Amak,

Go dyno the same car back to back, with the only change being more MIVEC advance on top... You will/should see power drop off.

 

I will be getting on a dyno soon.

JB- I was just asking a question. Your right, you can clearly see that the Mivec cam gear advances the cam. But how is it possible that I am seeing higher boost levels up top w/ more advance? Im just asking questions here, like we all are.

How did my question about how the cam rotates, baffle you? Do you know for sure, at which angle Mivec timing has to be at to shut off Mivec? Maybe I wasnt being clear enough? But I was trying to say, that maybe Mivec can retard and advance the cam.? Again, i think Im not clearly saying what im thinking. And Im just having conversation about it.. Im not trying to say you suck and I rule at tuning. But yes, I can tune Evo's. I have not tuned many, but I have tuned and logged my own car many of times. Seeing how the timing and fuel act and other aspects of the ECU. Im not saying I am the best at all. But I do know what I am doing. And every Evo I have tuned, I have RE-TUNED it after its been tuned from a professional tuner/shop. And I have seen sloppy timing and fuel maps, as well as low torque numbers and a week power curve.

No one here knows everything about mivec. I bet not even 50% of people know how to even properly tune it, simply because it cant be done very well with out a way to log it. Which I think, can be done maybe? By using the cam angle sensors some how.

Im only asking questions here. Oh I forgot, you were born, knowing everything and never had to ask any questions... come on man, I even said "sorry if this question sounds dumb" lol

 

Amak Start A New Thread. This thread is not about Mivec, nor is it about bashing shops or other tuners.

 

+1 This thread has nothing to do with Mivec. As the subject states its about lean spool disable and its effect on tuning.

 

Amak, PM sent.

Lean spool has some advantages if you are using it in conjunction with Meth or Ethanol, but even then only in certain rpm ranges. I still leave it off typically and then use a modified accel enrichment table and fuel map to achieve the tip in I am looking for.

In those instances I will only have it on for a short window and then turn it off. But using open loop fueling control as early as possible seems to be the best approach I have found.

 

Do you tune with lean spool disable for road race cars, for drag cars or for both?

 

sorry, but you are trying to reinvent the wheel here. Mivec has been done. Mivec on a Mitsubishi is extremely easy to tune. The concept tuning wise is old news, since Hondata started tuning IVTEC with Kpro. On a EVO is even easier, since it doesn't have an individual timing/fuel map every 10 degrees of cam rotation.

 

I hope those tuners who use lean spool would chime in here and tell their side of the story. There is no absolute right or wrong here. So it would be nice to hear both sides so that we can learn.

 

I would venture to guess that the only tuners that do not disable it are those who aren't aware of lean spool. This isn't a good place to ask questions though. For the most part, none of the big name pre-ECUFlash tuners ever post in this forum, so that segment would not be represented.

 

I agree. Many of the Pre ECUFlash tuners still uses EcuTek and I do not think it even have that option. I ask an EcuTek tuner about that and he told me that the forums talk a lot of $h** and it is not a good idea to keep the same AFR at all gears. But that was it, no more details or reasons were given. He usually don't post either.

Nevertheless I did disable it yesterday night and I am messing with the fuel tables now. So far I am still in the low 10 (and about 90% IDC) so I need to lean it a little more. Car felt OK and I note less knock during spool as compared as before. But I have only make a few logs so far. Lets see how it goes. Still debating if I take it to a tuner on a dyno or keep tuning myself on the street.

 

Well, I have seen some Post-Ecuflash tuners/enthusiasts also still using lean spool or prefers not to disable it. Just wanted to know more on the subject, thats all.

 

It would be interesting to hear from a tuner or someone who prefers having lean spool enable and their reasons for it. So far I do not thnink I have seen anyone saying they prefer to keep lean spool enable for tuning.

 

I leave lean spool enabled. If you keep the fuel map semi rich and keep lean spool enabled. During a heat soak condition the ECU will not "enable" the lean spool condition and your fuel will be alot richer to combat the "heat"
for those with lean spool DISABLED, the car will continue to run a high
A/F and the car will have to knock inorder to start working with the low octane fuel maps to keep heat in check.
Better to have inconsistant A/F during spool up with 0 knock, then consistant A/F with 3-6 Knock during certain occasions.

Sure you may not get consistant A/F during spool up, sometimes 11.3 others 12.2.

try this experiment, disable your lean spool. Set your a/f around 12.0 and do 5 back to back 3rd gear WOT runs, 2,000-7,000RPM in hot wheater 75 degrees F or so.

Next, enable lean spool with a lot richer fuel, 1 point or so. with same 6 back to back WOT runs. look at all the data determine what you should follow.

 

^ thanks. This is the type of reply I wanted to hear.

 

OK im gonna stop all this....

Razorlab is one of the best, most reputable ECUflash tuners on EVOm.net. He tunes cars everyday on a real dyno and is always testing theories. please dont doubt him.

FYI, PSI boost control and other mods are only available with ECUflash, thanks to cool people like tepra, mrfred, razor, etc.

and for the topic, I turn off lean spool on the cars I tune. Makes the AFR more manageable and makes gear to gear AFR more consistent.