LFX Engine Swap (GM V6) at GWR

Miata Parts, Intakes, Superchargers, Headers, Exhausts, Shocks, Springs, Sway Bars, Brake Kits, Autocross and track mods.
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Ryan @ GWR
Posts: 497
Joined: Fri Oct 17, 2014 11:37 pm

Re: LFX Engine Swap (GM V6) at GWR

Post by Ryan @ GWR »

Ah, I read above that you had only the big rear bar. If you have both front and rear Progress bars you'll be better shape in terms of balance, and that will help a lot with taming the body roll you'd get with those very grippy tires. Full stiff on the front bar and full soft on the rear will probably push, but not bad to start there and adjust as you feel it out. Tires pressures vary on a myriad of factors, the *right* way to set them is with a tire pyrometer, but without that I'd recommend airing up to ~28 cold beginning of the day and then bring pressures down once they are hot until you see signs of using the whole tire to the edge (a bit of chalk on the edge of the tire before the session can help show where you're wearing the tire to in just that session).

As for brakes, always suggested to at least get pads that can handle the high heat of track use. It's a whole different ball game than autocross. Factory pads usually don't last long. A set of Porterfield R4-1 will match well with those tires and give you lots of headroom to grow into as you get comfortable with the track, rather than street pads which have a low temperature ceiling and may be OK for the first half of the day but quickly overheat once you start pushing into the braking zones harder, etc.
DavidM938
Posts: 33
Joined: Fri Jul 26, 2013 10:20 am

Re: LFX Engine Swap (GM V6) at GWR

Post by DavidM938 »

Thanks Ryan for the advice. I just now ordered the Porterfield R4-1 front and rear. car has 39k, oem brakes so I have been figuring pads would be needed sooner or later. (I hope they are in stock and get here in time; track day is nov. 12th!) FYI, I do actually have a probe-type pyrometer, so will now get a chance to use it! I have been having troubles with the notorious sticking bushings when I had the Progress springs installed, have re-done the "rocky" method per Brian's instructions 3 times, and yet the right rear is still about 3/8 " higher than left rear. car does sit pretty low (13" lf, 13 1/8 rf, 13 lr, and 13 3/8 rr) I'm running about -2 front camber (all we could get) -2.8 rear, zero toe, and 5 degrees caster. Do I need to change anything for the track? 2 of my regular solo buddies are also running, one as an instructor, and I'm really looking forward to a great day! thanks again, and I didn't mean to hijack your fabulous build, but really appreciate you taking the time to help! David in Nashville
Ryan @ GWR
Posts: 497
Joined: Fri Oct 17, 2014 11:37 pm

Re: LFX Engine Swap (GM V6) at GWR

Post by Ryan @ GWR »

Time for a long-due update! I've been plugging away on the new front chassis section over the past month. In expected domino effect, changing one thing required changing two things associated with it and so on and so on.

Where we left off, I decided to cut off everything forward of the shock towers and build everything new to save any weight possible from the nose. Several things up front that this new structure needs to support; splitter, radiator, oil and power steering coolers, ducting, intake, front bumper, front sway bar, etc. I began with building a jig for all the existing mounting point positions that I knew I needed to recreate (pic further up this page).

Frame rail and front of tower strengthened and capped to build the new sway bar mounts out from:
LFX_frontchassis1.jpg
Building the new structure around the jig:
LFX_frontchassis2.jpg
If I'm going through the trouble to make everything, might as well build some tricks into it :) so the front sway bar mounts are fixed, but everything forward from there is removable:
LFX_frontchassis3.jpg
The front section removes with just one bolt and one quick disconnect pin on each side:
LFX_frontchassis4.jpg
Front section in place with the radiator and ducting being test-fit. I'm really excited for this removable nose section. The idea is that when serious engine work is needed, after removing the splitter (just pull 4 pins) and disconnecting hoses, I can essentially remove the entire front of the car in a matter of minutes as one intact assembly and set it aside, then it re-installs as a unit when done:
LFX_frontchassis5.jpg
I'm moving the front tow point to the passenger side shock tower to shift that weight back a bit. Added a mounting point for the new tow hook to the tower:
LFX_frontchassis6.jpg
I drew up a tow hook to go from there up through the hood, that's being cut at the waterjet soon.

Weighed everything that got cut off and everything before it was welded on. This project shaved 25 lbs off the front of the car. Might not sound like much, but with all the easy weight savings already done long ago, these days I'm looking for smaller and smaller increments of weight left trim, so a 25 lb chunk is a big bite off the nose.

With all that done, on to painting it. Everything is in primer here. In the end it looks pretty simple, belying the complexity that went into the many details - a mark of an efficient design:
LFX_frontchassis7.jpg
Just finished two tone paint in the engine bay today, so I'm just about ready to get back on track and start bolting parts in for good soon!
Ryan @ GWR
Posts: 497
Joined: Fri Oct 17, 2014 11:37 pm

Re: LFX Engine Swap (GM V6) at GWR

Post by Ryan @ GWR »

Paint is done. The bay is a medium gray and the cage in the car is pearl white, so I carried that color into the engine bay where the cage extends to the shock towers.
LFX_frontchassis11.jpg
LFX_frontchassis12.jpg
Ryan @ GWR
Posts: 497
Joined: Fri Oct 17, 2014 11:37 pm

Re: LFX Engine Swap (GM V6) at GWR

Post by Ryan @ GWR »

Big day, engine and transmission are officially in! For the final time (fingers crossed).

First, flywheel and clutch. The factory clutch and flywheel combo are over 50 lbs (!!!). While the standard clutch will likely hold up to lots of abuse in a car that's half the weight of the original, I wanted to trim weight from the combo for faster engine response so I went with the following combo by SPEC. More torque capacity is a bonus, it'll be more than enough for now and will give me lots of headroom if I get crazy down the road.

Flywheel part # SC36A-2. It's massive because it has to take up the space that the factory flywheel/flex plate combo used. Still, being all aluminum it comes in lighter at 18.85 lbs. The flywheel isn't cheap but with the replaceable steel friction disc it should be infinitely rebuildable, never need to buy another one again.
LFX_flywheel2.jpg
Clutch - SPEC part # SC361R-2-H. It's a part number that doesn't really exist on their site, Stage 1 clutch, organic full face disc, rigid hub, upgraded with higher clamp load option, brings the torque rating up to 470 ft-lbs. Definitely more than enough. Nice and light at 12.35 lbs.
LFX_clutch2.jpg
Combined weight of the new combo comes to 31.20 lbs, ~20 lbs lighter than factory clutch and flywheel combo:
LFX_flywheel_clutch.jpg
With that done, we joined the transmission and engine and put 'er in:
LFX_engine_trans.jpg
LFX_engine_in.jpg
Notes on installing engine...

We decided to put the engine and transmission in as one unit because room is tight around the top of the bellhousing to the tunnel and firewall. With the long flywheel/clutch assebly, it didn't look like it would be possible to get the bellhousing over the clutch with the engine already in place. With the front of the car absent we had more options than usual so with the subframe already in we lifted the whole engine/trans and dropped it in tail-first and then lifted the tail of the trans to align the engine mounts. This would have been very difficult with a front of a car there and was still a good bit of work.

Discussing options after doing it this way, we're thinking the best method in the future is to assemble the subframe and engine mounts along with the engine and trans out of the car, put that whole assembly on a dolly and then lower the car onto the assembly. We figure this is going to be the easiest method for those with an intact nose as well.

Other notes...

Before they went in I installed the brake booster and brake master cylinder. Here I'm using our wilwood 1" master cylinder kit with tandem reservoirs which pairs very well with most big brake kits.

Also installed the clutch master cylinder. For this, I forgot to snap a photo but I had to do a little grinding on the clutch pedal itself - the new Wilwood master cylinder's clevis on the end of the rod works mounts to the Miata clutch pedal, but the wilwood clevis is not as deep as the Miata's, so the pedal bottoms out in the throat of the clevis' "U" shape when fully pressed down or not pressed at all. You can easily see it when test fitting the clevis to the pedal. A little grinding on the pedal creates the clearance needed.

Funny, when you get rid of the front of the car the alternator and power steering pump clearances really open up ;)
LFX_engine_in2.jpg
Ryan @ GWR
Posts: 497
Joined: Fri Oct 17, 2014 11:37 pm

Re: LFX Engine Swap (GM V6) at GWR

Post by Ryan @ GWR »

Just before the holidays hit I was deep in connecting hoses and wiring for the final time. Bit of a mess while sorting through what still needs to be figured out, needs to be tweaked, etc. but here's a quick snapshot of about where we are at the moment:
LFX_inprog.JPG
And, decided to spring for some trick fittings to go hand in hand with the quickly removable front end design, still waiting on parts to arrive but for now here's a teaser of the dry break fittings that will be going on the power steering lines:
LFX_PSdrybreak.JPG
Ryan @ GWR
Posts: 497
Joined: Fri Oct 17, 2014 11:37 pm

Re: LFX Engine Swap (GM V6) at GWR

Post by Ryan @ GWR »

Doing some napkin math for other fun places the car may fit in.

Looking at NASA, when you move above the complicated mess of the lettered classes on up to ST/TT 1, 2, 3 things get much simpler. With a good bit of power taking the tighter-regulated TT4 out of the question it gets even simpler. Basically take a dyno and weight baseline which then applies modifiers for certain mods and you end up with an adjusted power/weight ratio and that's that. Everyone racing in the class has the same adjusted ratio. Obviously this favors a wide torque curve, and this motor should be great for that.

TT2 cars have an adjusted wt/hp of 8.00:1 or more (up to 10.00:1 which is TT3)
2300 lbs with driver / 300 whp = 7.67:1
Relevant adjustments:
Comp weight over 2200, less than 2599 = -0.2
Tire size 245 or smaller (DOT approved) = +0.7 or Tire size 275 or smaller (DOT approved) = +0.3
Non-production vehicle = -0.4

A note on the non-production vehicle bit.. have to take that due to the tubular front subframe, but this comes with some benefits. First, I don't have to take the -0.2 for cutting the rocker for exhaust routing for production vehicles, so it's really only -0.2 more than if it was considered a production car. But more importantly, with it considered a non-production car there's no concern about the tubular/removable front nose being OK.

So, with adjustments, 7.77:1 with 245 tires or 7.37:1 with 275's

Ballasting up to 2375 lbs with 245 hoosiers puts me at an est. adjusted 8.01:1, right at the pointy end of TT2.

TT2 is full of Corvettes and Vipers... always love a challenge! :twisted:
Ryan @ GWR
Posts: 497
Joined: Fri Oct 17, 2014 11:37 pm

Re: LFX Engine Swap (GM V6) at GWR

Post by Ryan @ GWR »

Continuing to wait on a few more parts to arrive, so I took some time to get some of the suspension bits assembled.

Pressed out all of the old polyurethane bushings and now installing for evaluation a spherical bearing kit for the factory control arms from a shop up in Canada.
lfx_bearings.jpg
Spherical bearings within the press-in sleeves:
lfx_bearings2.jpg
I've run into a couple snags with some of the parts in the kit, shot some feedback to them to get those bits resolved instead of having to machine my own solutions, and hopefully we'll get things sorted out. Nevertheless, the majority of the kit is installed and ready to rock.

Also going into the arms are Bauer extended lower ball joints and V8Roadsters rebuildable front upper ball joints:
v8r_balljoints.jpg
Finally, I'm replacing the rear upper arms with V8R's tubular Pro series arms. Feedback from Steve about what they've seen on other cars, the rear upper arms are the ones responsible for wheel hop and other funkiness when putting big power down as that factory arm twists with enough torque. The tubular arm solves this, and the pro series has spherical bearings to match the rest of my arms.

Oh, and in my recent powdercoating frenzy I had all the factory arms done.
thepass_arms.jpg
Ryan @ GWR
Posts: 497
Joined: Fri Oct 17, 2014 11:37 pm

Re: LFX Engine Swap (GM V6) at GWR

Post by Ryan @ GWR »

While waiting on the last fittings to arrive, this past week I've been working on wiring plans in the evenings.

Because race car I'm pulling the entire Miata harness on the chassis side as well and will make a new harness for just the essentials. For the record, if this was a street car with many more factory systems I would keep the factory harness and just add things as needed. But since that's not the case, there's some planning to be done here if I want to wire everything up in one nice clean harness.

The engine harness itself has already been set up nicely for my needs by V8R. They trimmed out anything unnecessary, converted it from auto to manual, added an OBDII port for me and extended a few wires at my request. They also fused anything that needed it and added a main relay. All that's left for me to do on that side is carry a few voltage wires from the cabin/battery over to the engine side.

But, that doesn't get me out of the woods. I still need to sort out a chassis harness which includes several systems like fuel, ignition, etc. as well as the Racepak dash plus the sensor module for the dash. I also need a cooling fan circuit, and I need to get the OBDII port and the drive-by-wire connector into the cabin. To make things easy to service/remove, almost everything will pass through a single bulkhead connector in the firewall.

One unknown I ran into during planning was the question of how much info the digital dash can pull directly from the ECU via the OBDII port. Anything the dash can get straight from the ECU saves me time and wires. The guys at Racepak couldn't make any guarantees, they said you really just have to plug the dash into the car, start it up and see what data it can pull. Well that's great except I can't start my car yet - I need the wiring done before I can start it... but if I want to do the wiring all at once and not have to hack it up and add stuff later I need to know this answer before I do the wiring. Gotta love catch-22's.

Sean had a great idea for a solution - rent a V6 Camaro and wire the dash up to it.
DACB848E-2783-46D3-8BBD-1272BCDD397B_zpslorh3u26.JPG
Turns out it can pull quite a bit of info. I don't need most of it, but here's the full list of what the dash is getting from the OBDII port - noteworthy items that I'll probably be displaying on the dash in bold:

Fuel system status
Engine RPM
Vehicle speed
Calculated engine load value
Short term fuel % trim - Bank 1
Short term fuel % trim - Bank 2
Long term fuel % trim - Bank 1
Long term fuel % trim - Bank 2
Intake air temperature
Intake manifold absolute pressure
Timing advance
Engine coolant temperature
MAF air flow rate
Oxygen sensor Bank 1, Sensor 1
Oxygen sensor Bank 1, Sensor 2
Oxygen sensor Bank 2, Sensor 1
Oxygen sensor Bank 2, Sensor 2
Run time since engine start
Distance traveled with malfunction indicator lamp (MIL) on
Fuel pressure
Fuel rail pressure (diesel)
Fuel level input
Fuel type
Commanded evaporative purge
# of warm-ups since codes cleared
Distance traveled since codes cleared
Evap. system vapor pressure
Barometric pressure
Ambient air temperature
Control module voltage
Absolute load value
Command equivalence ratio
Throttle position
Relative throttle position
Absolute throttle position B
Absolute throttle position D
Absolute throttle position E
Command throttle actuator

In addition to the above bolded items, I'm adding temperature sensors for engine oil, transmission, differential and power steering fluid. These four will tie into a Racepak universal sensor module which transfers the data from those sensors to the dash via one cable. Between the stuff above and these four added sensors the dash should be able to keep an eye on everything important. I can set up warnings on the dash for any of these inputs, so I can focus on driving rather than worrying about checking gauges.

I'm disappointed that oil pressure isn't on that list. The ECU monitors this, but it appears it doesn't send that info to the OBDII port. I'll need to wire up a second OP sensor or figure out if I can piggy-back on the factory sensor's wires. Not sure yet on that front, but overall some good info gained and I can finish up my wiring plans now.
Ryan @ GWR
Posts: 497
Joined: Fri Oct 17, 2014 11:37 pm

Re: LFX Engine Swap (GM V6) at GWR

Post by Ryan @ GWR »

With the last of the fittings arriving yesterday, today I completed everything that carries fluids in the front end. Now that I've finished that up and know for certain how it's all going together I can finally cover each system in its own post.

Power Steering

We begin with V8R's power steering kit. Included are fittings/lines to replace the hard lines that run along the rack itself with steel braided lines as well as fittings and a high pressure braided line for pump to rack. The kit leaves it to the user to sort out the low pressures lines (usually rubber) and reservoir (I've heard the factory Miata unit can be used), so that blue 180° hose barb fitting is supplied for the exit from the rack.
LFX_PSkit_zps4y9g4owu.JPG
I used everything above except the hose barb fitting because this car will use braided lines throughout.

Removed the old lines from the rack and spent a good deal of time cleaning the rack up. The power rack I got from a donor car seemed to have been competing for the coveted title of thickest layer of grime, but it’s shiny now.
56BE0661-DBD2-4EC9-AF33-8415F9B1A5D7_zpszphhfees.JPG
Here’s the rack with the V8R lines added. Also pictured is the early version of the rack to cooler line I made which I later added the in-line dry break to:
4B02A332-C334-45B8-867B-D8A110AB9C8B_zpsm5bf08uf.JPG
Closeup shot. This bunch sit close to the pan once installed so best to leave them loose and adjust the angles once both the engine and rack are in place:
404BCA29-CFFC-43F6-A6EA-6328773430AC_zpsbw0xjktt.JPG
Pic of the power steering pump. The black threaded outlet goes to the rack which V8R supplies a fitting for (that’s what I’m holding in the photo). The port above that is the inlet from the reservoir. That port has a barbed end for a rubber hose in the stock GM form, but as seen in this pic I removed that and drilled/tapped the hole to adapt it to an AN fitting:
E765680C-C745-4453-8DB2-DFCED6FD40DC_zpssefpevkv.JPG
A note on the power steering pump pulley -
To remove the pump from the engine you must remove the pulley from the pump first. This took us a combination of parts from a rather comprehensive pulley puller kit, something most home garages may not be equipped with. Reinstallation of the pulley is equally difficult. I’d recommend leaving the pump on the engine unless you absolutely have to remove it. However, there is a complication if you’re going to add an engine oil cooler; to remove the factory oil filter housing you have to remove the steering pump first because the filter housing’s bolts are too long and can’t be backed all the way out with the pump in place. For shame, GM! Later, when I installed the Keisler oil reroute plate in place of the stock filter housing I swapped two of the factory bolts out for shorter ones and now the plate can be installed/removed with the steering pump in place. At any rate, if you need to remove the filter housing you’ll have to take the pump off at least once.

Now back to our regularly scheduled programming…
The next piece to the puzzle was the steering fluid reservoir. The reservoir needs to sit higher than the pump as it is a gravity feed. The pump’s position on the motor is high enough that there was a good bit of head scratching and lots of looking around at various reservoir options/shapes/etc. to figure out what to do. The solution I came up with uses a Moroso reservoir mounted directly to the top of the pump NASCAR style. This eliminated the need for a hose and guarantees good flow from the reservoir to pump. This reservoir is actually intended for power steering so it has the appropriate internal baffles.

I don’t have a pic of the reservoir by itself but you’ll see it in following pics. The reservoir had an AN bung in the bottom for the drain so with a couple fittings the pump was set up for the direct-mount:
BB854EE8-FB48-412D-A037-214792F5811E_zpsrpkau5o4.JPG
To hold the reservoir in place requires a bracket :) Always up for challenging myself, I decided to make it from aluminum. Here is an in-progress pic about 80% of the way done, just before tack welding the two halves I made together:
F4DD01FE-E31F-46D7-8A64-FEB5E4ED7A36_zpsgwss29pz.JPG
It turned out to be a funky looking little thing but it’s nice and light, piggy backs on existing factory bolts, and does just what’s needed:
4EF0270B-DC3F-4638-B0B4-3372746359A7_zpsjzvufqtk.JPG
Here it’s mounted up with the reservoir. Note the factory oil filter housing is still in place behind there, but that is removed later for the oil cooler:
D36BB589-6998-4301-B588-AF385A0C1FB9_zpsy6fhuvax.JPG
The final piece in the power steering system is the cooler. Most cars doing any sort of performance driving will need one, you don’t want this system overheating and spraying flammable fluid around the engine bay. If you’re doing a more standard street setup with rubber lines there are lots of affordable cooler options with barbed ends built in. For this car I chose Earl’s 40700 cooler, which is a 13”x2”x2” unit, with -6AN ends. I erred on the small side to keep weight down but Earl’s stuff has efficient cores so I think it will do the trick. I’ll be monitoring fluid temp so I’ll know if it is sized well or needs to be upgraded:
32352005-DBB2-4D90-A077-C51DDF5C32AB_zpsum1samez.JPG
Back when I was making the removable nose I made the brackets to hold the cooler in place. With the cooler, pump and reservoir all settled in all that’s left is to connect the dots with the lines. Embracing the idea of having the whole front nose section quickly removable, I picked up a pair of Radium -6AN dry break fittings for the power steering lines:
7C075CF5-D0DC-49ED-AE73-0FF3025884E7_zpssc2cmohs.JPG
Long line below is cooler to reservoir, with the dry break junction fixed to the reservoir side. The short one is half of the rack to cooler line:
3DF54378-B6ED-4924-8B7F-BB56515AF132_zps4sm00mgd.JPG
Here’s the other half of that lower line, I had already fixed it to the rack and didn’t want to remove it for the last pic. This section has a fire sleeve since it's in the vicinity of the exhaust:
F4CF140D-5AE1-4008-BBB9-D77829B5DB6F_zpssnrzrfl4.JPG
Final setup installed:
81686093-065F-4A07-9D0B-41C1E60C6AE9_zpshbhelmx4.JPG
That concludes the power steering setup. Tomorrow I'll write up the oil cooler system.
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