lean on a 75 shot
 

I have tried a wet 75 shot on my car twice now and its been going lean both times. According to the plugs (white as hell). At first i tapped the fuel before the injectors so i thought it was robbing them of fuel so i moved the fitting to after the regulator, but the plugs are still white. I have a walbro 255 and the fp is set to 45 with the line unhooked. Have not had access to an external fp gauge but the gauge under the hood goes to about 60 when revving the motor. The car feels real good (lean):D but i dont like it with almost 100k and a stock bottom end. Any help is greatly appreciated. Thanks

Re: lean on a 75 shot
 

bump up the fuel jet

Re: lean on a 75 shot
 

nos recomemded a 40 n2o and a 26 fuel. I already have a 28 jet in the fuel. I was going to try a 30 soon but was just curious if any one else had the same problems.

Re: lean on a 75 shot
 

When I ran the 75 shot , I was using a 40 nitrous and a 28 fuel , same as NOS recomended in their book for the 75 aproximate RWHP shot.......this was plenty rich for mine as it is designed to be......you really need to get a visable manual fuel pressure gauge on there while making a full pass(NA) to see EXACTLY what the fuel pressure is doing under load gear after gear......also make sure of where your total timing is set, pull a few (3-4) degrees if you can....(and if you haven't already)go to a one step colder plug gapped at 35thou........:cool:

Re: lean on a 75 shot
 

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Re: lean on a 75 shot
 

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Re: lean on a 75 shot
 

a good rule of thumb on timing is 2 degrees per 50 shot. It is over kill in most situation but again is a good place to start. If you have not pulled timing, that is your problem, if you have, bump to 30. Every car runs a little different which is why there is so much difference between tunes and so on.

Re: lean on a 75 shot
 

did u remove the schrader valve when u put on the fuel line to the solanoid?

Re: lean on a 75 shot
 

Are you pulling the plugs out to read them as soon as you make the pass?

Matt

Re: lean on a 75 shot
 

Yeah, you basicallly have to turn the engine off right after you cross the finish to get an accurate reading on the plugs

Re: lean on a 75 shot
 

What a/f would you guys consider to be lean while spraying? May want to take it to a dyno and see what it is doing using a wideband.

Re: lean on a 75 shot
 

13.0 and up.

Re: lean on a 75 shot
 

i would pull some timing on it 4 degrees should be right on the money. you could also check the size of the jets on other companies. most nitrous systems are very similar