flyingtoaster

Yes there is intake and exhaust overlap. Our engine is cammed out. Your ECU will automatically add more fuel when the MAP sensor detects more air from an intake. However, the Hondata FlashPro is definitely a good upgrade for the price, regarless of whether you have bolt ons.

blacknboostn

This is an interesting read, would like to know the most efficient way to tune for the S2000 with only boltons. Would a VAFC be sufficient or would larger injectors be needed? What other tuning systems are available for something like this? I would eventually be supercharging and would update the tuning software once that is happening but I intend to have I/H/E before that and would be willing to tune for those mods.

flyingtoaster

What year is yours?

blacknboostn

I don't have one yet I have a Dodge Neon SRT4. Looking to upgrade in the handling department haha. I'm just here to learn. I'm a Honda guy at heart. I should be getting an 08 CR when the time comes though.

punchdrunk

I've no idea of the science of it all, but my 00 went from tunable afrs with i/h/hfc/60mm cat back to lean with i/h/70mm header back exhaust.

No need for a VAFC if you run i/h/70mm tp and cat back as you'll need to find a way to add fuel.

blacknboostn

I would assume that under that circumstance the way to add fuel would be to get larger injectors and then use a VAFC to pull fuel until the AFR is in an acceptable range.

That being said, are the stock injectors pretty much maxed out on the S2000? I've never used a VAFC so I don't know if there is a way to add fuel instead of just pull it back but I thought there was.

flyingtoaster

The stock injectors are stout as long as they are clean. I think we don't have fuel filters. 06+ models have a programmable ECU and the Hondata FlashPro piggyback is only $700, so it is a must have if you are willing to spend the money on IHE. Also look up the DesignCraft iVTEC conversion if you are considering power mods. IVTEC and supercharger kits require either an ECU reflash or FlashPro anyway.

Croc

so gas/air flow velocty may increase.
how this increase amount of air that eventually fills into the cylinder?

cylinder volume still the same.
nothing forces more air inside.

looks to me this can only happen in a case when with stock intake/exhaust the cylinder is not filled fully with the air.
only possible reason - stock intake/filter are so restrictive that sufficient volume of air doesn't manage to get sucked in

looking at the intake it looks like valve opening is more restrictive than stock intake tube/filter.

so this is still not good enough explanation....

flyingtoaster

The stock intake is a nice fat tube with a bigh high flow filter. These aspects are not improved upon. All the top aftermarket intakes make power by lowering the intake air temperature.

Croc

intake air tem decreases - this is absolutely true.
my Scangauge shows 15-20 degr Celcius less!!!

so how this affects AFR?
cooler air = denser air = more O2 molecules per given volume

is this how it works?