Does anyone know why I would be leaning out so much in the last 1,500rpms? I had it dynoed, and the a/f looks good til right at the end, and then its slowly gets leaner and leaner...Then they did a run on nitrous and it got so bad, they had to let off in the middle of the run. Im afraid to run my nitrous now because if it does lean out up top I dont want to cause any damage, or knock. How can I fix this problem? Or what can I do? It sucks having nitrous and being to afraid to use it....car gurus help me out!

 

Define lean. I am sure you know a NA car can be leaner than boosted cars. If you have a dyno graph, I am sure we all can help...

In fact, I wouldn't mind seeing the stock and the nitrous graph just because!

Kris

 

put your stock header back on man, it will solve all your problems.. that megan peice is throwing off your AF's... you are experianceing the same thing that i experianced on my friends car, full megan exhaust and it would lean out up top too.... and since you have a opened up exhaust system...(60mm) take out your plugs and regap them to a closer gap, i think stock is .044 so try something like .038 it should help out with your lean condition.

 

I cant find my damn dyno graph, but I know at the bottom it was a straight line at around 12? Correct me if Im wrong...then during the last 1,500rpms it starts a sharp upward curve...and even earlier and sharper with nitrous...so if I put the stock header back on, would I have to put the stock b-pipe back as well?

 

You can keep your b-pipe.

 

i dont think 12to1 is that lean for NA it's around perfect

 

12's in the AFR's is fine for NA. 12.5 is probably the highest Id go.
With nitrous, Id keep it under the 11.8 range. 11.5 to be safe. Also regap the plugs a little lower.

Interested in the power NA. What did you put down?

 

Yes it stayed at 12 until the last 1,500-2,000rpms and then the graph started climbing at a sharp angle up to like 18 or something, if I remember correctly.

As for the dynos...as a baseline with all my bolt-ons I made 103whp and 98ft. lbs, if I remember correctly. It was the highest NA dyno Ive seen yet...

 

well, I cant be sure exactly what ratio it was....I just know on the graph right at the end it started going up quick...and I am not sure if it got to 18 or not, but it did spike up...

I have never had a CEL with the header...

 

duude... im telling you that POS megan header is fukin up the AR's swap it out before you burn a valve. my friends did go up that high, but it did reach 13.2 up top.

 

if i find my graphs mine did 107WHP with 100 lbs ft all NA.

 

Anyone have any idea what the max output pressure and volume is on the Fit's fuel pump?

 

last time i checked it was 55 psi of fuel pressure.

 

Well, I guess to make sure, once I get the header off I will go and do a baseline again with/without nitrous to make sure the AF is not leaning out, and then once I do that I can post some dynos on here...

Thanks for the info everyone!

 

Damn, is that max unregulated pressure? and no word on the max fuel volume?

 

yes sr.... my pressure gauge show 55 PSI at idle

 

what kind of dyno u running on?? a dynojet?

 

Yeah it was a dynojet... I dynoed 103hp & 98ft. lbs NA, with nitrous I dynoed 146hp and 142ft. lbs with my 50 shot, but its a little low because they had to let off at the very end due to the leaning out...

 

It's funny you mention the lean at 1500rpm before redline. Edmunds.com log on their long term test fit states that theres no power above 5000rpm so they found it unnessary to run up to redline. So im wondering if a v-afc would help this car alot.

 

Well, I actually tried to use nitrous and shift early, and it didnt run well at all...if you shift that early it puts the next gear way out of its power band...so its useless to shift then.

My question has been and still is, would putting a V-afc on this car allow me to fix the leaning out up top?