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Discussion Starter #1 (Edited)
Hey everyone.

Last year in July (2016) I was finally able to get my NA d16z6 build dyno tuned and I was very happy with the results. It made 156whp and 115wtrq. All the details of the build can be found here.

In the off season I decided that I wanted to try to improve on this project by improving the airflow in, fuel delivery and exhaust flow. Last year I was using a generic air filter, 56mm d16z6 throttle body, 60mm ported y8 intake manifold, Megan Racing 4-2-1 header with 2" collector, Magnaflow high-flow catalytic converter and Tanabe Medalion 2.25" exhaust. I'll put the details of the current parts list below.

I was planning on using RDX 410cc injectors but my mechanic was unable to find the hats. That was last night and the tuning was this morning. Turns out that it was a blessing in disguise. The tuner told me that I wouldn't have been able to drive the car had they been installed due to the significant increase in fuel without a proper tune. I consequently found the hats in the Takata harness box...

I'll be getting them installed and tuning the car again. Stay tuned for a pre and post RDX injector thread with dyno graphs.

Parts List:

Exhaust:
- 1320 4-1 RMF header (2.5" collector) - (previously Megan Racing 4-2-1 header)
- Vibrant Metal Core catalytic converter (2.5") - (previously Magnaflow high-flow catalytic converter 2.25")
- Vibrant Ultra Quiet resonator 2.5" - (previously what came with the Tanabe Medalion 2.25" exhaust)
- Vibrant Ultra Quiet resonator 2.5" as muffler - (previously what came with the Tanabe Medalion 2.25" exhaust)
- Trubendz pre-fabricated 2.5" stainless steel mandrel bent exhaust - (previously what came with the Tanabe Medalion 2.25" exhaust)

d16z6 block:
- resurfaced 0.004", rebuilt: Top Line gasket kit
- bored to 75.5mm
- P29 pistons (Nippon Racing) - 75.5mm
- NPR piston rings
- ACL race bearings
- ARP rod bolts
- crank journals resurfaced
- Innovative Mounts AT-MT passenger side mount 60A (red) Polyurethane
- Innovative Mounts rear side mount 75A (black) Polyurethane
- Innovative Mounts driver's side mount 75A (black) Polyurethane
- 11.4lbs Competition Clutch flywheel
- miscellaneous parts (i.e. water pump, belts, etc) all Honda OEM

d16z6 head:
- ported and polished
- resurfaced 0.004" (IIRC)
- Rocket Motorsports stage 4 camshaft (re-grind of stock d16z6)
- Rocket Motorsports valve springs
- Rocket Motorsports titanium spring retainers
- AEM Tru-Time camshaft gear
- ARP head studs
- Cometic 75.5mm head gasket
- Denso spark plugs gapped and supplied by Rocket Motorsports
- Skunk2 intake manifold - (previously d16y8 intake manifold - ported to 60mm and polished inlet and runner outlets ported to match head intake ports)
- OBX plastic intake manifold gasket cut to match head intake ports
- 60mm b18b throttle body with KMS FITV block-off plate - (previously 56mm d16z6 throttle body
- generic short-ram intake
- Skunk2 air filter with velocity stack - (previously generic cotton air filter)

Miscellaneous:
- Mishimoto aluminum radiator
- B&M fuel pressure regulator
- B&M fuel pressure gauge
- chipped P06 tuned on Neptune
- Walbro 255lph fuel pump

The peak wheel horsepower was 158 and the torque was 116. At face value this seems like only a minuscule improvement over the previous setup. It can easily be viewed that way if you only consider peak output. However the greatest improvements are across the entire RPM range. The is more torque at the bottom, a nice horsepower and torque bump at mid-range and it stays consistently above the previous setup before it falls flat on its face close to 8000 RPM.

I've attached the dyno chart with both the 2016 and current 2017 information:


Here's the video of the final run:
NA d16z6 dyno

At the end of the session we adjusted the cam-gear to see what could be done. As expected, retarding it resulted in a loss of power. We advanced it 1* and made the most power but I opted not to attempt advancing it any further - for now. I can't be certain that there won't be piston to valve impact if we go too far. The deck was milled and head was resurfaced on a P29 high compression motor. Maybe I'll be a little braver when we do the next tune with the injectors. I hope to break the 160whp ceiling with the addition of the injectors.

Building an NA d16 has been an incredible learning process. I plan on making a new thread about it to help inform other SOHC builders based on my experiences.

Here are some pics of the exhaust and the engine bay. I'll be getting a proper tip in the near future.






 

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del Sol si '94
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Mine peaked at 7200 ish with a smaller cam, advanced 2*. Good number anyway!
 

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Discussion Starter #4
I wonder why it stopped earlier. Looks really good.

All the mods would lend you to think it would carry a little higher in RPM.
Agreed.

I chose to go with the 4-1 header and 2.5" exhaust for that reason. To make more power in the higher RPM range. It unexpectedly drops off earlier than with the previous setup.

Mine peaked at 7200 ish with a smaller cam, advanced 2*. Good number anyway!
Thanks!
 

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minor valve float? maybe the rocket springs want a little shim in there?

RDX injectors will definitely bring more power to the table over even brand new oem injectors for the z6.

breaking the 160whp barrier is possible. Dunno if new injectors alone will do it.

seems like being able to carry power higher into the rpms will help the most, but at this point, you are probably going to start noticing more and more low end loss as you go furhter up the numbers game.

SQL_CIVIC? has a supercharged 1.8 liter D series, he resleeved to allow 78mm bore. But that is obviously moving into custom piston territory, and perhaps for down the road if you decide a stroker build is in the future. the 1.8 liter build is old, and I have not followed or seen activity on it for quite some time
 

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Discussion Starter #6
minor valve float? maybe the rocket springs want a little shim in there?

RDX injectors will definitely bring more power to the table over even brand new oem injectors for the z6.

breaking the 160whp barrier is possible. Dunno if new injectors alone will do it.

seems like being able to carry power higher into the rpms will help the most, but at this point, you are probably going to start noticing more and more low end loss as you go furhter up the numbers game.

SQL_CIVIC? has a supercharged 1.8 liter D series, he resleeved to allow 78mm bore. But that is obviously moving into custom piston territory, and perhaps for down the road if you decide a stroker build is in the future. the 1.8 liter build is old, and I have not followed or seen activity on it for quite some time
Hey mattliston.

I went through my old messages with Robert (Rocket Motorsports) and he had mentioned that their valve springs are good up to 12,000rpm. It's possible but not likely. However thanks for the great suggestion!

Funny you mention the stroker. Before going ahead with this build a couple of years ago I was planning on a d16/d17 stroker build. I actually have the d17 crankshaft and other necessary parts sitting in a bin in the garage! I went with the d16z6 build because it's been done many times before successfully. I felt a little more confident with it. But.... when I finally get bored of this build I always have the option to build the stroker. Everything else (bored block, pistons, head, etc) are good to go.
 

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perhaps get some more info on the springs? not saying they are causing it.

But a statement like "good to 12k" sounds like a durability thing, not a "keep 100% valve control" thing.

Id run the idea by them about shims, show them the dyno, and ask what they at rocket would think. they have a LOT of experience, and might be able to help you out quite a bit.

those fuckers have a pretty badass topend setup for quite a few motors.
 

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Discussion Starter #8
Great idea!

I'm definitely interested in seeing what they think.

Thanks!
 

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nice bump all over, esp tween 5k & 6k!

I agree its odd it falls flat around 7k whereas the old build variation looks a lot more linear.

Either way keep up the good work & info!
 

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Those are some good numbers! I have a very similar setup, built d16z6 but with pg6 pistons and a Rocket stage 4 cam. It was street tuned by Robert from Rocket Motorsports, he said it felt like a ~140whp build.
 

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Discussion Starter #12
Those are some good numbers! I have a very similar setup, built d16z6 but with pg6 pistons and a Rocket stage 4 cam. It was street tuned by Robert from Rocket Motorsports, he said it felt like a ~140whp build.
I've never met him in person but I can't thank Robert enough for his help. He's asked for the tuning maps to see if he can help identify why there's a dip in power at around 7000+.

nice numbers. how does the car feel on the road ?

stratton.
Hey Stratton.

Feels great but you can only do some much on the road... I was planning on tracking the car the day after tuning it but the weather was terrible. I'll be tracking it later this month. Ill have a better sense then.
 

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pretty cool rocket is helping by checking stuff out for ya

would be nice to find out its perhaps simply an ignition timing adjustment needed, or fueling is a touch over or under what it should be, etc..

or for fucks sake, might just be ignition system a bit weak for high rpms. my ebay distributor doesnt break up on this stock d16y7, but even with timing dead on, it flops hard past midrange. oem 20 year old distributor with a good coil demands high rpms almost lol. but both get same gas mileage during work travel
 

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Discussion Starter #15
when do u speculate the rdx injectors will get installed and re-dyno?
Hey.

I'm planning on doing it in June. Both the tuner and I are pretty busy until then.

I'll keep everyone posted!
 

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Discussion Starter #18
an updates by chance?
Hey Louie.

Sorry about the unavailable pics in the posts above. I, like many others, have been screwed by Photobucket and their membership fee they started charging. F*** that...

Unfortunately the motor is toast. I took it to an open-lapping session on May 22nd. Was having a blast when an exhaust valve dropped and destroyed the motor. It was a short but good run while it lasted.

I'm working on another project for the del Sol right now. I'll be back with details when it's done.

Cheers.
 
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