85 Honda CRX Racecar

General talk about successes. See older information on MSRUNS forum.
whittlebeast
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85 Honda CRX Racecar

Post by whittlebeast »

I finally got the wiring almost done. The wires in the interior run the shift buzzers and the CAN network stuff running a Microsquirt IO Box in the future.

http://www.nbs-stl.com/CRX/CRX%20Interior%20Wiring.jpg

http://www.nbs-stl.com/CRX/CRX%20Dash.jpg

http://www.nbs-stl.com/CRX/CRX%20Engine.jpg

Here is the ignition. I will use the stock ignition with three of the four points ground off to create a cam position sensor. The original CRX ignition cap is just a dust cover now.

http://www.nbs-stl.com/CRX/CRX%20Ignition.jpg

The terminal strip is clean ground for sensors and ignition digital stuff on the left and high power grounds on the right.

http://www.nbs-stl.com/CRX/CRX%20Intake.jpg

The ITBs are off a GSXR with 30 lbs injectors from a Yamaha FZ1.

Next I have to sort out a cranking issue. Then taking on the first start-up verification.

Here is a wiring diagram that is fairly close to the final setup. The shift buzzers are on the upper left.

http://www.nbs-stl.com/CRX/Civic%20CRX%20Wiring.jpg

Andy
Last edited by whittlebeast on Mon Mar 21, 2016 12:34 pm, edited 2 times in total.
whittlebeast
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Re: 85 CRX Racecar

Post by whittlebeast »

Here is the main relay panel. The wiring changed slightly in the final wiring compared to this shot.

http://www.nbs-stl.com/CRX/MRC_1%20Relay.jpg

and here is the shift buzzer relay panel that I found for like 6 dollars on amazon. The relays are triggered by the 4 spare 5 volt programmable ignition output channels.

http://www.nbs-stl.com/CRX/Small%20Relay.jpg

It is set up like this in the squirt.

http://www.nbs-stl.com/CRX/Shift%20Timi ... 0Setup.png

Andy
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Re: 85 Honda CRX Racecar

Post by whittlebeast »

Update. It started right up. First try, the motor ran for about 2 sec and died. Second try, same thing. Disconnected the cam sensor to force wasted spark and it fired right up. Base timing was within 5 degrees. Fuel pressure came up about 60... no big deal. Time to start tuning.

I can post some logs if people want to watch how I bring a car up from scratch.

Andy
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Re: 85 Honda CRX Racecar

Post by slow_hemi6 »

Nice work Andy. Makes me a bit nostalgic about my old D16 twin cam integra.
Find the Manuals up top under Quick links: Manuals. :RTFM:
Cheers Luke
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Re: 85 Honda CRX Racecar

Post by whittlebeast »

Here is a few screen shots after a little playing on the dyno. It came up 125 HP at 7000 RPM The guy that owns the dyno builds Spec Miata motors and tells me that his dyno reads about 7 HP less than a Dynojet dyno that most people quote, so call it 132 HP. Multiply by 1.15 and you get 152 HP at the crank. Not too bad for a 30 year old, 3 valve, 1500cc motor that Honda rated at 91 HP.

http://www.nbs-stl.com/CRX/CRX%20Dyno%20Graph.jpg

http://www.nbs-stl.com/CRX/Dyno%20Pull%20Graph.png

http://www.nbs-stl.com/CRX/Dyno%20Pull%20AFR.png

Andy
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Re: 85 Honda CRX Racecar

Post by whittlebeast »

Here is a dyno pull

https://www.youtube.com/watch?v=-mUGL6i0rpg

and watching the fuel pressure regulator at WOT

https://www.youtube.com/watch?v=HGFV11KjfqQ

Andy
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Re: 85 Honda CRX Racecar

Post by whittlebeast »

The car ran great all day. Never missed a beat. I have some tuning to do. I am planning to go to a base speed density tune with a Alpha-n secondary table.

http://www.nbs-stl.com/CRX/CRX%20Basic%20Usage.png

Andy
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Re: 85 Honda CRX Racecar

Post by whittlebeast »

I got the Accelerators working this weekend. Here is data coming of an autocross. Here is a couple of screen shots.

http://www.nbs-stl.com/CRX/CRX%20Traction%20Circle.png

http://www.nbs-stl.com/CRX/CRX%20Autocross%20Trace.png

I did it with a $3.00, 3 axis, 3g board and a 3.3 Volt converter from Amazon. It is in a box, located just under the windshield surrounded in memory foam.

Here is a pic of the engine compartment. The accelerator is the black box.

http://www.nbs-stl.com/CRX/CRX%20Engine.jpg

And the car pic....

http://www.nbs-stl.com/CRX/CRX.jpg

And my son driving it.

https://www.youtube.com/watch?v=3iNdHm81lgs

Andy
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Re: 85 Honda CRX Racecar

Post by elutionsdesign »

Very cool!
Graduate of EFI University.

I build, repair, install and tune Megasquirt systems in North Dakota and beyond!
whittlebeast
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Re: 85 Honda CRX Racecar

Post by whittlebeast »

Thanks.

I am starting to think that you can't run closed loop and using autotune is fairly sketchy with anything that is this flying around the VE map this fast. I may have to resort to hand tuning.

No big deal.....

Andy
whittlebeast
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Re: 85 Honda CRX Racecar

Post by whittlebeast »

I got MLV HD to work with my QStarz data.

On the left, the color is MPH, and on the right, red indicates acceleration and blue is braking.

http://www.nbs-stl.com/CRX/CRX%20Autocross%20QStarz.png

Andy
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Re: 85 Honda CRX Racecar

Post by nyborggarage »

Really cool car and Electronics!

Sent fra min C6903 via Tapatalk
Nyborg Garage, Norway, Honda Tuning.
www.facebook.com/nybga
whittlebeast
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Re: 85 Honda CRX Racecar

Post by whittlebeast »

I spent some time working on looking at autocross data coming off the new setup. Here is what 7 autocross runs worth of data look like. I filtered out data below 15 MPH to get rid of data warming up the car and driving around the pits.

http://www.nbs-stl.com/CRX/Autocross%20CRX.png

Then I did some playing around with the Histogram graphing capabilities that comes with the registered version of MLV HD and came up with this.

http://www.nbs-stl.com/CRX/Autocross%20 ... Circle.png

This plot is what is commonly known as the traction circle. The goal is to always have a racecar out on the edges of the circle. You can get lots more info on google.

This wall all done with about $20 to get Geez data coming in on the 3 ADC input pins and $125 to collect GPS data that comes in on the MAF input. The GPS comes from CanDooPro. Talk to Jeff if you contact them as he knows what he sent me. It is not a standard piece on there site.

Have fun tuning

Andy
whittlebeast
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Re: 85 Honda CRX Racecar

Post by whittlebeast »

This is really cool. Did you ever wonder where you spend most of your time in the VE Map. This happens to be 7 autocross runs with 3 different drivers. Data was collected in about 5 min of driving.

http://www.nbs-stl.com/CRX/Autocross%20 ... 20Time.png

The blue lines are where the motor passed thru the map.

Andy
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Re: 85 Honda CRX Racecar

Post by whittlebeast »

I figured out how to overlay where The driver is on the brakes in red, on the gas in green and relatively coasting in white. White is not good.

http://www.nbs-stl.com/CRX/Autocross%20 ... 0Brake.png

If anyone wants to know how I did any of this, feel free to ask.

Andy
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Re: 85 Honda CRX Racecar

Post by whittlebeast »

Here is something I never expected to find. From looking at lots of data off lots of different motors over the last 10 years, I have have learned that on most motor designs, MAPxRPM is essentially air flow. The only motors I have found that do not follow this model is ITB motors. This is the first motor that I have had this quantity of data to look at.

see http://www.nbs-stl.com/CRX/ITB%20MAPxRP ... 20RPMs.png

What I did is created 4 filters. In the first screen, you are only seeing data from 3900 to 4100. In the second screen is 4900 to 5100 RPM and so on.... The color is TPS angle over a narrow range of 10 to 28 degrees.

Notice that in the far left 4000 RPM screen, there is a distinct bend in the curve at right at 18% throttle. In the 7000 RPM data on the right, the transition happens at 28 degrees throttle angle.

These kinks in the graphs is when the motor transitions from acting like a Speed Density like tuned motor and moves to being more like a Alpha-N based motor. If your motor does not have these kinks, stay Speed Density. If it does do this, your intakes are coming alive at some point in the power range.

Lately, I have been playing with a new field that I call throttling. It is created in MLV and defined as

[TPS]<1.001?0:sqrt(sqrt([TPS]-1))*32

I am finding that it is a decent predictor of MAP bases on throttle position.

see http://www.nbs-stl.com/CRX/CRX%20Throttling.png

Have fun tuning

Andy
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Re: 85 Honda CRX Racecar

Post by whittlebeast »

Here is a youtube video from the outside to get an idea of what the car sounds like on course.

https://www.youtube.com/watch?v=QWa8YQZkLR8

It has been running great. Here is a few logs off the car

http://www.nbs-stl.com/CRX/CRX%20Data.zip

Andy
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Re: 85 Honda CRX Racecar

Post by whittlebeast »

I was testing a new tune in the driveway today. I got a solid 13000 RPM per Sec on a throttle stab. I am running Speed Density below 3500 RPM, and Alpha N above 3500 using table switching.

http://www.nbs-stl.com/CRX/CRX%20Thrott ... sponse.png

Andy
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Re: 85 Honda CRX Racecar

Post by whittlebeast »

Here is the latest tune and the matching autocross data. Using Speed Density up to 3500 RPM and switching to Alpha-N above 3500 worked perfect. Unfortunately, we found the weak link of the motor when a rod cap left the crankcase. Looks like we are going to a B18C....

http://www.nbs-stl.com/CRX/CRX%20ITB%20Last%20Day.zip

Andy
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Re: 85 Honda CRX Racecar

Post by whittlebeast »

Here is the new B18C motor that I installed in the car. I am shooting for 220HP at about 8900 RPM. The squirt will be controlling the VTec.

https://www.youtube.com/watch?v=MxBc5SPIMaM

Andy
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