Hey guys,

I have a question... does the FMU work in both closed loop operation and in WOT? Or just at wot?

I ask this because if I want to tune for a low boost set up (5 psi or so) would I only need an FMU and that's it? Or what else? (going the cheap route and not using piggyback computers)...

I know i shouldnt do this! (but i have no other choice for my crossfire!)... please help! I need a way to tune the car without going electronically as it is very complicated (you know mercedes)...

HELP??

Thanks!

 

oh, thats the new crossfire with the f20C-F22C motor right?

you might want to check out what other cars the 3.2 liter motor came with and see if they had put some boost on it. I do recall that rentech tried doing that, but found that the motor wasn't very strong, and did a stroker kit instead... You also need to remember that there was a 3.2 liter version that came stock under boost. Whats the old saying... "never try boosting a motor that has one already boosted..."

I know on my comptech supercharger at stock boost, the stock ecu was constantly trying to take away fuel when the FPU added it, eventhough it wasn't on the WOT setting.

You may also have issues with the air metering system seeing boost, although im not sure if its a MAP of MAF system...

Good luck

 

Yes there is the srt-6 but it doesn't come manual (and trust me, I like challenges ).

I can fool the air metering system by putting a check valve in it which dissipates air in the vacuum line so it never sees boost...

All i need it the tuning part, I am thinking of adding an FMU and water injection so I don't have to retard timing... thoughts?

No one has been able to answer this for me! AHHH

 

FMU is boost sensitive so it will raise fuel pressure proportionally to the boost pressure. (8:1, 10:1, 12:1 so on) Since it is all mechanical it will work in both closed loop and WOT. 8:1 ratio is more than enough for our car at low boost (I'm using 8:1). I do recommend getting a wideband so you can make sure the AFR is in the safe zone. I also have a bleed valve to lean it out a bit b/c 8:1 on my setup was a bit too rich (need wideband to know that). Better rich than lean though.

 

^ wow, your 1 post coupled with your sig has just provided me with more useful information regarding low boost FI applications on the s2000 without electronic fuel management than I have been able to gather on s2ki using the horrid search feature. THANK YOU

 

You are welcome! I ran 10psi with FMU on my integra (stock B20 engine) for like a year w/o a single issue. As long as you keep you AFR conservative and make sure it's not knocking, Honda motor will hold up quite well. There is still no substitue for a good tune using standalone EMS but not everyone can afford that. I'll be using FMU for about 2 more months and AEM EMS will be on the way!

Pawan

 

One more thing. Driveability is great with stock ECU

 

see AEM EMS is just not an option for me, I'm a glutton for OBD2 punishment

 

Wow thanks a lot Pawan ! That helped... well one more question... why would i want to use an FPR?

I mean, i think my crossfire already has one (well, all new cars must have one)... so why would I want to use it? To my understanding is that its to keep afr's inline when boost is not on BUT I dont need to change the afr when theres no boost because the engine operates normally, right? So why would I need one or why are people running them?

 

I have an FMU for sale if anyone is interested.

65.00 shipped in the lower 48