Hey guys, please check out my dyno thread and see if you can help me with this nitrous problem.

https://ls1tech.com/forums/dynamometer-results-comparisons/606151-ls2-402-w-afr-225-s-w-w-o-spray.html

Thanks!!!!

 

ttt. Please follow the link and see if anyone has resolved this problem already.

 

HELP HELP HELP. I will post it over here since I am not getting the nitrous pro's to make the long journey over to the dyno section.

 

NA:
So I finally got everything to where I felt comfortable getting some dyno pulls made. We played with fuel and spark and the numbers only varied by about 5 horse NA. I was pleased with the NA results. Got it into the 500rwhp club finally.

150 NX Wet Shot:
So my buddy with the dyno shop says, "Let's see what it will do on the spray." I was not crazy about the idea of spraying on the dyno but since it is only a 150 shot, and I had 200 and 250 jets that I was planning on putting in soon, I figured what the hell! Boy am I glad that I did. I had no idea of the problems that I was having on the spray. You will see that on the bottle, my power peaks at about 5K RPM and by the time I get to 6K RPM, it's almost like I'm not spraying anymore. The bottle is full. The A/F is not really jumping around too much. It's like the solonoids are closing together gradually. Steve (the dyno guy) told me that he thinks that it could be an ignition problem (maybe plugs) but I don't think so. It is too uniform on it's downward curve. I did notice while driving home in the dark that at WOT (no juice) right at about 5K RPM, my headlights dime and the voltage gauge drops a bit all the way to redline. I don't think that this is normal. If this is the case, could the lower voltage be causing my solonoids to slowly close? The kit is very simple in it's current state. It consists of the bottle, the line, 2 solonoids (n2o and fuel), one nozzle, and a manual WOT switch. That's it. No window switch, no fuel pressure switch no electronic controllers of any kind. PLEASE HELP.


__________________

 

Check your voltage drop/charging issue.....if you are losing voltage you will have a problem keeping the solenoids open.

 

It looks to me like you started spraying at about 3500rpm and it takes a bit for power to come on rather that an instant torque spike (like it was progressed). You were also lean is this area which should/would normally give additionaly to the intial torque spike. So whats wrong, hmmm... I would get that voltage issue figured out. I know i was having some voltage drop from my bottle heaters, but otherwise it seemed fine, until battery started going dead, it was a bad battery, so you may have an issue like that and/or charging system. Check your noids with good voltage and just make sure they are opening correctly, make sure you have correct jets, correct fuel pressure and supply, check plugs, bottle weight/pressure. Then give it another go. Keep us informed.
Robert

 

Thanks for the advice. I was able to get one of these new fancy Optima batteries today but was working on the Honey Do list so I haven't had a chance to pop it in and scan a WOT run yet. Maybe tomorrow. I hope this solves my issue and I don't have to chase down a bad ground or change the alternator.

 

If you have a volt meter you can check the voltage output right off the alternator and see what it is doing, at idle and at increased RPMS . You should be geting something in the nieghborhood of around 13.4 volts. My guess is your charging system is not performing as it should , which in turn is causing your problems.Good luck!

 

Here was my problem. the charging system was working fine. However, with a bad battery trying to get it's charge at all times, the alt couldn't put out enough to supply needed batt charge and run all the acc. Once I put the new red top in, batt voltage stays stable even when both heaters and the fans are on, no more voltage drop like before. Volt gauge now reads mid 13's rather than low 11's.
Robert

 

I agree with what you are saying and that would explain the voltage problem ,but I figure it doesn't cost anything to check voltage output, so I suggested that as a starting point and go from there.I suspect the diodes are probably going bad in his alternator. Just a thought.

 

Yea, a starting point.
Robert

 

Well, I been trying to figure out my problem still. I was convinced that it was a voltage problem after doing some scanning. I bought a yellow top Optima (Deep Cycle) and a brand new (not rebuilt) alternator and I still have the same voltage drop under full throttle and it is worse with the nitrous. I took off all of my grounds except the ones that are attached to the back of the heads and cleaned them and the contact surfaces with a wire brush. I checked the ones of the back of the heads and they are tight. The surface is clean as I just installed them in January. Would belt slip cause this problem? I don't have an underdrive pulley so stuff is spinning at full speed. Not sure what else it could possibly be.

 

The tensioner is brand new stock tensioner. I bought it last month to replace the old (192,000 mile) one that was tossing belts.

 

try a katech tensioner(sp?)
cause it sounds like it is slipping.

 

There are grounds all over. There is a write up on this at vette forum, Bill Curlee did it. You would not believe how bad these grounds can become, and the problems they cause. Did you check the ground trminals on top of frame just foward of alt, actully one on each side. it's a grouping of grounds and gets corroded. you really need a manual to find all these ground junctions.
Robert

 

try a tensioner man..its a great piece to have and its cured alot of funky stuff on several cars I have done. No garuntee...but its not too expensive....or rig up a strap real quick to put extra tension on the tensioner.

 

You are using relays to fire the noids aren't you? I've seen guys just run um through a
microswitch so I have to ask.

 

one relay fires both noids.

 

Got it worked out. I think that it is normal for the voltage to drop under the heavy load. I have not verified it on another car. Perhaps someone could. Anyway, it was something very obvious. It was my plugs. When I originally put the motor together I had a different cam in there. That cam was installed a tooth out and I had some pretty severe detonation. I could have sworn that when I switched the cam I switched the plugs from the TR55i's to the TR6's. Well, apparently, I didnt. Soooooo we pulled a plug and saw a 57 gap with a severly pitted plug. It seems that I was blowing out the spark at 5300RPM on the nitrous and the reason that the fuel was leaning out rather than getting richer is that I wasn't burning the fuel, It was coming out raw thru the tail pipes and thus not reading on the wideband.

Thanks for the help guys.

 

that will do it! Glad you got it worked out.