PCV W Auto tune VS Dobek Gen 4....any thoughts?

thnewell · Feb 24, 2014

Has anyone used the PCV and Auto tune on a snowbike......??? I'm trying to decide on the new controller for my big bore Husky build and I am having a hard time making a choice between that and the Dobek Gen4. All the husky supermoto guys say the PCV all the snowbike guys like the Dobek. Both use a wideband o2....any thoughts?

Wheel House Motorsports · Feb 24, 2014

PCV makes fixed changes builds a map and runs off that. works good for someone riding somewhat static conditions, and within the factory well mapped parameters.

DP is always live making changes in the mid and high load settings based on the user programed settings. this works better when you start falling off the edges of the factory maps

thnewell · Feb 24, 2014

So are you saying that the DBGEN4 would be better for a heavily modded big bore motor?

I guess I really dont understand the differences...

thnewell · Feb 24, 2014

So are you saying that the DBGEN4 would be better for a heavily modded big bore motor?

I guess I really dont understand the differences...

Wheel House Motorsports · Feb 24, 2014

sorry, was busy at first and didn't have a chance to expand on things.

DJ is not "autotune" it is auto mapping. it collects a bunch of data of tps vs rpm graphs and compares the afr value at that given position to whats desired and makes a log of the % change of fuel needed to make that happen. then after a set amount of time in the learn mode you are supposed to go back to the run mode and it just runs off the map that it has generated based of what it learned. This works, and it works well, only issue i see is in the snow application, is that most of the bikes are mapped fairly accurately in the above freezing realm, go below that and they start getting all out of wack, most people dont ride bikes in the cold and snow... at all, hence the mapping isnt exactly dialed in 100% from the factory, so now say you go into learn mode and map when its 30 degrees, it makes a sweet map with just small percentage changes as the factory is darn close. well now its 10* out and your factory map is way off in lala land running pig rich. the map of required changes is now no longer accurate. never really 100% when we change conditions so easily. for applications where the stock bike is close and is used in reasonable conditions (so not snowbiking....lol) its a very practical and functional unit.

the DP unit is a true live autotune unit. anytime you are into the closed loop modes (load required depends on units exact settings) you are now constantly live tuning and chasing a target afr set by the user on the controller display. this fully live setup is very practical for this wacky application where we may ride in -10 to 40* in one day and are making massive elevation swings. so this way if your stock mapping isnt all it could be, it sort of just smooths things out and makes it run what you ask it to.

thnewell · Feb 25, 2014

Ok that explanation helps. Your close to Dobek arnt they in Belgrade..??? Do you work with them alot? I am building a 2008 husky 510 into a 530 with custom cams, crank, rod and polished head and throttle body, with oversize valves, etc, etc. and am probably going to run oxygenated unleaded race gas. Will the dobek be able to supply enough fuel??? do you have a contact there a good tech guy..?

Wheel House Motorsports · Feb 25, 2014

I worked there for a little over a year and a half and started putting the gen 4 on the snowbikes, rush44 had the first one, so yes, seen the units in action before

if the stock injector has enough fuel flow in it (most likely no problem) that would be the only issue you might run into, the unit can call for 0-100% flow from the injector. Other then that it would be a fairly simple deal, and im betting the standard dirt bike code would handle it. might need some minor tweaks, but nothing to crazy. so i would recommend getting a IrDa "dongle" to reprogram it if need be given the custom nature.

If you call up talk to either chris or matt, they both know their stuff up and down and will be able to get you rocking.

DynojetResearch · Mar 3, 2014

To clear up plenty of misconceptions typed here, the Autotune function is a tried-and-true auto map/auto tune device. The nomenclature is identical.
There are no graphs that process through the PCV, there is no fixed map once Autotune is enabled as it constantly calc’s trims to meet your desired AFR – there is no “Learn” mode mode in the PCV (just a switch to turn it on/off if you wish, but only as an accessory not integral to the operation) - and it does not matter how far out of the design scope of the Dirtbike you choose to operate it in (icy snowy conditions in our case). The AFR value is still a burn condition occurring inside your engine, is read by the wideband sensor, and relayed to the PCV.

Simply put and how ALL Closed looping systems operate -- an O2 sensor reads the ratio of air:fuel exiting the combustion chamber. If the wideband signal at the given operating condition is not within a spec'd parameter set by the ECU (or PCV with Autotune in this case), the device trims the fuel up or down to meet the specification in real time. You set the AFR you want to run, and the PCV keeps it there regardless of environmental operating conditions. We set a default failsafe range of +/-20% change allowed to meet your target AFR, but this bound is completely alterable by you – the customer. You can open this up to +/- 50% or have it only one sided allowing for +50% and -0% if you wish. This fuel change happens on the fly as you ride all day. Added feature of the PCV -- once an operating condition has been run through, the PCV remembers the trim that it had to come up with to meet your Target AFR from the time before, and already has the fuel delivery on par with what you desire and does not need to go back re-calc and re-trim to get there. [Closed loop ECU guru's might know this as "long-term trims" that the ECU may utilize as your engine changes due to clogged injectors, clogged air intake, or other operating factors.] Since all trims are stored and fueled upon as you ride - a bonus just for your own information, you can review the actual % trimming values to see how far off from your desired AFR the bike actually was.

For further illustration, check out our Dynojet Youtube channel for info. You can readily see by entering a desired AFR value into the Air:Fuel table, and watch the fuel become trimmed to meet that --- even while at idle (or any other condition) where your bike is at 14.0:1 in stock form, enter a value such as 12.0:1 for effect, and see the instant results!

Your Husky build sounds like a hoot! Since you will be running an Oxygenated race fuel, the stoich burn point of your fuel will be different than the common 14.7:1 for regular gasoline. Depending on the percentage of oxygen in your fuel, your power range might be lower in the 12.3-12.6:1 range.
I’m always happy to answer questions and help out a fellow Powersports enthusiast. The PCV will easily fit the bill to fuel your needs along with features such as engine temp compensation, start-up fuel trimming to help with cold starts, and even independent mapping for each gear on your bike!!
Hopefully this provides some insight and some education to the fellow 4M members.
Thank you for your interest in Dynojet Products!

cr500afx · Mar 3, 2014

I use / have used the PCV with auto tune on 3 turbo snowbikes.
Works well and auto tune dialed in the base map from the Dyno runs (100 deg OAT at sea level) to putting the bike on the snow at 0 deg at 10,000 ASL.

moto365 · Mar 4, 2014

I own Both and both work Perfect

I like the gauge on the afr4 and the price $350 vs $677 PC 5 auto tune
and you can change the Afr4 on the fly VS packing your Laptop in the mountains !!

PCV W Auto tune VS Dobek Gen 4....any thoughts?

thnewell

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Wheel House Motorsports

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thnewell

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thnewell

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