CLA803

above is the setup I am running on my car, note the placement of the MAF. I have several questions. I have put roughly 400 miles on the car since the swap and it runs really good but the best gas mileage I have gotten so far is 21 mpg. I am running a t56 with 3.23 gears, at 80 mph it is turning 1500-1600 rpm.

My question(s)
Is the placement of the MAF ok or would it be better somewhere else down stream of the air flow.

The tune on it as of now is a basic start up tune. Vats and all the emissions stuff tuned out. The cats are also removed and the rear o2s. Would a dyno tune help increase the fuel mileage?

Any advice appreciated.

i r teh noobz

iTrader: (4)

It looks ok to me.

21 MPG isn't terrible. I'm lucky to break 15 combined in my 5.3 300ZX, but I have 3.7 gears, a cam, a DIY tune, and a 5 speed with a .82 5th. I was barely hitting 17 combined on the stock engine. A dyno tune should help you get a few more MPG, but you won't be hitting 30 or anything.

casias

iTrader: (1)

I agree. 21 mpg is pretty good. The MAF is probably fine where it is at. Check your long and short term fuel trims. This will give you a clue if it is compensating for some reason.

CLA803

thanks for the info. I used to have a 91TT 300ZX before my TA. it will be a week or so before I can get it on a dyno. I had someone tell me the MAF should be closer to the throttle body is why Im asking.

casias

iTrader: (1)

Anywhere in a straight section, 4 inches or so, that provides straight airflow. Those elbows really don't affect it too much. Less so when they are downstream.

CLA803

thank you.

Rick Speed

iTrader: (55)

The maf can be anywhere in the intake system ( it's always going to read air flow). The only way it would be a problem is if this was forced induction. Then it really matters. Train of thought is that it should have 4" of straight pipe on either side. I would leave it where it is. Gas mileage sounds good to me. My stock Trans am sticker said 19 city and 28 highway. But there's always variences

CLA803

thanks guys. here is another thought on gas mileage, would the 3.23 gears actually be hurting the mileage due to needing more throttle to maintain speed. 3.42 was stock for the car it came from. I was thinking about a 3.73 or 3.90 later on down the road.

Rick Speed

iTrader: (55)

It should be helping although its not a big enough difference to make a huge change. The higher gears will put you at a higher rpm and that will make it burn more gas. As lo g as its set/tuned for the right gears it should be good. If its a used MAF you might try cleaning it.

CLA803

Thanks for the tips. I may move the MAF closer to the tb to see if it makes any diff. just for gee whiz.

Lrn2Go

iTrader: (1)

Sounds good... when your setup can be moved around like that, it won't really hurt anything by doing so. I'd always heard you need at least 4 inches of "cushion" room around the MAF... 2 inches in front, 2 in back, where the tubing was straight... and that you needed less straight behind the maf than you did in front. I've never seen someone I'd consider "factual" on the matter reinforce this, so I could totally be talking out my butt. Good luck!

Lonnies Performance

iTrader: (16)

Preferred straight runs for best accuracy is a minimum 5x upstream straight diameters & 2x downstream diameters. This is standard engineering practice for air flow stations. That is what should be done.... but obviously there is rarely this much room in any automotive application. All you can do is try to get as much as reasonably possible & test it to see how stable the readings are.