Today was the first day for the NG900 Project car on the dyno. I added a APC valve and a basic stg4 tune for the 15t5cm last week. I have never been a fan of the MBC. Overshoot in 2nd and not enough in second, well till it cooled off.. Suddenly with some reasonable boost management by gear we have 1 bar in 1st, 1.4 in second and 1.5 in the rest the racelogic wasn’t so important to have. This car has the 6cm 9k hot side. I know 18t right Just wanted to get some runs on a basic tune so it is more fun on the road while I sort the chassis. Turned into a little more than that. Here is the HD Video from today.
After the first few runs it was apparent that we were near the injectors on 20psi. Fuel was maxed from 5k. I decided to play a little more with the car after seeing the air temps! They were not so good. Almost exactly what we saw on ed’s 2.5 Viggen. Since I had more time this go around I added a couple more sensors so we could see temperature and pressure on both sides of the intercooler. While adding the temp/ pressure tap in the throttle bend I eased the entry a bit. Anything to help that guy. Saw no change on the wheels with that little change but I feel better.
Shown on these graphs is 4 passes 2 with each setup. The software is not finished, temps and pressures are focus. Knowing it was getting the greens and 3bar in the morning I cautiously ignored fueling.
We ran into a few problems along the way. The arm IC hose was only 2″ and would not fit on the new IC. Easy, steve grabbed a t7 one out of the junkyard. Fail! Now the turbo was not clocked right. In messing with that we ended up .5psi higher on base boost and decently frustrated.
So the data. Legend: IntTmp: Compressor outlet F, OilTmp: Oil in the sump F, TC15: Temp on the throttle bend, ManP_2: Pressure psi in the compressor outlet, ManP: Manifold Pressure, Air1P: Vacuum before compressor InH20.
We were using 19-20psi peak, ~12 at limiter. Pressure drop across the system was around 1 pist at peak boost and 3psi at the limiter. The pressure drop stayed close to the same with the change, need more investigation on that. Maybe piping, throttle who knows.
The temps are most apparent. Starting at 85 and ending in the 140s. a 55f rise is a bit much. With the ETS charge temp stayed within about 10f rise max! The problem is this added air density upped our power, yep we ran into those injectors. Also on the temps page you can see how much oil temp comes up on a 10s run!
Hp seems to be limited by the injectors and tq mixed around 300 and hp in the 270 on the wheels, 335tq and 300hp on the crank. Not a bad start.
ONe interesting pressure finding was the vacuum after the airbox, just before the compressor bend hose. We saw -26″h20 with the airbox in place. (Has KN drop in, and 3″ sewer pipe inlet. With the hose removed = no filter we only saw a little reduction in overall vacuum @ 22″ max there. I intend to investigate that some. Could be venture effect on the hose or some other real restriction. Thats all for now.