Reasonable.

I'd hope that dynos have a small percentage error, even if their mechanism has a markedly different design. From other posters (including myself) a stock Fit produces between 80 and 90 whp. Even if we take the high end of 90, this equates to an increase of 34% to make 121whp. How much of this would you attribute to dynamometer inaccuracy?

Published unverified gains list CAI and CAT-back has having well under 10whp gain on Fits. Anecdotal accounts are less. What gains are there to be had from removing the catalytic converter?

 

Still no information on how it works. You are still surmising.

 

That's all it can do based on its inputs and output. There's no guessing involved. If it only outputs a maf signal to the ecu then all it can possibly do is mess with the maf signal. You can be stuborn on this point all you want, but it can possibly do anything more.

 

I tuned and dyno'd my Spec V using a dyno packs, my results were higher than expected too. It's the nature of the dyno packs. But I wouldn't call it error, if anything tire slippage on the Mustang dyno (roller) is error.

Oh yeah I want to mention, I have used Air/Fuel controllers on my other cars to tune. I have seen some very good result (4-7 hp gain). I have never used the V-Force, and I am not familiar with it. My experience with afc: it's NOT a first mod, expect min gains with less mods. With a higher air flow set up (ie: Cai, Header, Catback, Injectors, ect..) is when it becomes worth it.

Good Question! Quick search and I found 3-5hp gain from going T1r catless. That's pretty impressive I have to say. It seems to be restrictive.

 

I have no experience with piggyback controllers, only flash tunes and that was on a factory turbo.

By AFC you mean generic Air-Fuel Controller I guess. In response to Loud, it doesn't take an automotive engineer to discern the difference between a con and a controller. More on this below.

The gains by CAT elimination of 3-5hp are reasonable. Were these listed by a manufacturer or actual results? What type of car?

We can "surmise" 5HP from the CAT delete, and 4-7HP from a legitimate controller plus other mods (CAI, injectors) for 12HP before going to forced induction. Is this your take? Is this on a Spec V or Fit?

The v-force intercepts the map/maf signal (one or the other, not both) and taps into the TPS and o2 sensors. And that's it. Its controls are limited to changing the brightness of the display. There is no adjustment of any "performance" variables or any external interface.

The AEM Fuel and Ignition controller pointed out by Loud for comparison has 46 potential inputs/outputs. It intercepts and modifies the following:
crankshaft position sensor
1 or 2 camshaft position sensors
MAF sensor
MAP sensor
Fuel injector drivers
O2 sensor

In addition it has its own pressure sensor (separate hose to intake manifold)

By intercepting and modifying signals to/from the crank and cam position sensors it's able to modify timing.

By intercepting and modifying signals to/from the 02 sensor, MAP and MAF, and fuel injector drivers it's able to control fuel pulses.

In addition it has a USB port for complete tuning adjustments via windows based PC. Fuel maps, ignition maps, MAF/MAP maps are entirely customizable.

They don't recommend it for anything other than non-factory forced induction applications.

So, Loud, what do you conclude?

 

I applaud u steve for having monk-like patience.

 

And I booo Steve for not acknowledging that he still doesn't know what it does.

 

And yet you have not posted anything to give us a reason that YOU understand it.

 

Then please, enlighten us. He's been saying what it does, even stating how aem fic works. If that doesn't satisfy you, then explain to us and steve how it works, instead of basically ignoring what he's saying.

Cheers!

 

I agree Steve, AFC (regardless of brand) are a waste of money IF: Hondata, Cobb or Jim Wolf make software/ hardware for tuning. But in the case of our Fit and my Spec V; there is not a company that has support for tuning. So our only option is an AFC. AFC are expensive for only being able to control air/fuel ratio.

One of the guys on this forum posted his T1R catless gains for his Fit. That's where I found the results.

My Fit is stock (not for long), I used Apexi AFC on the Spec V. And Cobb tuning software on my WRX.

 

It doesn't take a rocket scientist to figured out what it does based on the input and output. It states that you connect MAF/MAP and optional a/f. That pretty clearly means it can adjust the a/f ratio by altering maf/map signals.

 

To be fair to Mr. Bang, he did offer this 25 posts ago.

If the v-force box is altering the MAF/MAP signal during closed-loop operation, feedback from the o2 sensor will negate any changes introduced for the MAF signal. If the changes to the MAF signal are too much, it will trigger codes by the MAF sensor being outside of the normal voltage range.

Since realistically we're only interested in WOT performance when the system enters open-loop, if the throttle position sensor signal is used by the v-force box to trigger a change to the MAF signal resulting in a rich mixture (but only at WOT), this could result in more power.

This review of the device (skip to post #19 for the punchline) provides evidence it's altering the MAF signal during closed-loop operation pointing to the first scenario. This operation is consistent with the resistor devices offered on flea-bay for altering MAF signals.

The maker's description doesn't provide any insight.

 

I believe a 5hp gain (from 117 stock to 121).

I do not believe a 35hp gain, which the thread originally points at.

Regardless, I appreciate the OP posting his findings.

 

+1

Keeping in mind as that the type of dyno used typically uses a correction factor to provide "at the crank" HP numbers. So, an engine marketed from Honda as producing 117hp at the crank, moving up to 121hp at the crank is more than believable with the listed modifications (primarily the cat delete.)

 

nevermind...

 

[QUOTE=De36;1191649][QUOTE=Steve244;1191607]If the v-force box is altering the MAF/MAP signal during closed-loop operation, feedback from the o2 sensor will negate any changes introduced for the MAF signal.That's an awfully limited set of situations.

 

The point of an afc is to get a 12:1-11:1 ratio at wot. The engine doesn't need an 11:1 a/f ratio at any other % throttle. Only at wot. If more power is needed, give it more throttle. Steve is right, the O2 sensor at any other % (besides wot)throttle is going to correct it back to a 14:1 regardless of what the afc.

 

But you dont want 12:1 or 11:1 AFR

Best power for a naturally aspirated setup is 12.7-13.1:1 AFR In my experience. Ive tuned a couple 4 cylinder and 6 cylinder all motor, turbo, and supercharger setups. Every setup was different, but all the allmotor setups fell into that glorious high 12 low 13 AFR range for best power without riding the limit of reliability

Thats the BEST for MOST naturally aspirated setups.

11-12:1 is for boosted cars that see a surge of air and the engine doesnt react fast enough. If you do data logging that can record as fast as the ecu sees stuff, you will see a spike of over 13 on a very responsive setup. Ive even seen a spike to 16:1 on my turbo crx, and that was a laggy diesel turbo that was barely being stressed at 320whp

 

I was using those ratios as examples for the sake of simplicity. Yes, you are correct though, boosted cars like to run richer because it keeps head temps down (11:1) due to the higher pressures. Na cars run around 12:1-13:1 because it is a more complete combustion. It's different for every set up.

 

You are in a roll today with ignorant posts. I never said I did know what it does. The point you missed was stevie knocking a system when HE doesn't know how it works. Get it now?