Let's Talk Nitrous

[sask10]

So I have been trying to come up with a plan to comfortably break 700whp on pump fuel with my TVS set up (mods in sig). I had a plan worked out with a reputable tuner that involved L/T headers, NSR cams, and a 10% lower which would likely get me there but would be pushing the limits of pump fuel. It was questionable if we could keep the 10% lower but it was agreed we could test it out and see if peak boost was acceptable given my elevation. After considering this for a couple weeks, seems like a lot of work for something that may not work.

After accidently reading an article on a N2O injected 13GT500, I’m wondering if this is not a better route. My car is 100% street and for the most part I am happy with the power. It’s the 2 or 3 times a summer that I come across a ZR1 or tuned hellcat that has me wanting more. I’m wondering if feeding the engine a little giggle juice for these special occasions might be a more reliable and easier on the motor then trying to keep the other setup barely breathing on pump gas 100% of the time.

Now for the setup, I’m thinking the Nitrous Express wet kit with TPS switch and window switch and between a 50-75hp hit, but what about tuning? Does a wet kit need a retune at this low of shot or can I just retard the timing in the current tune? Or can I just leave tune as is? Seems in some of the mild setups nothing is needed but it’s tough to find any info on where the breaking point is where an absolute retune is needed. Anyone with first hand experience with a setup like this?

 

[SirShaun]

One thing I have read, is that Nitrous through a blower, doubles in strength. Your 50-75 shot will actually be a 100-150 shot.

General rule of thumb is 1-1.5 degree of timing retard per 50hp.

A wet kit contains both a nitrous jet and a corresponding fuel jet. The fuel jets are often times overly safe, meaning in some cases you could step down a fuel jet size, and still be alright.

It's a lot of variables (Bottle Temp, Bottle Pressure, Timing, Air/Fuel) also when your not spraying your going to notice the timing you pulled. I recommend getting a nitrous tune on the dyno and load it when you need it.

Also nitrous makes twice as much torque as it does horsepower. You will probably be over 800ftlbs if you bring it in low enough (2500 rpm). Make sure your drivetrain can handle that much torque.

Get ready to replace spark plugs, a lot. Nitrous is hell on plugs. It will blow the electrode right off of them.

Definitely use a window switch as nitrous can puddle in the intake. I believe it's recommended to only bring it in after 2500 or 3500rpm. It has to be making enough flow to feed the nitrous. You also don't want to smack the limiter while it is still spraying, so have it cut off a few 100 rpms before redline.

Also maintaining the proper bottle pressure using only heat can be a pain. Temperatures tends to fluctuate a lot and pressure drops off as the bottle empties. I always wanted to try a NANO kit on my 3 valve. https://www.nano-nitrous.com/

 

[Jam421]

I only ran nitrous on a carbed car . I had the window switch and bottle heater which are necessities. That nano-nitrous set up looks awesome because maintenance of the bottle temps can be a PIA....I wish I had that back in the day ! On my simplified carbed car with MSD 6AL ignition ( prehistoric right -? ) I wired the MSD nitrous timing Auto-Retard NOT to take out any timing unless it sprayed. Even with the switch armed I was at full timing. At first I only used the nitrous when things got difficult. I could use a pinky button on the front of the shifter or a palm held button if I wanted to hit it in 2nd which I stored under the seat . Once I pushed the button before the gas could travel thru the system the MSD Digital Ignition Retard plugged 6" from my MSD 6AL Ignition box instantaneously took out timing.

I did use one step colder plugs, NGK V-Power, changed 1-2X year but the car ran great 98% of time at full timing. I was only spraying a 125 shot but it was a 2270lbs Cobra kit car with a 510HP 351W . On the juice it made 89rw more with 75 / 100rw more with 100 & 140rwhp more with 125 jets. Go figure. I used this set up about every weekend for 7+ years and never had an issue . This was my only nitrous car ( with a baby 125 shot) so my experience is quite limited.

With regard to the GT500 I'd also agree that even a tiny 50HP shot would net fantastic results because on a boosted car we all make big heat. The nitrous would have such a dramatic effect on cooling the entire intake charge I'd bet you'd see way more than 50HP . I'm not intending to use nitrous but I used to be curious what effect a baby--baby 25HP jet would do to cool the blower ...make power...and reduce heat soak. I've heard of turbo guys using nitrous to reduce lag and blower cars adding power ....so why not ? I'd not consider this option unless the system was installed and tuned by a very reputable race shop experienced in nitrous/blower & turbo turning.

 

[yellow03cobra]

I ran a 100 wet nx shot on my 03 cobra and loved it. The 100 shot ended up being 100rwhp gain. You could maybe run a 25-35 shot but I don't really think it's worth the $1500. Generally speaking the limits of pump fuel is still the limit, doesn't matter how you get there imo.

 

[Jam421]

I guess what I was wondering was that guys invest big money in bigger blowers, heat exchangers, intercoolers , methanol etc or other means to cool down their blower. On my old carbed car with big cam, higher compression etc...we were shocked with rwhp gains of 105-110% over jet ratings. You never know what combos worked best .

Edelbrock once told me they'd provide ANY size jet for $15 with their 50/75/100HO kits. With my 2008 GT500 ported Steggie Eaton I once considered a 25-30 nitrous jet because in any summer temps near 75-90 degrees ...it might really cool the air & offset heat soak. Back then it was not a very popular idea.

Re: What OP sask10 is discussing I'd not seek big hits of nitrous as optimal selection for our GT500's.
But if cooling the blower intake charge was done with a very safe 25-30 HP nitrous jet ...might it result in 40rwhp gain ?
If not ? A baby-shot of 50HP would certainly do the trick . Nitrous can be so much fun.....but it's always best to approach from the cautious side especially with a supercharger.