BlackZ28629

iTrader: (8)

Hello.
I just got HPtuner and I ran a scan on my car. I noticed that the duty cycle of my injectors on my nitrous run (100shot dry) was at about 85%. Should I switch to bigger injectors? Also, what else should I do to better the performance? I want to add fuel especially for when I run the N20 and I want to take the TQ management out. Pointers are very helpful. Thank you.
Oh yeah, and I also noticed a knock retard of 4 at about 4300-4400RPM in the tables. Is that normal for a nitrous situation? The non-sprayed run: everything was fine.

CriminiSS

iTrader: (16)

I am relatively new to HPtuners aswell, but might be able to help. For as the injectors, 85% is fine no need to go bigger. I think you might want to pull timing @ WOT just to be safe tho and no, knock of 4 is not normal, its my understanding that anything over 3 is USUALLY real knock. You might be pinging while on the spray. I think pulling some timing will help you a bunch.

Gh0st

iTrader: (3)

the 4000-5200 rpm range is typically where you will see timing being pulled because that is where your car makes max torque. Look at your timing tables and just subtract four degrees of timing from that part of the table. Load the tune and see if it comes back.

BlackZ28629

iTrader: (8)

anyone else....suggestions?

Frost

iTrader: (45)

It usually only takes 1-2 degrees of pulling it back to keep even 4deg of KR (the MOST it is allowed to pull while in PE, OEM) away though if the car is N/A and the AFR is right

Look at the bigger picture though, what year is this car in question? With a lid, catback, and a 100 dry shot, many cars that are 98s, 01s, and 02s (years with 28.X lb injectors) are close to max duty cycle. If you have a 99 or 00, you have the smaller (26.Xlb) injectors they should nearly certainly be at max duty cycle. What does that tell you about your 85% DC on the bottle? You need to be sure that the knock you are seeing isn't related to a lean issue. Your next purchase should be a wideband so that you can make use of that tuning software and see if the car is lean on the jug, which is a guess based on injector size and my assumption of your fuel system being stock or just a pump.

/2cents

Gh0st

iTrader: (3)

Thank you for the correction. I am a newbie to tuning

BlackZ28629

iTrader: (8)

thank you... I dont think its running lean, but Ill add some fuel starting at 5% and get some bigger injectors. Ill look at the timing and pull some up top but I dont ever hear a ping when I spray...I did however ping when I had hypertech tuning installed..never could rid it of that so I took it out and never used it again. So maybe it could be running lean..?

richard head

iTrader: (2)

With a dry shot, you can use your IAT sensor to tune for the N20. Tune it well for the NA bits, and then make sure your nozzle is going to spray close (but not too close!!!) to the sensor. Then, in the IAT spark correction table you should subtract 4 degrees of timing for IATs of below 32*.

Frost

iTrader: (45)

The extra fuel comes from the MAF cooling, not the IAT. You cannot pull timing like this for nitrous, you will go through first gear and part of second before you get any timing reduction; the IAT is too slow.