Did you end up sending your own throttlebody or did you source an extra?

Good updates!

 

I had to send in my own. It'll suck for most people because they will have downtime and it's risky if somehow it's damaged or if the modification has an unwanted affect. You'd have to purchase a new one (expensive) or search for a used one. It's a chance I wouldn't recommend anyone take.

I trust Jorge (I spelled his name wrong before) of Maxbore's work though. So it's a chance I'm willing to take. Also, my curiosity gets the best of me and I NEED to know if this works. Hate having to wait on manufacturers.


13fit,
If this somehow works (More hp/tq), will you be trying to apply something similar to your year Fit? What maf sensor option would you try to utilize to do something similar? If it has been done already, my apologies. I searched and couldn't find any info about it though.

 

If I did something similar, I would buy a weld-on MAF bung from ebay that matches factory and then take some intercooler piping cut in half, and have someone weld on a thin plate of metal to bring the inside diameter in enough to be around 2-5% bigger then factory.

This way, I have normal sized coupler spots instead of the hacked up plastic of the factory tube.


Part-throttle driving should improve a bit. The ecu is figuring out how to best run when the MAF is saying its fine yet the O2 sensors are saying otherwise.

This mod takes full effect after an ecu reset (battery ground or fuse pulll), do the idle relearn, and then take a few tanks of gas to get all the trims setup. I like doing higher gear uphills to force the ecu to do the timing maps faster. short bursts of say, 1 mile of increased engine load, then downshift and let the ecu get the minimal-load tables setup.

Then go test it at the track!

 

I did 8 runs tonight. The first three I was testing a Maxbore Throttle body. Then I tested the Civic Maf sensor with the 2.5" and 2.25" inserts inside 2X. Then I removed the 2.25" insert to bring up my air/fuel ratios (Bad move) and did two more runs. Here were the results.

16.007@87.16mph (Maxbore Throttle Body)
15.853@88.99mph (Maxbore Throttle Body)
15.917@87.40mph (Maxbore Throttle Body)

16.038@88.23mph (Maxbore Throttle Body/Civic Maf Sensor Housing with 2.25" & 2.5" inserts to reduce diameter)
15.959@88.54mph (Maxbore Throttle Body/Civic Maf Sensor Housing with 2.25" & 2.5" inserts to reduce diameter

16.331@85.80mph(Maxbore Throttle Body/Civic Maf Sensor Housing with 2.5" insert only)
16.323@87.22mph (Maxbore Throttle Body/Civic Maf Sensor Housing with 2.5" insert only.

The first five runs were ok. The Civic maf housing with 2.25"/2.5" seems to have an average mph higher than using the stock maf sensor although the stock one had one nice run that was faster and quicker than both the Civic runs.

The last two runs got nasty. Ignition timing dropped down to the single digits (6-7). It was running in between 10-13 on the previous runs. Something happened during run #6 around 3000rpm. It died mid run, the ignition advance dropped (Detonation?) and it sucked all runs after that. Power was lost in the upper rpm range and air fuel ratio was 14.0:1 vs 12.0-12.3:1 in my previous runs.

So...what does all this mean. The Civic maf sensor has an inlet opening similar to the stock maf sensor housing but the outlet is larger. This outlet being larger may have a slight advantage at wide open throttle. However, off idle acceleration was slightly slower with the Civic maf (2.25/2.5").

NEVER use this maf sensor if you can help it. If you plan on experimenting, please use high octane gas to protect your engine. This is tricky stuff and I'm no tuner. I'm using 92 octane from now on. No further tests with this maf since gains weren't signifcant (Losses were). That's all for now.

 

You did prove the bigger throttlebody helps!!

And you showed that going bigger does help run a bit leaner during low loads/cruising.

Trail and error is how we go forward.

Definitely putting maxbore on my to-do list!

 

Some more stuff I want to share after looking at the videos a little more. I can't race tonight anyways due to rain. I'm logging all of this so I can reference later if need be. Feel free to utilize the info as you wish.

Average Air/Fuel Ratio (A/F), Timing Advance (TA)

1st run - A/F 12.2:1, TA 10.5
2nd run - A/F 12.3:1, TA 11.5
3rd run - A/F 12.2:1, TA 11.0

4th run - A/F 12.0:1, TA 10.6
5th run - A/F 12.2:1, TA 12.8 (11.8 after 6500rpm)

6th run - A/F 14.1:1, TA 8.7-9.4 *Bounced around*
7th run - A/F 13.9:1, TA 7.0-7.5 *Briefly 10.0 at finish line*

8th run - A/F 12.3:1, TA 6.5 *Start*, 7.0 *Half Track*, 9.5 *Finish*

 

Max Maf Grams Per Seconds, Max Horsepower (hp) - Max Torque (tq)

1st run 99.7g/s, 116.5hp, 98.7tq
2nd run 99.7g/s, 117.7hp - 100.1 tq
3rd run 100.5g/s, 114.6hp - 99.9tq

4th run 100.3g/s, 112.0hp - 95.9tq
5th run 100.9g/s, 116.6hp - 95.3tq

6th run 88.7g/s, 111.8hp - 93.7tq
7th run 88.9g/s, 109.2hp - 90.7tq

8th run 100.2g/s, 111.0hp - 92.0tq

 

your results prove how important it is to maintain a good timing mark.

I really do wonder what these motors are capable of if you run something equal to 96 or 98 octane. I run on 93 and its an improvement at the track over 91.

I wish I had money to throw in a few gallons of race gas, provided the ecu can actually up the fuel trims enough

 

I almost put in 103 race gas that evening. I'm running on 92 octane right now and will be for now on. At wide open throttle, timing advance stays pegged at 15.5. All the time now!

 

Do you have colder heat range spark plugs?

stock is NGK DILZKAR7C11S, so that is roughly equal to a denso 20 heat range.

Could step up to a honda s2000 oem NGK or denso plug and you get NGK 8/ Denso 22 heat range

I suggest this also because of price. spend $30-35 at partsstore, or alot more at dealership lol.

Just make sure if you do this, the S2K plugs are similar thread length. it is possible honda reduced thread length on GK to pull plug out of the chamber a bit, and getting similar effects to a colder plug without the different parts

 

How much of an improvement did you notice at the track? What was the difference between 91 and 93?

 

usually a solid 0.08 to 0.11 seconds. I had to o half a mile from track to fill up at gas station, come back, and do about 5 runs before ecu redid the timing.

Also, I didnt do full throttle at track much. do like 90%. WOT richens the fuel mix too much, and in some cases timing will be reduced slightly until after 5-6k rpms

This is on a GE of course, honda might have adjusted it a bit on your GK

 

Nice! Won't be going to colder plugs just yet. I downloaded a horsepower plugin for the Android Torque Pro app moments ago. I want to graph out what my horsepower curve is doing between the stock and Civic maf sensor housings. I know I won't be getting any detonation on 92 octane now so my timing advance should be maxed out . Will see how it goes!

 

I still went back over the videos to look at this because I'm in agreement with you so I had to be sure of the info I took. Yes, it seems the Civic maf housing took high maf g/s than the stock maf housing while cruising only. I never put up the details though. Here is what came up.

Stock Maf Sensor Housing
70mph - 14.5 g/s (Average)
75mph - 18.5 g/s (Average)

Civic Maf Sensor Housing
70mph - 18.5g/s (Average)
75mph - 20.4 g/s (Average)

 

colder plugs have more effect then switching from 91 to 93

I would say the effect (for me) was comparable between running 87 on a factory setup and running 91 on a factory setup

 

**Update 10/19/14**

I plan on changing out the stock maf sensor housing for the Civic maf sensor housing with the 2.5" Spectre insert inside of it today. I've been running on 92 octane for a bit now, with a fill our two (I never fill the gas tank up anyways).

I plan on doing a 'street tune' when I get off work tomorrow morning to see how hp/tq is. Air temperature will be around 39F at that time per Accuweather. It'll be interesting to see how the ECU reacts and what kind of possible 'gains' or 'losses' I'll see. Looking forward to it.

Wishing I could test this at a track Monday morning though.
**Cracking knuckles for two 15.5 second 1/4 mile runs someday soon**

 

quick question, if you were to put the MAF into the 3inch Spectre intake pipe and used a 3 to 2 inch coupler on the throttle body? would there be any ill effect on the motor?

 

Yes, there would be ill affects on the motor. See my post #9. I put the maf sensor into a 2.25" pipe and my air fuel ratios went up from 12.0:1 to 17.0:1 and my ecu detected detonation. Stock maf sensor piping is 2". It was too much air going through and the stock ECU isn't calibrated to handle that much air going through at wide open throttle. Even still, the maf sensor in the 2.25" piping was reading the airfllow going past it improperly because the 2.25" diameter is larger than the 2" stock diameter. The ECU was showing less air going through the maf sensor piping when there was actually more air going through. It was not detecting the extra air going through and under the sensor itself due to the wider diameter.

I wouldn't advise going up to 3".

 

Have you done any more tests and fiddling?

 

I'm at work now but when I get off in the morning, I'll be testing the 2014 1.8ltr Civic maf sensor housing on a strip of road (both directions) that I have been doing all my 'private' testings on since late August. I'm seeing how the colder temperatures (35F or so) will affect the car with 92 octane and the leaner air/fuel ratio (13.8/14.0) and horsepower. Last time I tested the Civic maf with the 2.5" Spectre insert, it retarded the timing WAY back and I lost 7-9whp and torque.

At least this way, I'll know if while driving during winter/cooler weather, will timing be advanced or retarded on 92 octane and how much whp/tq I'll can make or lose.

Both directions of this road has different hp/tq peaks (One way is always higher than the other). I've been gauging how much hp/tq I'd gain or lose vs all the previous runs I'd do with a said modification or change. Last highest I had was around 123-124whp one way and 118whp the other. Both were the highest I've recorded since testing on this road when in started. I do two runs in both directions and look at the data at home.

0-60mph, 1/4 mile time and trap speeds are tested at the same time too vs all the other runs I've done. I'll know if it is making more power or losing it here as well.

I don't report the whp/tq results because they are irrelevant and it's not a dyno. I just use it as a gauge to know approximately how much gain/loss I've made so I know that a modification works or not. I'm pretty excited to see where this setup goes because the air/fuel ratio target is almost exactly where I want it at Wide Open Throttle (13.0). Yes, 13.8/14.0 is not close but it's closer than the 17.0 I originally got. I'll have to more 'ghetto tuning' with the maf sensor piping inside to close it just a tweak more to get the air/fuel ratio to 13.0 or so.

Sorry for the long winded reply!