What RWHP can be expected with a 125 shot

snakepitt1 · #1 (**permalink**) 04-04-2010, 10:09 AM

Using the ZEX system on my 2009 6 speed challenger with a MBRP cat back, 85mm throttle body, CAI, Iridium plugs 1 heat range colder, presently the car dynos at 414.6hp and 420ft/lbs with out nitrous. So, what can I expect at the rear wheels with a 125 shot?
Thanks

iwannagofaster · #2 (**permalink**) 04-05-2010, 12:01 PM

Just like any other power adder, you can expect a 10-20% power loss through the drivetrain, but the hp ratings are pretty spot on. I would expect to see about 100 at the wheels.

snakepitt1 · #3 (**permalink**) 04-07-2010, 07:30 AM

I wanted to post an update. I had my car dyno tuned for the 125 shot this evening. Everything worked as expected. The tuner said that the ZEX system had the smoothest hit he had ever felt.
Final numbers showed a RWHP gain of 68.3hp and 158.7ft/lbs of torque. This was with the 125 shot. It appears that the ZEX system is overly optimistic with shot size while actual increases are MUCH lower than advertised. I'm sure that this helps keep any negitive customer issues low as no engines are damaged. I was just hoping for a bit more, that's all. Since the 125 shot gave me nearly 70 I am thinking about trying the 150 shot and see if it gives me an extra 10 or 15HP.
My base line was 414.4RWHP@6000rpm and 425.7 ft/lbs@ 4650 rpm

Final numbers on my 6 speed manual SRT8 Challenger..125 shot...
482.7 RWHP@5500rpm and 584.4 ft/lbs@ 3200rpm.

Only problem now is there seems to be liquid gas in my cold air intake tube. I actually poured out an ounce or so after returning home from the dyno. Is this normal? Or do I have a serious problem?

amick · #4 (**permalink**) 04-07-2010, 11:58 AM

Your rwhp gain seems very low for one of our kits, as every test out there has produced better numbers than that. What was your bottle pressure at and what was the bottle weight when you ran it? It is not uncommon to have a little gas in the intake tube.

snakepitt1 · #5 (**permalink**) 04-07-2010, 01:34 PM

I had just had the bottle filled for the first time. The first time the system was used was at the dyno. I do not have a pressure gage as one did not come with the kit. I believe the full bottle weight was something like 26lbs. The best numbers were achieved on the 3rd dyno run with 4 degrees timing taken out. I verified the nitrous and fuel jets at the time of install. Used a magnifying glass to be sure and matched the sizes up to the chart included in the directions provided. Ambient air temp was 89 degrees, engine temp was at about 170-180 degrees. My car has a MBRP cat back, 85mm TB, Mopar warm air induction and a 180 thermostat. 6 speed manual. Dyno calibration and software current and last checked in Jan 2010. Nozzle located just beyond the 90 degree radius in the elbow of the CAI pointed straight toward the intake.
There was liquid fuel in the filter and intake tube after the dyno runs. I actuall poured it out.
I need to know if there is a problem here.

amick · #6 (**permalink**) 04-07-2010, 02:05 PM

The pressure gauge is an extra that it is not included in the kit. The part number for the pressure gauge is 82005. The price direct throug us is $46.15. I highly recommend using a pressure gauge. All the jetting for the ZEX kit is figured on it being at 950psi of bottle pressure. You want the pressure to be between 900-1050psi when you spray. Even if you do everything else correct but the bottle pressure is low then it will not make the power the kit is capable of making. As I said in the other post the fuel in the intake tube is common and not something to be concerend with. The reason you get some fuel is that even when you let off the button and solenoid closes you will still have fuel in the line that will leak out of the nozzle.

snakepitt1 · #7 (**permalink**) 04-07-2010, 09:01 PM

I went ahead and ordered the bottle heater and bottle gage. With a fully pressurized bottle what can I expect for a HP increase.

iwannagofaster · #8 (**permalink**) 04-08-2010, 01:28 PM

I would expect to see right around a hundred out of a 125 shot, to the wheels. 70 is not bad, but it does sound like the bottle pressure could have been low. If you want to try the 150 shot, I would imagine you would see about 90-110 at the wheels if it keeps pace and about 100-120 if the pressure helps it out.

snakepitt1 · #9 (**permalink**) 04-08-2010, 11:41 PM

I was thinking about trying the 150 shot, but am a bit worried that my stock internals will decide to take a vacation on me. You guys are the experts on nitrous use. What do you think? Are the stock internals of a 6.1 Hemi strong enough to handle a 150 shot on a single one time only shot? There is a charity dyno shoot out next weekend, and I would like to step up with a 500+ RWHP pull. This will be a single dyno run. So... will a 6.1L Hemi with stock internals handle a 150 shot for a single dyno run?

iwannagofaster · #10 (**permalink**) 04-09-2010, 12:18 PM

I can not say yes or no on that one. If you are hitting it with a 125 now, I would think that the 150 would not hurt it one time, but that is not to say that it won't go horribly wrong. I would say pull two degrees of timing out just to be safe and let her have it, but that is just me. You may want to cruise some Hemi forums and see if anyone else has shot that much consistently and see what the outcome was.