So, I have an '08 2.L Auto.

I had my car dynoed on November 21st:



77*F, 16% humidity, 87 octane.

Then I installed a K&N Short Ram and ran it for a month.

I had it dynoed again today:



44*F, 29% humidity, 93 octane.

How the **** did I lose 2whp? My AFR drops like a rock. Seriously, 10:1 AFR on an N/A car?!?!

Help...

 

Why are you running 93 octane? That's your problem right there. No need for it and you won't gain a thing w/o tuning for it. Also, don't even compare dyno runs from separate months. If you want to do a comparison to see how much power a mod makes, do a base run and then install the mod and dyno again that very same day.

There is nothing to compare at this point. There are so many variables it's not even funny...

 

From what everyone says, 91 or higher is best for the 2.4L.

There was a base XFE there that put down 145whp. Same AFRs though.

That's what's concerning me. That's really low.

 

91 is fine but I wouldn't run 93 unless you were boosted or tuned for it. As far as numbers go, there are a ridiculous number of variables involved here so don't sweat it. You won't gain much from just an intake anyway so the numbers should be right around stock regardless.

 

91 is what the vehicle is recommended to run from the factory, iirc. Use that, and don't bother w/ 93 unless you are going to tune for it as there is no reason for it. Post up a pic of your full stock dyno sheet. What was the AFR on that?

 

im sorry but, with the way cars need to be tuned now, dosent the adding of that much more air need to be added in a tune.

and yah dont waste money on the high octane enless your boosted

 

from dynoing my car, i think 2.4's run really rich. thats why tuning gives it so much of a difference. plus, it may be like the headers i put on.... it may decrease the low end HP, but raise torque, which is better

 

send your dyno sheet to k&n. It would be interesting to know what they have to say considering all their products are "dyno tested"

 

That much more air? He added an intake...that is almost nothing by itself

They won't give 2 *****. The dyno conditions have way too many variables to be even considered. Like someone earlier said, if you're going to do a comparison dyno you gotta get on a dyno, install, get back on.

 

The temp differences alone are enough.
Muchless the different fuel.

hell the dyno operator could of just strapped your car down tighter

Too many variables. If it still feels faster then theres a good chance it is.



I have an 08 sport 2.4L auto which is the same as your car and trust me back to back with my families stock 2.4L auto theres a good difference in performance.

Me:
91-93 (depending on whats available) jet stage 2 chip (requires premium) and the Injen CAI (being ran as an SRI)
Family
Stock on 89 octane.

So I mean there should be a difference but theirs feels so lifeless after 50-60mph its not even funny. And theirs was faster than mine when we both had them stock on 87 (what the dealer filled us up with)


Also a few other things to think about. Your an auto. that xfe is a 5 spd which has less drivetrain loss. Also a stock 08 5spd will put down about 155-160hp. Automatics have higher drivetrain loss.
Just some food for thought.

 

I'm perfectly aware of the parasitic loss of an automatic transmission.

I'm pissed off because, it seems like I've wasted $300.

The colder weather, theoretically, should help the numbers.

I'm dropping back to 87 octane. Hopefully that will help to lean it out a bit.

 

For one we are in WINTER GAS now.... which will drop all performance.

2ndly you won't get a full gain out of those without getting a tune with it.

I would imagine most of the drop is due to the **** gas we have now

 

This man has another point. Winter gas will produce lower horsepower #'s. My gas mileage does also fall off during the winter.

So I wouldnt say you wasted money on the intake. On the dyno yeah.

 

There are too many variable like everyone is saying. Around here its hard to find 91 Octane. All the gas stations here have 87(regular), 89(plus), or 93(premium). Some of the gas stations sell 91 but I'm not going to hunt around for it

 

retune

 

thats amusing you have to hunt some for 93 around here

I end up running 93 but the jet module calls for premium anyway and the 91 stations are actually further away oddly enough but the car still feels a bit peppier on 91 than 93.

 

I never even thought of that.

The only thing that hurt more yesterday, was the bone stock XFE putting down 143whp.

You're a tuner, what would you recommend tune wise? I need something stealth.

 

Not many options for 08s.

LS2Edit
Trifecta
or Jet

 

What about HPTuners?

 

its the winter gas mix and the difference in time as other gurus have said.

also how did you guys manage to get a dyno run with an auto to go down accurately?

 

Just got it into 3rd and feathered into it.

 

No hptuners sadly.... Trust me I would been long since tuned if that was the case I got a great deal on the jet modules and went with them. they are better than nothing but thats about it.

 

Wouldn't I have been on winter gas back in November?

 

maybe maybe not. All depends on the station and area. Hell for that matter you couldve gotten a bad batch of gas or couldve gotten gas from a different station. Just too many variables.

 

I wish I could tune you... unfortunately I can't.

Trifecta prolly your best bet. But you need to look at the other variables.