I was wondering if anyone here experienced any kind of similar problem like mine. I have a dry NOS 5177 kit and I have run it on 3 seperate occasions. It runs STRONG until the 2-3 shift, then the car just feels weak. I ran it yesterday and it ran the best of 12.18 @ 111.12. At the very same track before the nitrous it ran 109.27 mph. I am only picking up less than 2 mph on the 100 hp jets? Seems odd to me. N/a it runs 12.90's so its picking up et, but on top end(after 2-3 shift) its a dog. I thought it was the fpss, so I bypassed it and it made no difference. I am going to look into a fuel delivery problem. I replaced the fuel filter about 3 months ago. I have stock tuning and a maft. I run N/A at -6 wot in order to get my o2's in the .890-910 range, when I run nitrous I bump it to 0 or 2% rich. I also think it can be torque management issues but not sure,for I am not too familiar with what exactly torque management is. Any advice will be welcome! I have LT headers and bolt-ons.

 

I had the same problem with my 5177 kit and never really got it resolved. How is your bottle mounted? If it's not mounted correctly, you might be pushing all the nitrous to the back of it away from the tube. Also, you might check to make sure you don't have any leaks where your nozzles are drilled into your air lid. Mine were leaking a bit, and I suspect that was the cause of most of my problems.

On this car I'm going with a 150 wet shot. Hopefully it will take care of those problems.

 

Pull your plugs and replace them with TR6's if you haven't already. I had some problems running on the stock platinums where the car would feel like puke in second and third.

 

I have TR6's and the bottle is mounted in the spare tire well. It doesnt leak, and it pulls strong in 1rst and 2nd, just 3rd it gets weak. Here is my time slip.. 60 ft. 1.707
330..4.92
660..7.68
mph..87.34
1/4..12.19
mph.110.03
It ran 109.27 N/A at the same track with similar conditions. I also ran a 12.18, a 12.26, and one of my runs was a 12.51(the 3rd one) and I didn't do anything too different. It did slip a little on the 2-3 shift on this run here and this is the slip when I bypassed my fpss.

 

May want to data log your next run and make sure you're not getting any knock retard or somehow losing advance. Otherwise I would guess that the nitrous is escaping somewhere.

 

Bottle pressure?
fuel pressure?
If your 02's are ok 900 area thru the whole run then I suspect bottle pressure, Knonk or just timing pulled as a result of TM.

 

I think the car is leaning out.

 

Thanks for the response! I have to log some runs and watch my o2's and fuel pressure, that sounds logical. I think an inline pump might be in my near future, or an in- tank replacement. Anyone ever have any maf problem? My bottle pressure was between 870-900. It just strikes me as odd that it pulls so hard until 3rd gear. I also think after the fuel system upgrade, I should delete this torque management..make sense to you guys?

 

Yup, log 02's timing and fuel pressure on a run. I think you might find a problem. A walbro 255lph in tank wouldn't hurt either.

 

An inline pump wouldnt have the same effect?

 

intank pump here.
870-900 at the start of the run or after? The pressure will drop quickly once the nitrous is flowing. Log definately.

 

I turn the maft setting from -6% lean N/A to 0 or +2 rich when on the nitrous. The o2's read 930+. I hope this helps.

 

Get that bottle pressure up to at least 1000, 800-900 is to low IMO.I like it at around 1100-1200.

 

I had that heater goin for a long time and it never got above 900, i guess if it took out the thermostat sensor it would go up, I should give that a try! thanks!