TTC

Hey fellas, im going to test drive a dseries tonight for drivability, im unsure what head is on it but it has stock valves and cam. Reason im asking is that I want to compare the drivability of the honda setup to how my car would compare. He has an hy35 on it and he tells me that it spools pretty quick, like full 10psi by 4000rpms. I'm trying to figure out if ill get roughly the same

I currently have a smallport 4age head with 256 264 hks cams with 8.3mm lift. He has a 3" dp i have a 2.5" dp and i have a log mani as opposed to his sorta half *** equal length.

WTF is it about Dseries heads that flow so well? Is it the vtack or is just port size?

What helps spool turbos air volume or velocity and do honda heads tend to have more of which or both? Franklly I found better spool with the smaller ported head as opposed to the larger one, its just physics and air velocity.

Hitchhikkr

Not sure about actual flow #'s, but d-series has TORQUE compared to an n/a 4age. Heads off the ports look very close on the exhaust side, intakes on the 4a's are bigger, but that doesnt mean they flow better. Even though the 4age is a "G" series head, the valves are still a pretty narrow angle. Both motors are limited by stock wimpy *** cams. They probably have similar flow #'s but the D16a6 (for example) feels like it has much more bottom end power, whereas the 4age (even red hat) has power biased to the top end of the band.

Neither motor really stands out in my mind as being a true performance motor, but they get the job done.
Ideally, id have a b18b LS motor in my MR2 for the win...

Hope that helps.

TTC

Hrm thx hitch, turns out hes got vitars and a z6 head. That was the info i was missing. If the holset will hit full boost by 4200rpms ill ---- my pants.

CXyD

---- your pants 10+ why?

Try 14psi at 2.5k to 7k with a sc14 on a bone stock d16z6

TTC

I mean ---- my pants in joy to get 10psi at 4200. I figure 10psi on a holset should make way more power than 16psi on junk 14b. BTW you put a previa SC on ur D lol?

Guy-Fast

D series heads flow like *** they are the bottom of the honda world.

CXyD

Yeah I have a SC14 on my D got the idea from my '96 Previa activate the a/c style clutch on my s/c using the a/c switch on my dash. I can drive w/o my s/c and get good 30 to 35mpg in town. And if I want really rapid acceleration I hit a/c switch and fly by who ever I want.
I originally did this setup to compete with the corvette club when they would invite my local scca club to particapate in the corvette roundup time trials held every labor day weekend. But we did not get invited this year b/c they actually over 70 'vettes from all over rocky mountain region so there was no more slots available for me to race.
If I us the s/c during auto-x I either plow cones or burn up my rt-615 tires.
I haven't maid it to the local dragstrip yet but I will summer.

Smith-02

Minor Threat

Yeah we know this, but how do they flow compared to yota heads?

Smith-02

find 2 heads. one d series one toyota head that you plan to compare. go to a flowbench, put both on, get numbers.
so one flows higher, okay. now consider the more important part
it still doesn't answer which is better. flow characteristics change from head to head, some naturally produce better topend, or bottom end.