I just got these parts for cheap and wondering if I'll benefit from them and if it will run nicely. I've heard I need to change the injectors aswell to match it with the maf? I dont understand...

The car is being sprayed 125 shot....

Thanks

 

As to the MAF much depends on whether or not the MAF is a so-called "calibrated" MAF. If it is it should have some indication on it as to what injector size it was screwed up to work with, and if you are lucky it was also "calibrated" to work with a late '02 to '04 Mustang GT stock tune.

Read more about calibrated MAFs here.

If it is not a "calibrated" MAF you will need to know the make and model, and have or be able to get the transfer table/map for it, and have your tune altered to work with it's transfer function.

Either way, if your car is otherwise stock (no cams, no f/i) then the 90 mm MAF will do nothing except create problems, especially if is is a "calibrated" unit.

FWIW when running n/a the stock 80 mm MAF is good to 350+ rwHP.

The 75mm TB and plenum will add a bit of upper mid-range pull at WOT, and let the engine pull a tad more strongly right out to the rev-limiter. Adding a good premium fuel optimised tune along with the TB and plenum will make a noticeable difference--with the tune being responsible for most of it.

 

The above post has it pretty much covered

 

unless its a LMAF i wouldnt bother with it...

the theory behind the larger MAF/smaller TB is that you get the airflow of the larger inlet pipe, then the velocity of cramming it down the 75mm TB...

think of fluid dynamics, rivers always flow faster in the narrower sections, since the same amount of volume needs to go by in the same amount of time, no matter how wide/narrow it is...

the stock TB/elbow combo are good to about 5900rpm on a perfectly efficient 4.6 motor (which none of them are NA)

FWIW im running a stock MAF, and a 75mm TB/elbow combo on my cammed motor and it runs just fine (well, at least once the tune is settled out) and pulls HARD to 6600...

 

I just put the throttle body and plenum on this morning and it runs as good or better than stock. After some acceleration testing I noticed a little more power around 4k rpm, may have lost some down lower though, but I could say there is some increase overall.. I paid $120 for it with a bunch of other parts so I cant complain.

Thanks guys

 

did you reset the idle properly??

 

I disconnected the battery before I started working on it then connected it after I was done, started the car and let it idle for 10-20 minutes as I put my tools away and cleaned up , then took it for a drive.

 

good enough, odd that you noticed a loss of low end power. whats your intake piping and filter setup? stock?

 

I'll do a few more tests, perhaps the gain at 4k made it seem like it was a little less powered under 4k! We are talking about minimal gains here. I have a K&N Intake system. Thinking about going to a cheapy cold air system though because my nitrous soleniod doesnt fit that well beside the big filter.