Allright first let me say that I love all the mods I have done to my Z so far especially the Crawford high flow cats and V5 plenum. I do have a question that you guys might be able to answer for me. After installing the plenum I have noticed a drop in mpg form approx 23 to 19. I waited a couple weeks to see if this was due to the ECU needing to adjust itself and to make sure I just wasn't flooring it cause I loved the new sound. Also it seems the the change is noticiable during city driving because cruising on the highway I get approx 26.5 mpg. Here are some possible causes that I have thought of.

A) Plenum didn't fit properly possible air leak- tried spraying carb cleaner around were it sounds like it might be leaking but noticed no raise in Rpm's

B) the throttle itself is not positioned properly and letting much more air in at idle and low speeds

These are the two causes I can think. I apreciate you thoughts and ideas on this matter.

Thanks in advance,

Greg

 

Simple fix... we have seen this before. Actually we regret to its very common.

We call it excessive jabbing the throttle pedal to induce thrills and chills!!

Fuel consumption is measured by how far your right foot goes down!!!

 

Actually I wish this was the case, but it is not. I even made sure to drive one full tank of gas without shifting above 3000Rpm just to check this. But the enthusiasm you have for your product is appreciated.

 

Just get an ecu reprogram. That will even give you more power and even if it doesn't tune our car for better gas mileage, it will give you a lot more tuned power.

This will ensure that you are not wasting any fuel at least, and that all the charge going in isbeing used to it's maximum capacity.

 

"your poo lil plenelum might be weaking some air"

 

Well, lets go on the theory its leaking air.

Talk to me about not fitting properly... Gaps??? If it didn't fit properly you would have audible indications of a leaks. Much like a vaccum cleaner trying to suck something...

Why has your throttle position changed???? No changes should have happened here as the plenum is morphed into what it is, from a stock plenum...

Call Doug tomorrow, something sounds rather odd... you need to elaborate this to him... 615-327-4159.

 

I have the plenum and my fuel consumption has not changed. We already have to put premium in the car so you should not be worrying about gas.

 

Pheonix,
Thanks for the reply, when I first installed the plenum I was talking with Doug trying to figure out if I indeed have a leak because I was hearing a hissing sound. Tried spray carb cleaner near where the sound was coming from (front left corner of the plenum) this would get sucked in and should raise the idle temporarily. But my idle to date has stayed rock steady. The reason I mentioned the throttle position is that when I placed the throttle back on the new plenum it looked like the plate was only 85 percent closed. I will definately get in touch with doug tomorrow.

Let me say this: this is in no way a complaint against Crawford Z Cars or Doug. They are great people, have great products, and offer great support. Hell, if I can't figure out whats wrong I might just drive the 8-10 hours to have them look at it just so I can meet the guys and see their shop. Well maybe a cams and header install might be in order too.

Once again thank you everyone for your help.

 

Keep us inform.

 

Now just understand... it IS tradition for us to throw a party when out of towners come in.

Just be ready!!!

 

You better believe him on that!! Hahaha!!!

 

Hell yes!!! I know the Z club of Texas Can wait for our Nashville Stop off on the road trip to The 05' ZCCA Convention!!

 

Hehehehe, Summer

 

Your stop???

You mean when you start seeing our taillights the whole way up??? Muahahhahaah!!!

Next time bring a bigger group homie!

 

It Should be a bigger group. I'll make sure to Get an Easy to find Hotel, so we will not be lost for 4 hours again

 

Beer?

 

I actually have a leak in the left front corner of my crawford plenum. I noticed my idle was real erratic one morning and then about an hour later the dreaded sqeaul started. I replaced the gaskets and it still persisted. I called doug and he recommended spraying the corner with brake kleen to see if the idle raised. The idle did not raise but the squeal came back louder than before changing the gaskets. Doung is sending me a new plenum on friday.

 

SQUEAL LIKE A PIG BOY!!!!!!!!!!!!!!!!!!!!!!