Cyclone on a 2G head.

[cheekychimp]

Following my previous thread here I was speaking with Ken (my mechanic here in Hong Kong) about a good build for the stock car. He suggested throwing an EVO III head on the car which is essentially a 2G head with different camshafts.

Now he suggests keeping the Cyclone and port matching the EVO III head to fit it. His argument is that it flows better up top. I was thinking about this and wondered if the Cyclone gives this impression because normally it lives on a 1G head which most people tend to agree flows more up top. I also find it suspicious that Mitsubishi never fitted Cyclones on 2G heads which tends to suggest the dual runner setup is redundant if you have the higher velocity of the 2G head.

Anyone have any thoughts, experience with this. For a daily driver and with a turbo like a 14b or 16G, I don't think the differences are going to be that large, it's just that I have an EVO III intake manifold and could save myself some port work if it will work as well or better.

Slightly off topic but worth mentioning is that I should be getting an AMG manifold and Head in soon as well. Initially I had thought about throwing that straight on the turbo shortblock since the cams are supposed to be more aggressive and the Cyclone bigger to take advantage of the 1G head at higher rpms (albeit a rather conservative 7500 rpms). I wonder which cams are more aggressive, the EVO IIIs or the AMGs?

 

[H05TYL]

Inhalation lift quantity (mm)
Inspiration angle (degrees)
Exhaust lift quantity (mm)
Exhaust action angle (degrees)

RVR SSG---8.5---252---8.5---252
Evo 1------8.5---252---8.5---252
RVR HSG---9.5---252---9.5---252
Evo 2/3----9.5---252---9.5---252
VR4---------9.5---252---9.5---252
AMG--------10----260---9.5---264

 

[RedTwo]

From memory the Evo 3 cams are Evo 2 cams which are JDM VR4 cams.
I've got head flow bench results (ported and unported) for someone elses Evo 3 head if you want some empirical data.
I've also got an Evo 3 head on my car, last dyno run started to fall off rapidly after 6000 rpm :/

 

[cheekychimp]

Damn guys, you are on the ball!

Mmmm there might be something in this then.

H05TYL, so you are saying camshafts in the EVO 3 head are actually going to no different to what I currently have in the car? Several people told me the AMG cams were definitely going to be more aggressive but I doubted they'd be as aggressive as 264s. I was at least half wrong there wasn't I?

And RedTwo I would be interested to see that data but do you have any data from a VR4 head to compare it with? Also on that dyno run you mentioned where it tailed off were you using a Cyclone or EVO III intake manifold.

I wonder if the AMG head would be a better bet then? Any thoughts?

 

[H05TYL]

yup, evo 2, evo 3 and vr4 cams are all the same.

 

[turboaddict]

Saying that the head fell off with out any details isnt saying much, as what cams, intake manifold, turbo, boost, along with everything else makes a huge difference.

for example my car falls off after 6500rpm on E85 and 26* of timng and I have fp2 cams, si springs and retainers with a88000rpm redline; a 20g turbo, a fp exhaust manifold, and forrester intake manifold. even with all of this information I left out a critical point. My boost is droping off from 35psi to 28ish, and my power nosedives after 6500-7000rpm as I am having problems keeping boost up. these motors can flow alot of air with out much done to them, having a turbo that can keep up and having a proper tune makes a really big dfference. so please; what else is done to the car. thanks

Quoting RedTwo:
From memory the Evo 3 cams are Evo 2 cams which are JDM VR4 cams.
I've got head flow bench results (ported and unported) for someone elses Evo 3 head if you want some empirical data.
I've also got an Evo 3 head on my car, last dyno run started to fall off rapidly after 6000 rpm :/

 

[Scientist]

Evo 3 head with Evo 3 intake manifold....Ditch the Cyclone. 2G/Evo head flows more, Evo 3/RVR intake flows more.
Port match throttle body.

This is the route i'm taking once i get my car up and running and my basemap dialed in on Jackal

 

[cheekychimp]

Do you have any data to support this Scientist? Not doubting, just interested.

 

[RedTwo]

For interests sake I had a complete Evo 3 head with about 1000km on it from rebuid - intake & exhaust manifolds, throttle body, fuel rail, TD05H-16G6 with healthy back cut turbine wheel, external wastegate off the manifold, 3" exhaust and downpipe. There was a restriction/lack of efficiency with the intercooler I was using at the time. So in a few weeks I will have another dyno plot with the current intercooler but otherwise unchanged setup.

 

[curtis]

One thing not brought up is overlap of the cams. Na motors don't have overlap but turbo ones do maybe mitsubishi did as well. /ubbthreads/images/graemlins/dunno.gif Don't know if a NA cam would work in a turbo application Paul. Only some one that has a degree wheel na, turbo and aftermarket cams available and a motor on the stand could tell you this. /ubbthreads/images/graemlins/dunno.gif

 

[EMX5636]

^ You could dial a little bit out with adjustable gears. It might take a few dyno pulls to get them right, but should be do-able.