dustinb

It could just mean that there's a huge variance in the quality control of these turbos. It seems like some people make great power, and others not so much. But there's so many factors that go into it it's really hard to say.

As far as drivability it's great. No weird lurch or anything when the timing switches. Needless to say, I wasn't expecting to make this kind of power. I was thinking 240ish.

miatauser884

iTrader: (11)

I think it is great. I'm hoping there is a difference between manufactures. I might even copy your timing numbers for a pull to see if you are on to something.

Braineack

iTrader: (62)

14-17° on a stock motor at 14psi isn't THAT conservative. That's what I've always run.

dustinb

Video of my run



Bah, embed fail
http://www.youtube.com/watch?v=CLe_0v_wEUk

dustinb

So folks, what do you think the effect will be of replacing my 2.5" test pipe with an OE 1.8 catalytic converter? Think I'm going to lose a bunch of power?

18psi

iTrader: (76)

20ish id say.....maybe more

dustinb

Ugh. I'll probably just leave the test pipe in for now. Wait till drag racing season is over and then see what I'm going to do with the car next year.

thirdgen

iTrader: (26)

In for drag timeslip!

Sentry

I figured I'd hijack this thread sorta, but has anyone including OP experienced surging with these china 2871Rs?

I have a Civic with a built D16 and an EMUSA GT2870, and turbomiata's members seem to have more experience with chinachargers than anyone. Quick rundown of my junk without going into too much boring detail:

JE pistons 9:1
Eagle Rods
Denso 720cc injectors
walbro pump
Mild cam (COMP 59300)
Unported head (stock flows decent enough they don't usually need to be touched)
Cast ebay mani
emusa (ebay) GT2870 .64AR turbine housing
3" downpipe and exhaust

At 20 psi it's a beastly little tire shredder, but in the higher gears (4th and 5th) it surges when it starts to make higher pressures (past 18 or so psi). I'm guessing the compressor and turbine are a bit too mismatched? Is my only option to avoid surge to reduce my boost pressure, and if so, what kind of horsepower do I stand to make with this thing at 18ish psi? It made 267whp at 15 psi (quite comparable to OP's setup) with my old 2.5" exhaust, I'd like to see 300+ whp/115+ mph traps/high 11 second ETs.

Also note, the 2.5" was choking it enough that it didn't build big boost, so it wasn't surging. When I upgraded to full 3" it spooled like whoa compared to before.

miatauser884

iTrader: (11)

Mine doesn't surge at 21 psi, and I have the same EMUSA turbo. What WG are you running? It came with a 24psi WG actuator and i swapped in a 14psi.

Sentry

Mine came with a 14psi actuator. Is yours a .64AR hotside as well?

I just have the arm threaded in enough for a little preload on the flapper, I do my adjustment with a MBC.

What kind of power you putting down/what trap speeds?

miatauser884

iTrader: (11)

only made a hair over 280 at 19psi, but looking back at some of our issues, I think the clutch was letting go. I'm going to get a few pulls on the dyno here in town. I turned it up to 19psi after tuning the closed loop boost control. The car is a beast.

Preluding

iTrader: (10)

Great numbers! You have almost the same setup as me without a built motor (and your car runs)

Amazing!

dustinb

Haha thanks! I'm really happy with it.

As far as surging goes, I would suspect the wastegate. Maybe time to upgrade to one that is closer to your target boost.

dustinb

Just posting an update on Turbo & Godspeed. I don't own the car anymore but current owner is boosting like mad with the turbo. It is holding up great. But it appears that Godspeed no longer makes their "GT28" model turbo, and have replaced it with a 2871 that looks like every other china charger made. If you are looking for a godspeed turbo, I'd suggest trying to find one that looks like their older models:
OLD:

NEW:


Many ebay sellers still have the Godspeed GT28 turbo for sale. Just be aware of the old and new style as searching for GT28 TURBO on ebay will bring up results for both.

BTMiata

iTrader: (5)

So just an FYI for anyone thinking about trying to get one of these GodSpeed T28's... I ordered one a few days ago from one of the E-Bay sellers. A few hours later I got a full refund with this message attached...


Chi Lao (atoz_autosportz@yahoo.com) has issued a full refund for your payment.

Message from merchant: Hi,
We just found out this product has a little problem, so we have returned all the items to the factory to fix. We issue the fully refund to you first.


Who knows exactly what that means, but I found it to be pretty shady and I have no idea why it's still listed. luckily I did get the refund immediately and I didn't take any further action.

... I did however, decide to send messages to all of the other E-Bay vendors who had this turbo for sale.... IT IS THE SAME COMPANY!!! I got almost an identical message to the one from my PalPay refund. Just figured I might save some people in the future from going through all this. It wasn't that big of an inconvenience, other than having to come up with a completely different option for a turbo. I ended up going with an ISIS T25/T28... Hopefully I have as much success with it as a lot of 240sx guys have had....