AWD Twin Engine Fiesta

[PapaJim13]

Hi All,

I've been recently digging through AWD swap ideas from using stock ford parts like the Ecosport and the Focus RS to stuffing an LS attached to a 4L80, BW4472, and corvette rear end to achieve a high hp AWD setup. I've seen videos of twin engine Hondas and I'm wondering about that process. I drive a 2013 Fiesta (so not ST) but I know there are very knowledgeable folks here. I know the platforms are almost identical so physically, it should fit the same ish, just no turbo. I also want to keep my car as my daily driver after the swap, and 400 hp might be a bit much for me, two stock NA 1.6's pushing ~210 awhp seems enough.

My idea would be to take a rear or side damage fiesta, cut out the engine, drivetrain, subframe, entire front suspension, and shock towers. I'd just have to figure out to fit that drivetrain/suspension assembly into the car's rear end. I'm assuming the grinder and welder will both be my best friends if I go through with this idea. Physically fitting it I don't think will be the issue as long as everything is lined up correctly. The rear seat area is much larger than under the hood, and since the suspension will maintain the correct geometry, I think it would fit in nicely from the bottom of the car. Obviously this drivetrain/suspension assembly will need slimmed down and strengthened before it can go into the car as a one piece unit. I was thinking I would keep the stock ECU from the salvage car and just run 2 ECUs completely separated from each other. My plan would be to leave the front end alone, keeping regular vehicle functions. and just mess with the rear end. I feel like I may run into issues with running the rear motor so I'd want to either trick it into running correctly or hook up only the required sensors so it has enough data to run off of.

A couple of things will also need to be addressed such as keeping those knuckles straight and retaining the stock rear camber as well as adjustability for alignments. I'll have to move the gas tank somewhere else. (trunk area?), I'll need to create two custom exhausts. I'm sure I'll run into heaps of problems.

I have a few questions before I even think about starting this as well:
Will front suspension work in the rear if I get custom springs to match the new weight balance?
How exactly do wheel speed sensors send data to the ECU?
Could I split the signal from one wheel speed sensor, or sensors of any kind to work as inputs for both ECUs? (If not I could figure out how to add a second wheel speed sensor to each knuckle.)
How many computer modules are needed for an engine and trans to work on it's own?
What sensors are required to run the engine correctly?
Since ABS is it's own system, would I have any problems with that?

If anyone has experience with anything similar to this at all, what kind of issues did you see? What future problems should I expect to solve?

 

[dhminer]

Are you doing all the fabrication yourself?

 

[PapaJim13]

Are you doing all the fabrication yourself?

I'd love to. I have access to a shop with the majority of tools needed. I know I'll need practice but I love learning and love building more.

 

[WannabeST]

Your ability to accomplish this is probably better than mine. I think this route would be easier than the other option you were suggesting.
This setup would only require fab work in the rear as opposed to front, rear and middle in your other setup.
Things I would ask myself If I was going this route;
Do you think all this time and effort spent on a base model engine is worth it? Why not an ST drivetrain?
Daily driving a car with 2 engines sounds very not daily able, personally. but it would be awesome if you did.
The first thing I would address is making the front drivetrain have no relation to the rear end, so some sort of exhaust solution would be 1st on the list, could do a side exit or a temporary turn down and maybe later tie both exhaust together? not sure how that might sound, routing the front engines exhaust around the rear engine would be hard to.
I would see what wiring is in the rear and maybe relocate, re route or heat shield, im no electrician, but I'm sure some of those wires were not made to be next to a running engine and hot exhaust.
I would strongly suggest a fuel cell, or at least a lot of heat shielding, the gas tank is currently very far from heat and im not sure how well that would hold up to a whole drive train wort of heat next to it.
You will at least need a fuel pump that is 2x as strong as oem (not sure how strong oem is) or 2 separate pumps which is easy in a fuel cell
I think your best route to getting the engine in the rear is to find a fiesta that was rear ended, this way you can chop off the whole front end (firewall to the front) you could remove body panels, and etc. This would make suspension geometry a lot easier to solve since you could just match control arm and shock angles to factory. would require lots of trimming but will work well.
I would suggest doing all the fab work to get the engine physically in the car first. You are going to be putting A LOT of weight on the rear and a whole new rear suspension design. you may need to get the car weighed and have a coilover company send you some custom valved coilovers because the car is going to behave vastly different. Once you get the suspension figured out and fully fabbed in the rest should be simple;
for one, you will need a firewall between you and the rear engine, it will get very hot in there without it. and will be massively unsafe without a firewall.
next how are you going to cool the rear engine? long hose routing to the front? if so you will need a massive radiator but this may result in different coolant temps from front to rear engine.
or you could do a rear mounted radiator which will require some sort of custom hatch ducting for heat venting, this may also be a challenge due to the exhaust routing under it
the exhaust could run open header if you are not concerned about volume of the car. if you want it quiet, the packaging will pose difficult
The next problem would be getting air to your intake, you will probably need a roof scoop or maybe a duct from one of the side windows, or a molded duct in to the door.
If you are throwing in 2 automatic cars, shifting should not be an issue, but if you want 2 manual drivetrains you will need to figure out a shifter solution, im sure being cables it is easier than a physical linkage but this still poses a problem.
I would strongly suggest some sort of emergency individual engine shutoff, if one start bogging down I imagine that could potentially damage the other engine in some way.
Same for the transmission, something to be able to shut one off in case of failure. I imagine if there would be a failure anywhere it is in the rear.

This sounds epic tho, lot of honda people chop off a whole front end and stuff it in the rear and then just relocate the gas tank up front. I can definetly see this being doable.
I think this is way more do able than the other awd method. Share your progress with us, I would love to see this be done.

 

[PapaJim13]

Your ability to accomplish this is probably better than mine. I think this route would be easier than the other option you were suggesting....

Why do you think it won't be dailyable? From the driver's seat forward it'll look the exact same LOL

I want to spend the time and effort on this car as it is my first car and I love it for sentimental reasons as well as being a blast to drive. It is also much cheaper than STs. Wrecked vehicles and parts are cheap and available for base model fiestas. Plus the 6 speed in the ST would not work mated to the existing 5 speed. I could buy a wrecked ST for the rear engine, and an other st engine to "drop in" to my car. Might be more than drop in honestly, I've heard the wiring harnesses are different.

I'll just cut the exhaust off under the car until I'm ready to run duals or dual side exits or something, it will look cool once finished i promise.

I don't think that moving wires from under the rear seat or under the car will be that difficult at all. It will all be apart and I'll have plenty of opportunity to run the wires anywhere that fits best.

A fuel cell is for sure going in. Not sure on the exact shape, size, or location yet. And to keep the cost down I'm going to use the stock fuel pumps. I would like to use as many OEM parts as possible, as it will be a daily driver and I want parts to be available. Plus with no possible power mods, there's no point for a stronger fuel pump.

I like the idea of the custom valved coilovers. I don't know much about performance shocks and their internal workings so it'll be fun to learn.

Cooling will be a bit of an issue. Hoping that the NA 1.6 produces less heat than its turbo counterpart. Is there a way to mount a massive radiator in the front and have both engines mix coolant? Seems like a bad idea if one blows but it would be easier to regulate the temperature plus the benefit of having a front facing radiator catching the majority of the airflow. I'm not super worried about these engines taking a shit though, they seem like they'll run long enough. I'd imagine there are plenty of radiators out there capable of cooling 2 small engines.

I feel like a custom exhaust will be required to sound good to begin with, and I'd like to not blow out my already damaged ears with an open header.

There will be a way to operate the front and rear clutch apart from each other if needed. This will be paired with a system to allow the rear transmission to shift to neutral regardless of the front trans gear position. Not sure how I'm going to do this exactly but the cable linkages should make it easier.

Currently looking for a 2011-2013 Fiesta with a 5-speed, <120K miles, and rear or side damage to pull parts from.

 

[WannabeST]

Why do you think it won't be dailyable? From the driver's seat forward it'll look the exact same LOL

Maybe I'm just projecting and saying " I won't daily this" in my own head.
I guess I just wouldn't daily it mostly for the sake of other people hitting it and ruining the car.
I have been rear ended 4x here in so cal and one side swipe (I was never at fault) and have been in the car 3x while someone else was driving and got hit. This is the main reason I don't daily my mustang.

The biggest problem I see is visibility, you will most likely be losing rear view mirror visibility, this can be easily solved with a rear live camera, or some sort plexiglass if you find a fire resistant one. but I imagine the heat may cause some sort of fog, or even just general light engine smoke.

For your radiator solution, One of my friends bought an old used nascar radiator on ebay for like $150 for his endurance honda civic and it works flawlessly. The fiesta may be a little more crammed for this but if you can throw an engine and drivetrain in the back, I'm sure a big radiator up front is not a problem. Also hot rod shops typically make or sell obscure sizes.

The biggest problem with a single radiator is that the rear engine will be running hotter than the front, because of the coolant taking longer to get to the radiator and it will slowly heat up by the time it gets back to the engine.
If the radiator is big enough, it may be enough to keep them both pretty cool. I think I would still look into venting the hatch even if you don't put a radiator back there. Your front engine can let some hot air out to under the car even if the top is sealed, the rear engine would need some sort of ability to get rid of heat, otherwise it would slowly heat soak.
Also, trying to bleed 2 coolant systems may potentially be an issue or very time consuming? I've never thought about how that might work. Maybe an additional electric water pump would help?

 

[WannabeST]

Currently looking for a 2011-2013 Fiesta with a 5-speed, <120K miles, and rear or side damage to pull parts from.

You can find these kinds of base model for $2-3.5k all the time here locally. I recently helped a friend buy one to be his daily. He paid $2.7k for an 80k mile 5spd, had some paint fading because it was left in the sun a lot but mechanically it is fine. I'm trying to convince him to track it with me lol.

 

[PapaJim13]

Maybe I'm just projecting and saying " I won't daily this" in my own head.
I guess I just wouldn't daily it mostly for the sake of other people hitting it and ruining the car.......

I get not wanting to daily it out of fear of other drivers but I feel like I'd be wasting my time if I didn't.

I figured I'd be able to make a fiberglass window in the firewall or just go search at a junkyard for a window panel that fits good ish then just fit it in. Maybe a pickup truck rear middle window. Can you cut tempered glass? I can run vents out of the small rear corner windows and more vents if needed. Cutting up my car isn't an issue lol. I could run some ram air vents into the rear hatch to push the hot air out of the window vents. Could do this in combination with electric fans for further venting.

I didn't think about bleeding the systems. Maybe I can work with valves to separate the cooling systems when needed? Or, two radiators would probably be easier to manage, still keeping the front unchanged. If I decided to have a large single forward radiator, an inline booster pump to help coolant flow to the rear would be a good idea.

I've been looking at car auctions and I've found some that have gone pretty cheap. Just had an issue with getting student loans for this year so I may need to push this back, or trade some stuff for a car.

 

[isis]

You’re going to have trouble keeping two engines cool in this chassis.

 

[dhminer]

I think you’ll spend more time and money doing this than you would to go buy an already AWD car with the same or more power. That said, there have been dozens of threads on this forum of people trying to build an AWD or RWD fiesta, none of which have panned out in any measurable way. I would love to see someone be victorious.

Like you, I have a sentimental attachment to my fist. Once my kid (or kids, god willing), is old enough to help, we’ll do something together like B or K series swap it but that’s 2036 at the earliest when I no longer have to pass emissions testing.

 

[Dpro]

I see this as a project in futility. It will cost one way more than it will ever be worth if and when it ever gets finished. If you want to do it go ahead be aware of the cost vs value factor . If you can accept you are going to pour somewhere between 30-40k in it is my guess go right ahead. You could buy several nice AWD hot hatch’s in that price range already though. Car projects can get very expensive fast. Good luck none the less.

 

[PapaJim13]

I think you’ll spend more time and money doing this than you would to go buy an already AWD car with the same or more power. That said, there have been dozens of threads on this forum of people trying to build an AWD or RWD fiesta, none of which have panned out in any measurable way. I would love to see someone be victorious.

Like you, I have a sentimental attachment to my fist. Once my kid (or kids, god willing), is old enough to help, we’ll do something together like B or K series swap it but that’s 2036 at the earliest when I no longer have to pass emissions testing.

I quite understand I’ll be adding slim to none extra value to my car but I don’t plan on selling it so idc. But yeah the wow factor of having an awd fiesta would be pretty cool too. I love this car and I want to make it better.

 

[PapaJim13]

I see this as a project in futility. It will cost one way more than it will ever be worth if and when it ever gets finished. If you want to do it go ahead be aware of the cost vs value factor . If you can accept you are going to pour somewhere between 30-40k in it is my guess go right ahead. You could buy several nice AWD hot hatch’s in that price range already though. Car projects can get very expensive fast. Good luck none the less.

I’m young and making my own money so ofc I don’t care about the potential cost I only see the finish line. Who knows maybe I’ll even finish it.

I appreciate the luck

 

[TyphoonFiST]

How much Skrilla $$$ you got? This is a pipe dreams for Normal joes. Good luck!

 

[sonicmn]

@PapaJim13

This is cool! It sounds like a hell of a lot of work but a really neat idea if ya get around to completing it.

I remember watching a video quite a while ago about a similar idea in a Mini! That always made me think it would be fun to do. Good luck with your project if ya go down the rabbit hole!

View: https://www.youtube.com/watch?v=7YL7pURth3o

 

[PapaJim13]

Very cool, gives me hope. Looks like he ran into many of the same problems I will. I wonder how he made the shift linkages to work together but also independently.

 

[PapaJim13]

Is 4 wheel steering more trouble than it's worth? Could be a cool concept, something to add on once it's complete. Not sure the performance benefits either.