I just installed a ZEX dry nitrous kit on my 98 Cobra. On my way to the track my girlfriend (who was following me in the other car) told me that the car was smoking a little. I then took a pass down the track without using the bottle and she said it was getting a little worse. I then used the nitrous for four or five runs and the guy at the timeslip booth said that on the final run I was "smoking pretty bad". BLACK SMOKE! I called it a night and drove home. The car seems ok power-wise and I don't hear anything funny. It never really smoked before. Well anyway, here is some info about the day of this smoking...if you can pick something out, please let me know what this black smoke is from. THANKS! I have the ZEX kit set with the 75 HP jets, I had a full tank of Sunoco 94 octane gas, I did an oil change (Mobil 1 synthetic 5w-30) right before going to the track, I also added a bottle of fuel system cleaner when I filled up. Also - I don't have any cats on the car - MAC off-road H-pipe. I appreciate the help, guys.
Black smoke after ZEX install???
- Thread starter HeyLittleCobra
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Go HoTO!
New Member
Hum, could be the cleaner...most likely is. Pull your plugs if you can to see how they look.
Do you have stock injectors and fuel pump? If not, you may be running rich with the dry kit. many of those dry kits work by pulsing the injectors to add fuel and if your fuel system is oversized you may be running rich.
Do you have stock injectors and fuel pump? If not, you may be running rich with the dry kit. many of those dry kits work by pulsing the injectors to add fuel and if your fuel system is oversized you may be running rich.
Go HoTO! said:
I pulled the plugs at the track...I am running NGK BR7EF plugs. (2 steps colder than stock - non-projected tips.) The plugs all looked the same...Not burnt but a very slight white residue on the outer side of the strap.
I do have the stock injectors and fuel pump. (98 Cobras came with 190 lph fuel pump and 24 lb. injectors.) I was thinking about upgrading to 30 lb. injectors. Is this possible with the ZEX kit? If so, what else do I have to do besides a new mass air meter to make this work with the spray???
Go HoTO!
New Member
Yeah, but that does not explain the smoke. Colder plugs won't hurt anything I don't believe.
Tell me more about the specific kit that you have. How des it work? I am not familiar with the ZEX. If this the one with the computer that reads bottle pressure and then adds fuel accordingly?
The fact that ALL the plugs look the same is really good. The problem with the dry kits is that your AF could be could overall, but running way too lean at one cyclinder.
Keep an eye on those plugs. With the juice. You should read them everytime you use especially when first using the kit.
I think you may have a little problem with your rings. Perhaps your black smoke is from oil, BUT I would think that you would see that on the plugs. Wouldn't you?
Tell me more about the specific kit that you have. How des it work? I am not familiar with the ZEX. If this the one with the computer that reads bottle pressure and then adds fuel accordingly?
The fact that ALL the plugs look the same is really good. The problem with the dry kits is that your AF could be could overall, but running way too lean at one cyclinder.
Keep an eye on those plugs. With the juice. You should read them everytime you use especially when first using the kit.
I think you may have a little problem with your rings. Perhaps your black smoke is from oil, BUT I would think that you would see that on the plugs. Wouldn't you?
ImportEater98
New Member
I have the ZEX kit and i get the same problem. There is not much black smoke, but i think its a combination between the o/r h pipe, and the fact that the zex hit, when spraying, puts negative vaccum on the fuel pressure regulator to dump more fuel into the fuel rail. N/A with the o/r h pipe (with MILS), my a/f ratio was 12:1 which is relativly rich (this was at about 4-5K RPM), so with the zex kit you are making it run even richer. Perfectly burning plugs will have a little bit of a gray/white hue to them. I have run 20 bottles through my 98 GT and compression is as good as new, and it runs just as strong as the day i bought it. I would keep an eye on your oil consumption just to double check, but i wouldn't be worried.
killbee
Founding Member
Well lets start with the smoke. Black smoke =rich condition, Blue = oil consumption, white= water vapor. Since yours is black we can eliminate an oil problem or a blown head gasket. Since you've dropped 2 ranges down in your plugs this could be causing you to run a little rich= black smoke. Try putting your stock plugs back in and see if it goes away, dont use the juice during this, drive a while to see if it will clear up. If it does only drop 1 heat range with the juice but I would suggest a good dyno tune before before running her too hard. If the plugs dont work start looking for any vac lines that you may have left unhooked or that could of come loose, this will cause a rich condition also. You can also locate these leaks by letting the car idle and spraying throttle body cleaner or starter fluid around your intake and hoses, if the idle changes you have a leak. Hope this helps .
this is kinda off subject, but will nitrous slow you down when you're not spraying??? i ask b/c i know a guy with an '01 SS camaro and i own him when hes not spraying, needless to say when he hits the 150 shot he leaves in a hurry, anyway i believe the zex kit is all electronic and almost idiot proof, heard nothing but good things about it, thats the kit i would get if i got one, but i want to know the answer to my previous question before i dive into the juice
Spike
Spike
killbee
Founding Member
Just depends on your tune, if you dont have a switch chip or a duel program, it could slow you down under WOT. If you are tuned just for the juice it will richen your A/F and usually remove some timing under WOT. If your tuned for N/A your have a leaner A/F and more timing which = more HP without the juice. Your best bet would be to have a duel tune or chip 1 for the juice and 1 for N/A that way you can have the best of both worlds.
FallenPhoenix
New Member
keeps sounding like a better and better idea, thanks for input, didnt wanna hijack
Fastime331
Founding Member
HeyLittleCobra said:
Hod on a second now. your sig says your best was a 13.029 @ 109.
What's the truth?
BTW Nitrous kits typically do slow you down. First off without an MSD timing retard, PMS, Tweecer etc... you will have to back off 2-4 degrees. Secondly you usually run one to two ranges cooler plugs. Lastly you have 30 more pounds on the car, which is minimal but is a fact. I lost, from experience, 2-3 th's and 1-2 mph when running NA on a nitrous tune for 150 shot.
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