redrotorR1

I'm thinking about going with some upgraded twins. I'm gonna stay sequential for quick-spool purposes (auto-x); but I'm curious how much boost I should limit them to with a basically stock setup (DP only). Lots of people run 12psi on the stock ECU with the stock twins ... how safe is it to run with 12psi with upgraded twins? Increased airflow ... is more air bad with the stock wastegate and intercooler?

rynberg

You would have to work your turbos quite hard to generate 12 psi of boost with stock intake and cat-back, especially on the secondary. And I disagree that LOTS of people are running 12 psi with the stock ecu because fuel-cut kicks in at 10.7 psi in the upper rpms.

Unless you have some kind of boost control problem, you are perfectly safe running the car with a downpipe+stock ecu with no forms of boost control. Of course, depending on the nature of "upgraded twins", they might not even be running effectively at that psi level. For example, the M2 twins are apparently supposed to be run at a minimum of 14-15 psi. This is obviously not possible with stock fuel and ecu systems.

redrotorR1

I had a long conversation with Cliff at Turbo Power ... his turbos are the creation now being marketed by Checkpoint. He seemed to indicate that the limiter on the boost pressure would be the restrictor pills. I'm not aiming for a huge compressor wheel upgrade; something modest that would still maintain the turbos' efficiency in the mid-range rpm level. I could care less about peak power; however, I have concerns about overwhelming the ECU. Where will I run into trouble and how much tuning will be required with upgraded twins?

I was hoping for a straight bolt-on swap, but it does not sound so simple the more that I think about it.

artguy

I run the m2s...tuning is a big issue...has taken me quite some time....they are not just bolt on replacements....you need to do your mods in the correct order and would need a similar mod list to mine or qwikrx7's if you want to run them properly.

rynb's post about the efficiency range is correct...they need higher boost to run in their proper range...Im running 14lbs now and they are just starting to wake up.

will be running 16lbs by the end of the week and 20 by the end of the month if all goes as planned...will let ya know how it works out.


there are plenty of other smarter things you can do first...ecu...IC...etc...

again...do your mods in the right order...get everything done and then ease up toward more power...tis the only way to do it right.

jason

the_glass_man

iTrader: (2)

Well as long as you have the fuel, run them as hard as you want.
They won't last long though.
You won't be able to get past 16 psi with the stock map sensor anyway.

artguy

cheers to glassman...well said.

j

DavidDeco

I have gotten my car back and have run (still rich) into 17's. I doubt they would last long there but I'm willing to be the board's guinea big I typically do not exceed 15-16 now.

The stock sensor is no good after 16. At the very least if you are planning running high boost get a 3 Bar map sensor and a PowerFC or other ECU top more accurately control your fuel in those uppser ranges.

I have chatted with people who purport to run 18 psi on stock turbos for years. I can't vouch for that personally but that's what they say and I've been pushing mine. The difference is that I can afford to experiment as when they go, it's just an excuse for me to go single....

Almost done with my summer project of rebulding my '93. When I have the time slips and dyno sheets, as well as photos, will post...Just some more tweaking....


David