99 vette m6
vararam cai
borla axle back
-2* timing via HPT
rpm limit 6500 via HPT
nx shark nozzle-150 jets (wet)
nitrous outlet dual tpas/digital window switch on 3400 off 6200rpm
hsw fpss
hsw bottle heater
bottle presure 950-1000

having a surge problem that increases with gear/rpm. never spray from 1st, usually from 2nd-4th on the hwy runs. 2nd doesnt do it usually, start to feel it top of 3rd and usually most of 4th gear, so appx 55-135mph ish.

the kicker is its intermittent, happens about 2/3rds of the time but not every time.

i bought the kit used but it was only a month old, the main -4 supply line did have 2 small kinks in it which i "massaged" out.

the nozzle is where the stock iat sensor is on the c5 air bridge, i moved the iat more forward, the nozzle doesnt protrude too far into the air bridge and the spray may be bouncing off the bellows boot, it doesnt stick in far enough to be aimed directy at the throttle blade. but the problem is inmt, so i assumed if it were a bad location it would happen consistently. im going to move the nozzle eventually but wanted to post up 1st.


i switched bottles , they were filled by 2 different shops and the problem is still there. bypassed the fpss, no change.

to me it feels like a bad bottle or the window switch "pulsing" the nitrous in and out.


i dont expect you guys to fix it for me but i just thought id throw this out there and see if anyone had similar problems and found a fix.

my plans are to bump the rpm up on the WS and just shift before the n2o cuts off (although it surges fom appx 4500 and up) and see if it goes away and try a different bottle once again.


any thoughts on nozzle placement and/or other suggestions are welcomed.


Thanks,
Ronnie

 

Bueller ?

 

Ronnie,
Have you cheacked your airfuel and fuel pressure?
Dave

 

no sir, not after the n2o install as far as the afr. thinking about ordering the plx from the group buy on here.

whats the best way to check fuel pressure on the vette, just tee in a fp gauge inline w/the fpss ?

are you thinking its rich causing the surge ?

i have HP Tuners is there anything i can look for on the logs, maybe narrow band output ?

thanks !

 

To things come to mind. Either your fuel pressure is droping as the motor starts to rap us requiring more fuel.( going lean) Or the car is going rich and starting to break up. You are playing with fire not knowing. Start with looking at the fuel pressure. You can simply tee in a test gauge or put a gauge in the car permently. A wide band is a great tool. But I can teach you how to read plugs as well.
Dave

 

yeah i need to pull a plug and take a peek at it , ill post a pic or two, i am by no means an expert at reading plugs but if its black its rich or if its speckled its has detonatation.

as far as the FP gauge, what am i looking at as far as idle FP, w/o an in cabin gauge there is no way to monitor during a WOT pull. ive read the vette is a "semi-returnless" system so i know on a standard car you pull the vacuum line to set base FP

thanks in advance