Are FMU'S that bad ?

[d112crzy]

an fmu can be good enough if you know how to use it.

first off,

you're not supposed to run bigger injectors with your fmu, thats a huge problem there. besides already being a tad rich with the fmu, the 450's are gona make you richer.

a better combo if you're gona use an fmu would be a fpr, and a new fuel pump. the fmu can/will fuck up your stock fuel pump, especially if you're running a lot of boost. you're gona make the fuel pump work twice as much it usualy does(42ish psi), if you boost at 12psi, that means your total fuel pressure would be 186!!thats like 3 times the regular!

this is one of the factors that cause engine failure. A lot of people don't get an after market fuel pump and a fpr. The fmu will eventually wear out the fuel pump, and will cause engine damage.

another thing is, even tho most of the time the engine will be running rich, there will be times where it will be very lean, even if its for a few rpms. time goes on and it builds up, those few rpms are gona fuck you up. You have no way of adjust for those rpms alone. you can only increase the pressure of fuel it adds, thats why fmu's are bad. there is no way to control them.

thats just a brief over view as to why theyre not great.


A LOT of people use them, mostly the ones that don't know what they are doing, but there are those few knowledged ones. also, those fords and chevy's and all those other makes dont have the technology that hondas have as far as engine management goes. well, they do, its just pretty damn expensive.

[Gettin_faster91]

Thanks d112crzy thats what im thinking if done right it would be ok. Fpr, 255 walburo and fmu, as far as leaning out it should not be by much thats why i wanna use the wideband find the point or points im leaning out then up the fuel pressure a bit to fix that. Yes its going to run a little rich much like a basemap for the chipped ecu does but thats a good thing a (lil rich = safe). And i dont plan to boost more that 6-10 psi anyways. So im thinking its going to be safe. But like i said before its not the best way to make big big power for the fact it cant be tuned to perfection but its going to make power non the less with this setup or so i think... t3 for less heat and more air, fmu,fpr, walburo, fmic,run it a bit rich im sure its going to make over 200 hp with the t3. And i would go with hondata if i had the money just for the fact the tuning shop is only 3 miles away. id let them tune it.

[Accord R33]

Shit ok i got $100 in my hand now your telling me i have everything ? like r33 said its going to cost me 140 just for the ecu. Even if i chip it myself its going to be about 60-100 just for the ecu, about 20 bucks for the diods (SP) and cap's soldering iron, solder chips burner and cables yeah its more than 100 bucks more like 200-250 for everything i need.

Well then i would say your not ready to boost. Im all about doing things for cheap (if you know anything about my old setup), but this is one thing even i would not hesitate to spend a little more money on. If you can't afford it, wait and save. If you cant wait and save, dont boost

[d112crzy]

yea, even the guys on hmt dont cheap out when it comes to engine management.

that is the biggest mistake you will ever make. Tuning is actually not that complicated or hard.

[Gettin_faster91]

Well r33 its not so much the money factor, on top of the fmu stiff there was going to be a fuel rail also so yes im looking at spend about the same as doing the chipped ecu. But the fact that im not a tuner and no one here can tune, well there are 2 places that tune but i dont want to drop 1500 for the aem ems or 500 for hondata, then tuning cost. They only tune with hondata and ems. I dont trust myself to tune a chipped ecu. < would be a different story if there were people here running uber and tuning with it but they are not. If i seen it done a time or two it would be a different story.

[Accord R33]

Well r33 its not so much the money factor, on top of the fmu stiff there was going to be a fuel rail also so yes im looking at spend about the same as doing the chipped ecu. But the fact that im not a tuner and no one here can tune, well there are 2 places that tune but i dont want to drop 1500 for the aem ems or 500 for hondata, then tuning cost. They only tune with hondata and ems. I dont trust myself to tune a chipped ecu. < would be a different story if there were people here running uber and tuning with it but they are not. If i seen it done a time or two it would be a different story.

So learn how to do it yourself. i didnt know how to tune before i boosted, neither did midnite. Like Midnite has in his sig "Knowledge is power, in every sense of the word"

It wont happen overnight, but it will be well worth it. you will have a safe reliable setup, and you will learn a thing or two.

[d112crzy]

thats why you learn how to tune. you cant do something you've never even tried or attempted. you also cant say you cant, because you dont know if you can or can. you just dont know how, theres a diff.

give it a few months, start reading up on it. I can help you if you have EDUCATED questions.

[WiKKeDV16]

hahah damn good point.. those fuckers do some low budget jerry rigged setups but boy.. do they make sure they have a chipped ecu... and 450s' lol

[92ex]

I don't think ignition was mentioned along with the fmu...

[d112crzy]

ahh yes, ignition. I cant believe i forgot.

Under boost, it's pretty damn smart to retard ignition, that is, unless you dont want to drive anymore.

[MRX]

1. If your gonna use an FMU you'll need a missing link also.

2. If you were to add 450's onto the stock ecu you'd run pig rich ALL the time. I literally got about 5 miles to the gallon or the spark plugs fouled out before i even got 5 miles down the road. Futhermore the car was too slow to drive around in traffic...felt like a geo metro...a heavy one!

3. The stock n/a fuel curve at WOT is flat and has a little hump to compensate for the peak torque at 3800-4000ish. For every f22 turbo setup i've needed to spike the fuel at peak torque to compensate for the cylinder pressure and the peak torque ranges from 3800-4800rpm depending on the size of the turbo. And the fuel curve was became a 45 degree angle at about 3000rpm, it was not flat at all. So even if ur FMU is dumping in lots of fuel to compensate it doesn't mean it dumping it in at the right place and u can't even target the rpm where u need to dump in the fuel. Which means u either raise the fuel pressure even more to meet peak tq's requirements and run extremely rich across the rest of the board or u run lean at peak tq...the most dangerous part of the powerband.

4. stock fuel pressure is like 38psi, with a 12:1 ratio FMU at 7 psi ur running 122psi of fuel pressure and it increases by 12psi for every pound of boost you increase it. How much do u think ur little fuel pump can take? Even if u got another fuel pump how much do u think ur little stock injectors could take? Making them run 3x the amount of pressure they were designed to run causes them to overheat and fail. They can either just stop spraying fuel or get stuck wideopen.

5. You'd have to retard the ignition timing and with and FMU setup u could only do that at the distributor. And just like the fuel curve u wouldn't be able to target peak tq. and decrease the ignition timing at that point you'd have to do it ALL over the map...not in just the boost section.

6. If you were to utilize 450's...u'd need something to control them. SAFC, chipped ecu, etc.

7. How many stock cars come with an FMU? None.

8. If your so cheap and still wanna boost then how are u supposed to have money for another block if ur setup doesn't work out and the engine blows?

9. Chipped ecu's aren't glits and glamour. I chose this route for a very specific reason. Accompanied by observing several F22 setups blow up and noticing the underlaying problem was engine management and a will to learn is why i chose the tuning route i did.