1JZ-GTE Head Flow Information

**131OWN** · 23-10-2008, 01:28 PM

Here is some flow data for the 1JZ-GTE non-vvti. Flowing was done on a Super Flow 600 bench.

**131OWN** · 23-10-2008, 03:13 PM

Pics were just uploaded, sorry for the delay.

**jztoyn** · 24-10-2008, 01:34 AM

is it true 1j heads flow better than 2j?what are the size differences in valves?are they a direct replacement?

**1JZ~lux** · 24-10-2008, 09:00 AM

That's some good info. I can't remember where I got it from, but I was under the impression that porting didn't make a difference to a 1JZ head. Thanks for the info. +rep

**131OWN** · 24-10-2008, 11:10 AM

Originally Posted by jztoyn

is it true 1j heads flow better than 2j?what are the size differences in valves?are they a direct replacement?

The 2jzgte head out flows a 1jzgte. 2jzgte have larger intake valves and smaller exhaust valves.

I'm using 2jzgte intake valves which are 33.6mm compared to 31mm STD 1jzgte valves in my 1jzgte head. On the exhaust side I'm using STD 1jzgte exhaust valves which are larger then 2jzgte valves, the 1jzgte exhaust valve is 30mm compared to a 29mm 2jzgte valve.

I'm getting a standard 2jzgte flowed the same bench as mine was done on to compare exhaust flow.

Porting does make a differences to the 1jzgte head, the hard part is find someone that actually good at porting JZ heads, they need to be able to increase flow at low lift. Any one can hog away heaps of material and get big flow numbers at .400+ lift, the key is you need to get maximum flow with removing the minimum amount of material as possible, this will increase velocity and in turn Power and Torque.

**JZA70 R** · 24-10-2008, 03:44 PM

the results look good on paper but what do they equate to on the road?

**131OWN** · 24-10-2008, 03:51 PM

Originally Posted by JZA70 R

the results look good on paper but what do they equate to on the road?

I made 344rwkw @ 18psi with 2jzgte intake valves before the Port and Polish, only reason we stopped tuning at 18psi was because the a340 let go on the dyno, as for the results this time round, @ 25psi we are looking at going close to 450rwkw without nos, I'll post the results here in a month or so.

**JZA70 R** · 24-10-2008, 04:03 PM

Originally Posted by 131OWN

I made 344rwkw @ 18psi with 2jzgte intake valves before the Port and Polish, only reason we stopped tuning at 18psi was because the a340 let go on the dyno, as for the results this time round, @ 25psi we are looking at going close to 450rwkw without nos, I'll post the results here in a month or so.

those figures are useless to everyone except yourself. before and after testing with everything else being the same would be ideal.

**131OWN** · 24-10-2008, 04:17 PM

Originally Posted by JZA70 R

those figures are useless to everyone except yourself. before and after testing with everything else being the same would be ideal.

I realize this, but it's not going to happen, things like quality of fuel, air temp, tyre pressure, humidity I won't have total control over.

**chris davey** · 27-10-2008, 01:03 AM

good info +rep

**YelloRolla** · 23-01-2011, 12:03 PM

Sorry for the grave digging.

131OWN I am interested to know how you solved the valve length issue with the 2JZ GTE intake valve being 1mm longer than the 1JZ GTE intake valve.

As there is only 0.9mm before the lash pad is below the surface of the lifter, one cannot take all of the difference off the lash pad itself.

I suppose the question is "how much to take off the top of the valve and how much to take off the lash pad"?

I realize that there is a couple of ways to skin this cat; I am just interested in how you did it.

regards
YelloRolla