Cyclone manifold on 2g head

[Blinkyblinx9]

I'm not trying to regurgitate the same questions that have been asked over and over but I have looked and looked through the forums for solid info on this topic and I have found few if any useful or productive and not conflicting replies. I also don't want anyone to think I'm trying to come off like an ass. I'm going to ask some stupidly specific questions that I feel were asked in the past but were phrased too broadly so the responses were quite generalized. So, with that out of the way on to my questions.

1: You can put a cyclone manifold on a 2G head right? I mean nothing is technically stopping a person from physically bolting it on and firing up the car and having it run (just run) with no trouble? The ports aren't offset in a way that prevents the parts from forming a proper seal? No other weirdness that needs to be considered?

2: If not then, what stops a person from just making like a 1-2inch adapter to port match instead of porting the 2g cylinder head itself? I have searched for days and days an the only thing I see is either "you cant do it" with absolutely no explanation other than the ports don't match or "you can but you would have to port the heck out of your head to the point that it eliminates the benefits of the 2g head" which does kinda sorta conflict with the ohh so typical "you cant" response. I mean, if it is just a difference in port size how big could it be like 3mil all around so 6mil diameter difference or less even? That can easily be blended with an inch or two long adapter.

3: Has anyone ever actually put a cyclone mani on a 2g head effectively whilst retaining the flow characteristics of the 2g head? If so does anyone have VE table adjustment comparisons from link or dyno sheets anything that shows any gain at all? Low end torque is rather hard to get a hold of on our cars at a reasonable price so if I can drop 300 on parts and machining and spend a few days fiddling around with this and get even just 10-20lbft at 3k without loosing anything up top its worth it to me over stroking the block. That's going to cost a few thousand and won't net me hundreds of lbft.

4: What other things need to be taken into consideration? For instance (if i remember correctly. its been a lot of reading on this over the past few days) I read something about a bracket that needs to be mounted to the AC compressor on 2Gs? I'm assuming the cyclone mani weighs a good bit more than the stocker so its just to help brace the weight and ease load on the intake manifold bolts and cylinder head.

I want to know everything I can about this before I pull the trigger on a 3-400$ likely month long experiment.

 

[Dericsh]

I’m sure someone will come behind me that has a lot more specific and helpful information, but I can start with something that will hopefully make sense.

The reason people say “you can’t” is more like, “because it doesn’t make sense”.

The port sizes are way different. So your options are to hog out your 2g head, and potentially ruin it, or engineer some sort of adapter that might not even be able to fit between the manifold and firewall? AND you still need a way to actuate the cyclone manifold, yes there are multiple ways to do the actuation discussed over the years. Of course, you could switch to a 1G head if you’re stuck on using that manifold.

Realistically, you’re talking about a months long $400+ experiment when, based on your goals, you could just source an evo3 manifold or sheet metal manifold and be done with it. There’s not much wheel left to reinvent after 30 years.

 

[Blinkyblinx9]

I'm not stuck on using it necessarily. I'm honestly quite happy with how the factory mani flows. The port sizes cant be THAT different tough. What is "way"? if its only like 4 mil wide and 10mil long that's not really way off. I mean its certainly relevant to flow but when considering the work to adapt one to the other its far from impossible or even complicated/hard to make that transition smoothly over a shortish distance. I'm not trying to say its NOT a bad idea as there is little concrete info around here to say either way. I just want to figure out why IF it's a bad idea when the goal is more low end torque. The engine in question rarely sees over 5.5k so I would like a bit more low end.

 

[1990TSIAWDTALON]

What about an EVOIII manifold?

 

[Blinkyblinx9]

There really isn't a lot of actual info on the E3 mani in regards to lowish torque either. Its mostly people saying it makes a bit more here or there in the mid range (mostly after 4k and holds up well at higher RPMs. It seems to have a negligible if ever so slightly negative effect on torque below 4k but again finding actual info outside of the repeating of already said statements without a source is all I could come up with here.

 

[Dericsh]

This is my definition of way different.

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[1990TSIAWDTALON]

Someone lay a 1g gasket onto a 2g head and see if it looks like it will seal completely. When I get home, I will, just out of curiosity.

 

[Blinkyblinx9]

Wow, that's what 40% larger it looks like? Wow, the width though. I can't find the thread where it was comparing each runner area of the cyclone mani to the port area but it came out to like 27% or something smaller than the 2g mani port which is what has me interested. ill keep digging for that.

 

[CrackedDSM]

I've had this discussion with some idiots before (not directed at you OP), but cliff notes is, it's not worth it. I got curious enough as to why these stubborn a**holes were digging so hard into trying it, that I had a friend test it for me on his car, and on the dyno.

Results were horrible, like I knew they would be. It lost torque everywhere that it should've gained, and HP numbers were like consistently 10-15HP less. Spool up sucked. The guy who tested theorized along the same lines as what I said, and that's even with an adapter that's a large sudden change for air to go through, especially forced induction. The 2G ports acted as a big, giant restrictor in the best case, and worst case (just bolted it up with no adapter, or filling the ports in the manifold to match the head) a giant wall for the air to slam into, tumble, then bumble its way back into the cylinder.

1G head ports are so giant because they were specifically designed for the Cyclone IM's dual runners. It's why the 2Gs (and every single 4G63 and Evo in general) after that had smaller ports designed for a single runner manifold. And even with how absolutely GIANT the 1G's cylinder head ports are, the Cyclone STILL acts as a slight restriction and you'll lose a few CFM of flow up top. Imagine how much worse that loss is gonna be with legitimately half the port size. To use a Cyclone IM on a tiny 2G head is like putting a 1.5" exhaust on a GT35R sized turbo.

Evo 3 IM's from in person ride-alongs and digging through the owners brains from everything I can find increase torque down low SIMILAR (not the same) to a Cyclone, but don't give up any top end gains either. Mid-range and top end are both improved noticeably. They pair exceedingly well with a 16G turbo (as does a Cyclone. Again, what it was originally intended to pair with). The Cyclone is just a very early solution to a problem that the Evo 3 IM perfected.


These are just my experiences though. Go ahead and give it a try, but I ask for posterity's sake you have some proof to back up whatever happens. Dyno it, track numbers, even some Dragy numbers. Anything for before and after's sake.

 

[Blinkyblinx9]

Thank you CrackedDSM for that explanation. It kept me searching for other avenues which brought me to a write up done by RRE on putting a 1g head onto a 2g block. It goes into the differences in port size. 1g measures 60l x 37w and the 2g measures 56l x 28w. That doesn't sound so bad until you actually see it and do the math on how much volume that is. That's a roughly 41.57% increase in area give or take .02% depending on how I modified the calculation to factor in the shape of the port. Everything from a square to almost a diamond shape. I averaged it out and that's the variance. Its also a 31% increase in width which isn't something that a mere inch or 2 can accommodate on its own. The incoming air would have to first run into that larger void before being necked down by the adapter into the 2g head. It would likely require filling in the manifold and reblending/reshaping the the runners to adjust how it flows while tapering it down at the same time to prevent a loss of velocity and eliminate turbulence. It's just not reasonable unless you know from the start that it will be worth it. Best to stroke the block with all the money that would have to go into it to get a decent result. Now that I have convinced myself that it's not worth the risk, what's this about the e3 mani having betterish low end torque? Here goes another x days of my life...

 

[19Eclipse90]

1: You can put a cyclone manifold on a 2G head right? I mean nothing is technically stopping a person from physically bolting it on and firing up the car and having it run (just run) with no trouble? The ports aren't offset in a way that prevents the parts from forming a proper seal? No other weirdness that needs to be considered?

There is nothing physically preventing a cyclone intake manifold from bolting up to a 2G head. Using a 1G gasket, the manifold should seal up against the ample real estate available on the 2G head due to its smaller intake runners.

2: If not then, what stops a person from just making like a 1-2inch adapter to port match instead of porting the 2g cylinder head itself? I have searched for days and days an the only thing I see is either "you cant do it" with absolutely no explanation other than the ports don't match or "you can but you would have to port the heck out of your head to the point that it eliminates the benefits of the 2g head" which does kinda sorta conflict with the ohh so typical "you cant" response. I mean, if it is just a difference in port size how big could it be like 3mil all around so 6mil diameter difference or less even? That can easily be blended with an inch or two long adapter.

Imagination, creativity, skill, funds, time. You know, the typical reasons things like this never come to fruition. I would expect most people would look at the port difference between the two and say, “Okay, what can I do right here and now to make these two go together and function slightly better than if I just bolted them together? Oh, hey, Dremel!”

Small tangent, it actually sounds like a fun design - I may just try it out one of these days. What doesn’t thrill me is the thought of adding another potential leak point with another flange and manifold gasket. But that’s a different battle.

3: Has anyone ever actually put a cyclone mani on a 2g head effectively whilst retaining the flow characteristics of the 2g head? If so does anyone have VE table adjustment comparisons from link or dyno sheets anything that shows any gain at all? Low end torque is rather hard to get a hold of on our cars at a reasonable price so if I can drop 300 on parts and machining and spend a few days fiddling around with this and get even just 10-20lbft at 3k without loosing anything up top its worth it to me over stroking the block. That's going to cost a few thousand and won't net me hundreds of lbft.

Not sure of the relevance of this question. If they had, they almost certainly hogged out the intake ports in the head to match the manifold. Otherwise, the mismatched ports creates significant obstruction to air flow from manifold to head which will hinder performance. At that point, the fact that it was a 2G head to begin with really doesn’t matter.

4: What other things need to be taken into consideration? For instance (if i remember correctly. its been a lot of reading on this over the past few days) I read something about a bracket that needs to be mounted to the AC compressor on 2Gs? I'm assuming the cyclone mani weighs a good bit more than the stocker so its just to help brace the weight and ease load on the intake manifold bolts and cylinder head.

I guess this depends on what your used to mount it. If using an additional adapter to match the ports, I would probably suggest a support brace of sorts. Otherwise, I would not expect the weight be significant enough to require a brace. Aside from the obvious actuation equipment for the butterfly valves, I can’t think of anything else that would be needed.

Just my 2 cents and an attempt at actually answering each of your original questions.

 

[Jk's97DSM]

What about an EVOIII manifold?

If you can even find one now.

 

[Canadian_CD9A]

If you can even find one now.

Lots out there. Since the RVR manifold is the same (except for the troggle body opening), it's quite a common item. And it rocks. For anything up to 700hp, I'd pick a ported Evo I-III manifold over anything else, it's a response and midrange monster.

 

[1990TSIAWDTALON]

I run one one on 1 HX40 car and a stock 1g manifold on the other HX40 car. The EVOIII will suit you well IMO. I really think the stock 1g has better up top flow than the EVOIII.

 

[Blinkyblinx9]

There is nothing physically preventing a cyclone intake manifold from bolting up to a 2G head. Using a 1G gasket, the manifold should seal up against the ample real estate available on the 2G head due to its smaller intake runners.



Imagination, creativity, skill, funds, time. You know, the typical reasons things like this never come to fruition. I would expect most people would look at the port difference between the two and say, “Okay, what can I do right here and now to make these two go together and function slightly better than if I just bolted them together? Oh, hey, Dremel!”

Small tangent, it actually sounds like a fun design - I may just try it out one of these days. What doesn’t thrill me is the thought of adding another potential leak point with another flange and manifold gasket. But that’s a different battle.



Not sure of the relevance of this question. If they had, they almost certainly hogged out the intake ports in the head to match the manifold. Otherwise, the mismatched ports creates significant obstruction to air flow from manifold to head which will hinder performance. At that point, the fact that it was a 2G head to begin with really doesn’t matter.



I guess this depends on what your used to mount it. If using an additional adapter to match the ports, I would probably suggest a support brace of sorts. Otherwise, I would not expect the weight be significant enough to require a brace. Aside from the obvious actuation equipment for the butterfly valves, I can’t think of anything else that would be needed.

Just my 2 cents and an attempt at actually answering each of your original questions.

I hadn't considered the additional leak point. Honestly I think the issue comes down to too much added complexity to the otherwise seemingly simple task of putting 2 things together. Its not that it wouldn't necessarily work its more that it would be WAY too much effort for an unknown outcome. Its actually quite a shame I don't have more time and money otherwise we would probably get a definitive answer in about a month. I legit live for this sort of pointless tinkering.

 

[Jk's97DSM]

I just know that there were always a couple googling for them and then there weren’t as far as Evo 3 manifolds.