Was posted on a different another site but would like your opinions also.

Mods yohsi slip on, Pro flow foam and stage 2 dyno jet kit at 1200 FT,
When i spoke to the guys at dyno jet they told me (144/146 4th clip)that running the air box lid off and an outerwear cover will not allow you to gain as much power on the low to mid range as if you just cut out your snorkle and leave the lid on, they said you will still get some low to mid range gain but less with the lid completely off... they said it is the air velocity that matters most, the small opening of the snorkle is made to funnel the air directly into the filter at a greater velocity much like blowing through a straw as compare to a roll to toilet paper. they said that the only gains made with the lid off will come at the very top end of your RPM and will not be seen by most sport riders. they said they have the dyno results to prove this......... they also said if i took the lid off to run the same jets and the clip on the 2nd grove instead of the 4th, I cannot believe the mains would be the same with the lid off too?? I would like to hear your experience on this air velocity theory??? I am just sport riding

 

This is my experience.
With the lid on my quad does not excellerate as fast as with the lid off. It was a very noticable difference for me.

 

Mine ran like crap with the lid on...it would stumble and do all kinds of things, I never noticed any loss (other than my lid), I would jet it lid off unless you run in heavy water...good luck


BRAAAAP

 

What did you do with the vent tube that is attached to the snorkle?

 

put a filter on it. AutoZone sells one that works, K&N also makes one to.

 

Mine ran bad with the lid on too, compared to the lid off. I did notice that with the lid I had more bottom end power but it seemed way faster on top with no lid and I did change the needle like they said. But I just got that kit for the lid on ebay with the outerware cover and installed that, didn't even touch the jetting and it runs even better now, I gained back the bottom end power that I lost with no lid and it has a pretty big hole so the top end was still great. To me this is the best set up yet on my quad. I didn't think it would be worth the $45 that he was asking but after installing it, I am very pleased with the results. I also had a stubble at low throtle that I thought was my jetting, but with the lid modified and back on it went away.

 

The elevation where I ride is about 1600. I talked to someone that has rode awhile and got a great set up. WB-E series slip on, dyno jet kit(148/150 3rd clip), pro flow filter kit with no lid. I have no hesitation or misses at all. A auto crank case breather filter fits right in the hose. Hope this helps.

 

I have the Dyno-Jet kit & was running with the lid on, raced it this way at FSW II. It always ran good, but I got to thinking...........Maybe more HP can be found with bigger jet's & a aluminum airbox?? This weekend at Dumont will be the big test. There will be many of the bikes I ran at FSW in attendance, so I will have many bikes to gauge gains or losses off of. I will post the turn out when I get back!!

 

I have the DynoJet Kit and the ***** pulls along ALOT harder without the lid, than it does with the lid!

I'm looking forward to your reports Ryan!

PS> I'm still waiting on some pics.[img]i/expressions/face-icon-small-wink.gif[/img]

"TOID"