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So you did end up using the focus aftermarket flywheel after turning it down...Thanks for sharing! I recall you mentioning about 1/4" difference, which would have to be removed to make it work, but do you recall what the thickness was of the flywheel remaining after you were done?

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-Justin

"Orville Wright did not have a pilots license." - Gordon MacKenzie

At one point, I was interested in turning the "excess" ring off of my flywheel. A little math revealed that would remove about 3 oz of iron. I never bothered to remove the flywheel as the amount was not worth the effort and I am not smart enough or adventurous enough to go any further.

For what its worth, the guys on the Turbo Ranger Forum say the stock 2.3 is good for 7200 rpm. I would think (but do not know) that includes the flywheel. I have no idea where they got that bit of info.

Bill

Well since 3oz. wasn't enough to be worth your while, would dropping 10lbs or so be more enticing?...Or are you happy enough with it as-is that you're no longer concerned about it?

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-Justin

"Orville Wright did not have a pilots license." - Gordon MacKenzie

I think that with the intended use of the car, 10 pounds would be too much. The car weighs 2500 pounds wet with driver and I don't want a car that is tricky to get underway. I had been hoping for 3 or 4 pounds.

Bill

just a thought, does anyone make a smaller diameter 2 or 3 plate clutch, because its not just the flywheel weight, it's also the clutch and the amount of mass at the outside edge.

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this story shall the good man teach his son,
and chrispin chrispian shall ne'er go by,
from this day to the end of the world.
but we in it shall be remembered.

Hi Justin,

Have a look at a flywheel from a Mazda 3.
Same motor, but flywheel isn't dual mass type as in the Ford. Heaps lighter.

The only snag is that the ring gear is ~5mm IIRC closer to the block face, & the Ford starter fouls it.
I just took a few mm off my starter pinion, and it works like a dream.

Cheap, too.

Cheers - Gavin.

I would recommend doing some searching about what it's like to drive a 2500lb car with a lightweight flywheel (of the same weight or even lighter than I'm talking about) over on Miata.net. I think you'll find most people who have actually driven one will agree that what I'm talking about is not only streetable, but actually adds significantly to the enjoyment of the sports car experience. This would use a stock type clutch so that if you want it to engagement can still be soft and smooth.

Think of it this way. The 20+lb flywheel in the Ranger is designed to allow even the most hamfisted of drivers to get a 3200lb truck plus 1500lb trailer moving easily. Now it usually takes a ~10% change for the average person to be able to really notice any difference. As pointed out by John just below your post, you must also consider the clutch weight as part of this too. For now let's assume 20lb for a stock flywheel and 20lb for a stock clutch. A 4lb reduction would just barely hit that 10% drop, such that it's noticeable but not by very much and certainly not enough to warrant the cost. There is a reason that nobody makes aftermarket "light weight" flywheels for modern 4cyl engines in the 16-18lb range, as it's nearly pointless. Then if you look at a 10lb reduction it's now a more significant, but not excessive, 25% total difference. While it may take a few drives to become fully comfortable with it, it is not as drastic as a nearly 50% reduction in weight to only the flywheel initially sounds. This would also be in no way like a "race" setup, which would run much closer to 12lb total combined weight (a 70% reduction) and would be an on/off switch that would be rather unpleasant on the street.

Honestly I'm not trying to convince you to spend your hard earned money on this if it's not going to be worthwhile to you...But I also want to make sure you don't overlook something you might greatly enjoy just because you're not familiar enough with it.


Yes, but even if it sees a good bit of track time I want this to be something that is fully enjoyable on the street.


Thanks for the thought. But since it appears that they use the same aftermarket flywheels as the Focus, I would be very surprised if it had a different height that would allow it to be used in conjunction with the Ranger transmission.

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-Justin

"Orville Wright did not have a pilots license." - Gordon MacKenzie

I have the Ranger transmission drawn into my plans and expect to go that way. Seems like a good choice to me and I have a Ranger dying in my driveway right now. This seems the economical route to go for transmission and the light flyweel would be nice. I'd do it to save 10 lbs. never mind the bonus of rotating mass!

Is there any chance the Ranger transmission is lighter or smaller then the Miata ones?

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Marcus Barrow - Car9 an open design community supported sports car for home builders!
SketchUp collection for LocostUSA: "Dream it, Build it, Drive it!"
Car9 Roadster information - models, drawings, resources etc.

I don't think so. I weighed by "new" jy M5 and it was a tick (maybe a half a tick) under 90 pounds. That was on a quality bathroom scale. I thought that I posted that, but can't find it. Anyway, there's a lot of steel inside that aluminum case. Guys over on the Turbo Ranger Site say the M5 is good for 350 hp.

Bill

Although not at this time planning a Duratec build, as a past owner of a 2500lb Miata equiped with a 9lb flywheel I thought I'd chime in on the driveablility of Light flywheels.

In 1 word they are AMAZING.

It completely transforms the driving experience. Throttle response becomes immediate. Downshifting is sped up due to the quickness with which the engine can build revs. Low gear acceleration is improved and driveline harshness goes down.

At the same time I owned it I spent a lot of time driving a fully preped ES SCCA Miata. Compared to the stock drivetrain to me driveability was dramatically improved all around.

Popular perception is that lighter flywheel is harder to start/stop. I disagree with that statement. Perhapse with a "race" type on/off switch clutch that allows for no friction zone that may be the case. Mine was equped with a uprated but otherwise stock type clutch. I NEVER in my ownership of the car killed it accelerating from a stop. Launching in a competitve fashion is unchanged; build revs, step off clutch.
Daily type starts are easy as well; Rev to 1500ish, get into friction zone, apply increased throttle, release clutch, go. In this environment the light flywheel actually helps. You don't "store" enegry in the flywheel but depend on the engines very quick response to throttle inputs to react through the friction zone. It is only marginally different than driving with a heavy stock clutch. I had no problems adjusting between the 1997 ES miata and the 1996 with the lightened flywheel.

Overall the driving experince is so much improved with a lightend flywheel. The "sporty" nature of the car is transformed. I highly recomend that if you can get the chance to drive in a car with a light flywheel but stock type clutch do it.

If Justin is successful in building this flywheel I may have to move the 2.3 duratec up in my list of potential engines for any future projects.

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MG midget bodied Locostish car in progress

I'm admittedly inexperienced with lightening flywheels and such, but it would seem to me that when you talk about a percentage change in rotating mass, you would have to include everything that is connected - crank, rods, pistons, flywheel, clutch, and all. So dropping 10lb becomes even less an impact percentage-wise. Or am I missing something?

John

Nope, you're spot on. Which is the same reason people building a Focus 2.3L will remove the balance shafts, as well as use the lighter Ranger crank which uses 4 counterweights instead of 8 counterweights. Trying to actually factor all of that in is a far more complex series of interactions than my greatly simplified example, which was just looking at the specific assembly of most directly interrelated parts.

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-Justin

"Orville Wright did not have a pilots license." - Gordon MacKenzie

I picked up my ranger duratec 2.3 engine and transmission yesterday. If i can help in any way with measurements, weights, etc. let me know. i def would want a lighter flywheel in my build.

Flywheel weight is very important. It's much harder to take weight off the crank. I didn't realize there are different weight cranks available, but would think there might be issues messing with balance weights on a crank.

I think there is a squaring effect on the flywheel though. The weight at the rim is further out from the crank centerline then the crank itself, so it has more leverage on the crank. It is also moving faster then the crank because of it's larger diameter. There really aren't that many ways to make a motor 10 lbs. lighter. It doesn't make it any cheaper granted. For an already light motor, this seems like a good addition. If you are going to do something like autocross, less rotating inertia at these slow speeds can be significant.

It would be interesting to calculate how many horsepower this gives you in first gear.

_________________
Marcus Barrow - Car9 an open design community supported sports car for home builders!
SketchUp collection for LocostUSA: "Dream it, Build it, Drive it!"
Car9 Roadster information - models, drawings, resources etc.

I had an 8lb aluminum flywheel on the Northstar in my Fiero. The car was over 3000lbs with me in it and it was still very much streetable with this flywheel and a SPEC stage 4+ solid-hub clutch. Needless to say, the throttle was very responsive.