06-11-2009, 04:39 PM
Join Date: Jun 2006
Location: Teh Back 40
Total Cats: 0
TEC GT tuning issue.. help?
Hey guys, running into a strange issue tuning this Tec GT and was hoping for some insight...
The problem is that VE is zeroed out for 30-40 kpa but 50 has to be -15 or so to get the mix right, and creates a funky transition.
Car: Mazda Miata, aftermarket turbo system
Est HP: 325hp (at the crank)
TOG: 7.5 (wizard-calculated TOG was 6.205)
460cc Injector Size @ 60psi base = 51.4lb, low impedance, 4 amp
Engine running staged/phased
Turbo currently running on the wastegate, no boost controller, ~7psi
I established the TOG by doing power pulls and verifying correct mixture at power peak (~6200 RPM). Ended up with mixture around 12.3 at that rpm/boost.
IOT was then established by idle fuel mixture, which is in the 14.5-14.8 range.
Originally, I had TOG set at 5.875 and IOT at .125. The idle mix was great but just off idle I was having to pull a lot of fuel out (-10 to -15) and then at higher RPM I was having to add a similar amount.
I realized the TOG/IOT needed to be set more properly, and now I have really good mixtures under WOT and high RPM, but low RPM/boost is crazy rich (9-10-11) until after the torque peak.
Strangely, at idle everything is great... 30-40kpa is just about perfect at all rpm with no load, but as soon as I get to 50+kpa it goes crazy rich and looking like I need to pull out a lot more fuel again.
Last edited by Rrrracer; 06-11-2009 at 06:20 PM.