B Feelgood

Thanks everyone!

Made 636HP and 850TQ to the wheels on the best run, #2. However, it's running extremely lean on a canned tune with an AFR of 13.5-14. On the first run the HP instantly dropped from 550 to 300 and TQ from 850 to 500 probably due to knock from running lean? If this was happening on a regular basis, it would explain why it felt underpowered.

I've contacted the tuner and sent the graphs to see what they think. From what I know the AFR should be somewhere around 11.5 - 11.8 to be safe?

V12TTenthusiast

636 rwhp is a good number for what mods you have. This is prob a cooling issue because the numbers should dip that much. It should loose a few hp but not 30-40 per run

tscales

I just replaced my IC pump and it made a simply amazing difference. At the strip, I could do one run and then it got slower and slower.

Now I can do runs all night.

B Feelgood

I suppose that I have nothing to lose other than a few hundred dollars to replace the pump. I couldn't find any specs on the Denso pump that is currently installed but I'm pretty certain that the motor does use brushes which may be worn and it's also 8-9 years old. I'll swap out the Denso pump for the Pierburg CWA50 that I have here and then get the coolant system drained/filled/bled on Monday.

Blackbird76

Check your ignition coils, they may be starting to go bad, you will feel an instant power loss if this is the case. ECU/TCU tune also puts huge pressure on coil packs. I had both banks replaced about 2 months ago and car now feels like it's running at full power.

DUDMD

B Feelgood - I'd recommend you don't get on it anymore until you get more fuel to it. 14-15afr at peak boost/peak torque is asking for trouble. While I was tuning my car, as I raised the boost, my AFR still stayed exactly the same pretty much in 11.8-12.0. I did keep my IAT consistent by changing the water in my trunk tank every 3-4 pulls. Not sure why your car runs that lean, either the tuner took fuel out, the IAT, or you may have a fuel supply issue.


Racehorse - I don't know much about a dynojet, but on my Dyno Dynamics I'm able to get rpm signal from injector 1 fairly easy, obd2 port or even roller speed when the other 2 are not possible.
During the tuning of my personal SL65 AMG, I used the injector as an RPM pickup (it's the most accurate and way more responsive than obd2 rpm), and obd2 port to log other parameters so I can check data later, such as boost/iat/timing. I'll be making a new thread for my little build thread for my car soon. .