E85 Nitrous Pull Datalog - Advice?

[EricM]

So I recently finished tuning my car for Nitrous, but before I up the jets to a larger shot, I'd like to get some info/advice from the more advanced members on here.

The car is on E85 and I've got 47# injectors and a 40a KB BAP. It's lean spiking pretty good on initial nitrous hit, but recovers very quickly (around .4 second). Would you guys consider this a safety concern? It goes nearly 13.8 in the spike around 4,000rpm.

I've got a progressive controller to help ramp in the nitrous slower to cure the lean spike. Although if I could, I'd like to eliminate using the controller for roll racing.

Here is a log of the 125 shot on the dyno without utilizing the progressive controller. Tell me what you guys think about it. Nitrous hits at 3800 and ends 7100.

View attachment 125shot.zip

 

[INEEDA_TERMI]

Being on a stock bottom, I wouldn't do that. To do nitrous right, you need an auxiliary fuel cell and fuel pump so that the fuel is always there. Lean spike will kill it.

 

[Sick_Mustang]

From what I see it doesn't look terrible. Not perfect.

Like I said before, 1000 psi of nitrous racing 55 psi fuel pressure to the manifold from the noid opening. Which do you think will win the race? My suggestion, if you want to experiment move the nitrous solenoid to the trunk, or have an extra long line made and just wrap it in one big circle. This will help, how could it not?

In addition to the above, judging by how much your stft's are pulling and how rich it is running, id say its safe to step down one jet size on fuel.


Also, much easier to speak in terms in lamda than stoich of each fuel.

 

[INEEDA_TERMI]

Auxiliary fuel is the best way to go. That's how the pros do it. That way, you don't tax your primary fuel system trying to make it do something it wasn't designed to do. You can't tell me a dedicated system won't work better than trying to do it all from one pump. Because Think About It, even the fuel at your solenoids has to come from the primary pump. That's why the lean spike. Your taxing the fuel system. If your primary pump fails on you, bye bye motor. Any time you induce nitrous into an engine you have to have a comparable amount of fuel. This is old school hot rodding 101. Call some of the mainstream nitrous companies and ask them the BEST way to do nitrous. Trust me. I've seen too many guys blow engines from lack of fuel flow, burned plugs, detonation, lean spike etc.

 

[EricM]

From what I see it doesn't look terrible. Not perfect.

Like I said before, 1000 psi of nitrous racing 55 psi fuel pressure to the manifold from the noid opening. Which do you think will win the race? My suggestion, if you want to experiment move the nitrous solenoid to the trunk, or have an extra long line made and just wrap it in one big circle. This will help, how could it not?

In addition to the above, judging by how much your stft's are pulling and how rich it is running, id say its safe to step down one jet size on fuel.


Also, much easier to speak in terms in lamda than stoich of each fuel.

Thanks for the helpful info! I see tons of people spraying a 150 on pump gas, with less safety measures. Do you think the E85 is hurting me, more than helping? I'm almost feeling like going back to pump gas will allow me to spray a 150 safely since there is less fuel volume.

As of now I'm running a 52N and 42F, so I could definitely bring it down some.

As far as a secondary fuel system, I have no desire to do that on this car. There's plenty of other people spraying nitrous just fine without that.

 

[INEEDA_TERMI]

Sure, your car man, just trying to show you another aspect of the game in case you weren't aware. You asked the question so obviously you're concerned about your car.

 

[JUIC3D]

Ok, looked at the logs and have a few comments.

1) WAY too big on fuel pill. It's pulling 7-10% fuel once the nitrous comes in and 20-25% from 6300-7400. That's not good. Either your bottle is empty/low psi, or if its a steady 9-950psi, then your fuel pill is way too big.

2) 19* on the hit and 24* peak is a lot of timing for a 125 pill but that might just be my overly cautious attitude.

3) Your tune is commanding .82 lambda on nitrous..thats not good. You need to have the correct commanded fueling otherwise tune till never be right. These cars have widebands so you can't just put in a fuel pill for the nitrous and not expect the computer to try and compensate for the overly rich condition. If you want .77 lambda on spray, then you need to command that in the tune.

 

[mastwolf]

Ok, looked at the logs and have a few comments.

1) WAY too big on fuel pill. It's pulling 7-10% fuel once the nitrous comes in and 20-25% from 6300-7400. That's not good. Either your bottle is empty/low psi, or if its a steady 9-950psi, then your fuel pill is way too big.

2) 19* on the hit and 24* peak is a lot of timing for a 125 pill but that might just be my overly cautious attitude.

3) Your tune is commanding .82 lambda on nitrous..thats not good. You need to have the correct commanded fueling otherwise tune till never be right. These cars have widebands so you can't just put in a fuel pill for the nitrous and not expect the computer to try and compensate for the overly rich condition. If you want .77 lambda on spray, then you need to command that in the tune.

This.

I'd Command .80 lambda and adjust your fuel pill to that, just like Justin said.

 

[EricM]

Thanks guys! Adam Browne is the one tuning the car, so I'll relay this stuff to him. What kind of timing would you recommend Juic3d?

And did you ever have the lean spike issue on a 150 with E85?

 

[mastwolf]

Thanks guys! Adam Browne is the one tuning the car, so I'll relay this stuff to him. What kind of timing would you recommend Juic3d?

And did you ever have the lean spike issue on a 150 with E85?

I used to run ~24* when I used to spray damn near a 200 shot via direct port. On pump/race gas mix. I'd say 24* on E85 would be safe. Looking at your logs I did not see any knock.

Side note, this was on the same motor Im making 750+ with right now, and 62,000+ miles...take it for what its worth.

 

[EricM]

I used to run ~24* when I used to spray damn near a 200 shot via direct port. On pump/race gas mix. I'd say 24* on E85 would be safe. Looking at your logs I did not see any knock.

Side note, this was on the same motor Im making 750+ with right now, and 62,000+ miles...take it for what its worth.

That's extremely impressive. My ultimate goal is to spray a 150 safely, so I'll talk to my tuner about at least richening up the commanded lambda.

As far as that initial spike, is that something you also dealt with?

 

[JUIC3D]

24* is most I would push on a stock motor 150 kit if you want it to last for any amount of time. All nitrous kits have lean spikes. nothing to worry about. Yours wasn't alarming by any means. You can give it a little more fuel in the maf when the nitrous comes on to help with the lean spike, but you'll be rich at that point when you're on the motor so its a trade off.

 

[EricM]

24* is most I would push on a stock motor 150 kit if you want it to last for any amount of time. All nitrous kits have lean spikes. nothing to worry about. Yours wasn't alarming by any means. You can give it a little more fuel in the maf when the nitrous comes on to help with the lean spike, but you'll be rich at that point when you're on the motor so its a trade off.

Gotcha! Well I'll see if he can send me my file with the user settings enabled after he's done that way I can remove another 2* globally. I would probably feel a bit better about it.