Good evening everyone,

I have just finished the install of my Kraken manifold, with a chinacharger GT2871, attached to a kraken 3" Downpipe and a 2.5" straight pipe exhaust.

I am having a problem with too much boost. my wastegate starts to open at about 7psi or so according to my mityvac pressure tester, and is fully open by 14psi, but i am getting a steady boost curve up to the high teens (219KPA!!!!), no plateau in the datalog or anything, its just like the wasegate isnt doing anything. Which of course im afraid of destroying my engine from.

has anyone ran into this before, or do you have any suggestions on what to change?

Tune and Datalog included in attached files

Details on the engine are as follows:
1993 LNC 1.6
550k miles give or take 10k, decent compression all cylinders, totally stock inside.
cold plugs gapped at .022. factory coils
flowforce 640 injectors in Batch Fire

currently running Speeduino Engine management, but have a MS2Enhanced also, just have the tune good on the Speedy, and havent started with the MS

 

Check to make sure your wastegate arm isn't binding, you can pressurize the can to check the stroke.

You will need to port the wastegate if you haven't already, pretty much every internally gated China charger has horrendously low wastegate flow in stock form.

Also, I'm assuming the half a million miles on the engine is a typo?

 

Arm is not binding, i have checked.

Half a million miles is correct, entire car has just shy of 800k miles, original SNC 1.6 let go at 340k~ and was replaced with a junk yard 1.6 with 150k on it
Original 5 speed made it to 747k miles before grenading under boost from a cx racing kit years ago, original VLSD blew up at 769k miles, was non boosted at the time, just worn out.

Currently has a 80k mile NB 5 speed, and a 105k mile 1.6 Open diff.

and by porting, you mean drilling the wastegate hole larger by a bit? noticed it was small compared to the cracked sr20 turbo housing i had laying around.

 

A carbide burr on a die grinder is the ideal tool IMO. There should be some threads with pictures if you search around.

Speeduino has a boost limit function. You're going to want to set that up and then pray you haven't bent any rods.

 

Everything has beed said, BUT you really should tune/adjust your VE table, it only goes up to 170kpa and you were hitting 220kpa with a big compressor wheel...

Otherwise having that big of a turbo on a stock engine with a wastegate over 0.8 bar is asking for trouble, you should get a 0.5bar wastegate, if you want to have fun with this thing and
port the wastegate channel like mad. THEN you can adjust with a boost solenoid, everything else is just wrong.

edit:
Your spark table is wonky, too!

 

Go search in YouTube for "mkturbo porting" and watch the video. You will need to do the same thing to your turbo.

The wastegate exhaust holes on chinese turbos are smaller then on real Garrett's.

 

All of what you said (overboosting), and all of what they've said (porting the turbo, smaller WG). The only thing I would add is to go with EBC to control your boost. Without that, you're at the mercy of (what probably is) a marginal WG. On my setup (Kraken top-mount, 2871 clone Chinacharger, 2.5" exhaust) I had to add a "helper spring" to encourage the WG to stay closed at high-ish boost pressures - it was being pushed open at about 170kpa even when the EBC wasn't opening the solenoid yet. One day, when I get rich and famous, I'll get a quality 2-port WG actuator.

 

Thanks for the replies everyone. It looks like I'm gonna pull the turbo back off, and get to porting!

The spark map I know is wonky, but, it works without knocking.

The ve map stops at 170kpa, because I never expected to build more boost then that lol. Luckily, the afr maintains 11.5 even when up there.

I don't want to run my engine above 8psi or so, because of the stock head bolts. The pull to 18psi in the log above was a flirt with engine death that I don't want to risk again.

 

Your VE is probably stable ish above 170 kpa if not dropping due to exhaust manifold back pressure so your ECU is still providing more fuel above 170 kpa through the fuel model. This relies on the 170 kpa sites being mapped. Best to be accurately mapped at any point hit although note your holding your AFR.

Set your boost cut to avoid going past your mapped points.

 

Stock head bolts are no problem, it's the rods!