jdm92_accorn : 1992 Accord LX

[jdm92_accorn]

honestly over the years ive concluded that smaller plenum and larger throttle body make for a much more responsive and enjoyable street car. it may not make a bunch more power but the throttle response makes up for it.

[dwhacks]

Why is it that people are stacking IAB plates and buying spacers and such? are there applications where more volume is better? I thought the whole reason for the H23 intake manifold was to get a larger volume plenum?

[DCB7]

honestly over the years ive concluded that smaller plenum and larger throttle body make for a much more responsive and enjoyable street car. it may not make a bunch more power but the throttle response makes up for it.

Dam. How is that even possible?
I wonder what effect larger valves has on throttle response?

[jdm92_accorn]

Not enough to notice on a street car

[Chrisnick]

That's my take on it as well. I don't think I'll fully gut the plenum as it'll take runner length down to about 7.6-8" and push power up too high. Probably just take the runner down to the webbing and oval out the port opening in the plenum.

[jdm92_accorn]

Just for fun I thought I'd share the exhaust sound on my custom cam at a 1200rpm cold idle.

[jdm92_accorn]

hot idle 900rpm

[Chrisnick]

If I sent you an F23A1 and F22B1 camshaft, would you be interested in possibly designing a profile for me? I'd like to keep the stock valve springs and emphasize torque utilizing a shift point around 6500-6700RPM. Basically, drop in, tune, and go. I have an adjustable cam gear, too. Probably pair it with my cut down/ported F23 intake manifold, a refreshed/decked .040 F23A1 head, ported JVT upper header portion+2" secondaries+2.5" collector and go 3" on the exhaust.

We can talk through PM's if you'd like, but I'm ready to start throwing some coin around to make better power. The B-series cars I've been beating up on all summer are going to be a little quicker come spring, and the ol' dirtbag CD7 needs to be ready to party.

[jdm92_accorn]

We can work something out im sure. It really depends if you want to go hard weld or regrind though. Regrinds are potential limited by material but are relatively cheap. With the hardweld it is expensive but there is alot more room to make power.

[jdm92_accorn]

Going to be doing some more intake tuning Saturday, ill post my results.

[jdm92_accorn]

i also added about 8" to my aem v2 intake. bam triple stacked. logs show i now need a larger throttle body. its showing .5psi positive pressure up to 5000rpm and about 5200rpm it goes to -.2psi and by 6000rpm it is -.6psi vacuum. here it is though.




ignore the rough looking engine bay, i played in the mud the other day and when i pressure washed the engine i accidentally hit the header and it ruined the wrap.

[dwhacks]

A few posts ago you said smaller plenum was more fun and now you seem to have triple stacked plates? why is that?

[jdm92_accorn]

Plenum is stock size, the stack plates are used to lengthen the runners. Small plenums and properly sized throttle bodies are always more fun on the street. Im lengthening the runners for testing purposes.

[Chrisnick]

Attempting to build better torque under 5000RPM and sacrificing top end for it?

[jdm92_accorn]

Im trying the Helmholtz tuning method to reach a higher "natural boost". Total tract length now is 19.6" and with no plates it was 16.6". Im hopefully going to be able to reach my 2nd, 3rd AND 4th harmonic instead of just my 3rd and 4th. It seams to be working well up to 5300rpm~. I datalogged and it went from 0.0psi @ WOT to .4psi at WOT. And you definitely feel it. Up top im getting a restriction so I've ordered another 68mm throttle body to do some more testing. The engine is wanting more air up top now, its showing -.4psi vacuum above 5300rpm which is in the 2nd harmonic. So either the runners are too small or the throttle body is too small. The throttle body is $80 and it only takes a few minutes to port matched the throttle body to the plenum vs alot of work to enlarge the runners. I should get some dyno time soon and ill compare.