First post under new name, not that I had that many before....

Just picked up an '01 Roush Supercrew, gonna get a tuner soon, was wondering if there are any gains in a bigger air meter since I could get the maf curve changed at the same time? My stock meter measures about 78mm, I've got a friend with a 90mm off his '03 Cobra that I can buy cheap. I've got a K&N inlet tube that is around 4.3" (109mm) right behind the meter, so I have basically zero restriction right behind the meter. The filter right now is a K&N in the stock airbox, if I went with the Cobra meter I would also switch to an S&B Powerstack filter that he was using. So, are bigger meters worthwhile?

 

on a stock truck u probably wont see any diff at all.... If ur gonna get an aftermarket maf get an 80mm lightning MAF, and have it tuned for it. If ur planning some decent mods, then it might help, but if its gonna stay close to stock, its a waste.

 

If I was gonna upgrade my maf, I would go with the newer lightning 90mm maf. Started putting them on in 01.

 

Why would I replace an 80 with another 80? The truck will be bolt-ons only, don't know if a 90 would pick up any power, but I can do it quite cheaply so ???

 

Sorry i meant 90. Lightning MAFs i believe have different calibration.

 

typically, a larger maf is only needed when the current maf pegges out, or reaches 1023 AD counts (5 volts)

At this time, you must use a larger maf, to have proper fueling and spark.


Ryan

 

Hi 01 Roush,

Actually, in the stock factory program the MAF pegs out at 980 AD counts, not 1023 - that translates to just 4.78 volts, and there's quite a bit of difference in airflow (CFM’s) available between 4.78 & 5.0 volts - but the ONLY way you can get that full 5.0 volts (or 1023 AD counts) is to have a custom tune done, you do NOT get that in the factory program at all, on ANY FoMoCo vehicle from the factory - just so you have factual information.

Next - what you have stock on that truck is actually a Ford 80mm MAF meter - it's not the same 80mm MAF that came on the 1999 & 2000 Lightnings in terms of it's electronic (CFM) capacity, but it's basically an 80mm unit - so it's not bad size-wise.

That stock 80mm F-150 unit can support a max of about 340 HP at the FLYWHEEL, which on a 5.4 (since they are all automatics in the F-150) would only be about 265 HP at the rear wheels. So by the time you had one of our Troyer Performance custom tunes, a top-shelf intake kit & cat-back exhaust, you wouldn’t have much capacity left - and you will run out of fuel injector capacity well before that, by the way. The stock 19# injectors are only good for about 310 HP FLYWHEEL with the BSFC (brake specific fuel consumption) seen in the F-150 – not the 339 HP some magazines mistakenly claim by running the injector at full 100 % capacity under absolutely perfect & optimal conditions in a much lighter 5.0 Mustang, so don’t forget that.

Now, let’s get to the heart of your question, and get you a CORRECT answer to what you really asked for help with in the first place! Which was, will installing a 90mm MAF meter along with having a proper custom tune done get you any power increase just from upgrading to that 90mm MAF. The truth is YES! It most certainly WILL!

Contrary to what some think, even on a BONE STOCK 5.4 F-150, you will see about an 8 HP gain form doing that once the A/F’s are dialed in, simply because of the reduction in restriction presented by the sampling apparatus due to the larger diameter tube in the 90m MAF – it’s extremely basics airflow (physics) that anyone who actually understands anything about MAF on these trucks should know instantly. And on a truck with any decent intake kit & cat-back exhaust system, it’s worth 8-12 HP – so the answer is actually YES, upgrading to the 90mm MAF WILL get you a nice power gain.

Now, do you actually NEED to do that upgrade? Not unless you are making about 330 HP or more at the flywheel. Most Roush trucks are compromised of appearance/handling packages, so very few of them actually have a supercharger or significant power gains. The typical Roush F-150 package includes their intake kit & a cat-back exhaust, taking that 260 HP 5.4 to about 280 HP – maybe 290 HP at the absolute most (this is again at the FLYWHEEL, not rear wheel). So at that point, no, you do not actually NEED to upgrade the MAF meter – but you will still see a nice 8-12 HP gain in peak HP by doing so, thus it’s not a bad idea since you’re getting tuning anyway.

If it were me and I was going to be getting a custom tune from us anyway, and had the opportunity to get a properly functioning 90mm MAF for a good price, then yes, I WOULD do it.

Now if that Roush truck actually has their supercharger, then yes, upgrading that stock 80mm MAF is an absolute must, as you are in fact saturating (peaking) it.

One last thought – the combination of our custom tuning, any decent intake kit & cat-back exhaust, is going to cause you to run out of fuel injector capacity – so plan on upgrading to 24# injectors (this is assuming no supercharger) as part of this, and we can provide an excellent package deal on all of this for you, and make everything work correctly so that truck will really rip - and it can be done very affordably. The bottom line is, if you now have an intake kit and a cat-back exhaust on that Roush truck, and go with our Troyer Performance custom tuning, the 90mm MAF and a set of 24# injectors, you are going to gain about 50 HP at the flywheel on that truck, and maybe a tad more – and the improvement in acceleration times will be even greater than what a 50 HP gain would indicate on paper. That will make that truck a LOT more fun to drive as well as allowing you to really surprise some people. This is just some food for thought, I really don’t mean to play salesman here with you. J

Now I know all of this is a lot to absorb, and there are a lot of opinions out there and so this can be confusing – so what I suggest is to simply give us a call at our number listed below & we can go over all of this in proper detail, so that you will actually have correct and accurate information upon which you can base an intelligent decision.

Our phone number is listed just below for your convenience.

Best of luck whatever you decide, & please don’t hesitate to call us – we’re happy to go over all of this with you with no sales pressure, etc., so you’ll have accurate info to think about!

 

Mike, thank you very much for the thorough reply. Do you have the maf curve for a '03 Cobra 90mm on hand? The truck is a stage 1 so its not supercharged, just gonna remain with bolt-ons. I can sure dig another 50 hp though.... E-fans will be in the mix too, but if I do the maf and injectors with the tuner may need to wait a while on the fans. My order will be coming soon, just need to sell my current truck or Mustang first (the Roush is replacing both).

 

Hi Dan,

Sure, we have the STOCK 90mm Cobra MAF transfer function on hand, but that is only a *starting* point - it will still have to be dialed in from there, just like on *any* vehicle where you have the MAF meter, there is never any substitute for that. Every air intake tract is different, and will require proper datalogging to get that dialed in so you have single-digit fuel trims and the engine is actually delivering the commanded A/F's in O/L. In other words, that's SOP and is just just one of many things that the XCalibrator 2 allows you to do, is to get us that data.

When we do a custom tuning package, we include all of those adjustments along with though instructions on how to get the data from the XCal 2, so you can get those adjustments made so the A/F's are spot-on - no problem!

Good luck with that fleet of vehicles you have there!

 

LOL, hopefully it'll be a much smaller fleet real soon, if I even mention buying parts for the new truck right now my wife gets kind of a funny twitch to her face....

 

Yeha, I know that one - in my case, I just have to buy my wife's truck all the same go-fast parts that I get for mine, and then I'm out of the dog-house - but twice as broke financially!!