Yeah, have fun with that when there are no tuning shops left anymore dude

How would you expect a shop that has overhead (as in rent, electricity, dyno maintenance, etc, etc) to compete, on pricing of course, with someone that has no over head and is willing to risk not only their life, but the life and property of their "customers" by road t00ning.

Sorry to derail the thread like that, and for Bryan.

 

Yeah, seriously, let's get back to MIVEC here!!

I'm stoked that there are guys like GST and HB Speed who have years of knowledge and I'm also stoked that there are other guys here like myself that are thirsty to learn for themselves as amateurs...

rock on guys!

 

It looks like more boost = less advace on the intake side and more retard on the exhaust side vs less boost.

Someone correct me if i'm wrong.

Thanks GST!

 

I think that's the general idea, although it's really more airflow that's driving that trend. It's probably why retarding the exhaust in the upper RPM's on my larger turbo yielded power and advancing the intake didn't seem to do much.

 

I created a new intake map with less advance from 200 load up and I lost 1.5psi of boost but it doesn't seem like the car is down on power. I'm going to put my numbers into VDR later and see what exactly happened.

 

any updates on your VDR input??? 1.5 psi down and how's the power now? That's what Bryan mentioned on the first post, less boost and more power right?

 

According to VDR, I didn't make any more horsepower, but held more horsepower to redline. Prior, power was peaking at around 6200rpm and falling about 40hp by 7500. Now, there is about 10whp less at 6200rpm, but it holds it out towardss 7k and falls only slightly. According to VDR I now have 25whp more at 7k and 30whp more by 7.5k. All I did was lower my intake advance from 6500 and up.

But, my eyes must have mislead myself while watching the boost gauge because boost has not dropped anymore by redline. I actually have 20.7psi by 7000 and 18.5 by 7500 which is pretty much the same as before. The extra umph came strictly from less intake advance.

 

It's stock turbo?
Which values your are using now for 6000-7500 rpm range?

 

Thanks Bryan for sharing your base maps! I made a version similar to your maps and saw a VDR gain of about 5-10 hp in some of the low rpm areas over gunzo's generic mivec. My map had less intake advance and exhaust retard overall, and I didn't have time to try pushing it further. One thing I did change was I that around 5500 rpm's and up, I used less intake advance and a bit more exhaust retard. My car seemed to like this more, but it's always really hard to say without a dyno. I tried using VDR to compare power output, but it's not always super consistent because of the road. Anyway, just wanted to say thanks for sharing!!

 

^^ it seem the majority of people are using less intake advance top end and more exhaust retard. What is the relaionship between rpm and valve position vs performance?

From what I understand more intake advance allow more air/fuel mixture mass to enter the cylinder for higher potential energy. But, too much intake advance may lead to exhaust gases being recirculated into the intake, which allows a small percentage of burned gas mixture to occupy valuble cylinder space.

More retard on the exhaust side would allow more of the burned gases to escape and be replaced to a certain point where the scavenging process is most efficient. Correct me if i'm wrong I havn't played around with the maps yet.

What specific numbers are you guys using? stock?

 

What is the purpose of setting the intake map to 35 if we are limited to 30*?

 

The intake cam has the capability of 25 degrees of movement which is from 10 to 35 degrees on the map.

 

so is everyone using the same intake/exhaust map in both tables (#1 & #2)? I couldn't find any information on when the ECU uses one or two.

 

Anything less than 10 does nothing?

 

I'm trying to get up to speed on the ins and outs of MIVEC. I read through the 44 page thread for the Evo IX. The basic theories I heard in that thread were:

IX MIVEC

The limits of cell values is 0-28.8 and 28.8 being fully advanced.

During spoolup you want to advance the intake cam because this creates more overlap, which in situations where back pressure is low (spoolup), overlap promotes cylinder filling ergo more efficiency ergo more exhaust gasses ergo spooling the turbo.

At the top end, you don't want to advance the intake cam much because of the high back pressure the stock turbine housing creates. This very significant back pressure will actually hurt the benefits of overlap / scavenging and you might get some reversion.

The JDM RS MIVEC maps are damn good. Changing this MIVEC map so it is more aggressive with advance during spool will get you a very good MIVEC map.

It's thought that the 0-28.8 is in crank degrees, therefore the range of motion of the cam is 0-14.4 cam degrees. And it is thought that a value of 20 in the MIVEC map equals the approximate lobe centerlines of an Evo VIII intake cam.

What was not discussed much was ideas about why you want to start the intake valve opening earlier or later in general disregarding overlap.

Also of course, it's never one size fits all and each car is different to what it wants.

Am I missing any other nuggets of wisdom from the IX MIVEC thread?

X MIVEC

Can someone summarize the understanding of the X MIVEC as I did above for the IX?