LOL. MIVEC does NOT switch cam lobes. MIVES is like the "I" in I-vtec. It just changes the cam gear timing (advances or retards) of the intake cam. Theres not extra lobes or special rockers like a honda Vtec motor.

On to the topic, like most said theres a couple reason, first being that honda head has a better flowing design and better combustion cambers. Honda engine are all bout effietcy.

Next, would be the fact that the aftermarket turbos they use are bigger, there for, they push more air at lower boost levels.

Last would be the less drivetrain loss.

BUT whats good with that much power if you can't put it to the ground.

 

the only problem with the K23 is that it's in the wrong car. 240hp and 260 lbs-ft, who said honda engine can't make torque. it would be sweet if they put this engine in the TSX along with SH-AWD, then they might have an Evo fighter on their hand.

 

The only things hondas lack is the combustion chamber design/piston combination that turbo cars have. Not saying detonation cannot happen to a factory turbo motor since we all know it can and detonation has no friends, combustion chambers of turbo motors are designed to cope with detonation better than honda motors. You get 30 counts of knock on a 4g63/ecu still has time to pull timing and save motor with out any major damage maybe a lil stress on the rod bearings. Get 30 counts of knock on a honda motor and even though the ecu pulled timing the damage has been done and the ringlands are gone or something else is gone. Maybe just on the B-series, the K series may be a tougher.

 

video of how VTEC works - http://videos.streetfire.net/video/d...52f982ed3a.htm

 

At least not in the Evo IX's version of MIVEC. The system on the older 4G92 was more like the tradtional VTEC system. Even the MIVEC on the current 4G69 and 6G75 are more complicated then EVO IX's system. We'll have to wait for the X to see what a more sophisticated MIVEC system will do for a Mitsu turbo motor.

 

I know how vtec works. **** Ive built Vtec motors. I was just say how MIVEC doesnt have extra cam lobes like vtec.

 

why would extra lobes be necessary? when you have a good variable valve timing setup you can just get larger duration and lift base cams... no idle problems... all the benefits.

 

alot of honda guys run into issues with boost and the Open deck blocks found in most honda motors i have seen..even the K20a out of a RSX is open deck. Block guards, posting or full out re-sleeve the motor seems what most high boosting hondas owners do. So now that we have the RDX i wonder how they worked to block?

But honda did great work on head design.

 

+1

Cliff notes:

Basicly we raise the boost (psi) on the 4G63 to make up for the lower VE
if you talking the same CR, Displacment, Turbo and other supporting mods.

now to Calculate required manifold pressure required to meet the horsepower
400hp = 44 Lbs/min of air



Where:

· MAPreq = Manifold Absolute Pressure (psia) required to meet the horsepower target
· Wa = Airflowactual(lb/min)
· R = Gas Constant = 639.6
· Tm = Intake Manifold Temperature (degrees F)
· VE = Volumetric Efficiency
· N = Engine speed (RPM)
· Vd = engine displacement (Cubic Inches, convert from liters to CI by multiplying by 61.02, ex. 2.0 liters * 61.02 = 122 CI)

Using the 2.0 4G63 as a example and 44lb/min flow (example)

· Wa = 44 lb/min as previously calculated
· Tm = 130 degrees F
· VE = 92% at peak power (guess)
· N = 7200 RPM
· Vd = 2.0 liters * 61.02 = 122 CI



so it equals 41.1 psia – 14.7 psia (at sea level) = 26.4 psig boost

Now say you increased the VE to .95 and RPM the same (to make math easy..LOL)....Note: increasing RPM also helps

you get 39.79 psia - 14.7 psia (at sea level) = 25.09 psig boost

...increasing VE , N or Vd will help lower boost needed to make power.

this is just showing the OP on effects VE and boost levels needed. There are plenty of other factors to consider too...but there is not enought time to go over it all.

Do the math yourself: http://www.turbobygarrett.com/turbob...o_tech103.html

 

That is why I stated earlier in this thread that I would rather raise the boost 1 psi on 9:1 compression than run 10:1 because the 1 psi of boost will give you more hp than that 1 compression point.

 

 

which part of this deals with the hondas not being able to run more boost>?

 

sorry you must have confused my two posts...I tend to ramble at times...the first was about honda engine blocks and their abilty to hold boost.

the second was about how VE effects the amount of Psi needed to attain certain power levels..

If you want i can explain how CR plays its role in all this also...but like i stated earlier i didnt have time at the moment. hope this helped. and

 

let's sum all this up.

more boost doesn't mean ore air in the cylinder. an engine with better Volumetric Efficiency require less boost to put the same amount of air in the cylinder. and at the end of the day, it's not how much boost you can run but it's how much power an engine can generate.

 

well to add to this sum up... my point all along was that in order to generate a certain amount of power you have to get rid of the waste heat and maybe that's what hondas (being naturally aspirated in genesis) aren't equiped to handle.

this would limit an engine from producing even more power at elevated levels of boost... something is giving... i'm wondering if my theory is correct.