De-Cat Pcv Autotune.

[dynajohn]

Thankyou dynojohn, for all your input, as it is I am more than happy with what I have achieved with my VFR1200 project, my bike runs a lot smoother, is more responsive, and is very quick, the top speed restriction, does not bother me one iota, I could loose my license very easily, as it is. I am just at the final stages of my suspension upgrade, once that's sorted, it will be BST Carbon fibre wheels, and a brake line upgrade, because that's all the brakes need, I will run standard Honda pads, because the brakes on the VFR1200 are first class.

Can we keep this thread, as the title, we seem to be getting yet another ECU re-flash thread, with respect I have shared all my expertise with you all, and I know it works, so please show this thread the same respect.

And thanks to you Dave, it was your work with the cat removal that that enabled me to get results quicker than I would otherwise have been able to.

[Auron]

Hi Auron, I dare say it would be slightly louder removing the cat, but I have not noticed it, and I run with the LeoVince end can, without the baffle.

I was thinking I'd like to keep the stock pipe, remove the cat and get an autotune. Does that sound like a good setup for anyone that wants it to remain quiet?

Hi mate, I have a standard pipe that I decatted with autotune and a Dam exhaust, can't say that it is any louder just a different tone.

That sounds great but kinda hard to believe. If I get the DAM with quiet baffle it really isn't any louder than stock?

[f3racer]

i was reading somewhere else that tuning is required with a cat delete because it will cause engine issues. now with everything ive learned about cars and bikes, i seem to think that this would only be an issue with a updraft and downdraft o2 sensor system. if you only have an updraft o2 sensor than it should not cause any differences.

now i completely understand that tuning is the best thing you can do after a modification like this, but everything ive ever known tells me that even if i dont tune it then it will cause no issues other than a stronger fuel smell.

am i thinking wrong?

[hvfrdave]

I would always recommend getting the A/F set up correctly on a dyno, with a technician who knows what he is doing, when you de-cat the VFR1200, you need it set up correctly, my VFR1200F went from 147bhp at the wheel to 167bhp at the wheel, that's how much the standard exhaust system strangles the power. I have since done 5 VFR1200s, and on average you gain 18bhp & 8lbsft of torque.

[f3racer]

Roger that!

[Fasty]

hy, could you give more info how you made the part that replaces the cat?

[hvfrdave]

Fasty, as photos on page one, the Y-piece was made up with the same dia pipe, as the original header pipes, just as they enter the cat. :smile2:

[arrow]

I finally took my bike to a tuning shop last night. I already knew about this guy who had a dyno shop within 600 meters of my office building so I called him two weeks ago. We had a chat and I told him that I wasn't chasing maximum numbers but a smooth powerband and predictable throttle response. He said that's what he's aiming for as well so I decided to try my luck and made an appointment. He told me to block the PAIR before bringing the bike to him since it apparently confuses the dyno readings. I took the bike to my dealer yesterday who blocked the PAIR and cleaned the K&N air filter; good thing too, since it was pretty dirty.

I filled up at a gas station and rode to the tuning shop after work. He bought me dinner in a mom&pop style restaurant next door to his shop and then we set to removing the fairings. We put the bike on the Dynojet dyno and he started working on it. He noted that almost all the values in the PC-V were on the poor side, some quite so. Certain parts of the powerband were really really terrible and this reflected my experiences about the bike. After he was done, we started putting the bike back together, when we noticed that we hadn't measured the power! We had already put everything back together, we did a run without getting the signal from the coil and got 157 HP at the rear wheel. This seems to be in line with what others have seen, I had my dB-killer in place so I'm guessing 160 is within reach. I don't care though, as all I'm interested is smooth and progressive throttle response. I couldn't test it properly as it was late and I had to get back home but I noticed the improvement as the bike now feels fluid and smoother, rather than buzzy and strained as before.

I will be riding this weekend through my favorite backroads to test it more. I enjoyed riding the bike but the throttle response was pretty bad, and demanded a lot of clutch work. I hope that most of that is gone now. I'll keep you posted...

[BiKenG]

I know this isn't a re-flash thread, but I'm thinking about de-catting AND re-flashing so it's kinda relevant to both.

To those of you who've done a lot of the pioneering work on these mods (hvfrdave and dynajohn), what do you think about de-catting etc and then using a re-flash without a PCV since it can incorporate a suitable new map anyway?

In this case, would there be any need for any O2 sensors at all? What exactly does the ECU use the O2 sensors for? It doesn't use them to adjust fuelling in the same way the PCV uses Autotune - as far as I understand it. Or am I wrong about that?

I guess what I want to achieve is the best I can, but without needing a PCV in the mix and I'm thinking that with a re-flash this is actually possible. But where do the O2 sensors fit in (I mean logically, NOT physically )?

[lshark]

i believe that the sensors are used to adjust for altitude and barometric conditions,etc, in real time

[luvtoleanit]

I know this isn't a re-flash thread, but I'm thinking about de-catting AND re-flashing so it's kinda relevant to both.

To those of you who've done a lot of the pioneering work on these mods (hvfrdave and dynajohn), what do you think about de-catting etc and then using a re-flash without a PCV since it can incorporate a suitable new map anyway?

In this case, would there be any need for any O2 sensors at all? What exactly does the ECU use the O2 sensors for? It doesn't use them to adjust fuelling in the same way the PCV uses Autotune - as far as I understand it. Or am I wrong about that?

I guess what I want to achieve is the best I can, but without needing a PCV in the mix and I'm thinking that with a re-flash this is actually possible. But where do the O2 sensors fit in (I mean logically, NOT physically )?

Yes it would work but you'd need to borrow a PCV and it would involve several trips of your ECU to Don. If you decat you want a custom map,definitely. But once the map was made Don could put the map tables into the ECU for you then you could remove the PCV from the bike altogether as your custom map would be in the ecu. But you'd need a PCV to get this done. Maybe you could borrow one from someone in the winter and get it done.

Autotune, is too valuable to me so I run the PCV with a custom map and the Autotune adjusts that map based on conditions (same setup as hvrdave. This way I can ride outside my geographical area where temps are different, elevation, humidity, etc, and Autotune compensates for that and will change afr as need be. It's the ideal setup for fueling, and tailored to the bike 100%. This is probably going to be a 10-20 year bike for me and I wanted as close to perfection on the motor as possible.

Talk to Don about it. He might be able to put a map in that is close if you don't want to futz with the Dynojet stuff.

[BiKenG]

Ok, so the Autotune compensates for changing conditions, that I already knew. But in what way is this different from how the ECU uses the std. sensors. If you have a good map for the engine configuration and Don re-flashes the ECU with this map, does the ECU not now adjust the fuelling, based on that map, but corrected to suit current conditions using the built-in O2 sensors, just like the Autotune would do?

I'm trying to get to the bottom of what advantage there is, if any, in using a PCV with Autotune (and it's own O2 sensor) against a re-flash with that same map and then just using the original built-in sensors.

In fact, why does the VFR have 2 sensors, when Autotune uses only 1. What are the advantages and disadvantages?

[SimonAudi]

I sent Don an email last week basically asking the same

I assume when he reflashes Ecu and changes fuel map he also changes the target air ratio to keep it a little richer ( less lean)

The only advantage of the Pcv is you can make the changes yourself or the dynotuner can or the ecu self adjusts ( auto tune)

If you live near Don then obviously he could reflash the Ecu on his Dyno on your bike and you do not need the PCv to get perfect

If you are remote - then Don can reflash the Ecu based on a theoretical set of values for your bike and setup

If you do that then it's obviously not going to be perfect but very close - like a standard Ecu

I would suggest when the reflashed Ecu is fitted the bike is dynoed to ensure no errors and the fuelling ratio is good and there is no risk to damage bike just as a double check - this Dyno pull won't be that costly

The sensors will then optimise the air ratio to Dons new value just like they do now on a std Ecu

That's my take - but I would like if Don could confirm

The auto tune uses 1 sensor to adjust all 4 cylinders - the standard Ecu uses 1 for front 2 and one for back two cylinders

The original sensors are ignored with Pcv when it is fitted.

[arrow]

How important would you say the Autotune is? I still seem to get some hesitation at partial throttle at low rpms, nothing serious but kind of annoying. My tuner says that this could be solved by Autotune but I would love to hear your comments...

[hvfrdave]

arrow, the Autotune would fine tune the A/F readings as you ride, it can work up to 20% + or - of your standard map, so it would fine tune it, not just at low revs, but throughout your rev range.

[Guest]

Well i fired her up today, on the PCV Map & de-cat, and what i noticed straight away is how responsive she is when you blip the throttle, can't wait to road test it now.

Dave here's a question.... in your original post's photos the airbox cover is removed. I was wondering did you leave the cover off after installing the KN filter?

If you've reinstalled the cover did you keep the 2 rubber boots as well?

[hvfrdave]

nickolaus, no I re-fitted the Airbox lid, and also the Air-intake rubbers.

[Guest]

Very informative thread Dave. Thanks a lot for sharing your experience. The bhp gains made are very impressive indeed, and so is your clear and crisp style of communication.

I am based out of Mumbai, India and plan to emulate your project on my recently acquired 2010 model DCT. Would it be possible for me to get your bikes map?

Cheers

V

[arrow]

I'd get the bike set-up by a dyno right away if I were you. I got a map from Dynojet UK for the same setup (decat, K&N Air Filter, and Akrapovic slip-on) and it was kind of OK but I wasn't totally happy with it. When I finally got it on a dyno, the tuner told me it was running on the poor side just about everywhere (it was up to 16:1 in some places, really really poor). The gas we have here in Turkey is way different to what they have in the UK, and I'm sure that's the case in India too. Get a dyno shop to set your bike up right after you do the upgrades, you won't regret it.

After the tuning, my bike's rideability improved immensely. I didn't install an Autotune on my bike, so I'm probably missing that last bit of precision that Dynajohn, hvfrdave and others are experiencing but it's miles better than the stock form...

[Bassie]

DynaJohn also has a Don Guhl ECU reflash, and after he added a PCV.

Funny is, I didn't do any of this and just did a Don Guhl ECU reflash with a new map and it runs just as the topic starter describes, but I use stock exhaust and airfilter.

Don't forget, Don puts an optimised PCV map into the ECU (or one that you want).

The EU-ECU's have serious flaws in them due to EU-regulations, take those out and the bike flies, with or without PCV.

[Guest]

@arrow: you are probably right mate. However, 2 hitches in my case

A) i dont think one can get the DCT on the dyno. I think Don Guhl tried that already. Something about rear wheel not moving fast if the front one isn't moving.

B) and even if we could, we just dont have any dynos near Mumbai to fiddle around with the maps.

I figured i might as well use Dave's map given that my set up is similar to his now, only difference being i am getting my ecu reflashed by Don Guhl as opposed to using a pcv+auto tune. I could be wrong but it has as much probability of working as does any other map Don would have put on my ECU. Lets see how it works. Hopefully i get my ECU back by next week.

And yes, you are right about the pump gas in India being anemic. We get 91 octane here, i mentioned it to Don and i think he has tweaked the fuel map i sent him to incorporate that.

Lets see how it pans out.

Cheers and thanks for your thoughts.

V

[Guest]

So i got my reflashed ECU fitted on the bike with Dave's map, bike decatted and with scorpion slip on. K&N air filter still in the mail.

Took it out for a short ride in the Mumbai traffic: first impression is that its become a totally different bike. So much more power and smoothness of power delivery in every gear and all the modes including the Dog mode.

I am itching to get up at 5.30am and take it down the highway for a 200km plus ride.

Dont know how to put up pics using the phone so will do that on Monday.

Thanks a lot Dave for showing us the way to make this bike better. I was earlier debating selling off the vfr as i didnt get the arm wrenching acceleration i desired. But now, with these mods and reflash, i am in love with the bike. Now its a keeper in my view.

Have a good weekend you all.

V

[hvfrdave]

Since I last posted on this thread, I have now uprated the front and rear suspension,

K-tech front fork revalve, and Linear fork springs, we set the front re-valve with a lot more compression damping, to stop the front forks diving so much, when coming of the gas, but more so when under braking, so now the front dives a lot slower than the standard set-up, which helps a lot with weight transfer. The front fork air gap is 180mm standard, but I have tried the air gap as little as 140mm, but settled for 160mm, for those of you that don't know, the air gap works on the bottom 1/3 rd of the fork travel, 160mm works fine for me.

Linear front fork springs, to get the front sag correct we went for longer springs, but standard 9.5 Nmm, but I am going to try standard length Linear springs, but a heavier spring rating of 10 Nmm, I will let you know which I prefer after testing them, front sag is key, if I can't get the front sag with the latter springs, I will go with the set up I have now, which is the longer springs standard 9.5Nmm.

[BiKenG]

Y-Piece Jetex REF U905145/R is almost a perfect fit.

Could you possibly elaborate on that please. Obviously it will require trimming to fit in the gap, but did the pipes then line up? The calculations look like the width of the 2 inlets wouldn't match to the Honda pipes, but in practice, really how close was it? Were you able to just weld it straight in (after the trimming)?

[hvfrdave]

BikenG, or you could send the headers up to me, and get the correct Y piece welded in, but that's up to you ofcource. :smile2: