Hi all,

Apologies if this is a repeated thread.
I am planning on building my engine (L15B1,CVT)
What im proposing is Drop In cams
246°/248° - 201°/208° - 9.50mm/9.75mm - 0.30mm/0.80mm (pri)
300°/248° - 232°/208° - 11.00mm/9.75mm - 0.45mm/0.80mm (Vtec)
Head Porting
AFE Takeda intake
65mm Throttle Body
Custom intake manifold (YAY/NAY)
Uprated fuelpump
ECU Reflash
Decat on the stock exhaust and a HKS Hi-power silent exhaust

I can't swap to a manual, since a member of my family is missing a leg to engage the clutch

Thoughts?

Questions:
1) Can i run a slightly higher compression piston on the stock ECU (Reflashed)
2) Do i have to change injectors?
3) Does head porting make a difference on direct injection engines?
4) Are there any mods that can be done to the CVT gearbox ? (EG pulley gear ratios)
5) Can the CVT gearbox be tuned since it has a REV cut at 4K RPM when in neutral ? (Can't be removed with ecu reflash)

Much feedback is welcome!

 

You might get more attention here.
https://www.fitfreak.net/forums/3rd-...fit-today.html

 

You should also look at Z062FIT's build. He's done alot of what youre looking at, although he's going to change compression from swapping pistons and rods. If he's not too busy, hes probably a good currently active person on here to ask. There's also a couple other "Max Effort" NA build logs around here. In regards to cams, keep in mind when Myxalplxal dis his cams, they were ground with a higher RPM goal, and the CVT software will not rev over a certain point. I don't know how your cam profile is geared, but make sure it falls into the CVT powerband RPMs.

Generally, you're going to have to be careful with higher compression as our NA engines are already the highest compression variant of the current line of L15 engines. The L15B in our GKs are already pretty much tuned to be as high efficiency as possible at the factory, and I'm assuming they've maxed out the compression ratio/reliability to the ends of meeting "Earth Dreams" goals. Of course this is rated on 87 fuel. When running 91/94 or ethanol I don't know how much more room there is to increase compression safely, and AFAIK on here I haven't seen anyone really push it. I'm running a 91 tune with exhaust mods (no intake mods), and my car ends up pulling timing due to knock adjustment at WOT by about 5 degrees on average (it's about 25-30C here). On 87 I've seen it go into 15 degrees. I know as far as timing too, KTuner shows up to 30 degrees of timing advance when it's happy with everything. TL;DR... Increasing compression isn't as common a modification, so if you're going to do it, you may be breaking new ground. Let us know what you find!

It seems commonly accepted that the injectors can handle about 30% more volume, so depending on what your goals are. These again can easily be tuned for via KTuner/Hondata, as Myalplyxal did to his GK when he still had it. (Replaced with RDX injectors if memory serves). Your bottleneck is probably the intake, as there are a lot of restrictions in the air path. Elpapas on here is modding his throttle body with a S2K one I believe, but I havn't seen any high-flow high-volume aftermarket GK intake manifolds. Z062 cut the EGR and freed up a lot of cross sectional area, it will be interesting to see if the increase in airflow is getting close to maxing out his fuel injector volume. I don't know how increasing cylinder pressure will affect injectors, as the high pressure pump/regulator is built with a certain pressure in mind. Also GK's are not known for having the most robust injectors, and they are a common point of (expensive) failure. TL;DR... if you're not increasing fuel volume by more than 30% you're fine. Be aware of potential damage to injectors at high compression.

Head porting increases air flow by smoothing the flow path. DI or not, more air = more fuel = more power. A number of people on FF have done this. Again check out Z062 because you'll see that the largest bottleneck (literally) is probably the EGR in the neck of the intake manifold. The stock intake with KTuners stage 1 tune on my GK runs rich at WOT after about 4-5k RPM (it's something I want to adjust if I ever get around to remapping the stage 1 map). TL;DR... Porting the head helps, but it's not the main bottleneck.

I havn't seen much of CVT modding. You could always go 14" wheels with smaller tires, get a better final drive ratio and decrease unsprung weight. Of course your odometer/speedometer will be off, it may look funny, but acceleration! There might be other CVT pulleys you could swap, but I've never seen that in my casual browsing. I've only seen final drive ratio kits for the 6MT (from companies like mFactory).

As far as I know, no one has cracked the CVT software. Theoretically yes that's possible, but there's not enough demand for a CVT tune. Some people have said throttle commanders help, and for the engine response side ECU tuners can modify some parameters. Myxal had some post when he said there's a way to 2-step, but it's not a true 2-step. KTuner or Hondata can adjust for compression, and pretty much anything fuel map related is super easy to change and tune. I think your only limitation is boost, which according to Kroner (KTuner) is not possible on GK.

I hope I'm not being too discouraging, theres potential but you've got to pick and choose. I think I'm hitting a wall myself in terms of modifications, and I'm craving more out of the engine. However there's a number of people that have done or are doing interesting mods to squeeze more performance out of the L15. As wasserball mentioned, that thread has a lot of posts that will point you to where and who to look for to get more information.

I hope you post your progress on your porting and custom intake. It's new ground but someones gotta do it! Have fun and good luck with your project

 

-RV6 header axionind.com
-Tanabe medallion amazon.com
-Ktuner ecu through local dealer you can hook you up with my dealer
-Modded CR-Z short shifter axionind.com
-Shifter cable bushings and pedal relocation bracket acuityinstruments.com


Intake mods...

-Covered up all sound deadening holes on oem airbox to force all air through intake to the throttle body
-k&n drop in filter

Fun part...

Got ahold a used but nice condition CR-V throttle body and since it WON'T fit the oem intake manifold a friend of mine and I fabricated an aluminum spacer to adapt it...

-I also disassembled the oem elbow from the airbox and used a 63mm x 70mm 90 degree elbow since that is the "bottleneck" of the tiny intake....

SIDE NOTE:
i haven't been able to dyno it, but... the "butt dyno" feels pretty good after the mods