Not sure on the cam spec yet, but I wondered if anyone had experience or ideas of tuning MIVEC on a 2.2 stroker with Cosworth heads and a GT42? I've tuned big power stuff before but never with VVT.

Factors to consider:

Exhaust manifold pressure
Cam overlap
Octane
Airflow
Engine speed

I could of course set a flat MIVEC profile and test acceleration or power across the range, then draw the best MIVEC plot.

It may be a case where less MIVEC advance gives more torque, and also where less taper is indicated.

Any hints/experience/discussion/theory would be interesting...

 

I would add EGT to factors to consider. I would think you'd want more advance at higher rpms.

Here's an informative article if you havent already seen it. It's actually a article about cam gears but since Mivec is an on the fly adjustable intake cam gear...
http://www.team-integra.net/forum/di...g+Common+Topic

 

Nice article, thanks.

I suppose we really need to add the effect of the turbo to that though. If we have exhaust manifold pressure greater than inlet manifold pressure if we are pushing the turbo hard for peak power then during valve overlap we'll have flow reversion, so retarding inlet cam timing would be helpful. We might have to do this more on wild cams with a lot of overlap, and less when running a large turbo that keeps the exhaust manifold pressure more sensible. I suppose I'm looking for real world experience on GT35R upwards on how the MIVEC maps have ended up compared to the stock turbo.

 

I ran into this last night as I was tuning the basemap on my 3586. The S2 map that I had posted in the MIVEC map was what I had been using with the scaling pretty generic.

 

If i'm not mistaken 9sec9 had an hta3586 and FP5R cams on his evo 9. It's a 2.0L though, but i'm sure he can be of great help if you shoot him a pm.

Good Luck

 

Aaron, do you mean that you were running into significant turbo back pressure or vice versa?

 

Aaron, I don't understand also.

 

From looking at his Mivec map posted and the dyno plot I think he's saying less advance = more torque although he's not fully retarding the cam at higher rpms. I'd still like to get some clarification.