Need Crazy Ideas: Wastegate actuator broken: Turbo Confusion

[jessef]

Yes. More like an 1/8th of a turn. 1/4 is too large increment.

[Mephisto]

Sounds like you got it workin half decent, in my own personal opinion running more than the recommended boost is fine, but you'll want to keep an eye on your EGTs. The problem you are having is the flapper arm isn't opening enough because you welded it, the pop off valve is preventing rediculous boost levels, effectively capping what the engine sees at 16psi, but your turbo is spinning extremely fast since the wastegate flapper isnt fully open. If you disabled your pop off valve yould probably be making upwards of 25psi. It also seems as though you're coming onto boost a little late, although I could be wrong, I always came onto boost around 16-1700rpm with my 4D56. All in all I would still suggest to fix it properly, but I don't think you'll do any damage driving it the way you have it. On my 4D56 I was running ~27psi, but I had a larger turbo and a large front mount intercooler, I never had an issue with the engine even after over two years of flogging it. On my 4M40 I'm running about 18-19psi, but I have the stock turbo and stock intercooler (pajeros come with a small top mount) and water/meth injection. Being that you don't have any way of cooling your intake charge your inlet temps may be getting high but if you don't beat on it it should be fine. Turning down your fuel will reduce the max boost you make (but as I said you are probably well above the 16 cutoff from the pop off valve so you probably won't notice a reduction in max boost for quite a while), but it will also reduce power and how fast the turbo spools up. It's easy to figure out which way to turn the fuel enrichment knob, an increase in fueling will result in an rpm increase and vice versa.

[freestyler]

For those who are interested...

After getting the actuator arm fixed and the Boost gauge installed, I then tested everything and had to adjust the the turbo actuator to ~95% open using this http://www.delica.ca/forum/adjusting-tu ... -1441.html. I know this as I wanted to keep adjusting the boost level down but ran out of threads and then had to increase the adjustment to what I considered the safe minimum.

It was somewhat sketchy at the time but the boost gauge was reporting numbers that were 1-2 PSI higher than what Delica.ca seems to think is normal. Knowing this, I drove about 3000km. Vancouver to Canmore and back. Then to Vernon and back in the span of a week, both trips over the Coquihalla. I'm happy to report that there was no issues whatsoever.

Behavior:
- Turbo kicks in at about 1800 RPM with 2-3 PSI and ramps up to ~11 PSI under load, climbing the Coq with normal driving habits.
- If I hit the accelerator to the floor I can get it up to just shy 15 PSI but this is only under very, very hard situations at highway speeds. Such situations are easily avoidable and only happened when I was deliberately stress testing to see how high I could get the boost.
- For city driving, 12 PSI is as high as I can get when traveling under 60 km/hr and for the most part normal load is 9-10 PSI for both Highway and city acceleration.
- Cruising fluctuated between 5 and 9 PSI for both flat highway and city driving.
- City driving basically had no change on my mileage ~ 500km per 50L
- Highway driving to Kamloops (up the Coq) yielded 400km per 50L during testing/running hard while Kamloops to Canmore put me back at 500-525 km per 50L. This is considering the Rogers Pass as well.

I didn't see much in terms of heat increase, if anything it 'seemed' to run a bit cooler. That said I don't have a pyro and was going off of the stock coolant gauge and my impressions. Also, I have a full 2" side exhaust.

If you guys and gals have any questions let me know.

Cheers!