I can't seem to get the search to work at the moment, but I remember a thread a while back about the Nismo heads. I thought someone posted about increased flow in addition to the smaller combustion chamber.

I just asked Jason at Performance Nissan if he knew if the flow numbers were any different, but he said that they had not seen any numbers.

For FI, the increased compression ration is not really a benefit, but a flow increase of 10-20% or more certainly is (still have to get new pistons for strength and ratio in the end anyway).

So, my question is if anyone has bought and used the heads, seen any numbers, or know where to send me for more information?

 

these heads may not be right for fi. they are off of the vq30 so are smaller displacemnt which will push the comp ratio to 12:1 in the vq. these are more for an extreme n/a setup. if you do use them in fi you will need to lower compression somehow, yes they are supposed to flow much better.

 

Yup, much smaller combustion chamber (42cc or so). They also use Infinity valves, high lift springs, and Nismo only cams (JWT may work). All this must be purchased separately. Also, this would be plain dangerous with FI. Unless of course you put in a dished piston.

 

Right, I know all that. It's 46cc instead of 42cc too. Stock is 56cc. JWT will work as well and the valves come from Infinitis with the VK45 or from a Nissan in Japan called the Cima (I think it might be the same as the Q45).

I appreciate all the input, but I understand the compression ratio issue as well. At a point where flow rates to matter enough to buy $2K heads and $1-1.5K cams, the engine is already going to have to be reinforced (pistons, rods, sleeves and crank). For example, 15-18 psi on the GReddy kit from those TD05s.

And since someone will jump in with the issue of the mass airflow sensor- yes, I understand we don't have a neat workaround yet either. It might be solved with some speed-density setup, but the big-boosters are already looking at this stuff.

And that is why my question still is: Do Nismo heads flow better? Has anyone seen any numbers? Has anyone used them?

Thanks a ton!

 

Go to Performancenissanparts.com

 

Why is this so painful?

 

A while back we tried to install a set of these heads on my car.... Never did get them together and after tearing my engine down.... ended up sending the heads back to Nissan and just porting & polishing my stock heads. Since that disaster we haven't been very willing to work with Nismo and their heads. I have been told by Nismo USA that the heads will now be shipped complete with valves and springs, which was the whole problem in the first place. As far as numbers.... I've yet to see anything floating around. That's one reason we wanted to try and make them work with my toy.

 

these heads are not officially relesed in the states i think that perfomance nissan got a "prototype" or maybe a demo. he is waiting until after race season to put them on bc hes doing a full build up but his shop is busy. they have not been tested independenly but they are the ones used on the nismo jgtc touring cars so i guarantee they flow better but we do not know how much.

 

Jeff --

Why not just throw the heads on a flowbench? Surely that would be easier than trying to install them on your car.

Easier said than done though, I know.. good flowbench testing isn't extremely expensive, but it's not free either.

as a side note, what kind of gains did you get from P/P on the stock head? (flow and hp/tq numbers, if you have them)

 

yah.. please do

 

Any Sound Clips floating around? Would love to hear the headers.

T

 

the conversation is about heads, not headers.