Question about performance (DC5)

I bought a brand new DC5 in August last year. I ran it in gently for the first 1000k's (didn't once redline which was very hard for me) After the first 1000k service I cranked it up to redline and was blown away with the boost the VTEC engine had, it was very noticeable when I hit 6000rpm and really gave me a buzz. After a few weeks that boost seemed to diminish to a point where it wasn't noticable at all. I had a 5000k service a couple of months ago (I mentioned this to the dealership before the service) and it still feels like there is no change in performance when I hit that magic RPM figure. Sometime if I try to rev the car (when it's warm) in neutral (push excelerator flat to the floor) it just coughs and splutters around 5 grand, whats with that!? Bad fuel? Clogged injectors? Have I done something to the engine that I am unaware of by redlining it?

Any advice would be appreciated..

the engine in the dc5 (k20a2) won't allow you to rev past 5,000rpm in neutral..
it's a fail safe mechanisim...
there's nothing wrong with your car

also the dc5r doesn't have as much of a kick in the butt feel when VTEC is engaged compared to the dc2r...but it's still just as fun...

welcome to ozhonda and also check out www.clubrsx.com
there's loads of people in the australian section mostly with dc5r or dc2r there

Quote:

---

the engine in the dc5 (k20a2) won't allow you to rev past 5,000rpm in neutral..

---

That makes me feel better thanks, still not sure why I don't feel the timing change anymore.

Perhaps it was a new sensation - I've been riding an Aprilia RS250 for about 6 months now and the kick when powerband arrives isn't as noticeable anymore. Hell, it might be an idea to take it down the strip/g tech/dyno it and see if any numbers appears unusual

All those feelings your describing come down to a few things, mainly your you have got used to the power / feeling of your car…

But more importantly your ECU has adjusted its air fuel ratio and ignition timing and crank angle to suit your altitude type of fuel and environment conditions.

The K ECU is a very smart ECU, one of the smartest ECU ever made in the world, its ability to self learn and self program is unbelievable, having said that the whole goal of the ECU is to not only to operate the engine, but to minimise emissions and provide a safe none torque steer ride and increase economy, all of which decreases performance, but Honda from factory put user drive ability emissions and economy before performance. Why did your car feel fastest when you first fanged it, because the ECU was still learning, can you do anything to reverse this, no resetting your ECU by unplugging it is pointless and dangerously and won’t work, within one or 2 full rpm pulls everything will be back to normal because the ECU running in closed loop mode. This is where our new product from Hondata will revolutionise the market, because soon we can tell the ECU to run in open loop, put performance first and not to change settings over time, as well as custom tuning the ECU fully taking advantage of users modifications. Honda from factory actually have de tuned the K engine significantly even with simple tuning you can soon undo this !


Hope that information helps !! I’m not sure what state your in, but any of my dealers can help you, we even have BETA tuneable ECU’s available now, along with flash able programmed ECU’s.


Regards James

Woah thanks for the info, it really makes sence.. Would driving at higher rpms initially during the break in phase affect the outcome @ the end?

Quote:

---

This is where our new product from Hondata will revolutionise the market, because soon we can tell the ECU to run in open loop, put performance first and not to change settings over time, as well as custom tuning the ECU fully taking advantage of users modifications.

---

I'd buy that for a dollar ;)

nup it would't it will learn at what ever RPM you drive at.... peroid.
But no one sohuld be driving a new engine hard....

Regards James

hey James, when is the programmable K20A2 flash chip coming out?

thas very interesting

talking about ECU i want to get one would hondata have a good one for the dc5r, cause i want to get NSX injectors for it do you think the guys from hondata can help me with this

sounds good - whats the approx price for the new ecu from hondata? ... APC are the distrubtors in qld right?

hey James
is there the K20a3 auto reflash available here in Oz?

We decided over 1.5 yrs ago not to release the flash in Australia, because we had under development the fully tuneable ecu. This product is due for release in the last week of March in Australia ( if all goes to well )

Price is still unconfirmed but somewhere around the $2000 + mark.
So yeah another month and everything will be sorted.. !!and the future of the K engine will be born !! As the only fully tuneable K ECU will be released on the market !!

Regards James

doesn't MoTec also have their version of the tunable ECU that can adjust iVtec?

nope the K ecu is by far the most complex ECU ever made !!! trust me ;-)

Regards James

Quote:

---

Originally Posted by Tofu

doesn't MoTec also have their version of the tunable ECU that can adjust iVtec?

---

yep.. http://www.motec.com.au/camcontrol.htm but cost a lot more than Hondata!

I think you will find motec cam control is able to controls the vtec solenoid when engaging vtec, this does not control the cam angle use'ed in iVTEC on the K engine.

This cam angle along with cam control provides 3 dimensional tables for full i-VTEC mapping including, multiple fuel & ignition tables for different intake cam angles at all MAP readings, all on individual maps, then you have all IVTEC setting… very very complex.

Regards James

Motec has been able to control VTEC actuation for at least four years, just recently they have introduced variable cam control, as per the link.

Quote from Motec - `With more stringent emissions requirements placed on the OE’s and the constant quest for additional power has evolved fully variable camshaft timing. MoTeC can run up to 4 camshafts per engine such as the BMW V8 Dual Vanos and the Honda IVTEC'

http://www.enginemanagementsystems.c...g-Rev-104b.pdf

I have also heard this directly from MoTeC, it's about an AU$800 option on the M400.

Back to topic at hand, I have to agree that Cr@ckerJ@ck has probably just got use to the VTEC engagement - perhaps try a 0-100 test with a friend timing and if still worried put it on a dyno.