General Stock 1G with 16G, Stock Tuning Options

[PredatorSniper]

Hello All,

Just acquired a 1990 TSi. I've owned 2 other DSMs before this one. As I am older, I'll be taking this car much more seriously, as they are getting more rare and are becoming, arguably, more important (to me at least). The car is basically stock, stock injectors, FP Manifold, stock MAF, aftermarket I/C pipes, stock I/C, MHI Big 16g, 2.5" downpipe into 3" exhaust, manual boost gauge (currently set at 18psi MBC according to previous owner), it does have an in tank re-wired 255 fuel pump, aftermarket fuel pressure regulator. I have big plans for this car (see profile if interested), but for the time being, what can I get away with safely, or what do I need to monitor on this setup to keep the afr's safe? 18 psi may be high from what I'm reading with the stock 450s and stock I/C on pump gas (91 octane). I've read about purchasing a 2g MAF but I'm probably not going to max out the stock 1g MAF. Future plans are a SD setup on DSMLink on e85. But for now, while I'm saving for the fun parts, I'd like to enjoy the car with this 16g.

Thank you all in advance,
Mike

 

[pauleyman]

450s on a 16g and 18psi is asking for trouble. It should be fuel cutting unless somebody has modified the maf or done something else.

 

[Dericsh]

Rix has a killer deal right now, $800 for ecmlink with a free tune.

 

[Spleen8urLSX]

I ran my first evo 3 16g at 15psi on a stock ecu, injectors, and maf. At wot by 5k rpm on that much boost my injectors were at 100% duty cycle, it’d keep pulling and peg the wideband at 10:0 rich, but knowing the injectors are wide open at that point is too much in my eyes. At wastegate pressure it was fine. I turned it back down to wastegate pressure until I put my 560s and safc in it (sounds like I’m talking 2001 but surprisingly this was in 2016 or 17 haha). With the 560s, safc, and hacked maf (by hacked I mean lower combs removed and calibration screw backed out flush, not cut up like we used to try back in the day) spiking 22psi and falling back to 19-20 was no issue at all.

Every car is different (keep in mind I was on 9:1 compression stock non turbo pistons and non turbo cams) but based on experience I would turn the boost controller all the way down or remove it until you have means to tune assuming the previous owner took precautions to prevent the 16g from boost creeping. I’d call that safe until the day comes.

 

[Xarzor]

This is anecdotal.. but I was running a b16g at 19psi on a stock 2g GST. I did have Ecmlink and several times my stock 450s hit 100% duty cycle. I had zero knock. But I'm at 5280ft of elevation, I have much thinner air and I can run more boost than most people.

 

[curt-s]

Definitely anecdotal. In fact, if your AFR was anything but 10:1 on pump with no reported knock at 100% duty, I'd be looking at goo coming out of your sensor.
Your turbo was actually working harder through a higher shaft speed to produce that 19psi than it would at sea level due to the thinner air.