Kryckter

Well, I took my trans am to the track last night to run. Made a few all motor passes and then decided to go with the juice. When I launched with the juice, I dumped at about 4k and launched on the juice. It came down to a bout a steady 3k and then pulled through. 1.7 sixty foot. It did fine and then had some hesitation in third gear. Still ran the normal times in does on juice. I came back to watch the video and on the launch, It dumped out black smoke, Imagina a diesel truck smoking to the 10th degree. It covered the track area with think black smoke. It cleared up and did fine the rest of the way. Well, Now the engine is knocking pretty good. Havent gotten into it yet, But it sounds like bearing knock. I have a fuel pressure safety switch, And was running 109 unleaded gas with the 150 shot. Any ideas or thoughts to what went wrong and what could be wrong......
Thanks in advance

texlurch

Did you check bottle pressure before the run? Sounds like the nos solenoid didn't open and you dumped fuel only in there.
Pull the dipstick and and see if it smells like gas.

Did you purge the system before the run?

Kryckter

I thought about that and the N2O solenoid didnt work theory, But it still pulled a 60 ft. that I see with nitrous. And yeah, I did purge the nitrous system well before the run....Any other ideas?

texlurch

hmmm, ok. How is your fuel system set up, are you using the stock test port for the nitrous fuel?

strokedTA

Sounds like that to me too. Nitrous didn't kick in, just fuel.
Been there. It will still pull a little better because of the extra fuel, but nothing much after that.
If you were adding all that extra fuel the whole pass then you are lucky you didn't hydrolock the motor and seriously hurt something.
It is possible that you hurt the rod bearing a little.
I'd change the oil and see what you get after that.

Check your grounds!
I run separate relays for the nitrous side and fuel side (but I have 4 noids).

Good luck and hope you didn't hurt anything too bad.
FWIW: I've had customers spray 150 without race fuel. What timing are you pulling? If any? What is your total timing? what is your fuel pressure?

Dave Brown
Wheels Up Racing
http://www.fastrides.net/board/image...3b85b39f3d.jpg

texlurch

Heck, I've sprayed 250-300 on 93 octane.. all in the tune.
Of course, the motor has only lasted for 5 years so far, and it is in the process of getting a supercharger put on for something different..

Just remember that "nitrous kills motors".. or was that Mustangs?

DrewHMS97SS

lol, or cobras

Kryckter

I was using 109 unleaded gas. No timing retard. Fuel pressure for the nitrous system was 45. The motor's fuel pressure is around 43-44 psi. It seems that we have found out that it bogged under nitrous coming out of the hole. I launched at around 4k and i guess with the RPM's declining and the nitrous flowing, It loaded up on juice. The motor is out of the car. Rod bearing was descent looking. It broke a side skirt on a piston

strokedTA

Sorry to hear that.
Good luck with the next build.
Maybe a higher stall will be a good Idea. I don't know why it'd bog on the spray though.

Dave

DrewHMS97SS

ouch