flatspot at 2500-3500rpm

[u mad?]

hey guys, my dc2r with I/H/E +tune has an annoying flatspot at those rpms, and according to the wideband censor gage its leaning right out (18-1+...). though it only does it on partial throttle (leaning out+ flatspot).

apparently the previous owner had it tuned like that on purpose for good fuel economy.

is there any way to send my ecu to a reputable tuner and have him get rid of said flatspot without my car? obviously the tune wouldn't be perfect but anything is better then this bullshit i have to put up with atm.


the ecu is a hondata s300 btw.

i live in cairns so it wouldn't be practical for me to take my car to Sydney just for a tune.


So, would anyone be able to rid the flatspot without the actual car? (sorry if its a stupid question, dont know whether you can just hook the ecu up to computer and do yo thang without an actual car or not lol)

any help much appreciated!

[trism]

It'd be possible, they could put it on another car with those mods and try to change it, but it'll never be the same.

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[egb16b]

even if you find a car with the exact same mods as your car - chances are you still won't fix the problem. something simple like different fuel can stuff the tune.

only way to really fix it is to chuck it on a dyno so they can suss it out.

[u mad?]

It'd be possible, they could put it on another car with those mods and try to change it, but it'll never be the same.

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yeah i don't mind if its not perfect, just need something better than how it is.

even if you find a car with the exact same mods as your car - chances are you still won't fix the problem. something simple like different fuel can stuff the tune.

only way to really fix it is to chuck it on a dyno so they can suss it out.

is hondata easy to tune? if it is maybe it may be easier to get one of the local tuners to have a look? I dunno.

[egb16b]

i will never take a car to get tuned if they've never tuned that type of ecu before, for e.g microtech, haltech, hondata in this case,

I always select my tuners carefully. Even asking them for previous cars' dyno sheets that they've tuned.

It's your choice man but they might fck shit up worse. If i was you i'd take the trip and get it done properly - if it's that much if a problem.

[na-118]

start by doing a little diy's for the car and for good measures :

did you get bad batch of fuel?
remove spark plugs - re gap them
check oil levels
check oil filter
check air filter
check fuel filter
spark leads for wear or damage, if so clean it up and wrap damage area with electrical tape to see if it solves any problems
get a fuel pressure guage and check the readings
compression test
leak down test
borrow a timing light, re- check timing for advane or retarded timing,,
visual inspection on all sensors, plugs, switches etc

if you can get your hands on a cheap 100 dollar ob11 readers its worth while to have one,, plug it in and see if it throws any codes up,, and go from there

[mugen_ctr]

well since its tune related, so no matter what u do mechanically, it always behave like that, only way to go about it is throw it on a dyno for a proper tune to iron out the flatspot. If u had access to the software an a laptop, and had some idea of tuning it, mayb, just mayb u can toy around the tune, but thats very risky! and u need the right tools to monitor the vitals

[mao]

hey guys, my dc2r with I/H/E +tune has an annoying flatspot at those rpms, and according to the wideband censor gage its leaning right out (18-1+...). though it only does it on partial throttle (leaning out+ flatspot).

apparently the previous owner had it tuned like that on purpose for good fuel economy.

is there any way to send my ecu to a reputable tuner and have him get rid of said flatspot without my car? obviously the tune wouldn't be perfect but anything is better then this bullshit i have to put up with atm.


the ecu is a hondata s300 btw.

i live in cairns so it wouldn't be practical for me to take my car to Sydney just for a tune.


So, would anyone be able to rid the flatspot without the actual car? (sorry if its a stupid question, dont know whether you can just hook the ecu up to computer and do yo thang without an actual car or not lol)

any help much appreciated!

Yup you have a tune issue. Every 2 cars are different and even if they have the same mods, the VE or volumetric efficiency of the combustion camber differs between 2 different engines.

Did a motec m4 on a civic last week. It had a B18C engine in it. Car came in with the motec already in it and the vehicle had a flat spot at 3000rpm and at vtec chg. I re-did the AFR mixtures and twicked the timing and sure enuff, the flat spots and rough chg on vtec engagement became smooth. Best bet is to bring to a reputable tuner and get it retuned. Also, make sure that the tuner has a relatively new wideband o2 sensor for accurate afr tune.

Have fun!

[u mad?]

Thanks allot for all the replies everyone, much appreciated! Would rep but my rep power is too low to make a difference anyway lol.

[EG30]

Yup you have a tune issue. Every 2 cars are different and even if they have the same mods, the VE or volumetric efficiency of the combustion camber differs between 2 different engines.

Did a motec m4 on a civic last week. It had a B18C engine in it. Car came in with the motec already in it and the vehicle had a flat spot at 3000rpm and at vtec chg. I re-did the AFR mixtures and twicked the timing and sure enuff, the flat spots and rough chg on vtec engagement became smooth. Best bet is to bring to a reputable tuner and get it retuned. Also, make sure that the tuner has a relatively new wideband o2 sensor for accurate afr tune.

Have fun!

Great to see you here Mao helping out with your tuning exp and welcome abroad. You are the guy with the speedshop in Bentley with the impressive showroom and new dynopack dyno right? I've been your shop once last year with a fren but I dont think you would remember me.

I too have a problem with my car leaning out, but at high rpm ie 8000-8800rpm at the track at times. The check engine light comes on and I'm suspecting the car runs out of injector duty at high load+revs. I'm running PFC on my eg with B16a with type R cams, stock inj and FPR ( set to 44 psi from mem ). My Performance Box datalogger shows I lose accel in 4th gear everytime the check engine light comes on at the end of 3rd gear.

The car had been tuned by a tuner in Perth who is very familar with honda cars and PFC, I mentioned my concern to him shortly after the last tune and he suggestion was I should try different intake setup ie CAI, short ram vs the existing Whale P setup.....

Sounds like I should come to your shop for a second opinion Mao, I wont go offtopic any further esp this is u mad? thread after all. I'll PM you soon with the full details and history of my car/tune and you can let me know if you can resolve my issue or not.