The Surge menace I think I understand
Nah, that's too easy.
Mine didn't really start surging too bad until I changed my exhaust system. Before that it surged a little but not enough to worry about. At WOT it's fine. I know when it surges and can stay out of it, but it would be nice if there was an easy way to eliminate it. The Tornado seems too good to be true but I'm still going to try it.
Jim
Jimmy glad to hear your finally going to put the Tornado where you were encouraged to put it in the 1st place.
I know it sounds to good to be true. Was researching the different gas laws Boyles, Charles,Bernuilli, Ideal gas law,Ventrui and the one that seems to make some kind of sense was Poiseuille's gas/fluid flow equation of air flow thru a cylendrical pipe whether straight or curved takes into account velocity/speed, radius of tube, cross section , steady flow, radius and swirl components yadi yadi yah .
But in research come across the biggest culprit is gas flow speed thru engine that can cause surge was the type of cam one used. Ran across a site call turbodynamics that had a lot of info. Some meat and potatoes. Important factors are cylinider head porting and camshafts making . That bigger cams( big lift and overlap) isn't always better with a turbocharged car with NA cars yes. The cam design ( big cams with wild lift and overlap)can have serious side effect that induce "compressor surge" because of 'GAS SPEED" the other item that can cause surge or increas gas speed thru engine is slapping on a 3.5-4.5 " exhaust. Turbo systems were designed to run with some amount of backpressure. That some believe larger in general(big valves ,big cams,big turbo,big exhaust) is always the way to Power Nirvana. They said there were 2 camps of belief when it came to exhaust systems and they tend to go with smaller 2.5-3" mandrell bent exhaust versus 3.5-4.5 " drainpipes. Reason being That the turbo oil seal systems runs on a pressure differential and lack of backpressure causes turbos to leak not just at idle but also overun.They go into port matching blue printing, mapping, turbo matching, high boost big turbo versus a lower boost with a more efficent turbo matched to engine.
Noticed some said they got surge when they put on a larger exhaust system, this probably decreased backpressure and increased gas speed thru engine. The surge started when I went to a larger turbo(Te44 at least 300cfm more then the stocker I was using) but at same time I also changed to a straight thru muffler design(single exhaust with no CAT )as the other muffler I changed out had a multi chamber design thus it created more backpressure. It may not have been the turbo but the combination of decresing backpressure and increased turbo cfm thus causing flow thru engine to move much faster causing the turbo map to move towards the surge side of map. Putting in the Tornado probably slowed down the intake gas flow enough to compensate for the decresae in backpressure caused by new strau=ight thru muffler/exhaust so it swung the turbo compressor map back to the efficient side of the map curve thus eliminating commpressor surge.. What would be interesting is to take out Tornado and get an exact or similar multi chambered muffler put back on that still alllowed decent flow but increased backpressure just enough so that it brought the pressure differential within turbo back to normal. But sense it works now with no surge I may just leave it the heck alone the old saying if it works don't fix it..yeah yeah I think it makes perfect sense now ,complete understanding..LOL
Man I don't even know really what I said it sounded kind of intelligent though.
Well if you can't dazzle them with brilliance , baffle them with BS!
