I was looking for a little advice for my C6... After reseraching this, I'm leaning towards a dry shot because I can keep the stock tune and have the ECU enrich my tune on the nitrous. The only thing that concerns me is the fact that my stock tune is very lean.... 13:2... The other thing that worries me is descreeing the maf will really throw my tune for a loop....

My cam is 215/232 117lsa, so I think it should really like the nitrous... Maybe a 75-100 shot? I apprecaite any help....

Here is my A/F

 

Descreening is not an issue, and likely will cause no problems usually does not. The benifit of a good dry shot is the fact that n/a a/f can remain baically static if set-up correctly. I run mid 11's on spray and low 13's n/a. what is happening is the maf reads a colder/denser mix and tells the computer to increase injector pulse width and thus adding fuel only while spraying. Keep you nozzles about 3 to 4 inches from MAF and you will generally start off with a mid 11's a/f, as long as you have the injectors to support the size hit you plan. In the wet vs dry thread is the math for figuring injector size and if upsizing is needed.
Robert

 

Robert,

My concern is a lean spike with a dry shot. I was under the undertsanding (based on what I've been told) that the A/F will spike and that it takes the fuel a second to "catch up" leaving a lean condition for a 1000 rpms or so...

Thanks for taking the time to answer my questions...

 

Well it can if the nozzles are to far away. The MAF dosen't get a good cold reading right away, the mix is diluted, so it takes a micro second for the chill factor. If close enough, it'll be almost instantanice. If you look at my dyno sheet in the wet vs dry thread you cans see my a/f and it goes rich the exact point that nitrous is introduced. No lean spike at all, none, nada, zilch. 3 to 4 inches from MAF and directly pointed at MAF works the best. I run low 13's n/a and mid 11's on spray with this set-up above, and no lean spike. Even the wet hits that have a lean spike, under a second total lean is generally accepted as ok and not an issue.
Robert