nigelt gets bored and adds displacement (ecotec 2.4 turbo build)
 

This thread will document my swap to an ecotec (LE5) turbo, which takes the engine from a Chevy Cobalt SS (and HHR, G6 and others), combines it with the turbo gear from the 2.0 Pontiac Solstice GXP, and bolts it up to the Miata transmission. This is not a new car for me, but in the interest of more succinctly sharing knowledge of this swap with the community here, I'm branching this off from my current build thread.

A bit of background. I bought a totalled 2002 SE back in 2014 with the idea that I'd just bend it back into shape, shoot some paint on it, and slap on a turbo. At that point I had done a few autox events, but had never considered track days. Here we are almost 4 years later and from the terrible influence of this forum, it's now got a well sorted out MK Turbo kit, Xida GS suspension, aluminum seats, LS coils and a handful of other goodies. Along the way I put together a GT500 injector kit for myself, and in finding that other people wanted them too, I started Flow Force Injectors. My engine now needs a valve job, and I'm ready for a boost in reliability and power. Which brings us up to the present.

https://cimg6.ibsrv.net/gimg/www.mia...8a499ba20a.jpg

I was originally planning on doing a built engine, and bought most of the parts for it, and then changed my mind. I just couldn't wrap my head around the idea that if one thing goes wrong I could blow a $5k engine. Inspired by Ryan's LFX build, I started looking at alternative options. The LFX really appealed to me, but the costs on that swap really do add up, and there's a fair bit of modification required. The K24 swap gets pricey too, and I would take low down torque over wailing high revs for street driving. That led me to the ecotec swap.

My goals for the build:

• 300whp/300wtq with a wide torque curve
• Disposable junk yard engine
• Reasonable price point
• Fab work is within the scope of my abilities
• Possible test bed for my new Flow Force 960cc injector kit

And the LE5 fit the bill. The early years of this engine (2006-2007) came with forged rods and are supposedly good for 400whp+ in stock form when boosted. Also all the turbo running gear from the 2.0L LNF bolts right up, meaning OEM reliability and junk yard prices even for the turbo kit. Lastly, there's a good transmission option from the 5 speed Pontiac Solstice which should hold 500whp if I blow my 6-speed.

well that's pretty cool

The parts that are going in this car:

Engine
I was shopping for an eBay or junk yard LE5 from 2006-2007. They tend to go for $600-$1000, although I've seen reports of people finding low mileage power plants for around the $500 mark. Then I found a fully rebuilt LE5 with the stock forged rods from Alpha Fab for $1400 including shipping. I went for it to save myself the time and effort of doing jobs like the timing chain, head gasket etc. The downside, other than a slightly higher cost, is that it came as a bare long block. I had to spend a few hundred more tracking down things like the intake manifold, COPs, hardware, etc. If I did this again I'd probably spend the $1000 or so to get a really low mileage engine with the wiring harness and all accessories, and toss it in the car without worrying about the maintenance items.
https://cimg0.ibsrv.net/gimg/www.mia...16e14bced9.jpg


Turbo
The turbo on the 2.0L turbo version of this engine is a fast spooling Borg Warner K04, and it bolts right up to the 2.4. You can get a brand new manifold, turbo, and oil and water lines for about $800. I found one of these that had been bought for a miata swap and upgraded to the "big wheel" version, which has a bigger compressor wheel for better high-end power for a couple hundred extra. It's quite surprising how easily it bolts up. I only had to drill the block for the oil drain, and pick up a couple other parts from the 2.0L to make it all fit.
https://cimg1.ibsrv.net/gimg/www.mia...d2126829e1.jpg

Swap Kit
I went with the ecotecmiata.ca DIY racer swap kit, which tips the scales at $950. It uses the stock subframe, and just requires drilling the miata flywheel to bolt up to the LE5. I ordered it about 6 weeks ago, and I'm to understand it will be shipping out shortly.

ECU
Most people who run NA ecotec swaps, and even some turbos, use the GM ECU. It's reprogrammable, very capable, and reportedly well known by tuners. However it isn't as easy to tune yourself as megasquirt, and a license for the tuning software (HP Tuners) is a whopping $500. I'm going with Megasquirt, and picked up a built MS3x and 8 foot wiring loom from diyautotune. I'll build my own harness from that with the connectors I pull from a cheap cut LE5 harness I got off eBay.

Injectors

For the initial swap I'm probably going to fit a set of Flow Force 640 injectors. That will let me test out my work horse product in a new engine and hopefully open up a new market. Then I'll drop in my new 960cc kit, which will provide the fueling I need to put down the big numbers, and let me battle test that new product. For both the 640 and 960, it's not a direct fit with the Miata kit, but it's close enough that I can make it work with a few tweaks.

https://cimg3.ibsrv.net/gimg/www.mia...22b340521c.jpg


Intercooler
I'm going to keep the eBay intercooler I have now, and keep the 2.25 inch piping on the hot side. On the cold side I'm going to go up to 2.5 inch. I think I can keep the same piping routing, even though the intake and exhaust sides are switched.

Down pipe and Exhaust
I think this is going to be the hardest part. On the ecotec motors the exhaust is on the other side, and routing with the stock subframe is tough. My plan is the go 3 inches straight off the turbo and sneak it down the space available. I'll probably have to do some cutting and pounding to open up enough space. Then I'll cross over under the transmission and join up to my current MK Turbo exhaust. My plan is to cut and tack weld the down pipe myself, and then take it to a shop for tig welding.

At present, I'm collecting parts and assembling the engine. Within the next month I'll pull my engine, rip out PS and AC, and get it cleaned up and ready. Then at the end of April I'm planning to drop in the LE5 with plenty of time to fine tune and work out the kings before a weekend at Laguna Seca in June.

Please continue to post all your details so I can press the "easy" button next winter and duplicate your setup in my NA.
Seriously.

KTHXBAI.

:party:

You betcha! I'm also planning to do small runs of parts that are difficult to source or custom to make it easier for other folks.

Excellent. I plan to return to MMRLS (or whatever they end up calling it) in 2019. I may be out in the south these days, but California will always be "home".

Do yourself a favor and buy a V8R front subframe. Makes exhaust routing SO MUCH EASIER. Really helped our build in December, since they had a black Friday deal, and I think we got ours for around $600. Doesn't hurt to ask if and when they'll go on sale again.

I usually suggest moving the right motor mount as well, but since your exhaust is pointing straight back from the rearish of the engine, instead of straight down from the middle like N/A cars, it's probably easier to just route it by the slave cylinder and heat shield the crap out of it. Run your down pipe first, then decide if a banjo, 90*, or 45* fitting on the slave will work best, I believe it's currently going to stick right into the are you're planning on routing the exhaust.

Awesome, will be following this closely.

Yes please!!!

Well this is exciting.

What, when did this happen? Cool build, can't wait to see it running.
960's running well :bigtu:

Subbing bc this sounds cool as heck and i may/may not want to replicate it when my 1.6 throws bananas someday

In fairness, it hasn't happened yet. It's just a pile of parts in my garage :D

Subscribed. Going the same route end of the year.

another good swap thread to keep up with!

Please post how you handle exhaust! My major concern about this swap is the difficulty of routing a suitable exhaust system without having to literally move everything around (fuel lines, slave, etc.). I think this swap could still be cost effective even with the cost of a new subframe but it definitely increases complexity...

My current plan is to keep the stock subframe and go down and back on the passenger side and cross over under the transmission. I'm making extra space by replacing the clutch line with a stainless flexible line with 90 degree banjos. I'm learning to TIG weld to do the exhaust myself, and am hoping to learn some things that will help other folks going this route. I agree with you - the exhaust is my biggest concern at the moment.

I'm almost done prepping the engine for the install, which will kick off this weekend. I also returned my ms3x for a ms3pro evo and am having the leads made up into a harness to save me some trouble.

I also decided that I'll need to do my down pipe and exhaust myself so I got some welding gear and taught myself to tig weld. I built a welding cart to practice my as yet not quite mad skillz.

I have tig wants.

Nice, that's something I've always wanted to do!

Not too bad, looks like that cart was a good lesson.

Okay, the engine is prepped as far as I can get it without having the BP pulled. Pictures for anyone who is doing this themselves. There are a few finicky bits, but the LNF turbo bolts up to the LE5 beautifully. I just had to tap a drain line into a spot on the block that looks absolutely designed for the purpose. I especially love how compact everything is. That's the kind of fitment you can only really get with OEM parts, all cast and heat shielded and designed to go 200k miles.

https://cimg9.ibsrv.net/gimg/www.mia...b134f121e5.jpgTo delete PS and AC, use the belt off a '05 Cavalier without AC (IIRC) and you are good to go. Everything else stays the same.
https://cimg3.ibsrv.net/gimg/www.mia...e54787f9d2.jpg70mm eBay special throttle body. Only took a little porting of the LE5 intake manifold, and a bit of bolt hole enlarging on the TB to make it fit. This allows me to keep the cable actuated throttle for ease of install and MS tuning.
https://cimg5.ibsrv.net/gimg/www.mia...64313c8b88.jpgNext up is to bolt on the transmission adapter plate, modified miata flywheel, and FM clutch. I may need a clutch upgrade down the line, but at that point I'd probably need a beefier transmission anyway.
https://cimg7.ibsrv.net/gimg/www.mia...c33da10114.jpgThe turbo comes with a stock electronic boost control valve
https://cimg8.ibsrv.net/gimg/www.mia...2d493cbfd1.jpgFitment on the starter motor is insanely tight. I can probably fit a single sheet of paper, just barely. When it heats up it will probably touch and make some annoying sounds. I don't think it will be catastrophic though, but I'm all ears if anyone thinks it's worth grinding away some space on the motor mounts.
https://cimg9.ibsrv.net/gimg/www.mia...f26cd2a05b.jpgOil drain. I had to cut away some space on the motor mounts, but it's a non-critical spot. The drain taps very nicely into the block.
https://cimg0.ibsrv.net/gimg/www.mia...97d512dfcd.jpgThis is the thermostat housing from an LNF, which makes space for the turbo, plus the ecotecmiata spacers to make space for the transmission.
https://cimg2.ibsrv.net/gimg/www.mia...a91906e027.jpgNice an compact. Should fit just fine. I'm attempting to do a 3.5 inch to 3 inch downpipe, since the turbo outlet is 3.5 inches.

I really enjoy that little clip on the wastegate actuator nuts.

The things those GM engineers think of!

^ Is that starter stud going to get a little "sparky"? That'll ruin your day.

I figure all the metal on the starter is grounded to the chassis except the positive terminal, which has some space around it... ¯\_(ツ)_/¯

isn't this little snail made by borg?

Indeed! A well-engineered quick spooling little snail, capable of several horsepowers.

More starter pics:

https://cimg3.ibsrv.net/gimg/www.mia...205f4ce663.jpgPositive terminal is in open air
https://cimg4.ibsrv.net/gimg/www.mia...29c038ba10.jpgthe bolt that's likely to touch connects to metal that connects to the block

Sorry, pic made it look way close. Others show way space. Carry on... nice!

You can always be extra safe and put a rubber boot/isolator on it

I'm very eager to see your downpipe routing.

That makes two of us!

Start saving for that V8R subframe...

The starter won't make annoying noises, if it hits the motor mount, they all move together. I doubt they'll be much vibration on a beefy starter like that. At least ours didn't in 20min of testing before the oil pan cracked.

My swap is going to be slightly delayed while I figure out whether I can manage some inspection related challenges or just bail and keep the car as track only for a while.

But anyway, the TB I'm using doesn't have an IAC. I'm eyeing the early VW valve for its self-containedness and simplicity. Any other suggestions?

This is the VW valve:
https://cimg8.ibsrv.net/gimg/www.mia...a0edf7ca85.jpg
Two wires. two holes. Easy.

And this is another type:
https://cimg5.ibsrv.net/gimg/www.mia...9d7f8eee01.jpgOEM replacement part on a Ferrari, so it must be fast.

You can make a plate to do this with the miata valve.

https://www.miataturbo.net/bellengineering-miata-accessories-31/begi-bell-engineering-groups-terrible-intake-manifold-87081/#post1294307

That's pretty cool! I'll do that. Saves me from a) buying anything and b) figuring out something new.

Very little progress. I had an unexpected curve ball in the shape of an off-cycle smog requirement. I did a sketchy smog last year, and a whole bunch of sketchy smog shops we're raided. Now I have to take it to a referee. As in, the top of the smog system food chain. They scrutinized very intensely and even after a full return to stock the found some things to take issue with. I'm working through all that to get the stamp of approval before I pull the engine. Yay California...

Timeline update - after two tries I made it through the smog referee and can now drive my powerless car. I'm up for my next smog in December, so it doesn't make sense to do anything major like an engine swap right now, and I foolishly sold all my go fast BP bits. Between now and December I'm going to try to knock out as many little things as I can. And since I can't do any major work on the car right now, I decided to spend my time and money on a lift.
https://cimg1.ibsrv.net/gimg/www.mia...39240edba5.jpg

I got a low miles steering rack and depowered it. I figured that would make it easier to do the depower and de-AC in one go since I need my car for transportation a couple times a week. I couldn't find any good guidance on welding the pinion so I just went for it. I ran my TIG at 165 amps and used 3/32 filler rod. I laid it down in 3 beads and did a second pass over 1/3 that didn't penetrate well enough. I also dipped the bearings in water after each bead so they didn't get messed up. If I did it again I'd drop the amperage to 150 so I could go slower and use 1/16 rod for a finer final bead. Still, came out well enough that I'll trust my life to it...
https://cimg0.ibsrv.net/gimg/www.mia...d755c77385.jpg

So I've decided that my life wouldn't be complete if I simply put all this together and then was transmission-limited in terms of power. So I'm going the AR5 route. It also leaves way more room for the exhaust since it doesn't have a clutch fork.
A brand new AR5 transmission for a Solstice is just $600 (plus $300 shipping), which makes it a pretty attractive option.
Clutch choices are pretty limited, as in there are two options. In reading Solstice forums, it seems that people have had poor experiences with SPEC clutches. Or one guy said he did and it became legend. Either way, no rave reviews and some bad reviews. So the only other option is DDM, which seems a pretty good option other than the fact it's $1100 for the cluch/flywheel combo.
Ecotec Miata has a coming soon AR5 install kit that includes everything but the drive shaft, which I'll get custom made.
All that together, and I should be good for ~375whp/400wtq if the internet forumz are to be believed. Anything remotely close to that and I'll be a happy camper.

I've still got to wait until December before I can pull the engine out, but I should be able to tiptoe my way closer by piecing all this stuff together.

Swap kits are available now ;)

Yes, insofaras I bought one. But it doesn't have a drive shaft and it's not on their site. But yeah, I wouldn't attempt this without a kit.

Buy a stock clutch and take it to a local clutch rebuilder to have the pressure plate resprung stronger. That's a good solution.

That's an interesting idea. The stock clutch can reportedly hold about 250 ft-lbs, so I'd want to achieve about 50% more holding power. Is there a parallel for Miatas? If that was a good, affordable option, why wouldn't it be a go-to for people running low boost turbo Miatas?

It would be if they thought of it or knew about a local clutch shop. Most people just buy them from the store because they are unaware such shops exist. Local clutch shops can reline your clutch disc, respring it if it has springs, and rebuild your pressure plate and respring it to hold a higher torque. I really enjoyed my ACT clutch that used a gently engaging stockish clutch material paired with a really strong pressure plate. It held a lot of torque. Adding 50% more clamping Force does not add 50% more clutch effort, either. It depends upon the lever ratio of the diaphragm arms.

We have clutches and pressure plates rebuilt locally all the time for work. And the shop we use does a lot of race car clutches as well as heavy truck.

The only real progress to report is that I've properly depowered my steering rack and ripped out the AC, since I won't be keeping those post-swap. I love the feel of the depowered rack, I'm not sure why I waited this long.

I also got a pile more parts. I bit the bullet and bought a clutch and flywheel kit from DDM. Since I would have had to buy a flywheel either way, and this setup uses a different flywheel setup, I figured I'd just spend the money and do it all at once. It's rated to 450ft-lbs, so it should serve my purposes. I also got a new AR5 transmission. I waited for a 15% off sale on eBay and picked it up for $500 (plus $300 for shipping :-O ). The internet says these transmissions feel kind of crappy, but are much improved with this short shift kit so I got one of those from DDM as well.

https://cimg3.ibsrv.net/gimg/www.mia...6ff580fdc4.jpg

Still twiddling my thumbs until I can get the car smogged in December. I'll be running with the stock engine at M@WRLS, going slow, and driving poorly.

Better than sitting on stands waiting for things.

Alright, I'm starting to work on this again. My goal is to have it running by January 1 (no year specified).

What I'm working on now is the drive shaft. The Solstice uses an odd type output shaft flange with no known off-the-shelf part that bolts up to it.

https://cimg9.ibsrv.net/gimg/www.mia...9b4a13366a.jpg


That leaves me with two main options:
1. use an adapter, such as the one from Drift Motion
2. Remove the flange entirely and find a slip yoke that fits

I'm inclined towards option 2, not only because that adapter will cost $140, but also the adapter option leaves no room for play in the drive shaft. I'd have to get the measurements exactly right, it would leave less room for adjustment in the diff and engine/transmission angle, and I feel like it would put unnecessary stress on the transmission and diff. All of those could be address by adding a slip join to the driveshaft, but that again adds cost.

I didn't have a puller on hand so I whipped one up with stuff I had laying around.

https://cimg6.ibsrv.net/gimg/www.mia...a2a29fe520.jpg

And with the flange off, I can see that it's missing an inch or so of spline, which means if I went with the yoke option, I could have as much as an inch of play without losing strength over the flange option.

https://cimg3.ibsrv.net/gimg/www.mia...e2e69eb4b4.jpg

My next step is to try and find a yoke that has the same outer diameter so that the seals that are already in place will continue to work. It appears to be a standard size with a 1.5 inch diameter.

An alternative option would be to essentially use this part as a yoke by not bolting it in place and fixing it to the driveshaft. I'll save that as a last resort as I imagine it won't be as strong of an interface if it's backed off even a little from being fully pushed in.

Does anyone happen to know if there is an off-the-shelf 1350 series flange for a driveshaft that bolts to the stock diff?

The standard yoke that fits the spline has a 1.5-inch outer diameter rather than 1.575 that the Solstice flange has. I found a seal from a 1984 Toyota Pickup which has the proper OD, and the ID is 1.495. It fits both the transmission and the new yoke, although creates a little resistance when turning. I imagine that resistance will go away when the transmission is full of fluid. Can someone correct me if I'm wrong there?

So, this kinda concerns me. Could you possibly take the yoke to have someone machine a few thosandths off to fit the seal. It would need to be polished too. Perhaps you can fill it with oil and see if it spins more freely, but I doubt it will.
Sorry I don't have anything more positive to suggest.

I tested it with oil, and it's still got some resistance. I think I need to find a different seal, or failing that, take the yoke down as you suggest.

Those lip seals are pretty common. I will have a look around and see if I can come up with one for you as well. I actually used to have one of those Toyota trucks, was my old work truck.

Okay, I'm bailing on the "turn the output shaft and a yoke into a slip joint" plan. The AR5 takes a metric sized seal, so there is literally no seal that has the right metric OD and also the right imperial ID to fit a 27 spline slip yoke. I could have it machined down to fit a metric seal, but there are so many ways in which this plan is far-fetched that I'm going to skip the innovation attempt, and go with a proven method.

Instead, I picked up this Drift Motion flange adapter. It adapts the AR5 output flange to mate with a standard u-bolt flange. From there ordering a driveshaft will be easy.

Today I got the engine and transmission mated together, and dropped them in for a test fit and to measure for the driveshaft. It fits!

Awesome result Nigel!

Driving by wrls 2019? :D

Most definitely. I'll be set up to do rides :skid: