Finally went to the dyno since installing the nitrous.

First run with 100 shot:

Power 415...Max Torque 530


Second run with 125 shot:

Power 432...Max Torque 560

Are these number decent?

A weird thing though on both runs, when the nitrous is first engaged, I run really lean(15.0) then it richens up, slowly. Is that normal? (The pic is the 100 shot run.)

I have the switch turn on about 3300 RPM's.

Thanks,

Jason

 

Seems like accurate numbers, what kind of LTs do you have?

 

Not sure, they were on the car when I bought it.

 

Any fuel system upgrades? What was the botle psi? Maybe pump not working fast enough.

 

No fuel upgrades...bottle pressure was right about 1000psi.

 

I had a LPE 383 vette that I had nitrous on...I had a Holley Strip annhilator ignition system that had two separate rpm-based window switches...i had one to activate the nitrous solenoid and one to activate the fuel solenoid...I had the fuel solenoid to come on just slightly before the nitrous (1100 psi flows a LOT faster than 48 psi)...so I had the fuel to activate at 2800-2900 and the nitrous to come on at 3000...this solved the lean spike you are referring to. I am not sure if any product for LS1 engines is available that would do this, but you could always just buy another rpm window switch and put one on each solenoid.

SDB

 

Thanks, that is a good idea. I just need to look and see if Nitro Dave has something that will work.

Jason

 

You could always make the fuel line shorter, and the nirous line longer to achive the same effect.

 

when you have the bottle open the nitrous is waiting at the noid and the fuel will be waiting at the noid. unless you wanna add alot of line from the nitrous noid to the fogger which would look kinda ghey

 

Yeah, sounds like the typical lean spike. Some people have had success with using a carb FPSS after the fuel solenoid to activate the nitrous solenoid.

 

What is a carb FPSS? I am a newbie to N20.

 

fuel pressure safety switch

 

you shouldnt be hitting the nitrous til at least 3000 rpms, 15.0 is not good at all. Set a window switch for 3000

 

Gotta agree here, 15:1 is not good. As stated previously don't engage the N20 below 3000 RPM. Then you need to hook up a direct presure reading gauge to the end of the fuel rail and see how low your fuel pressure drops. Then I would set the A/F on the rich side for the lean spike and maybe pull 2 to 4 degrees of timing. Make sure your running at least TR-6 plugs for the N20.These things combined will help. You may need to upgrade your fuel system to a better pump and bigger injectors wouldn't hurt either.

 

I thought the 98 models had bigger injectors(28lb)? I have the nitrous starting at 3500.

 

if u have it starting at 3500 then why is it soo lean before that...On your dyno graph it shows your lean spike until you hit 3500 rpms...So if this is the case then your fine on the bottle but for some reason real lean before you spray...Are you sure your window switch is working right

 

From your Dyno graph, looks like to me that your window switch is not wired correctly and the nitrous is hitting as soon as you go WOT. You're seeing huge torque numbers at 2,200 to 2,500 RPM on those graphs. The torque should be much lower and then spike up at the window switch setting. That's a good way to blow your **** up. Don't spray until you get the switch fixed or wait to go WOT after 3,500 rpm.

Also, I'd think about another shop. They should have caught that on the 1st pull.

 

I see what you mean about the graph, I wondered the same thing? I checked the install directions twice on my BMN window switch and everything seems to be fine.

I sprayed 125 shot last night and got some detonation. My motor was about 210 degrees, not sure if that has anything to do with it?

Thanks,

Jason

 

Just because it's wired right doesn't mean it's working right

 

Ok,
Jason.Sorry Im a little behind.I just read your email.
Your lean condition is for two seconds.A spike is normally not as flat as that or that drawn out.You are lean right off the bat.
Questions.
What is your air fuel on motor?
Is the window switch set on the low voltage mode for the LS1?
Do you have a fuel pressure drop?
Let me know so I can help you out.
Dave