2139 replies to this topic

[The Batman]

Good guess!!



Annoying dip at 7k! But gained a little I. Other places

[Ormes]

9k....  

[The Batman]

Does scream well bless her! The car does aswell

Edited by The Batman, 04 October 2016 - 12:56 PM.

[rob999]

You don't need the ponies josephino

[The Batman]

Meh extra 20/30bhp would be nice lol

[Nev]

Meh extra 20/30bhp would be nice lol

 

Bahh, I'd just be happy with it and drive it, not one of our cars is perfect, you just have to live what you've got I reckon. Nipper sure isn't perfect, for a start he doesn't have a vital carbon cam cover or any stick on carbon go-faster bits!), but I am content so long as he is drivable.

 

How come they don't phase the cams in so that the bump in the mid range is a little more gradual? Or is that not a manifestation of the cams?

Edited by Nev, 07 October 2016 - 02:40 PM.

[The Batman]

That's the vtec yo!! The cams are standard as I didn't have valve clearance with the ones I bought and was on a time crunch

Edited by The Batman, 07 October 2016 - 02:51 PM.

[Arno]

How come they don't phase the cams in so that the bump in the mid range is a little more gradual? Or is that not a manifestation of the cams?

 

 

As it's an N/A other effects are getting more and more pronounced at higher rpms like the resonance frequencies in the intake and exhaust systems that can either boost the system efficiency (and giving a bump or smoothing the graph) or set up a bad resonance that actually reduces the cylinder filling.

 

A different exhaust and intake manifold and a re-map may well give a very different profile.. With dips likely somewhere else

 

Cam angles can be adjusted (ony on the intake on the K20 though) but only up to a point in the load range does this make very much difference.

 

Mostly noticable at low/mid load where it smooths out things a lot and gains it a nice lump of even torque across the rpm band, but once the load goes up then the cam angle map tends to go to 'max' advance on the cam angle (50 degree on the K20) and dial in as much overlap as possible. (also cam angle changes are a physical movement/adjustment thing, so they take time to adjust and you can't go instantaneous from one angle to another if you had to fill in a short dip with a different angle..)

 

The switch to the wild cam profile is basically completely independent of the cam angle adjustment so these are mapped separately and the K20 ECU basically has 10 fuel and ignition maps you need to fill. It has a fuel+ignition map for 5 cam angles (0 to 50 in 10 degree increments) and then a second set of these for the high cam profile. And then there's 2 cam-angle maps that are then built from the best results of the 10 fuel/ignition maps to create in the end a composite map for the low and high cam profiles for all 'best' cam angles.

 

As you understand it does take a diligent and good mapper/tuner for these engines to work through and build all these separate maps (by locking the cam advance in the ECU at a point and then using the dyno to work through all the cells) and then also do the final step of making a good composite map and then going back and smoothing out any corner cases and transients between the various cam angles and also the switchover points (also load dependent so that's also a 'map') between the cam profiles.

 

Often you see tuned/worked K20 engines in civics that make good 'pub figures' but are dogs to drive as the 'chooner' only worked/bodged the full throttle and full load setup with a quick 1 hour mapping session and didn't bother to adjust anything else.. Awful..

 

If done right though you do get an engine that feels completely smooth from idle all the way to the 8600-9000rpm redline without any 'VTEC yo!' points in it. Only the change in intake note gives it away that the (big) cam profile change has happened.

 

It's funny that both Honda and Toyota (in the 2ZZGE) explicitly set up the OEM ECU config so the cam change happens only at a single rpm (irrespective of load) and at quite a crappy location where the power from the 'small' cam drops away badly and does not mesh/match with the power from the 'high' cam.. They explicitly wanted the 'VTEC yo!' feeling from the engine where it suddenly 'kicks in' when it's completely unnecessary.. Just done as a sales/marketing thing   

 

Bye, Arno.

[Ormes]

Interesting read cheers Arno

[The Batman]

 

im running 40deg with a hardstop fitted

 

i have always wondered why you get alot of higher pub figures out of civics than you do out of my spec engine! Also often that they introduce the vtec very low down

 

the car is very smooth throughout the whole rev range and just gets louder about 5k daveE can confirm this!

[Arno]

 

i have always wondered why you get alot of higher pub figures out of civics than you do out of my spec engine! Also often that they introduce the vtec very low down

 

Civics getting better K20 N/A power levels is basically because their exhaust system is almost a straight run of pipes and silencers out the back and they have the space to fit loooong 4-2-1 manifolds.

 

In the back of an Elise/VX/etc. you quickly have to start 'folding' the manifold and exhaust in many 90-180 degree turns and that's not very nice for good N/A performance.

 

To get close to their performance levels you'd have to sacrifice the boot in an Elise/VX and go with an over-the-subframe manifold with long, gentle bends in it and in the rest of the system.

 

The Civic boys often can also fit bigger intake manifolds under the hood by moving the radiator a little or fitting a more narrow one where in an Elise/VX you run into clearance issues on the firewall.

 

So for higher power N/A builds on Elises you see that people cut out the firewall and move it forward inside the cabin and can then fit bigger manifolds or ITB's.

 

Combined these give similar power levels to what the Civic boys are running, but may be a little 'extreme' for people who still want to use their car for normal drives/trips/holidays and not just as track weapons.

 

Still... For more power you can always slap an SC onto it and have big power and 8600 rpm to play with

 

Bye, Arno.

[smiley]

Rotrex

[The Batman]

I don't need a sc just need bigger balls I'm currently running the rrc intake which is bigger than the usual rbc intake civic boys usually use but like you said my exhaust is definatelt letting me down

[gaffer1986]

Are you saying you need bigger balls and pipe?

[The Batman]

No no Bigger balls and a longer pipe

[Zoobeef]

I'd struggle with the 6 point harness 😂

[gaffer1986]

So Joe's pipe isn't long enough for his car, I never new the V in VTEC meant vagina.

[The Batman]

Happy to do a trackday to see what na is quicker (Mark not included )

[gaffer1986]

Eat my oil slick....

 

Am I allowed to use this:

 

2016-10-09_02-50-30 by Richard Fanders, on Flickr

[The Batman]

had a awesome day at brands today,

 

tested 98db for static which is pretty good for me at 5250revs and didnt set the driveby off and wasnt letting off at all.

 

had a couple of problems with my skunk2 70mm throttle body though, mid corner my throttle body butterfly decided to stay open causing me to accelerate when i wanted to brake!! rather scary but managed to get it back to the pits (it was red lining!) gave CPL racing a quick call after checking all the obvious bits. Guy told me to check a 4mm screw had unwound it self which is used to set the fully shut setting so obviously this was staying open! only had gasket sealant so used that on the bolt, but going to remove the screw and loctite it instead.

 

then later on in the day i had the hard throttle pedal again(first 10mm then its fine) i had this in zandvoort aswell and turned out to be the spring on the butterfly, sprayed it with wd40 and all sorted!!! will spray some white grease on it.

 

now debating about buying a different throttle body!

 

anyway, the car performed amazing and handled really well. i think the only thing that was quicker than me was the radicals which are seriously quicker

 

awesome little track and would love another day there soon as i will bring my balls next time

 

will upload some videos later!