread says nothing about timing, boost at X rpm, AFR, etc. I didn't search further than his dynosheet thread.

Frank

GrahamC

iTrader: (4)

Yup, head, displacement, general health of the engine, timing, fueling, heatsoak, spark plugs, gearbox issues .... hell, anything could affect the power the car puts down.

I can believe that a genuine Garrett is more efficient than the equivalent Chinese copy, but the tests need to be more scientific to ascertain exactly how much more efficient. The 1.6 vs 1.9 in completely different car, different tune, spark map, and fueling comparison doesn't do it for me.

Braineack

iTrader: (62)

1.8L absurbflow manifold vs. 1.6L begi manifold (granted i was at like 12psi and he was wastegate)



Same curvez.




Regardless of everything, railz turbo still spools like dickhole.

GrahamC

iTrader: (4)

Braineack

iTrader: (62)

Here's how Phil's built 1.6L with his 2870 chinacharger looked compared to everything...looks more in line with how it should, just died out up top...i blame the stock IM for that.

TurboTim

iTrader: (9)

Uhh actually I put a little special secret sumin-sumin magic on my manifolds when I'm making them. I do hope you use gloves when installing or working on it, or at least wash your hands thoroughly with hot water and antibacterial soap, 20sec minimum per CDC. Close attention should be paid to the nail areas, as well as the area between the fingers. A squirt of Purell afterwards can't hurt too.

That **** don't burn off either so do not think you're safe just because you've put XXX time on that setup. Being the first vband setup I did, I may have gone a little overboard with yours.

Savington

iTrader: (31)

That's the kind of curve I would expect to see given the displacement/head difference, BTW - same spoolup but just moved forward several hundred RPM. Clearly, the ~900rpm spool difference is the benefits of having the 1.8 and VVT on my car, and the turbos perform the same.

Wait, that's not right - I forgot to mention that Phil runs 9psi more boost to produce the same torque numbers that I do.

I'm done, guys. Maybe I'll do the comparo just to silence the doubters, but I doubt it would have an effect - I'd just get some bullshit about how the air density was 2% different or how I didn't spend enough time on the china turbo tune or the moons of Jupiter were out of alignment or some other bullshit.

The data we have isn't perfect, but it's close enough to convince me. I welcome the day that someone matches my numbers with a cheap turbo, but I'm not holding my breath.

18psi

iTrader: (76)

You tested the racelands. Everyone was really glad you did.
Why not do this?
No one will make excuses, I think you're the one that's taking all this way too seriously. You do a back to back dyno pull changing absolutely nothing at all besides garrett/chinacharger and post results and you will be the 1st to do something like this and have that much more respect.

Then you can shut people like us up with one single post instead of arguing for a whole page and still not being able to completely convince any of us for certain.

You could probably care less about "convincing us", but I'm just sayin.

dustinb

People are getting way to excited about this. I would expect the garret to be better then a China but I didn't care. The fact that I can make over 200 HP, reliably, with a $250 turbo is awesome. I'm happy to make that trade off.

Savington

iTrader: (31)

e: nm, not worth my time or effort.

miatauser884

iTrader: (11)

Sav: Hopefully I'll be able to do this in the near future when I get my clutch situation sorted. I talked to the local dyno shop and he has a used 2871 that he said he'd let me have for $400. I'm going to try to get him to throw in some free dyno pulls with it.

Must this comparo be with a garrett 2871 or can it be with a comparable sized "name brand" turbo like precision or whatever?

Savington

iTrader: (31)

Baller. I think we all want to see it done with a 2871, since that's the nomenclature that the China turbo mfgs. are ripping off.

Honestly it wouldn't even take dyno pulls to compare - swap the turbo on the street and leave the fuel map alone. If you're tuned for the China turbo and the Garrett runs lean, then you know which one flows better.

miatauser884

iTrader: (11)

2871 it is then.