Its funny you should mention this Zippy. Ed Mack's truck pins the MAF right at launch which makes the fueling difficult using the MAF tune while spraying. Any tips in this area to keep the fueling stable besides raping the Pe EQ ratio table? The truck is on a logged wideband and never goes above 11.8 when spraying however there are times when it is pegged at 10.0 (I am assuming it is even richer than that). Regardless, it hauls *** with the 75 shot.

When not spraying, the truck runs what is commanded as the Ve and MAF are dialed in for non N2O WOT.

 

wet or dry?
why dnt u just try meth to keep it cool...

 

The IAT sensor is in the manifold of the Radix and it maybe just too slow to react to the change..I dunno.


I definatley will...just waiting for the temps to get high again so I can do a comparison.

 

One thing that I have learned recently through threads like this was that nitrous used to cool the intake air doesn't work. I can't understand it as nitrous is so cold, maybe meth for the sole purpose of cooling IAT looks to be the best option. It's added octane and ability to run more boost and timing would be an adding benefit. I would have bet money that nitrous at -127 would cool IATs a good bit.

 

Thats exactly what I thought and was the main reason i added nitrous but it definatley desnt change them...I do think however it stabilizes the IAT's. In my logs my IAT's plateu and flatten out...that could be from nitrous I think.

 

Nitrous HAS to have SOME type of cooling effect in the intake..There is no way around it. I dnt think the IAT sensor is able to pick it up IMO...

 

What would the amount of nitrous be compared to the amount of air going through an engine at 3000 rpm and up? That little bottle holds enough nitrous for several runs. If you had to bottle the air that an engine goes through on one run, how many bottles would that =. I'm guessing a bunch.... even compressed. That might be one reason the nitrous doesn't cool things much.

 

Part of the issue on the older truck systems is how far the nitrous has to go to reach the cylinder heads and how much hot aluminum it passes on it's way. The older J-tube systems have a long ways to travel to get to the blower and then down to the cylinder heads. It's not uncommon to see a decent boost increase when spraying which also doesn't help the heat issue. You make more pressure which made your cooler air hot air. The location of the IAT sensor in the older Radix systems also has some effect on it as Brad mentioned.

Kevin, I'm guessing by how I'm reading Ed's issue is that the problem only occurrs when spraying. If that is the case only tuning the nitrous system or doing a 2 bar tune can help fix that. It is not uncommon to see a spike of lean when you first hit the button which can be somewhat lessened by having the nitrous line double the length of the fuel line from the solenoid to the nozzle. The only other big thing you can do to help that is to make sure the fuel and nitrous pressure are as close to the same as possible on every pass. Running dual bottles really helps that.

 

well to answer your question for every 2 revolutions of the crankshaft you would be able to displace just under how ever many liters or CI your engine is. mine =6L so for ever two rpm thats about what i can displace at 100% efficiency unless you compress the air which gives you the same volume but a different density. as for how much nitrous is flowing depends on jet size and i have no idea and will leave that to the experts

 

Alright..just got back from the dyno..it ended being 406 hp on motor..then tuned it "down" for a small dry shot..it was a #26zex dry shot...with the tune for the spray it ran 397 on motor..then 422 with the spray...this was on #9 of boost...Yes i was scared to spary it more..