Air Box Mod Consensus

[Hinkman]

I know this has been discussed in length, but I am confused.....

I have read a lot of posts about modifying the airbox and am wondering what the consensus is. Some say go for it, works great. Others say you'll lean it out and the CO adjust will only compensate for the low/mid range, you'll need a power commander for the top end.

I have modified mine, probably a little different than everyone else. Now I'm wondering if this was a smart choice or not. I do run this thing clamped on high speed railroad beds for miles. I have bumped my CO to +20 for now, but have not had a chance to run it yet.

My rough calculations show the cross sectional area of the 4 throttle bodies around 28 square inches. The inlet at the bottom of the box is around 14 (about half). I decided to cut 4 square holes out of the ribbed section (drawing warm air) under the filter to bring my inlet area close to 28. I realize this area does not provide the best air flow or coldest air, but I just wanted more flow and didn't want to worry about icing.

I can post a pix if anyone wants to see it. Aside from the air box mod and a 23 tooth upper gear, my sled is bone stock.

What are your thoughts?????????????? Am I headed for a melt down when I clamp it on a long run???

Regards,
Hinkman

 

[ROCKRTX]

I have modified mine, probably a little different than everyone else. Now I'm wondering if this was a smart choice or not. I do run this thing clamped on high speed railroad beds for miles. I have bumped my CO to +20 for now, but have not had a chance to run it yet.

I have done the air box mod and my sled run good at +5 on the co.
+20 might be a little rich but every sled is different.

 

[Hinkman]

49 reviews and only 1 response..................maybe more people have the same question.

ROCKRTX,
I just set it to 20 as a precaution. It does seem rich on idle and idle rpm is down a bit. Maybe I should drop it down. Have you run it flat out for a few miles and looked at the plugs?

 

[ROCKERDAN]

run it...you will love it!....running my ramair system now for 4000+miles and its always the strongest apex in the group.....ran 120 on the gun last winter(off the bottle) and works well.

I believe mine is set at +15 on the pod .....

I was the one who tested the ram air on radar,ran a 114.6 with ramair that day,then put stock TOP on the box and ran 110.3.....proved to me how well the ramair works.

Lots of pics of mine are in my "Made my own RAMAIR" thread found here
http://www.ty4stroke.com/viewtopic.php? ... ht=ram+air
...on page 3 of the thread I even took out more material to allow more airflow...runs awesome,sounds awesome.

Merry xmas
Dan

 

[KnappAttack]

There's a better way to introduce additional air without all the noise. I'll post some pictures after Christmas. Be careful, you can get it too lean if you have not done the testing on where to add intake. You guys realize the CO adjustment only affect idle right? Going up will have no affect in mid or top-end fuel delivery.

 

[ROCKRTX]

49 reviews and only 1 response..................maybe more people have the same question.

ROCKRTX,
I just set it to 20 as a precaution. It does seem rich on idle and idle rpm is down a bit. Maybe I should drop it down. Have you run it flat out for a few miles and looked at the plugs?

You should only raise the CO if you have a bug wen you blip the throttle ,no i did not check my plug because it will not effect fuel curve pass 7000 rpm.i try at + 10 and my sled feel too rich.so i back at + 5 and my engine feel healthy with no bog.

 

[07 GT]

I don't mean to hi-jack this thread but how do you do the CO adjustment? My sled has a slight hesitation right off of idle when you wack the throttle. Maybe this could cure it.

 

[Kevin Garceau]

it can be found at www.ulmerracing.com I dont know if we have it here or not.

 

[Hinkman]

Thanks ROCKERDAN, I have read your thread, but never been able to see the pictures, so I wasn't sure what you did. Now I can see them for some reason, nice job BTW. You're pulling in cold air and are at +15 on the CO's..........seems like if anyone was going to run lean, it would be you. 4000+ miles must account for something............


KnappAttack,
Last season my buddy tweaked his CO values and then we hit the railroad beds for a test run, he was getting slightly faster after each adjustment........its gotta be doing something to the fuel tables besides just the idling values. We both had stock 06 Apex GT's. Mine was significantly faster for some reason, then he wrapped his secondary to 60 and did the CO adjustments.........then he made me work for it. Before that, I could walk him whenever I felt like it (my CO's were all zeros).

Where are you getting your info about the CO adjust from....I have the Yamaha EFI Theory & Diagnostics DVD and it just shows you how to make the adjustment, but no theory or mention of what you are really adjusting.
I also didn't see anything about it in my service manual. Please understand I am just trying to learn how this works.

When you post your pix after christmas, would you please also discuss the LEAN issue you've seen.

Regards,
Hinkman

 

[SledFreak]

There's a better way to introduce additional air without all the noise. I'll post some pictures after Christmas. Be careful, you can get it too lean if you have not done the testing on where to add intake. You guys realize the CO adjustment only affect idle right? Going up will have no affect in mid or top-end fuel delivery.

Ulmer said the exact same thing... Too much air will hurt the performance.... It has to be in the right places and not to big of a hole.

 

[Pureadrenaline]

We really need someone who has a dyno, run it with the stock cover then the modded cover in the same day.

 

[MUSKOKA APEX RTX 07]

Over 2000 Miles with Ram-Air and no probs and i didnt NOT set any setting. just put on modded lid and left it and all is well here.my machine didnt not even run close to Rockerdans till i put on the Ram Air and Fixx kit now we are neck and neck HAPPY HERE !!!!!!!!!!!

 

[trailmarker]

i must have the slowest apex, i did the air box mod, louder at idle... it barks, no increase in speed... i will have to come up to mary lake and run against dan and muskoka

 

[Hinkman]

ROCKERDAN, MUSKOKA APEX RTX 07

This is prolly a dumb question, but do you guys run wide open for miles???......I'm concerned about leaning it out on a long run.

 

[Daranello]

I always leave her stock when running long wide open runs.
Some of my runs at WOT are over 20miles strait.....that's noting to mess around with.