Ford 3.5L Ecoboost and Transaxle

[Tom Veale]

I've looked but have only found the usual Chevrolet powered GTMs here on the forum. The 3.5L Ford twin turbo "EcoBoost" driveline that was used in the Flex and Taurus SHO cars is a power plant of personal interest to me. The Flex and SHO both were "all wheel drive" packages, so the transaxle would have to be changed with some sort of blanking plate for the "rear" drive. I keep thinking that at 73 I might have one more FFR car project to do. Of course, at 73 I guess I should try to get in and out of a GTM first!

I know it's state of tune for the highway is 'only' about 375 Hp, but I'm not planning on any activity other than street or maybe some club track time. At around 2500lbs for the finished car, it seems to me the 375Hp should move the car along at a reasonable pace. The paddle shift automatic would also be what I have in mind for the transmission.

Any constructive thoughts would be appreciated.

Best wishes,
Tom

[ohmygosuness]

Hi Tom. I believe with enough money and determination (mostly money), you can do whatever your heart desires.
(Also some cutting and welding)

But on a serious note, if a stock twin-turbo ford ecoboost only makes 375hp, why not just stick with the LS platform which the GTM was designed for? It saves the hassles of modifying the chassis and it makes around the same power. If too much low-end torque on a relatively light car is your main concern, slap a single turbo on it and call it a day

[beeman]

I'm guessing the engine bay is too narrow for a transverse gearbox, you're probably going to have to go longitudinal. Kennedy Engineering Products site says they make a 3.5 Ecoboost adapter. KEP typically adapts to Porsche /Audi /VW with lots of gearbox options. I've been happy with their products in the past, about $1k for adapter and flywheel, find your own clutch.

That being said, you'll have much fewer headaches with an LS. Much less plumbing, much less heat, easier tuning and engine management, more reliability, less maintenance, probably equivalent weight all-in. 3.5 Ecoboost doesn't have more exotic sound either.

[Alan_C]

If you go with the Ecoboost, in the end you will have a less desirable and less valuable car. Unique, yes, but uniqueness alone does not make it better.
As said, just staying with the LS makes the most sense as that engine family is what the car was designed for. Also there are almost endless performance parts for the SBC, so a cheaper way to go too.

[beeman]

I sat in a FFR GTM demo car at the London Cobra Show in Ohio before I bought my kit, it was awful getting in and out so I pretty much trashed the idea of building one. Then I was able to sit in another one and it was much more pleasant. It's all about how you build the car and what seats you use. I'm 6'3", 45 years old so I can't comment on the age component, although my dad would certainly struggle, he's 75.

[beeman]

If you go with the Ecoboost, in the end you will have a less desirable and less valuable car. Unique, yes, but uniqueness alone does not make it better.
As said, just staying with the LS makes the most sense as that engine family is what the car was designed for. Also there are almost endless performance parts for the SBC, so a cheaper way to go too.

I think if he did it right, it could be more desirable. Something different, and related to a Ford GT or Noble/Rossion.

[ohmygosuness]

I think if he did it right, it could be more desirable. Something different, and related to a Ford GT or Noble/Rossion.

It would be different, for sure. But will be more desirable with the GT500 engine instead of a Ford ecoboost. Then just pair that up with Ricardo's transaxle.

[rthomas98]

The current GT does use a 3.5L V6 currently. Superformance did make a GT40 with the 3.5L and used a Quaife 5 speed transaxle. These are not cheap. Below is article on it. Might help you out or might not. But some food for thought is all.

https://kahnmedia.com/superformance-...018-sema-show/

[ohmygosuness]

Oh I was talking about the gt500 shelby.

By the way, I spoke with Ian from mendeola transaxle few months ago. He said he doesn't browse here as much as before due to the GTM being discontinued, but he did mentioned to me that he's been getting a lot orders from people trying to build gt40 replicas using the mendeola transaxle. Maybe you should give him a call. But the lead time is crazy. I've been waiting almost 2 years for mine, still hasn't arrived.

[Tom Veale]

Thank you all for the insightful comments. I have been watching the Riley IMSA cars with Ford's 3.5L engines for a number of years and that's what got me thinking about this.
I can see that the standard transaxle (transverse) would be a major stumbling block. Going back to "in line" gets rid of the original idea, so yes, it would make sense to select a gearbox/transaxle first, no matter what the power plant.

Also, I didn't realize the GTM was in the "cancelled" mode. I guess I missed that announcement! I had a good time on the Hot Rod Power Tour in 2022 (in #007 HR) and had been thinking about building more of a grand tourer. Maybe this has turned out to be just a half baked idea.

Thanks again for all the thoughts,
Tom Veale

[VRaptor SpeedWorks, LLC]

I worked with a customer who put a 3.5 Ecoboost in a GTM. From my conversations with him, the electronics are the biggest headache. Ford does not offer a "crate engine" option for the Ecoboost last I checked....and after months and months of trying to get something to work, I'm not sure if he ever got the engine running. He had direct connections to people within Ford to try to create "work-arounds" to get the ECU to run the engine, but not sure it ever panned out. In short, unless you have every electronic module and sensor and emissions control completely intact from whatever the donor vehicle was, the engine won't run.

Personally, I really like the idea......I'd even happily settle for the 2.7 Ecoboost engine in a GTM. That's what I have in my F150. I went from a 7.3L Powerstroke to pull my 20' enclosed car trailer to the 2.7 Ecoboost and I can tell you that there is absolutely no comparison. The 2.7 runs circles around the 7.3 as far as towing. Not even a close contest.

[crash]

If you get to the point that you decide to go ahead with this 3.5 idea, I have a guy that was the first in the country to make the Eco Boost run in a race trim format after other tuners failed at that endeavor. That was about 10-12 years ago. He has done many at this point. He is not cheap and it means going to all aftermarket electronics, but he can do it for you. Turbo control, direct injection, all that new high tech stuff is not the easiest to control, but he can do it.

Personally, I don't understand moving away from the LS platform, but to each his own.

[Ajzride]

I worked with a guy who was putting a 3.5 in a Superlite GT-R. You will want an Ecoboost from an F150, not from the Expedition or Taurus. The F150 engines are oriented same as an LS. He used a transmission from an Audi R8 / Lambo with an adapter plate from Kennedy. If you use Gen 1 Ecoboost engine there is a Ford Performance Control pack out there, I believe they are discontinued but you can still find them. If you use a Gen 2 Ecoboost, your best bet is a 3rd party ECU which can handle the dual injectors and variable cams. I believe he used a LifeRacing F90RX ECU with a custom wiring harness.