Numbers don't add up
 

Bought a used NX kit and didn't get the results I was expecting. Currently am a h/c - bolt on car and am making right at 400rwhp. Thought I'd be safe on the stock bottom end and only run a 100 shot. Well TOO safe is what it turned out to be. It ended up netting me 5mph/5 tenths at the track in similiar weather - here's what the car did:

11.82 @ 116 N/A
11.33 @ 121 100hp shot

The car has since picked up near 2 tenths and a best of 123 mph, but that was with a good DA.

Got the car on the dyno on Friday to check a/f, and sure enough, only gained about 50hp. A/F seems to be good at 12.8 across the board. Guess for now I'm just going to jet higher to a true 100hp :eyes:

Remember the lower the ET the more HP it takes to drop a tenth or gain a MPH.

Good luck

Wes

Wish I was going fast enough for that to be it. It's just not putting the number out.

You sure you are using the right jet's...could be a simple mistake...??Whats your bottle pressure while you are spraying?let us know how it goes. Good Luck

Wes

Just to make sure I've checked the jets, and then the next day I checked them again. Bottle pressure is controlled by my NX bottle heater and stays between 900 - 1050psi as confirmed by pressure gauge.

What plugs and what are they gapped at?

Dave

Still TR-55s, but thought that would effect detonation. Picking up TR-6s today and am going to gap them at 40.

That was your problem probably...your plugs were gapped too wide. I would suggest 35 versus the 40 you considering gapping them.

Dave

I gap my TR-6s at .038 with good results. Ben

Gonna give that a shot and run it on Wed.

well the type of cam you have may be effecting it some as well

Got the TR6s in and have them gapped at 38. Went to fill the bottle and at least now I have an idea of what's going on. After 6 full passes on a 100 shot the gas was only down 2lbs! Looks like I'm not getting the nitrous flow either from the bottle valve or the solenoid. I upped the jets to 125 to see what would happen and ran the same as the 100.

Might want to check the nitrous filter. Did you blow the lines down after the install before spraying the car? I would think you should have used over a pound per run. I use about 1.5# per run with a 125shot. if your really using the 100 jets I dont think bigger jets will help. you must have a restriction in the line. Could the hose be pinched somewhere?

I didn't expect changing the jets would solve the problem, just another confirmation that the gas isn't flowing. I've got time to figure it out, the track is closed for a month.

Tr6s gapped at 38 here 110mph N/A on a 125 shot 122mph you have got something going on with your system. And I cant hit the spray until im halfway through 1st gear.

A/F on the nitrous is lean. Do you have an intank pump in the car yet. If not id strongly suggest one before you go boom. You should be seeing an A/F of around 11.2-11.5 on a wet kit. TNT usually hits at 10.8 then level off at 11.2 FYI. NX should be used at around 11.2 for optimal results from my experience with it.

Yes, have a Walbro 340. After the wideband I've gone up on the fuel jet to be safe. Next pull I make I'll see where it's at.

So is 11.2 for a/f optimal on a 100 shot and if I go higher should I keep it at that?

YES! Dry kits usually make good power at 11.5 and wet kits usually like to be around 11.2. 12.8 is way too lean for nitrous though. Gap the TR6's at ..038. Anymore nitrous then id close the gap to .035 or even run a TR7. I usually put my TR6's in right out of the box since they are wrapped in cardboard. That means the gap has been preset from NGK. Unless you've dropped them or something id throw them in right out of the box. Pull the pills check for blackage, and also check your nozzle for blockage then reinstall.

Give us the specs on your car as well. As that plays a huge role on what power the car makes. With alot of valve overlap the nitrous kits have to be pilled higher just to make 100 rwhp. THe nX kits should make 100 rwhp easy with the 100 hp jetting.

Mike

The TR6s are currently gapped @ 38. Right out of the box they were 40. I've checked the pills and nozzle twice and they appear to be clear of any blockage. I'm convinced though that there's either blockage in the bottle valve or a bad nitrous solinoid due to the low volume that the bottle is putting out.

Here's the specs on the car.

Comp Cams XR 228/228 .571/.571 113lsa
Stage II heads, Ferrero 2.02/1.57, Comp 918's
LS6 Intake, VHP MAF ends, polished TB, TB bypass, 160 t-stat, Direct Flo lid, K&N filter
NX wet kit, MSD Window switch
Midwest 4400 torque converter(non lockup), B&M trans cooler
LS1Edit tuning by Norris Motorsports

Exhaust
Jet Hot Headers, Hooker ORY, SLP dual/dual, Flowmaster muffler, exhaust cut-out

Suspension
Front sway bar delete, BMR sub-frame connectors, HAL QA1 front shocks/springs, CE rear shocks, BMR lower control arms and relo brackets, Spohn torque arm with spherical rod end

Misc.
Pro stars, ET Streets 26x11.5
Chrome moly, weld in, custom 6 pt roll bar
Jaz racing seats, RCI 5 pt harness
Walbro 340 intank fuel pump, Aeromotive fuel pressure regulator

Probably more info than anyone would ever need, but cut n paste makes life easy!