Nitrous Help Please?


New Member
Aug 7, 2001
Im posting for a buddy of mine. He wants to know what kind of shot he can run safely with his mods for this weekend. He runs stock turbo, small 206 cam, stock heads and intake, upgraded IC, 50 # injectors, dual walbro fuel pumps, and hes running a 93 oct street chip. The nitrous nozzle is installed in the MAF pipe. He is wanting to run 50-75 shot with an initial 18 psi of boost. What do yall nitrous junkies think of this idea? He also wants to know what kind of performance gains he can expect from the NOS. Thanks for any help!
If he is running racing gas I would start with the boost set at 16lbs (pre nitous boost) because he will see a 3lb increase with a 75hp shot. I hope he has the nozzle in the uppipe instead of the maf pipe. Not sure what affect the intercooler will have on the atomization of the nitrous. Sounds like he as the fuel setup for the nitrous but it would be nice to have a knock gauge to ensure all is ok. Not sure what the timing is in that chip but 19-20 would be best.

The timing on the chip is 21 * and he said a 75 shot would be the max he would shoot. Could you explain the MAF vs. Up-pipe for the nozzle. Why is the up-pipe better? And can he still spray through the MAF. He doesnt have time to mess with changing the nozzle location. O, he has 10 gal of C-16 he plans on using. Thanks for any more help!
Timing is close I would recommend a knock gauge or scanning tool to watch for knocking or you might be changing head gaskets.

With the nozzle in the Maf pipe (hopefully after the maf because the maf are expensive and the instant cold tempatures could ruin it) the nitrous is going through the turbo, intercooler, and intake. So by going through the intercooler it might not stay mixed with the air well.

One of the main benefits of using nitrous on a car is its extreme cooling effect. If you spray this directly into the turbo (which is normally at 1550 degrees or so WOT) it tends to eliminate any cooling effect of the nitrous.

I actually attempted this with a dry kit and felt absolutely no gain whatsoever on the butt-dyno. However, after I tapped it into the up-pipe, car was a beast.

I ran C-16 with a base (before nitrous) boost setting of 10 pounds just to try it out. Unless you have a wet system or a fancy way of demanding additional fuel, such as a nitrous chip, SpeedPro/Fast engine management, etc..., it is very possible to lean the car out very quickly. When I hit the button, the boost jumped to 16 pounds and felt damn good, but it leaned out and destroyed a pretty good section of head gasket on both sides of the motor, one broken valve spring, a wiped cam lobe, and other minor cuts and bruises to my car.

Bottom line...for me, I bought a bigger turbo and a front mount. For me, that is all the cooling effect I need. Now if I go to a stage motor and a more sophistocated engine management setup, I'm gonna spray the piss out of it:cool:

Hope this helps!

Wet system is the only way to go. If you run a walbro 340 pump that should be plenty of fuel for a 75 shot of nitrous. With a 75hp shot you should only see 2-3 lbs of boost jump. With 6lbs I would think you had 150hp jet which you need everything prefectly setup to run that much. I have run 75 on a stock motor with a good fuel system and proper chip several hundred times with no problems.
But I understand other people have different preferences to get to the safe objective.

Well my buddy tried it out this weekend! He used a base setting of 16 psi with a 50 shot (he stepped the fuel pill up one step for a little extra fuel). The 2nd Walbro 340 is set to come on at 17 psi. Remember, his nozzle is in the MAf tube..... He would hit it in 3rd and when he reached full boost (16 psi) he'd hit the juice! Boost jumped up about 2-3 pounds, but as soon as the second fuel pump came on.......the car would start to shutter! Tried lowering and raising fuel pressure with no positive affect. Seemed to me like when the second fuel pump came on it was spraying too much fuel. I dont know? Seems to me.......yall were right.....the up pipe would be a better choice! Even if the car would have ran smoothly, an increase in performance would have been minimal. Maybe .1-.2 in the quarter......waste of time in my opinion. We didnt have time to change the nozzle location to the up pipe, but if i were to spray my car......thats the only way i would do it! By the way....THANKS for your help!