850 T5 chip problem

[Pedes]

Hi,

I have a nice 850 T5 2.3 manual from 1994 with 340.000 km on the clock. It is in good stage 0 shape and has no oil or water consumption.

I bought 2 cheap tuningchips (50£) on ebay just for the fun of it, and have measured one of them on the dyno.
Result chip "1": 245 hp at 5400 rpm and 360 Nm at 4000 rpm.
Boost is approx. 0.8 bar.
I was promised 1 bar and 275 hp and 400 Nm on both chips.....................

However I am experiencing a studder/judder/cut-off feeling at full throttlle at approx. 4000 rpm, as if the ECU is cutting the power.
It comes with both original and tuned chips!

If I turn back the wastegate preset pressure I can make it go away, but then it feels sluggish building up pressure and power is down.

A vacuum hose to the WG fell of and it was able to make +++15 PSI at 2500 rpm, so the turbo is capable of spinning.........

- Any ideas what is causing the 4000 rpm cut-off?
- Should I go through all the vacuum hoses again?
- How can I get a nice fat torque-burst at 3000 rpm?

Thanks for help - it is a fantastic website!!!

[burnout8488]

Are these "chips" just little boxes that you splice into the MAF wiring? Or are they actually tuned ECUs that you installed?

Any "cheap" tuning chip for only 50£ I would worry that it is a scam.

[Matty Moo]

Sounds scummy..... Like that g-force trash you see advertised constantly.

[jblackburn]

Buy a real tune please before you blow up your motor trying to build boost way too early. A boost spike at low RPM will create havoc in just a second.

That fuel cut above 4000 is the car trying to save you from destroying it without any real tuning whatsoever.