MADJAK's NA8 - 200+HP N/A

Magpie · Postby **Magpie** » Sun Jul 12, 2015 5:04 pm

Hopefully not getting off topic.

The below is a screen dump of my rear suspension sensors on a normal drive. The key is to remove the influence of acceleration/sideforce when assessing data.

At 47 secs the car is accelerating hence the change in suspension height. However at 1:1.60 acceleration is almost zero so the downforce is 22kg (1.70mm x 6kg + 2.09 x 6kg). At 1:39.45 it is 18kg of downforce a change of 4 kmh.

Ride Height by Eipeip, on Flickr

madjak · Postby **madjak** » Sun Jul 12, 2015 5:35 pm

Zabinskii wrote:do you have any specs on the motor? bore size, comp ratio?

Engine is a na8 (bp), stock bore and stroke but built bottom end with rods and wiscoe pistons. Compression is around 11:1 - 11.5:1 with a decked head which is very heavily ported with oversized valves and very agressive cams (310+ duration). It has a few other secrets that I don't even know.

Manifold is the Honda skunk2 street with a modified flange with 70mm throttle body. Exhaust has custom extractors into a 3" aluminium exhaust and magnaflow straight through muffler.

Dynoed 215 wHP at 8300 but power was still climbing.

madjak · Postby **madjak** » Mon Jul 13, 2015 1:15 pm

Honda Skunk2 Ultra Street Manifold and Skunk2 70mm Throttle Body

Note: this is a repost to bring this content into my garage thread. Here it the original thread: http://mx5cartalk.com/forum/viewtopic.php?f=29&t=67635

At the start of the year I saw a Honda Skunk2 Ultra Street intake manifold and 70mm throttle body on gumtree and figured I'd give it a go. I've always figured this manifold would fit nicely in my engine bay and I've been searching for a better option than the stock NA8 manifold. I was torn between ITBs and a plenum design and this pushed me over the line.

Here is a summary of my build. This has been posted on various forums for those who would like to follow and test it out on other engines. Just a not of caution my engine is is NOT stock so if someone replicates this design on a less developed engine the results may be different. Having said that, please do and post your results!

My original aim was to modify the Skunk2 manifold via drilling new holes and filling in the ports. This didn't work out due to the angle of the manifold causing the TPS on the throttle body to hit the chassis and that the injector ports on the manifold would need to be welded then cut in half to clear the mazda injector ports.

This has been done with other Honda manifolds in the US successfully but for us RHD cars we have the brake booster in the way of the manifold so the tapered plenum is critical to clear all the brake lines etc. The typical Skunk Pro / Blox manifolds wouldn't fit without major mods to the brakes.

here is my test fit. A scale printout... looks good so I hit purchase.

My manifold rocked up 3 weeks later at the start of May.

Test fitment looked good. I needed to angle it up a bit to clear the throttle body on the chassis rails.

I cut off the flange on a table saw, had a new flange waterjet cut from 12mm ally and made up some braces and it was off to the welder. Note the angle of the cut so to lift the plenum up away from the chassis rails.

Once welded I machined it flat on my mill... Don't look at the mounting points, not the best!

Get it welded professionally if you do it. The guys in the US have had big issues with the welds cracking due to the vibrations, which is why I added the bracing underneath.

Here is it all welded up and mounted to the head. I machined the face of the flange down a few mm to take out the warping caused by the welding. Fitment is brilliant with the plenum missing the brake lines, biasing valve etc as well as all the throttle body clearing the chassis by at least 20mm. I have solid engine mounts so the motor can't move a lot. Also the throttle body aims the intake path to clear the pop-up lights.

Last of all... a dyno graph. Done on a dynopack hub dyno.

Red line is stock manifold (overlaid based on previous dyno)
Dashed line is 98 (95 Ron)
Solid line is E85

The gains were more than I had expected, with the harmonics lumps sitting nicely over my target rev range... 6200-8200. If I had have run the engine harder on the dyno I think it might have hit 8500 or more before the power band started to head down. The power difference at 6750 is around 50HP increase from stock manifold (10HP due to E85)

I doubt many engines would see the performance increase mine saw from this intake. I had suspected my engine was limited by the intake and this shows what a free flowing manifold on our engines can achieve. My calcs also showed the runner length of the Skunk2 to be ideal for my target rev range. I think I fluked that one to be honest but it's nice to get it right.

https://lastpixel.box.com/s/vwdgkpy65ok26o0gykhd984iew4my92a
Above is a link to the cad profiles I used for anyone wanting to try it. PM me before you do as I think the CAD of the inlet flange needs a few mods to make it easier.

madjak · Postby **madjak** » Mon Jul 13, 2015 2:28 pm

Hot off the press is my prototype print. I like printing in the bright colours as they come off a bit cleaner. The grey part will be made from aluminium once I've checked the fitment with the plastic proxy.

Thanks for all the info on the 12bit AD resolution. I think it should be fine to feed in 5 volts and log the range between 0 and 2... I have a clean 5 volt feed from either the ECU or the Datalogger so I'll connect to that and won't need a standalone voltage regulator. Next issue is mounting it on the car. I'll probably tackle that in a month or two once I've got everything else sorted after the full cage install and the RCP is connected and working.

madjak · Postby **madjak** » Wed Jul 15, 2015 8:14 pm

More 3D printed stuff...

I've designed a Nexus 7 mount to that I can mount the tablet on my MX5 center console. It's based around the 2012 model but I think will work fine with the 2013 model also. It has a side port for access to the USB socket and a bottom port for the docking pins.

It's made of two parts. The main bracket holder which the nexus clips into, and then a face plate which can be 3D printer or laser cut from aluminium / carbon fiber.

I've done a test print of the main bracket holder and the Nexus slots in nicely. So nice that you hardly need the face plate and the USB port has the secondary purpose of keying the Nexus into the bracket. I'll probably manually trim the face plate from a carbon fiber sheet I have.

Postby **beavis** » Thu Jul 16, 2015 5:52 pm

I feel like thats a little over engineered hah.

I just bought a $5 ebay tablet case for my Nexus 7 and mounted that to the dash of my MX.

http://mx5cartalk.com/forum/viewtopic.php?f=57&t=58668&start=135

madjak · Postby **madjak** » Thu Jul 16, 2015 6:40 pm

If I tackle something myself then I like to think how I'd make a better version of the product. This often leads to a design that might be a bit over-engineered, but it should fit well to how I want to use it.

I'm keeping my main dash for revs, speedo and fuel gauge, so I'm building this to be mounted high up on the center console (so it's visible) and to be a dock, ie just drop the tablet in with no plugs required. It will receive power from some spring loaded pins that can interface with the Nexus 7 dock points so I won't have to plug in a USB cable. My data logger will let me review the session on the tablet so when I'm finished, I want to undock it and go sit down outside of the car and have a look at my logs / times etc.

speed · Postby **speed** » Thu Jul 16, 2015 6:46 pm

Love your work! Always well thought out and original.

Postby **mrpham** » Thu Jul 16, 2015 10:29 pm

Very cool!

I love MSDroid, but haven't had a chance to try the latest version yet.

madjak · Postby **madjak** » Thu Jul 30, 2015 6:27 pm

The RCP is all up and running in my car. I had to write a CAN interpreter script that reads the CAN data streaming from the Haltech, finds matching ID, processes the data into real values and maps them to virtual channels in the RCP. It's taken me a little while to learn the scripting language and also understand how the CAN bus works but it's very satosfying to see that data live on the tablet. This all occurs at 25Hz so the feedback is great. Hooked up to my Nexus 7, the gauges feel almost instantaneous which is really better than I was expecting with a bluetooth link.

So far I've written the code to capture the following channels:
RPM, TPS, AIT, MAP, AFR
Coolant Temp, Oil Temp, Fuel Temp
Oil Pressure, Fuel Pressure
Fuel Composition (Flex)
Injector Duty Cycle

Really you can capture data from any sensor hooked up to the Haltech as well as internal tables / calcs broadcast over the CAN like timing advance, knock, CAS trigger, fuel consumption or fuel economy etc. Once decoded these can be mapped to channels on the RCP and displayed and logged, or used in calculations.

I've also hooked up a multistage shift light with error warnings. So the outer green lights activate at 7000 rpm, the next bank of yellows activate at 7500rpm and the final central red lights activate at 8000rpm. If coolant temp gets past 100 deg then the yellow lights blink, if the oil pressure drops below a certain PSI at different RPM then it will flash on the red lights. This is all achieved with a simple scripting language that turns on or off a digital or analogue channels on the RCP. Pretty easy to code!

I'll post up some pictures of the tablet and shift light once I get it all mounted up in the car. Thats all I'll be doing for a little while now... I have ordered some K-type thermocouples and a 4 channel amplifier off ebay for a total of $100 that will give me EGT sensors on all cylinders, and I also have my DIY ride height sensors to integrate. But for now I'll put these other projects on hold as I've got a few events to do in the lead up to the National Hillclimb champs and I'm going to focus on driving well rather than start new projects on the car!

Jeo · Postby **Jeo** » Sun Aug 02, 2015 12:53 pm

Honda radiator! Civic presumably? EG/EK?

Jeo · Postby **Jeo** » Sun Aug 02, 2015 11:46 pm

Sorry for the double post but I realised that I might as well ask both parts of the question I'm ultimately going for at once.

The main reason I ask is that it look like an EG/EK radiator, but the lower outlet is on the opposite side of where I'd expect it to be. The EG/EK radiator is perfectly sized for another project I'm working on but the outlet would fit better if it were on the bottom left, as yours appears to be. Did you have one modified or is it from a different model?

madjak · Postby **madjak** » Mon Aug 03, 2015 12:21 am

I had the radiator modified. So I cut the neck off, and made a round disk to weld over the hole, and then re-welded the neck on the passenger side. Neater that way!

It's an ASI Honda radiator. No idea what model Honda though.

Jeo · Postby **Jeo** » Mon Aug 03, 2015 10:49 am

Legend, thanks Madjak. It looks just like an EG/EK radiator, apart from the lower neck, so I too will look into the modification route.

madjak · Postby **madjak** » Mon Aug 03, 2015 2:30 pm

No problem.. the cnc profiles for the radiator hanger I made are linked earlier in this thread.

Here are a few shots of my Nexus 7 holder mounted on my center console. This position is only temporary as I'm going to be building a switch board with breakers and battery isolation in the lower half with the tablet mounted higher so its more visable.

Here is the link to the obj and cad profile for the face plate if anyone wants it: https://lastpixel.box.com/s/gczim6t7mo4ot44a5pq8lvm9d52g35x4