Just got the car dynoed this weekend at the Sport Compact Nationals in Raceway Park, New Jersey. I was a little dissapointed in the results. My A/F Ratio was all over the place. at about 6000 RPM the a/f went down to 10. What should I do? UTEC? Also a guy with a bone stock 2003 base got 249 HP.

MODS:
Top Speed Headers - Injen Intake - Crawford Plenum - IMR test pipes - Borla True dual Exhaust.

dyno shhet:

 

I would have to say you need a custom tune. Whether it be a UTEC or a Reflash. You want to take advantage of your mods. There is more power to be made out of your car. Did you get to see what the A/F ratio was on the bone stock car? Just curious if it was off. Sometimes the tail pipe sensor does not read right. Just a thought.

Later
Aceman

 

mike i feel your pain man.... i have very similar mods, and my AFR is also screwy. my car turned a 243 on the Dyno Dynamics at MRC (which another 5AT with just intake and exhaust pulled the same). i think we both have more power to be had with a proper tune

 

Thanks for the charts. I'm surprised that the air:fuel ratio goes wild rich after 2,500rpm. I would expect to see lean.

BTW guys, what is the preferred ratio for a naturally aspirated motor? 14.7:1 to 13.7:1?

 

well at 14.7 you will burn all the fuel possible. now for best gas mileage with performance this is perfect. now to make more hp and throw out the gas mileage you want your AFR more towards 12.7s NA.

i will be dynoing my car very soon to see where my car makes the most power NA and will let you know my results...

 

This is the very reason I am getting engine management. The stock ECU does retarded **** when you put mods on the car.

I want the ECU to have a good map and stick with it. No more stealth adjusting, losing hp etc.

My guess is the mod causing you to run rich is your CAI. Long tube intake probably can't get enough air to the plenum. I could be wrong, but one way or the other you need engine management.

 

What are you looking to get steve? maybee we can get a deal at MRC with 2 cars. and to top it off, driving home from englishtown I got abused by an 1989 Turbo Supra. I felt like a loser, lol. We raced from a dead stop and he let me pull ahead about 100 feet, I hit 4th gear around 100 or so and he flew by me doin 140. I gotta make my car faster...

 

Yeah either a re-flash or a piggie back will work great.

 

well, a Supra is no joke, even an old one... the Supra motors are one of the strongest and most boost friendly motors around, even the 1JZ motor in that '89 MKIII that blew you away

trying to compare the G/Z to a Supra, or like an EVO, is impossible.... either of those cars can do only a few thousand $ worth of mods and be extremely quick. the G/Z requires alot more cash and work to make that kinda power.

as for the mods we have now, i feel that we can probably pick up a solid 20whp more from our current setups with the installation of a UTEC and a good tune. i need to goto MRC sometime in the next few days to fix a problem with my cats, so i can talk to them.

 

I agree with Wired 24/7, you might like to try removing CAI first. I don’t know if Mr350Z had same CAI, but he *gained* 15+ WHP by going stock.

https://my350z.com/forum/attachment....2&d=1146023769
https://my350z.com/forum/showpost.ph...&postcount=230

 

Vantage has confirmed that the wideband in the dyno at raceway park was way off point..His A/F was perfect on our Dyno last weekend..

 

Yea, their A/F censor was pretty terrible. All they had was a little clip on my exhaust tips. MRC's was much better.

 

Doesnt suprise me one bit. I have never seen a DynoJet lazy **** wideband read even remotely accurately (at least on the 4 that I have used). They require constant cleaning, and are often not well maintained. Dyno Dynamics all the way!

 

Anyway the first chart looked decent and typical. The Factory software is set for reliability and durability to meet EPA and warranty requirements on cat life............ by running richer and richer as rpm and load rises to WOT.

Because some driver will try a long top speed run in hot summer conditions with marginal low quality US pump fuel and damage the cats if the are set to 12.5 AF.

 

Don't get too tied up with AFR numbers... tune the car on the dyno so it makes the most torque at the wheels.
Lean it out until it starts to platau, and give it a point back.
AFR is very dependant on where the sensor is, age of sensor, free air reversion to the sensor, brand of sensor, brand of brain the sensor is attached to, calibration, fuel used etc.

I've done type R Civics that have made their peak torque at 15.5:1 on one dynos Lamdba setup, and 13.8:1 on another dynos setup.

Tune to the car, NOT a number.. number is just to tell you if you are in the right ballpark.
If its still making its peak torque, then its not knocking.

BTW Sharfic, you will cry when you have a play with a Dynapac setup if you think the Dyno dynamics machine is nice

 

Cry in a good way? Or a bad way? Most dynopaks are limited in how much power they can measure, and will max out at 600-800whp. And I dont enjoy jacking up cars, and taking off the wheels.

 

i feel the pain also guys...i have similar mods and dyno'd around the same as the original poster of this thread.

i am thinking about going with the utec since with my mods i know i should be making more power.

they had a baseline z dyno'd almost the same as me! i know all cars are different but with my mods i expected much more...dissappointed as well here

btw i have dc sports ss headers, crawford hf cats, fuji y, fuji ti, crawford plenum, and cda intake

 

Just an FYI....I tuned an out-of-the-box Vortech car yesterday on the dyno. After 5500rpm, AF ratio dips deeper than 10.0:1, so maybe you gauge isnt too far off. After retuning, we netted a 40whp improvement, on our Dyno Dynamics dyno....probably even more on a DynoJet.