What is the best way to determine if the plenum is leaking? I installed the Kinetix V4 2 weeks ago and removed it 4 days ago and put back to stock. Ever since the V4 was on and now since the stock one is back on, my MPG is around 11. I dont' hear any air leaks, double checked all hoses, and still i can't figure out why MPG is so down. Should i have put on a new gasket???
I did reset the ECU.

Thanks.

 

Are you going by what the gauge in the car says or by tracking your mileage and gas consuption? You may need to reset the mpg gauge in the car for it to reset. If you had a plenum leak you should hear it as it would be a fairly loud pssssst on acceleration. Have someone give the car some gas while you listen with the hood up.

 

if its back to stock... hmmm

you reset the gauge I assume. try testing it for yourself like zzzya said. have you notice rapid gas use?

 

Why did you take the v4 off to begin with?

 

I have reset the gauge several times. I'm now at 11.9. I can't figure out what the hell is wrong. When putting the new plenum on, i lost a bolt on the back passenger side corner. However, each mechanic i took it to said it was not leaking. I'm getting the new bolt today.
I didn't not like the way the V4 Fit, it was rubbing and causing a vibration in the body. Also, didn't care for the sound it created at all.

 

The fit sucks.
It really doesn't make that much sound. The you are hearing is it rubbing against the strut bar. Take your strut bar off and the rubbing will go away.
This damn plenum is not worth the problems.

 

You might try spraying some brake cleaner around the perimeter of the plenum while someone revs the engine. If it sputters, then you've got yourself a leak. If not... start looking elsewhere. Are you sure that you have all the hoses connected properly and free from obstructions? How about the hose on the bottom of the Air Intake tube? Is that on properly?

-Chris

 

THat would destroy the purpose of the Kinetix design.

 

I have just checked everyhose and connection over and over and sprayed brake cleaner, no leaks. HOWEVER i think i hear where the hissing sound is coming from...The passenger side Header. I'm nearly positive that that is where the leak is coming from and why my MPG has gone down to 11-12 mpg!!!!!!!!!

ANY THOUGHTS??

 

No, there is a normal hissing noise that comes from the front of the passenger side. Not sure what causes it, but I hear it on every Z who's hood I stick my head under.

The header is definitely not the problem.

-CHris

 

Really!! you may be right, i guess i'm being paranoid! It sounds like it is coming from the passenger side headers up top right:??

 

Sounds like the vacume hose connection on that side is leaking.

 

They sure as hell didn't design it for ease of installation.
I wouldn't have minded buying the extended strut bar if I would have known that the damn thing would rub against it.

I had to use 2 1/2 washers on each mount point and tighten up on the strut bar so it would bend out of the way.

I think they just thru the V4 out there to satisfy the people that had cracked v3's without considering fitment issues of the strut bar.

They should have designed it without the grove for the strut bar and like Crawford did, offered a replacment strut bar. Maybe they would have gotten a few more hp from it.

It is good though considering that I get to keep my original plenum instead of being charged a core deposit like Crawford does.