[Zoranan]

Okay guys, I'm doing some very preliminary research on super coupe swaps. Trust me I've tried searching (for days now) both on this site and on v6power.net. I've real a lot and some things are confusing me

for the record, my car is a 1998 v6, 5 speed

I've found the write-ups on how to put the m90 blower onto your single port v6 engine and it seems like it would be cheaper to buy the entire super coupe engine.

If I bought a complete SC engine wouldn't it be easier to just drop the whole SC engine into my stang? Thats how I thought you were supposed to do the swap until I started reading all these threads about Frankenstein-ing the SC engine with your stock engine. I thought the SC engine was basically the same engine as the single port 3.8

Now I'm trying to learn more about engines. I understand the basic components and am pretty mechanically inclined. I've never done an engine rebuild or anything but I've gone as far as swapping a DOHC cylinder head (ford probe 2.0). If you think this swap will be too difficult for someone like me, please let me know.

Okay so here are my questions...

1. Can I buy a working super coupe engine and swap it into my car? (with a little fab work)
2. If I swap the entire engine... do I need to do anything with my transmission or will that all bolt up as well?
3. I read somewhere that only the 94 and 95 super coupe had forged rods and pistons... is this the case?

I'm looking for some direction. I originally planned on making this a project that I could dump money into over time, and I was thinking about finding a new edge 3.8, forging the bottom end, and putting that engine into my car so I could add a pro-charger or even an m112. It may sound like I'm just dreaming. I kind of am at this point (since I dont have anything properly planned yet) but I do have the resources to do this over time

 

[b1lk1]

Best power adder for a single port V6 is a turbo, hands down. S/C engines make decent power but the supercharger is the limiting factor as far as air flow.

 

[wmburns]

Just wondering about what are your thoughts for two questions..........

Assuming that you are able to install the supercoupe motor between the rails and bolt it to your existing transmission (it will bolt up), what are your plans for engine management? IE, HOW do you plan on interfacing the supercoupe motor to the 98 PCM and sensors?

Why aren't you considering a bolt on kit designed for your car?

FWIIW, are you aware that the supercoupe motor was designed during the days of a speed density PCM strategy? Where as the 98 PCM is built around a mass airflow strategy? So at the very least, modification of the PCM tune is needed.

Since you asked for an option........

This is a bad idea. It's a TON of work and depending upon your experience might never work. Whereas purchasing a model year specific engineered super charger kit will likely:

• Be "do-able" in a weekend
• Will make more HP
• Will pass inspection
• will be less work
• After EVERYTHING is said and done, likely will be cheaper.
• Will be easier to find parts for
• Has all of the engineering done for you. Ovoids you having to become an engineer

Ask yourself this question. would you rather be driving your "project" or looking at it setting in the garage?

 

[Zoranan]

I was told on another thread that the super-coupe engine was a direct swap and it peaked my curiosity a lot. I was also told the 98 pcm could be tuned to work fine. Did a lot of research on it and then ran into confusion, so I'm glad to have your input. Because you're exactly right, I'm no engineer. If it would cost close to the same, if not more for me to attempt that job, I'd definitely rather not attempt it haha.

 

[metalman302]

1. This is exactly what I said already, it will work, many people have done this over the years. Yes some minor things will need to be adapted but the blocks, heads, sensors, everything are basically the same.

2. Already answered in the other thread as well, they're both essentially the same blocks which means the bellhousing pattern is the exact same. (FYI the 3.8, 4.2, 5.0, 5.8 all share the "windsor" pattern)

3. Not positive but I believe all SC rods are forged but the 94 95 were beefier and stronger. From what I remember all SCs had forged crank and pistons.


Do some searching over at SCCOA.com.

 

[Ryan S]

I'm not sure exactly how the SC engine would connect up to a 4R70W, but the 4R70W would be stronger than the AOD or AODE.

I would personally just swap over the entire engine, instead of the supercharger, because you'd still want to do the intercooler, as well. But know that it will be a fairly large amount of work, but some people have done it. The SC engines were incredibly well designed, and despite some longevity flaws (head gasket problems, voodoo in the system with boost leaks, etc), they still are. But the sands of time haven't been as kind--when they need work (and many of them do, since the newest of the breed is now 20 years old), they're expensive and time consuming to work on, mainly because there is so much technology, tubing and things like that, that are crammed in there. Changing spark plugs will take you 5-8 hours. Some guys claim that they can do it quicker than that, but they've worked on several of those engines......it took me about 6 or so hours, some busted knuckles/ scraped arms and going under the car to change plugs. On the driver's side, there's just no way to change at least two of that side's plugs, without having to go underneath the car. Some take off the intercooler tubing, but I didn't find that made it any easier at all.

The 94/95 engines have a revised Eaton M90, in conjunction with 36 lb injectors (89-93's have 30 lb injectors), and the revised Eaton creates less heat and less stress--with more power--as it has a more efficient design. They make 230 hp/ 330 torque, as opposed to the 89-93's 210 hp/ 315 torque.

You can also run an 89-93 pulley on the 94/95 blower, and it will overdrive it a little more. So the 94/95 can be overdriven more and will still put out less heat than the earlier models.

The SC's had forged crank and piston rods and reinforced hyper pistons. The stock pistons are still more than adequate for some bolt ons and some increased overdrive on the supercharger pulley.

 

[metalman302]

If it was a 4R70W from a 3.8 Mustang, it would bolt right up to a SC block since they're both 3.8s with the windsor pattern. A 4R70w from a modular V8 obviously wouldnt work since it would have the modular bellhousing pattern.

Irrelevant anyways since he said he has a T5.

 

[b1lk1]

Supercoupe engine = OBD I

1998 V6 = OBD II

PCM will not work and you'll need the entire wiring harness/pcm from the supercoupe. Then you will need to have wiring diagrams from both cars to attempt to mate the S/C engine harness with the 98 body harness.

You are mistaking the fact that mechanically everything bolts right in but the computer systems are vastly different and that will need to be adressed for it to ever run.

Turbo would be so much better, not sure why people bother with these swaps, the M90 is very limiting once you start craving more power.

 

[6stang02]

+1 to b1lk1. You will have a very troubling time trying to pass your car if you have emissions.

 

[Ryan S]

Overall, I'd have to say that it's not worth the time and money to do a SC swap, just because of the.....time and money. BLK1, I'd have to disagree with the engines not making power--they're not top end engines (many people struggle to get to 350 rwhp, and getting past 400 rwhp has eluded many), but they make lots of 0-60type of low end torque with just a simple 10 percent overdrive pulley swap. If you're pushing 15 psi, that's some serious low end. The real question is how long you want the head gaskets to last, though.

Ford had really discovered how much R&D was involved to design a roots styled blower engine that put out good power and could survive the rigors of daily driving (plus, winter driving). You wonder how many of the engines had got killed because of people routinely running 87 pump gas, even though it says "premium fuel only" on the gauges.

 

[b1lk1]

You get the same or better low end grunt much cheaper with a V8 as well making it even more less worth it. It's the M90 that is the big limiting factor, upgrading it is not easy as well.

Scroll style S/C is better, much more scalable and are nowhere near as limiting.

 

[Ryan S]

You get the same or better low end grunt much cheaper with a V8 as well making it even more less worth it. It's the M90 that is the big limiting factor, upgrading it is not easy as well.

Scroll style S/C is better, much more scalable and are nowhere near as limiting.

The 89-93's I'd agree with you, for the most part. Where we differ is that a revision 1 M90 from '94/95 SC's is a far better design with better rotors, less heat, and provides more boost with less psi. If you port it (which isn't that difficult to do), it's even more efficient. Those are all pretty easy bolt on things.

The main difficulty is sourcing a good enough engine that hasn't been thrashed, as well as the OBD1/ OBDII thing. That's where it really starts to get expensive, but if you're handy and can source a good engine for a good price, it could be well worth it. If one isn't handy and cannot find a decent engine in decent shape, it could be a constant money pit, however, and could be a bad idea.

Upgrading is easy--you just up the boost. 10 percent overdrive supercharger pulley (a 50 buck or so part, with maybe a half hour to an hour's worth of time) is an incredibly good bang for buck upgrade/ modification. For example, the guy in the video below claims that he has only a 10 percent overdrive pulley. That's a 5 second (my stopwatch says about 5.04) 0-60, and if you have the 'nads to go more overdrive with a jackshaft pulley, it will be even faster than that....in a nearly 4 thousand pound car.

Coupled with 36 lb injectors, bigger MAF/ plenum and throttle body, Moates Quarterhorse with tune, for $1000 or less (depending on what price/ deal you can get), you're probably going to be looking at 330-350 rear wheel torque.

https://www.youtube.com/watch?v=rQcYrlimOYQ

 

[b1lk1]

THat's way too much work for only 350ft/lbs of torque. What I'm talking about as far as limiting is that you won't see many M90 cars near/over 400HP. That's about the airflow limit. It's called diminishing returns. You hit a point that no matter how much you throw at it you're done.

That is why a turbo is a far better route. Turbos are scalable and can be replaced with larger units easy if you run out of breath. The single port motors respond very well to turbos and can match the split ports hp output if not better it. Fastest V6 car on this forum I've seen in my time is Shine1stang's and he had a 97 I believe with a single port pushing 600HP. No amount of money/time/effort put into a M90 will ever get you close to that.

 

[Ryan S]

Agreed on the horsepower--I've even mentioned that in the posts above about 400 horsepower being tough to meet. Also agreed on the breathing limit.

I disagree with your part about the power.....you overlook the fact that the M90 engines have a ridiculous amount of low end torque, which is stock at 315 ft lbs at 2600 rpm. It's all about where they make their power, not the end numbers. I wouldn't personally try to put too much effort into even cracking the 300 rwhp limit....260-275 is more achievable. If you're talking light to light 0-60 torque, you'll rarely find a quicker way to get there. Roots blowers have an immediate response that doesn't show up on a dyno sheet, where it needs to be felt to be appreciated. 1/4 mile races will see other cars catching up, but in a 0-60 race, you'll beat most of the competition. In the video above, time his 0-100--that's impressive, too. I keep on referring back to that video, because I would, of course, put a simple pulley on, but not without the proper upgrades first, so that the gaskets don't blow.

In regards to the rest of this thread, I thought more about it....the SC engine swaps into Mustangs, I think, more often than not, they don't get the engines fully dialed in and in tune and don't fully materialize. It could be the OBD1/ OBDII thing and hiccups in the A/F ratio or whatever, because the engine will pull timing. On YouTube, there's a "darkfirejosh" that had done the transplant, but I think his last video(s) were about needing to tune it and there doesn't appear to be any more info or DIY R&D. On top of that, I think that some of the transplants are expecting out of the box race styled numbers, but the SC engines were oriented more towards longevity and gas mileage and need some massaging to get them to reach their full potential.....a bigger/ more efficient intercooler helps, for example.

But the SC engines can be had for extremely cheap. You can get the engines for $500 or less (in varying condition......a very low mileage one may go for $750), and you have a forged bottom end already in there, and if you're handy on replacing head gaskets (just to make sure) and can do an engine swap, I doubt it would cost much more than $1000-$1500--including engine-- to drop in. Ask yourself where else you can get a supercharged engine and forged bottom end for that sort of deal.

Shine1stang built a full out race motor for a gazillion dollars, i'd bet. Even if he donated his own time on the build (which I bet he did), his forged parts/ pistons/ rods/ turbo/ intercooler/ piping/ wiring/ heads (his time is money), and transmission probably cost him what most people pay for a down payment on a house ($6000-$10,000). If one is going the all out race mode, that's great.....but the OP here was asking for something that would give him decent power, not something that he only uses in weekend racing.

The only reason i'd advise against the SC motors (explained in posts above) is that they're getting older and they become more of a risk. The better engines are usually still in well maintained SC's, and the junkyard ones tend to be the ones that are higher mileage and in need of a rebuild and are often better off avoided. The riskier examples could end up being very expensive in the end. I'd run the highest octane in one's area just to keep the heat/ detonation down. But if you know what to look for and could source a good one, you could make out like a bandit.

There's no real such thing as the "best build", either. Turbo'd, supercharged, etc.....it's all about what you're after and what power you want in the curve. Roush has a great writeup on the different types of blowers.

http://www.roushperformance.com/blog/2014/02/type-supercharger-roush-employ-mustang-f-150/

 

[metalman302]

Supercoupe engine = OBD I

1998 V6 = OBD II

PCM will not work and you'll need the entire wiring harness/pcm from the supercoupe. Then you will need to have wiring diagrams from both cars to attempt to mate the S/C engine harness with the 98 body harness.

Stang wiring works fine and so does the PCM with the proper tune. Plenty of people have done it over the years. Doesnt matter that the computers were I vs II; it's the basically the same engine. Kinda like how you can use an 96+ Explorer engine in a foxbody just fine with a few minor tweaks.

Turbo would be so much better, not sure why people bother with these swaps, the M90 is very limiting once you start craving more power.

A boosted V8 would be so much better than a V6 turbo, but at least a M90 V6 is way better than a stock NA split port V6.

I think you're underestimating how much the extra torque translates to speed. A couple of sc swap examples:

stock except OD pulley and exhaust
221rwhp
326rwtq
13.9 @ 102 on street tires thru an auto

4.2L and upgraded M90 MPX
367rwhp
425rwtq
11.7 @ 114

 

[Ryan S]

Some good points, Metalman.

There are times where I kind of wish that the SC engines had a higher torque peak. 1st gear has that "hold on for dear life" feel to it, and you can tell exactly when the engine/ computer is starting to pull timing in a 0-60 sort of run. It's almost too much torque at that low of an RPM level, because traction becomes a real issue. I'm wondering what 3.73's would feel like in that case, because with 3.27's, 1st gear in an automatic is already so short that I can only imagine what 3.73's--or 4.10's--would feel like, especially in a manual.

 

[Ryan S]

Also cool about this article and why it keeps on coming up:

1990 Thunderbird Super Coupe Modifications - Muscle Mustangs & Fast Fords

...is that it is dyno proof that a simple K&N filter drop in gives a legit 8 rwhp/ 22 rwtq gain. I paid $70 bucks for it (retail in Canada) and it is a mod you can actually feel, since it generates a ton of torque.....not sure what a full CAI would do (likely nothing or would just heat up the incoming air due to the metal tubing), but the stock airbox/ tube is more than adequate. That's just under $9 per rwhp, and a whopping $3.18 per rwtq. The deal gets even better if you can get the K&N used or cheaper than that. It gives an idea of how easy it is to create low end power in these engines.