LFX Engine Swap (GM V6) at GWR

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Re: LFX Engine Swap (GM V6) at GWR

Postby Ryan @ GWR » Thu Jun 15, 2017 9:46 am

Another item not directly related to the swap but equally important. This was also one of the final things left before this thing is rolling :)

V8R/Stoptech STR21 rear brake kit. This is a race only kit with no e-brake. 6 lbs lighter per side than my old rear brake setup.

Pads are Performance Friction 11's to match the front.

Ryan @ GWR
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Re: LFX Engine Swap (GM V6) at GWR

Postby Ryan @ GWR » Sat Jul 08, 2017 10:10 am

Got some work done yesterday after work. After test-running the engine we found the coolant expansion tank that I had been using with the 1.6L was too small for the LFX. So I picked up a Moroso tank with just about double the capacity:


The larger tank needed a new home, so tank position is moving to go up against the right side firewall. Because the lines to/from this tank need to be easily accessible to disconnect if I'm pulling the front nose off, I broke the lines up into two lines each, joined by bulkhead fittings on a little plate I made:


Tank and lines installed:


The tank takes up the location on the firewall where the relays and fuses were living. Because those items stay attached to the engine if the engine is pulled, and the tank stays with the chassis, I move that stuff forwards of the tank via another bracket so that it's still just one M6 bolt to remove to release that from the car. All this stuff is waterproof, but there's a splash shield integrated into the bracket, just in case:

Ryan @ GWR
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Re: LFX Engine Swap (GM V6) at GWR

Postby Ryan @ GWR » Wed Jul 19, 2017 12:15 pm

Juuust about to go for the first test spin... turns out the clutch isn't disengaging. Wonderful. Hydraulics checked out, so there was nothing left but to drop the transmission. Hey, on the bright side this was an opportunity to go through the whole engine removal process and take notes for next time ;)

Cooling assembly off:


Whole assembly out as a unit:


A view we don't usually get of things:


Turns out.... the clutch disc was in backwards! The doofus who installed it (yes me) missed the small mark for which side was supposed to point to the flywheel.


Going back in today.
Ryan @ GWR
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Re: LFX Engine Swap (GM V6) at GWR

Postby Ryan @ GWR » Mon Jul 24, 2017 11:18 am

Time to get a hood on this thing!

The project began with a donor hood from a scrapped car. Bolted it to the hinges and set the hood down on the engine... and this is where it stopped. We're going to need to get out the grinder!


Cut a big ol' hole and now it closes.


That's it! Hood's done.

Ok, perhaps not quite. With the hood cut to clear we can see how much of the engine sits proud of the NA hood line:


Made a template for the contour needed in the hood:


Time to get the actual hood. I've had this one sitting in my garage waiting for this project. It's a dry carbon piece with integrated headlight lids. Not the prettiest finish on it since it was a function-only part and I got it second-hand but it's going to be covered in matching livery with the rest of the car when all is done. Transferred the template over to the carbon hood:


The "cut once, measure twice" point... or was it the other way around?


After many, many times of cutting, test fitting, cutting a bit more, etc. (also cut a slot for the tow hook):


Then installed the Aerocatch latches:


And it's done! I'll be adding louvers and a radiator exit duct later, but this gets the hood fitting the car and suitable for driving:

Ryan @ GWR
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Re: LFX Engine Swap (GM V6) at GWR

Postby Ryan @ GWR » Wed Aug 02, 2017 12:11 pm

The engine's out again. I'll get to that update when I have it concluded.

While it was out of the way, I added heat shielding on the firewall behind where the engine resides:


I also added a new shield for the transmission tunnel. This is a modern-style thin aluminum layer with an air gap between it and the tunnel. This began life as a tunnel shield from an ND Miata which I then trimmed/hammered into shape to fit the NA tunnel. Extremely light weight:


Ryan @ GWR
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Joined: Fri Oct 17, 2014 11:37 pm

Re: LFX Engine Swap (GM V6) at GWR

Postby Ryan @ GWR » Wed Aug 02, 2017 12:13 pm

So many are wondering why the engine came out again. It certainly wasn't just so I could add some heat shielding ;)

With the car running I drove across the street for an alignment (sitting in the pic here waiting to go on the rack)...

IMG_7006-L.jpg (70.97 KiB)

On the drive back across the street to the shop, the rear tires locked. Fun times sliding into our parking lot. Motor was seized. Oil pressure was strong and everything was running right so best guess right now is that it was the thing I had feared in the back of my head from the beginning - this engine had come from a donor car that we discovered had been flipped, so if the engine had been running while it was upside down, the bearings were doomed from the start.

Not going to allow this to stop me, I gave myself one day to come to terms with things and began the hunt for a motor the next day. Made some calls and found that Cord Bauer of Catfish fame had a unicorn of a motor sitting around that he was willing to part with - this one from a 2013 with only ~500 miles on it (!!) Thanks Cord!

That engine is here already, and I'm about half way through transferring everything from old engine to new:

Ryan @ GWR
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Joined: Fri Oct 17, 2014 11:37 pm

Re: LFX Engine Swap (GM V6) at GWR

Postby Ryan @ GWR » Thu Aug 03, 2017 11:31 am

LFX's are growing on trees around here! That's the new motor on the right, with nearly everything swapped over:


A peek inside the pan from the old motor confirms that yeah those bearings are done! Thoroughly cleaning everything in the oil system before swapping over to the new engine (pan, pickup, adapter plate, lines, cooler, etc.)

Ryan @ GWR
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Joined: Fri Oct 17, 2014 11:37 pm

Re: LFX Engine Swap (GM V6) at GWR

Postby Ryan @ GWR » Tue Aug 22, 2017 12:45 pm

Engine is in and fires up. Tying up loose ends right now.

Top of that list is some frustration with the Racepak stuff. Bottom line is it simply can't read any PIDs from the 2012 ECU I have. Not with the OBDII adapter cable or with the CAN hi and low hardwired directly to the dash, despite the fact we can view live data streaming via that same diagnostic connector with either a scan tool or HP Tuners. Racepak themselves have no idea why it can't read this ECU, and I've verified this particular dash will pull PIDs via the adapter cable to diagnostic connector on other cars such as an ND that was here in the shop.

SO... I'm bypassing the 'read the ECU' plan. Wired in a temp sensor for coolant and adding the Racepak GPS module for speed. RPM is the complicated one because these ECUs have no conventional tach signal output. Autometer tach signal adapter part number 9117 was the solution.

Pic here shows how it's wired in, this was just temporary crimps to verify it worked before wiring it in properly...


The signal adapter gets wired in-line with the two main +12v supply wires that go to the coils, one wire to each bank. Follow the instructions included for an LS engine but your wire color is different. Pink/black is what you're looking for in the LFX harness. Start at the coils and follow the light gauge pink/black wires up-stream until you find where they split out from a thicker gauge pink/black. That's the wire to intercept. There are two of these wires, one for each bank. The autometer box outputs a lovely +12v square wave standard tach signal. The Racepak instantly reads it. Change the Racepak to V6 Even Fire (default seems to be V8) and voila. We have RPMs.

Next up was some issues with the oil pressure readings on the Racepak. Using an ACDelco D1800C sensor which is equivalent to the factory Camaro pressure sensor but there is no scaling info available for this sensor. Since we're talking about oil pressure here, I wanted to be able to have complete confidence in the reading so I decided the best approach would be to test it personally and then manually calibrate the Racepak based on those results. So I needed to build a bench tester for the pressure sensor.

Here's what I made. Figured I'd take a little extra time to make something that could be useful in the future. NPT ports for all the common sensor sizes, two air valves so I can fill/bleed and monitor pressure without switching back and forth, portable enough that it can be placed in the engine bay so the sensor is operating on the vehicle wiring. Can be used to bench test temp sensors as well by standing it vertically, removing the end cap, filling with water and then heating the water and validating the temp with a thermometer.



With the bench tester, I confirmed it's a 0.5v-4.5v / 0-130 psi sensor. However, thanks to testing the sensor this way, I was able to calibrate the Racepack very accurately to the specific scaling of this particular sensor. Dash reads oil pressure perfectly now.
Ryan @ GWR
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Re: LFX Engine Swap (GM V6) at GWR

Postby Ryan @ GWR » Tue Sep 12, 2017 12:49 pm

Tons of things going on, a lot of it is little details. Need a small bracket here or a tweak of something there and before you know it many hours have disappeared.

Some of the big stuff...

The Getrag diff was not operating like an limited slip unit. At first we chalked it up to the fluid and additive still needing to get cycled around better since it hadn't driven around much, but after a lot of figure 8's in the parking lot and still no improvement I started digging. GM superseded part numbers so when you call your GM contact to find out if the PN on your diff is for an LSD, they might know that number was superseded by a different number or they miiiiight tell you that's not a number that comes up in their system and have no idea. Eventually we got it nailed down and it turns out the salvage yard that advertised this diff as an LSD unit got it wrong. That was over a year ago so nothing to do now but buy another one.

As for those part numbers...

3.42 NOT LSD:
15793753 - superseded now by 25873499
3.42 LSD:
15793754 - superseded now by 25873500

New diff arrived, correct original PN on it. That diff now lives in the car.


Lots of little bits here and there to get bodywork on and working. Then went on to hood venting:


Hood is cut now, finished pics once louvers are back from powdercoating :)

New fence on the splitter to seal behind the lower edge of the bumper skin:


Plugged all the now-unused holes in the bumper skin that used to feed the oil cooler and front brake ducts. This pic reminds me, still need to relocate that "tow" decal to the hood:


Went to reinstall the fire extinguisher, discovered the new frame rails blocked the holes the extinguisher bracket had used. Made a new bracket with wider mounting points that tucks the extinguisher up as much as possible under the front edge of the seat:


Tires arrived and mounted on 15x10 Tungsten 6ULs. This is the 245 Rival S 1.5. Tire tech evolves crazy fast, even from just a couple years ago... back when I was running street tires to fit into a certain class for Miata Challenge I was on the original RS3... then the original Rival came out and it was better because you could actually use the brakes! Now for RLTA and GTA my class requires 100tw or greater, but these "Super200's" are faster than the 100tw options. I'm betting this combo here is easily 2 seconds faster than the old worn out 225 NT01s on 15x9 that I ran at Superlap in 2014.
Ryan @ GWR
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Re: LFX Engine Swap (GM V6) at GWR

Postby Ryan @ GWR » Mon Sep 18, 2017 3:01 pm

Managing the air that passes through the car.

Hood venting:



The louvers pull pressure out of the engine bay to optimize airflow through the coolers and reduce lift. It's rather incredible how well they work - with the radiator just venting into the engine bay like normal the louvers will pull the majority of air that passes through the radiator up and out through the hood. Since this car is about getting that last little bit everywhere, I'm also ducting the radiator's exit up towards the hood vents to maximize front downforce.

Work in progress:


Finished duct:



The ducting directs the radiator exhaust directly up to the larger middle two vents and isolates that flow from other pressure sources I'll be playing with in the nose of the car.

Ryan @ GWR
Posts: 235
Joined: Fri Oct 17, 2014 11:37 pm

Re: LFX Engine Swap (GM V6) at GWR

Postby Ryan @ GWR » Mon Sep 18, 2017 3:01 pm

More fab this weekend of various small bits, then drove the car around on the street to do some datalogs. Confirmed, car is loud and moves with urgency.

Back in the shop, mounted up a small wing ;)
This is a Kognition wing I had built back in early 2015 for my car. It served for a brief stint on the GWR turbo NC since my car wasn't using it but now it's finally on the car and ready to be used.

Ryan @ GWR
Posts: 235
Joined: Fri Oct 17, 2014 11:37 pm

Re: LFX Engine Swap (GM V6) at GWR

Postby Curves » Tue Sep 19, 2017 12:59 pm

Will that Wing even fit through the gates at Qualcomm :D
How much camber do you in the rear, looks like a lot -3+?
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