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So I decided to try and toy around with some nitrous tuning. Not just behind the laptop but to play with other variables to find the most power that I can before moving onto a big shot. First the engine was tuned to max power naturally aspirated before we sprayed it.
Engine is a
87X99 12.5:1 K24/20
Drag Cartel 4's
Skunk2 Pro Series on a 74mm TB / Excessive 58mm centerfeed mani on a q45 TB
ASP Header w/ megaphone
E98 Fuel
Nitrous kit is a basic shelf Nitrous Express wet kit jetted for a single 75 shot nozzle. We use a Nitrous Outlet heater and mount kit. It works ok, but we have had better luck with it by junping the relay and forcing it to be on full time.
So most times when we tune nitrous we just set up our jets, get our bottle pressure up, and just tune to make the shot safe while making some power. This time around I decided to go ahead and try some different variables to make power. Here is some cliff's notes on what worked for me.
Bottle pressure...
Between 900, 950, and 1000....950 hit the cleanest and gave me the smoothest power. 1000 psi had a violent hit that made a ton of power on the initial engagement but had a short lived powerband.
Intake Manifolds....
I swapped them(Skunk2 Pro Series w/ 74mm TB vs. Excessive 58mm Centerfeed w/ q45 TB) around after the hits were dialed in and continued to fine tune a little. The Excessive was worth about 8whp all motor but about 18 on spray. My guess is that the engine wanted more while it was under the shot and the bigger intake manifold was able to shine and carry the power. By about 8900 RPM the excessive was able to carry close to 30whp over what the Skunk can do.
Jet Placement
I tried moving the jet in 2-3 inch increments away from the throttle body. I went as close as 3 inches and as far as 12 inches away from the throttle plate. I was pretty damn surprised on how much of a difference in made on the graph. 8 inches from the throttle plate was the key position. I found at least 15whp in jet placement.
Tuning
Individual cylinder trims were key after the basics were dialed in. Adjusting the trims according to what the spark plugs were telling me resulted in a clean 6-8 whp gain across the board. Range 8 plugs were the happiest in there.
The fun part about this all is that this is the first of 2 stages we are doing. I plan on hitting another 30 per cylinder direct sometime in the spring.
A little off topic but how do you like the cartel cams?
They are easy on the tensioner, quiet in operation, and make good power. I like them. I'd wait until Skunk goes public with their new Ultra cam lineup if you were in the market for cams though. Them ***** is bananas.
Originally Posted by D-Rob
Good call on the late engagement, Mikey.
I have a plot I can grab of a buddy's stock K20 we played with for a few years on progressively larger shots of nitrous as time went on.
It finally gave up with a 160-shot after a few years of abuse on the dyno, and made a nice show.
You and your stock K20's.
I figured we are past peak tq and everything is already up to speed by the time we hit it. Also these noids don't like to hang for more than 2500 RPM...they start to taper off. The Nitrous Outlet units i've messed with before seem to keep a shot going for as long as you need it to. I know once we hit it direct it'll be tough to keep the violence in check. I've got a few ideas on how to hit the shots while on track to make it effective. Now to only wait 4 months til the track opens again.
Because spray is considered a form of FI. You aren't really "all-motor" if you're spraying happy gas.
It's rare that we see real nitrous threads around here, especially with as much attention to detail as you've put in. I'm still not a fan of the bottle, but it's good to see you've made it work right and put the effort into it.
Nice thread. I've never run nitrous on my Hondas but had an ls1 that was addicted to the bottle. If you have it set up right u almost get pure hp per shot size. Seems u have surpassed that. I made 506rwhp on motor and 527rwhp on a 125 shot and that was with the wet zex kit set up like it comes. No tuning involved. So 121whp out of a 125pill. I just don't trust going nitrous on my d16s but with informative threads like this I may give it a go on one of my cars.
They are easy on the tensioner, quiet in operation, and make good power. I like them. I'd wait until Skunk goes public with their new Ultra cam lineup if you were in the market for cams though. Them ***** is bananas.
YeaI've been seeing David Hsu posting about them. They look promising althoughwho knows how much they'll end up costing lol
Great write up! I have seen quite a bit of per cylinder trim needed for the single nozzle setups on the non center feed manifolds. Unfortunately being on management that doesn't allow individual cylinder ignition trim we left some power on the table to keep the cylinder receiving the most nitrous happy but leaving the others lower than ideal.
About how much different were your timing levels on and off the nitrous for that motor?
I don't understand how this is forced induction related
Well it's not All Motor. I didn't want to put it in Drag Racing because i'm not one to bench race. Sorry if you feel that i put this in a wrong spot or if it ruined your H-T lurking experience.
Originally Posted by HAVideos
About how much different were your timing levels on and off the nitrous for that motor?
My assumption was that cyl's 2 and 3 would be favored heavily but it wasn't as drastic as I thought. They did see a hair more fuel but from the looks of the plugs it looks like the nitrous spread even pretty well. As far as timing goes, i pulled a few degrees on the initial hit and ramped some back in as RPM's went up. The e98 gave no fukcs. For all i know i could've gotten away with the same timing I was on.
Excellent, well that's good to hear. I planned to use e98 this year. We were using e98 mixed down to an e85 with a gasoline that turned out to be doing more harm than good. I was forced to take out quite a bit of timing for anything over a 50 shot. The combined (130ish) shot put us around single digit timing levels. Felt like trying to tune on 85octane instead of e85 lol. Still made great power picking up around 190hp but was an indication of an issue. Anxious to see how it reacts on simple e98. Thanks for the info!
Love the facts drop in the thread. Makes the build legit and ready for discussion.
Thank you for taking the time to do the work and giving the clear results. NOS needs a new start like this to be realized in common form builds. Just a little goes a long way.
I'm glad that there is some appreciation to this effort.
So anyone reading this that has done any sort of nitrous testing. Have you had similar results? Is my theory of the engine wanting more as far as manifolds under the shot correct? It seemed like the engine loved the extra volume of the intake manifold when it was on the shot. Has anyone experimented to see if different nozzles make more power?
Just like so much other stuff i've learned on the dyno....i'm teaching myself how to maximize nitrous. Seems like a lost art IMO.
I'm glad that there is some appreciation to this effort.
Has anyone experimented to see if different nozzles make more power?
Of course many, many different theories and efficiencies have been created from different design of nozzles. Various sorts are good at fogging and some are not.
Fogging upstream with lower HP systems is adequate but troublesome as mixture distribution becomes unbalanced. Also, nitrous displaces oxygen in an intake manifold. Though it replaces it with a higher overall concentration. If the intake manifold were allowed to draw in ambient air and just at the point of the valve openings, LIQUID nitrous was injected; a much more concentrated ( oxidized ) mixture could enter in to be combusted. There are many other reasons to inject the nitrous as close as possible to the combustion chamber. The greatest advancement to come will be direct injection systems being tested and developed now by a few individuals.
Here are the best nozzles on the market at this date. They are different from every nozzle on the market and have been tested proven winners in massive systems overseas. I have these for my build and can not wait to start getting data.
awesome writeup. thanks for sharing this valueable, detailed info. Im running a stock internal b20vtec on a wet single fogger 125shot on e98 fuel bkr7e vpower plugs, and your right, e98 doesnt care about timing, and can be run pretty dam lean. My fuel pump started giving out and the filter sock fell off and caused the AFR's to go really lean on my last run at the track on my last outting, looked at the datalog and in the 13's for afr's. Checked the plugs, the pistons, motor still has good compression. e98 seems to be very forgiving. this info you posted will help me out with my setup, thank you!!!
Bottle pressure is huge. Guys want to run this insane amount of bottle pressure and its so hard to maintain, it makes the nitrous hit very, very inconsistent.
I've found 850-950 is very constant... and can be maintained. I'm using all Nitrous Outlet, the bottle holder/warmer work very well, and hold the pressure at 900+ through many, back to back pulls.
Jet placement as well as line length i've found to hold another key part in the actual hit.
The closer to the TB, the more torque, further away, i've found to make a broader, more nicer powerband. Most B's found liking around 5-10 inches.. atomizes better i assume.
I love the nitrous setup, thanks for sharing mikey.
Tyler, i'm going to look into those. That's new to me. That idea of the intake manifold makes a ton of sense. I wonder if the same plenum volume theory applies to a direct fogger kit?
Originally Posted by seelback
what plugs and gaps were you trying out? i know gaps can change from dyno to the track(road) cause of load difference.
BKR8EIX gapped at 28 has worked the cleanest for me.
Originally Posted by DDTECH
..<3 Mikey.
I'll concur with alot of what you posted.
Bottle pressure is huge. Guys want to run this insane amount of bottle pressure and its so hard to maintain, it makes the nitrous hit very, very inconsistent.
I've found 850-950 is very constant... and can be maintained. I'm using all Nitrous Outlet, the bottle holder/warmer work very well, and hold the pressure at 900+ through many, back to back pulls.
Jet placement as well as line length i've found to hold another key part in the actual hit.
The closer to the TB, the more torque, further away, i've found to make a broader, more nicer powerband. Most B's found liking around 5-10 inches.. atomizes better i assume.
I love the nitrous setup, thanks for sharing mikey.
Good info to know. I never dabbled this far into nitrous setup in a B series. THe most we've done is direct nozzle placement from the precasted Victor X location to down the runner closer to the plenum. That worked very well.
Originally Posted by Muckman
Love this. Great data. Thanks for sharing with us.
Besides the late engagement is there anyway to soften the engagement to reduce stress on the engine? (and help traction)
How did you test nozzle placement? Did you have several intake pipes pre-fab'd ready to go?
A nitrous controller can do just that. We are also going to experiment at the track with different engagement techniques and engagement times.
For nitrous nozzle placement I have so much misc tubing and couplers that I was able to make different nozzle spots before fabbing up a fancy final one.
12-30-2014, 04:34 PM
125whp out of a 75 shot on a 300+whp K24
