I'm gonna have to give this article a read as well.

 

I look forward to your results! My tuner said a shorter intake around 10 3/4" (not unlike your AFE) would help with low end tq in the 3.2-3.4K RPM range si I might play with that at some point, although it will be neat to see what yours does Have you logged IAT's with your setup?

I've wanted to do a full on NA buold for ages!!! Nothing like the sound of a high rev high compression (dare I mention ITB'd) motor up on song!

As far as crank work, I am nearly certain it would be beneficial. Both me and a friend noticed that down about 1qt of oil, we were seeing HUGE bumps in mileage (5-10 MPG.) Makes me think that at indicated full on the dipstick and under load our little engine is probably frothing the oil in the sump and or at least getting parasitic drag in it. I wanted to see what these guys could do to one of our cranks FFWD - Butcher Crank

While were going nuts... the HPD L15A7 crate motors that are sold in kits to covert old Formula Fords are dry sumped ...

Engineering the Formula Fit - SAE International

 

I data logged the car after it was dyno'd to see were the KR spikes were happening. I'm not sure what the IAT was when it was dyno'd. We'll be retuning the car either next week or the week after when the header and midpipe come in.

Interesting you say that about shorter intakes. I was curious if I was getting the best power with the AFE intake. I read good reviews on the intake when I purchased it like 2 years ago. Plus I got it at a steal of a deal.

 

I will start an NA build thread once I start getting parts to compare.

I know either kinsler or TWM worked with rywire to do DBW ITBs on his b18c. Worked out rather well for him but I definitely won't be going that far in depth.

Current plan is as follows:
Hydrofoil crank
Install tri metal bearings
Knife edge gridle to help reduce oil spray
Port oil pump
H beam rods to reduce weight
L15a7 pistons (still unsure about ceramic coating the domes)

Now for the top end I will flow test stock head to get some baseline data since no one else has solid numbers.
I will work on deshrouding the valves and blending the seat and valve guides.
Possibly do a polyquad valve job if I have a spare head to see if that can improve low lift air flow due to the 12 valve setup of the l15a1 before vtec activation.

Test fit an l15a7 valve train onto an l15a1 to see if they are interchangeable and if it adds any flow.
If that does work out then I will definitely be giving colt cams a call for their triflow cam to make as big of mid range torque curve as possible.

With this project I'm not trying to achieve big hp numbers but more answer questions about what can be done as far as creating a hybrid valve train to give the first gen a true vtec.

And having a fun daily driver will definitely be a bonus.

 

Sounds epic!

Why A7 pistons?... After market forged stuff is fairly affordable. ..

 

Because I'm cheap. I'm actually looking for other pistons that could be used honestly. Looks like a few 1000cc bikes use the 73mm bore 18mm wrist pin combination that I'm finding. Plus they are super light weight and designed for high rpms.

 

Dont bother messing with the bearings, All the performance shops I have been in have stated OEM Honda bearings have lasted the longest when compared to even the higher end bearing offerings.

I doubt honda has gone down in quality of their builds. The L15 series is after all, built with marine,racing, and super long life in the minds of the engine designers.

Good ITBs to start with would be Suzuki or Honda sportbike throttles. A set of 38 or 40mm plates and a way to run an extra set of injectors would work great. Two sets of injectors means you have the head-located injectors for good low and mid rpm mix, and exterior set spraying the butterflies directly for high rpm mix.


I would LOVE to see a 9k rpm L15!!

 

Honda coated OEM L15A7 piston skirts and tops for less friction and increased combustion efficiency. Translates into power, gas mileage, and longer engine life

 

And so it begins....

 

IIRC L13 and L15A1 pistons are also coated,

"The piston skirts are coated with 'pulverized molydebnum'. Molydebnum coated piston skirts are first used on the famous B18C Spec R engine on the 1995-2001 DC2 Integra Type-R. In the case of the Lseries, the molydebnum are first 'pulverized' into powder form and then embedded into the piston skirts using a high pressure shot. The molydebnum enhances the 'lubrication' between the piston and the cylinder liner walls, adding to that which is already provided by the engine oil and this greatly reduces internal power loss through friction in this area. Honda says this is a world's first"

The Truly Amazing Honda Fit/Jazz

 

I dont doubt it at all, Honda has gotten some pretty awesome efficiency figures from the L series motors.

Makes you wonder why Honda limited it to 7k rpm when the CRZ guys who have swapped in GE8 valvetrain have revved to 7500rpms on stock springs.

I bet tossing in a zinc additive and getting stiffer valvesprings or even some double beehives would let you hit 8k rpms.

My old squad leaders stock parts crv-tec setup has hit 9500 with its bigass turbo and survived, and I 'think' honda had that b20 originally limited to 7k or less. Only thing aftermarket about his motor setup was the extra oil line to feed the b16 head for proper pressure at the spool solenoid

 

Here's a similar texh article on the 15A7 Honda L-Series SOHC i-VTEC Engines for the new GD Honda Fit/Jazz

I forgot that 15A7 valves got Bigger!!!

Right now I hit 7.5K on the daily

Valve float occurs at or around 8K+ on a stock setup

I run Amsoil Dominator specifically due to the zinc content!!!

Until the most recent exhaust setup and subsequent retunes there really was no need to wind it up like that though. Tourque drops after 5K and you get up over about 6.25K and the skinny pedal really becomes a volume control That's just the limitations of the stock head/cam I'm very certian. I've seen GE sheets where they pull all the way to redline. I'm sure the three rocker i-VTEC plays a major role in that...

 

I was gonna say I shift at 6300 because it drops about that point so we noticed. Nit sure how the new setup will do. The only advantage for me to raise the shift point is on the track sometimes. There has been a few races were I push the car bouncing up limiter over the finish line.

 

Subscribed for more info!

Is anyone running an aftermarket/regrind cam here? And who does them? Delta? Bisimoto?

 

A few of us are stock since we race in STF class for AutoX.

No cam here.

 

In my exspairiants just for a little quicker response and pick up cold air intake ik22 plugs and light weights wheels probably the best bet for keeping prices down

 

Most of the folks in this thread already have those covered

But yes, bang for $ / butt dyno wise, reducing rotating un sprung weight is key and for 3-5 whp at $40 and a 1/2 hour of wrenching IK-22 are by far the best value!

 

Big thanks for this article! It is a very interesting read.

Also, I need to read up more about these plugs (IK22). I kept thinking it was all hearsay about installing them and hp/tq gains but people are still recommending them. I'm specifically interested in these with the new 2015 Fits.

 

just go grab a set of plugs for a honda s2000.factory denso 22s. Pk's are platinum, IK's are Iridium. No performance difference, just price. $30-40

 

There was a user on here that did an all motor engine build. I forgot what he did exactly but it had easily 15psi I might be wrong on this.

I, too have been interested in doing an all motor build, it's just the lack of money haha

From what I can tell, there's pistons, rods, camshaft, titanium springs, titanium retainers, high flow valves, sleeving and a better performance head gasket. All and all I totaled around $5300 on parts alone.

For your question about the weapon r intake manifold, it will in fact make more power because there's no restriction at all.