[Si2See]

Ok I am putting a 92 Sohc vtec d16z6 into my crx si. I was wondering if I can use either intake manifold liek are the vetc plugs different or anything. Also which one would be better to use cause I am gonna pull it off and port and polish it to match with an ls throttle body. Thanks

 

[5gencivic]

the best is the d16y8 intake manifold, from the 96-99 civic ex's. second is the d16z6 from the 92-95 ex's... and the absolute worst is the d16a6 intake manifold from the crx si's. if you can get your hands on it get the d16y8 manifold. it improves top end immensely with the right camshaft.

 

[Si2See]

Yeah I have the d16z6 one but would all sensors and all match up or what I havent looked at either of them yet.

 

[skidtron89]

No all the sensors don't match up and you should use all the parts that are correct for the engine you are using if you want it to be good and not stupid like most peoples swaps. BTW the Y8 manifold is not the best it just allows for more bottom end and a bit more torque as the ports are slightly bigger. If you are going to be running FI it won't matter anyways for a street setup. And also if you go NA the slightly smaller intake port will increase airspeed velocities hence making the D16Z6 manifold better again. Plus the Y8 is not a very good engine as a whole anyways as they have oil pump problems. And IMO are not as sturdy as the older D-series motors.

 

[5gencivic]

ok i'm going to beg to differ.
the y8 intake manifold was recommended to me by 4 different people from three different shops here in orlando and by larry from endyn. basically the reason being that the path the runners take to the head is a more direct path rather than the down and then 90 degree turn to the head the d16a6/z6 intake manifolds take.
also the port of the y8 intake manifold is the size port that endyn and dpr use for the intake ports on their d16a6 heads, so they recommend that manifold because it doesn't need any porting and is relatively cheap to purchase.

what i'm wondering is how does the y8 intake manifold provide more bottom end when the runners are more open and would provide less airflow velocity at lower rpm. in my mind the larger ports of the runners would flow more air at higher rpm.

 

[Si2See]

Yeah thats my opinion about the y8s too. So the z6 intake wont work cause of all the different sensors? I just need to port and polish the crx one?

 

[skidtron89]

ok i'm going to beg to differ.
the y8 intake manifold was recommended to me by 4 different people from three different shops here in orlando and by larry from endyn. basically the reason being that the path the runners take to the head is a more direct path rather than the down and then 90 degree turn to the head the d16a6/z6 intake manifolds take.
also the port of the y8 intake manifold is the size port that endyn and dpr use for the intake ports on their d16a6 heads, so they recommend that manifold because it doesn't need any porting and is relatively cheap to purchase.

what i'm wondering is how does the y8 intake manifold provide more bottom end when the runners are more open and would provide less airflow velocity at lower rpm. in my mind the larger ports of the runners would flow more air at higher rpm.

I agree with you to a point but we are talking about on his Z6 and the best manifold for that motor is the stock one if the head isn't being ported to match the Y8 manifold. Notice he said port and polish the intake manifold. And I know that Endyn does that but thatrequires doing the head too. It is true that it is a more direct path though now that I think of it. But the bigger the ports the more torque as the engine can empty the whole mainfold in like the blink of an eye. So if you have a bigger volume of air sitting in the manifold at any given time you would have quicker throttle response than a smaller port. Also you would get more torque since that same air is there and ready to be sucked in instead of going through the air filter and intake tube and all that. That is the same principle as the intake tube with the huge bulge in it. The Idea is to have the air sitting (Iknow it's not sitting still and the suction is constant at idle) and ready to be sucked up right away with out further restriction. Although the funny looking intake isn't good except for low end torque since as soon as the air needs to be going really fast it can't because as it comes in on the tube it's going fast and then it gets to the fat part and has to slow down again as it expands to fill the tube and then has to compress again to get through the throttle body. Also other things to point out is all the expanding and compressing adds heat to the air hence negating a lot of the performance gained. Anyways like I was saying though the bigger port size will generate better torque. Also if you are going to build a serious engine then the bigger size will flow fine but on this guys engine which is mildly tuned or stock at best it won't matter enough to not have the engine work as a nice running completey stock setup. And the guy doing should most definetely use the Z6 parts. Use everything that goes to that engine as I stated before. Then after you get it all running straight you could start messing with stuff. Just make it run right first if you get too much shit going on it will never even run half assed.

 

[5gencivic]

ok you're right on that one so i'll agree. in a ported application the y8 intake manifold would work better but for stock running conditions then stock intake manifold would be best.