2139 replies to this topic

[vocky]

Having converted mine from a 2.2 to a 2.5 I can honestly say you cannot tell the difference in how fast it revs, only the extra torque gives the game away it's a 2.5 litre 4 pot 

 

Much like the quote 'the z22se doesn't like to rev', well it does if you tweak it 

[Arno]

Not saying it doesn't want to rev at all... There are even bored and stroked K24's out there that are closer to 3.0L and people make 'em go well over 8k rpm.

 

The question becomes one of projected lifespan and intented use.

 

A boggo or mildly tuned K20A runs 8600rpm on OEM components and cast pistons with tight tolerances and is happy to do so for 100 to 200K miles without much more than regular oil and sparkplug changes.

 

A highly strung long-stroke K24 pushing similar rpm's with forged pistons and steel crank and the like quite likely will need some engine work 30-40K miles.

 

Second situation is of course fine if it's a track or weekend car where this still translates in many years of use. First probably more suitable for a (semi-)daily driver that may do 20+k miles each year.

 

Horses for courses and all that... Both are perfectly fine.

 

Also there's personal preference of liking an engine with lots of low-down grunt or enjoying hanging out at 7000+rpm for most of the time and revving it out on each gearchange.

 

Bye, Arno.

[vocky]

I totally agree 

 

The lifespan of any tuned engine should be considered to be at least half the expected lifespan of an unstressed standard unit 

 

But a 'track day only' engine may not last quite as long 

 

Joe needs to decide whether he wants more torque for the road or a rev happy track beast 

 

 

 

 

[Rosssco]

I love the characteristics of the engine but it is a bit gutless!  

 

I think 'gutless' is relative though.. Gutless is a characteristic of this engine!

 

Comparing to an engine using FI, then yeah it won't have the low - mid range torque.. But then if you want 'guts', its difficult to match an engine with FI from that perspective. Will an extra 0.4L really provide he guts that you speak of?

 

Alternative is an (even) shorter gearbox FD / gearing..

 

I guess this is why a standard(ish) engine with a SC is probably the optimal (but well-trodden) route..

[The Batman]

Ok maybe a little harsh with the phrase gutless The gearing is 4.4fd so it really does suit the engine but this is sacrificing cruising speed even with 6th gear I love the Way it screams over 5k and keeps going to 8k and I would love it to do more so I am thinking 2.0 now and raise the Rev limit a fair bit with the new engine The car isn't slow, it's considerable quicker than a Na Vx but Its not as quick as a stage 2 sc I think a 300bhp na will be perfect

[fezzasus]

Sounds much more in keeping with the spirit of the engine, look forward to seeing how you get on.

[rob999]

I'll let you do the development work for me Dude

[The Batman]

[CHILL Gone DUTCH]

If your determined not to SC your car joe I would Deffo go throttle bodies

[vocky]

and a decent over the subframe 4-2-1 exhaust 

[The Batman]

Problem is the air filter will have to be inside the cabin as clearance really is an issue Also they don't actually seem to add that much power at all..

[Arno]

Also they don't actually seem to add that much power at all..

 

Yup..

 

With a decent plenum intake manifold like a Honda RRC or RBC or some aftermarket ones (which may already need some firewall mods to fit.. Depends on the conversion and engine position/tilt) the gains from adding ITB's are often not that great as other things become a bottleneck like the convoluted exhaust on these cars compared to a civic which is virtually a 'straight-line' pipe to the back.

 

A decent plenum does not have to be too much of a restriction on these engines.

 

Usually on other engines the problem with a single TB and plenum becomes that wild cams which make big power up high in the rpm range will mess up the intake pulses at low speed and won't run on a plenum at low rpm's anymore. The VTEC setup works around this by the fact that the 'low' cam profile, even on uprated cams, is usually still quite tame (2400-250 degrees or so..) so it will happily idle and run at low rpms. Add the VTC system to vary the overlap between the intake and exhaust cams and you can dial out pretty much all the overlap at low loads and idle for OEM runing (and usually easy MOT's!)

 

By the time it goes to the agresssive cam profile of 300+ degrees duration and high lift at >4000 rpm (usually load/rpm dependent on Hondata equipped ECU's) the airflow is so high that the pulses are no longer a problem and they work fine to the rpm limiter.

 

An over-the-subframe exhaust manifold with large radius bends and optimised diameters and lenghts does usually add a nice bump of torque and top end power. Just a little annoying in a weekend car to lose the boot

 

Civics with K20's can still get decent gains with ITB's, head work and such, but they are simply less limted/restricted by the packaging so can make use of the extra availablle air input and exhaust output capacity.. Similar reason why Rover K-series powered Sevens tend to get better power from the same engine configurations compared to Elises.

 

Bye, Arno.

[TFD]

Guy in my area runs a K24 with 357 bhp N/A...... Sounds like a motorbike and runs like a beast. Should be awesome in a VX!

No idea how long it'll last...

[Nev]

Guy in my area runs a K24 with 357 bhp N/A...... Sounds like a motorbike and runs like a beast. Should be awesome in a VX!

No idea how long it'll last...

 

Wowzers, that's an almost unbelievable amount of power from 2.4 litres. It must rev to kingdom come.

Edited by Nev, 24 March 2015 - 05:44 PM.

[The Batman]

yeah and the itbs fitted to the elise really dont add much at all as you have to do a tight 90 degree angle to the filter which isnt ideal at all from what ive read and then a custom air feed will be need to be fitted otherwise heatsoak will be an issue

 

i definately wont be sacrificing the boot as this will mean i cant do euro trips or many trackdays without a trailor either to be honest and then its a slippery slope!

 

tfd dont suppose you can get me his engine spec can you please?!

 

read some interesting info and on a standard engine with rrc intake, exhaust and they did back to back testing of tbs and they made no difference at all. so i will be sticking to a ported standard tb for the current engine and possibly move to a 70mm tb on the project engine

[TheHood]

Dave walker did a quick test with 90 degree elbows when playing with his new engine dyno HERE On that particular setup the difference was very small.

 

If you do go ITB, I would look into using some kind of idle air control valve if that's not already part of the setup on Honda kits. My experience so far suggests it's very tricky to get a consistent idle under varying conditions relying on ignition timing alone.

[FLD]

Have honda looked into variable geometry intakes?  I know it was big in F1 before it was banned so it might have filtered down. 

[Aerodynamic]

Guy in my area runs a K24 with 357 bhp N/A...... Sounds like a motorbike and runs like a beast. Should be awesome in a VX! No idea how long it'll last...

Do you have any info about this engine to share? Br, Per

[TFD]

Search Facebook for "0118 Racing" to find the guy's Honda stuff / contact them.

[The Batman]

Honda rrc manifold

Polished inlet
Wider and longer runners
Wider inlet
Extra webbing

This will be bolted to the current engine along with jdm cams and a ported and polished tb and we will see what power it can get which should be enough for the summer

Depending on the engine mounts I have fitted to the car depends on whether the bulkhead will need to be cut.

The intake will also be used on the project engine unless it is proved to be restrictive but should me more than fine