about to boost on fmu...few quick questions

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about to boost on fmu...few quick questions

By oneandonlyblack
- Thu Nov 26, 2009 11:20 pm #158577 about to boost my car in about 3 or 4 hours...literally :) got the intercooler mounted and all the intercooler piping ran...im using a hf mani with adapter plate and 14b...just a little fun till a get my other stuff finished...vitaras eagle h beams built head...the whole nine...ive never used an fmu and always done things the right way...my quiestion is if i get everything mounted up and ready to start i should be ready to go..i have my walbro in and ill have the fmu installed...the stock map sensor should be fine for up to 11 lbs correct? ive heard of getting a check valve and runnin that between the map sensor and the throttle body so the map sensor wont see boost...
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By teal_dx
- Fri Nov 27, 2009 5:21 pm #158655 be careful with FMU's...
Yes stock map is 11 psi.
I would think that if your map didn't see boost then your engine would run terrible :?
I'd take your time and do things the right way the first time :thumb:

By oneandonlyblack
- Sat Nov 28, 2009 3:14 am #158709 not to call you out but are you aware of how fmu's work? cuz im running a stock ecu....if the map sees boost it will set a cel for a map sensor...run like crap...i have no afc or data logging so its not like i can make the ecu see boost therefor it chouldnt

By oneandonlyblack
- Sat Nov 28, 2009 5:55 am #158728 and who posted a rule that says using a FMU is the wrong way? by whos standards? because they came with the old paxton and vortech supercharger kits.....and theyre people who are proffesional engineers.....you're saying they're wrong? :shock:
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By chrono404
- Sat Nov 28, 2009 6:17 am #158735
oneandonlyblack wrote:and who posted a rule that says using a FMU is the wrong way? by whos standards? because they came with the old paxton and vortech supercharger kits.....and theyre people who are proffesional engineers.....you're saying they're wrong? :shock:


Having a car tuned using modern tuning software and a chipped ecu is a more dependable option then having a FMU. Reason the FMU's come with kits is becouse not everyone has the huge aftermarket of tuning options that OBD1 Honda ECU's have.

You can have your car tuned on an FMU, thats had hondas were tuned back in the early-mid 90's. However as times change, technology gets better, Working with newer tuning software you can tons more then an FMU can, Such as change the amount of Boost depending on gear, You can control nitrous delivery(dry setups), Change maps depending on different switches(I.E. having the A/C be a button to go into a more fuel efficient tune. then when its off go back to your more powerful tune.)

Any Stock Honda ECU(Besides the turbo'd K23) that sees positive pressure on the map will throw a cel. Almost all honda engines are n/a. This is why the engine needs to be retuned to deal with the additional air. Running untuned is only asking for rod knock, Its not a matter of "If" Its a matter of "Will happen" and only a question of "When?"

If you want your setup to last, Get a professional tune on a chipped ecu. You can get good tunes on FMU's, however if your going to have your car tuned by a professional, have them do it the correct way so you wont have to rebuild your engine in 6-12months. Dont believe me? Talk to any well known tuning shop and ask them how you should proceed. They will recommend going with a chipped ecu and give the above reasons if asked.
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By itCouldgeTwoRse
- Sat Nov 28, 2009 7:11 am #158740 i used an fmu for about 3 months on my boosted sedan. i was running 10psi on a stock d15b7 that had 250k+ on it. all i replaced was the head gasket and yes i did reuse the stock head bolts that had more then one torqueing on them (i know biiiiig no-no.) but as far as the map sensor. i used a "magic box" it was like 10 bux. and i didnt get a check code. and it ran great boosted nice and always returned to idle. as far as i know the kid that bought it still has it and its still running.
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By Sentry
- Sat Nov 28, 2009 2:36 pm #158760 On an OBD1 Honda it just makes zero sense to use an FMU when you can have the hardware to properly tune it for just a couple bucks, and the software for free.
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By teal_dx
- Sat Nov 28, 2009 5:10 pm #158773 exactly :thumb:
An FMU on Our cars is a step backward, old school technology which is less reliable.


on another note, Your stock map giving a CEL at 11 psi is a 'free' way to let you know if you are spiking or have boost creep.

By oneandonlyblack
- Sat Nov 28, 2009 9:42 pm #158803 boosting my civic that did not come with a turbo equipped from the factory is a step backwards?
i would highly disagree.
but i do agree that using an fmu is a little on the iffy side...not trying to say its not...
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By teal_dx
- Sun Nov 29, 2009 12:16 am #158817
oneandonlyblack wrote:boosting my civic that did not come with a turbo equipped from the factory is a step backwards?
i would highly disagree.
but i do agree that using an fmu is a little on the iffy side...not trying to say its not...


nobody said that boosting a civic was a step backwards, but using old technology to boost it is. I'm not going to repeat what has already been said above, you can boost your car however you like.
Plenty of people still use old school methods and they get the gob done. After you get your current setup together and car running, I'd start looking into a setup less hacked and more reliable. A chipped ECU is not much more expensive for all the benefits of tuning and reliability. :thumb:

By oneandonlyblack
- Mon Nov 30, 2009 1:09 am #158964 i dont need to speak with a well known tunning shop....i have sold my AEM and traded off 2 of the ostrich's ive had in the past....i dont take my car to get tuned...whats the fun in that? none....i have unlimited dyno time also....like stated i am only using the fmu for a short time...car is running perfect in and out of boost...no detonation...nothing...(used a buddies aem to monitor for a little) i mean dont get me wrong it drinks fuel like a freaking elephant haha but only in boost as you would think....
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By itCouldgeTwoRse
- Mon Nov 30, 2009 3:31 am #158996 uh oh someones getting mouthy with the ledgend :o :lol:

if you got the dyno time why risk it though. the car i boosted on an fmu was a (as much as i hate to say this about my beloved eg sedan) beater.

just doesnt make sence why you would waste money on an fmu if you have the resorces to have a good tune put on it :?

By oneandonlyblack
- Mon Nov 30, 2009 3:37 am #159000 i did not buy the fmu....if ive had aem's and osrtichs wouldnt it be ok to assume im not new to this and that i am aware of what it takes to tune a car? the fmu is only temporary like stated...not trying to get lippy here...its just like everyone assumes im an idiot because im using an fmu and had a quick question....
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