[chevrolet]

I just finished my air intake modification to my 2007 H1 as was wondering if I need to rejet. I stayed with the 1 1/2" size and cut the stock hose of right outside the airbox and put a 1 1/2" elbow on it. It doesn't sputter but I here they are really lean from the factory already. I just don't want to ruin my engine from running it too lean. I' ve attached a couple of pictures to show what I've done. Any advice would be helpful. Thanks.

 

[Steve07]

I thought about doing that with mine. I was always concerned with the amount of heat coming off the belt exhaust though. In the summer, my H1 plastic under the pod around the toolbox area got HOT from the belt exhaust. It may be an issue to watch. I ran a 1.5" snork on my airbox out to open air with no rejet at 2600-2700' elevation with a nice tan-brown plug.

 

[Sanny651]

Probably wouldn't be a bad idea if you're running lean right now. Check your plug like Steve mentioned.

 

[enilkm--off]

How much did the intake mod help performance?

 

[sammydogs64]

Checking plugs is not that acurate any longer due to the Ethanol/oxygenated fuel. I cut an opening on the piece of plastic on the front side below the pod and put a grill in it. Thats lets the air flow through and feed cool air to my hidden snorkels. Do a search for hidden snorkels and you will see the pictures or look in my profile.

 

[massmudder--off]

<div class='quotetop'>QUOTE (sammydogs64 @ Dec 31 2006, 05:33 PM) <{POST_SNAPBACK}></div>

Checking plugs is not that acurate any longer due to the Ethanol/oxygenated fuel. I cut an opening on the piece of plastic on the front side below the pod and put a grill in it. Thats lets the air flow through and feed cool air to my hidden snorkels. Do a search for hidden snorkels and you will see the pictures or look in my profile.[/b]

CHECKING PLUGS ISNT ACCURATE ANYMORE :rofl:
i dont know who had told you that,that statement it totally FALSE.
doing mods and not checking the plug for proper jetting is totally like going to a gun fight with a knife.

 

[chevrolet]

I checked my plug and is looks good after doing some test runs however, my top speed is way down now. I can only go about 30 across a field and I used to be able to go about 55. Also, when it is wide open it seems to stutter and starving for something. I used a 1.5" elbow on the stock tube coming out of the airbox, did I reduce the air too much? I messed with the air/fuel mixture screw a little bit going each way with no difference. If I can't figure it out I will probably to back to stock(I hate the word). I would rather have it running good throughout the powerband than have intake higher but not running right. Thanks for all of your replies.

 

[GoFastCat]

From the sounds of it you are running lean. When running lean it tends to feel like it is hesitant or straving like you described, unlike when rich which is sluggish and boggy.

How did you do your plug chop and for what distance was ran? The mixture screw will not make a difference in your WOT runs so your best bet would be to set that back to the factory setting.

I'm not sure what the whole intake system is like on the 650H1 but it appears that the stock setup gets its air from a secondary airbox up front and then is routed into the main airbox via that hose you cut and added the elbow on?? If so then by eliminating the other airbox and hose then the engine will be able to suck more air in due to the shorter and less restrictive intake you made, causing it to run lean. There is no need to put it back to stock, just order a couple of jets larger ten the stock one and rejet :thumbsup: