Best flywheel weight for highway driving

[GasSavers_Erik]

I am finally in the process of building my 87 CRX HF (Stingray) and getting it on the road. It will have a 1.3 liter CVCC engine (10:1 compression ratio) and a 5 speed HF trans. I am ready to install the flywheel, and I have two choices:

The 1.3 liter flywheel, pressure plate clutch + all bolts weight 25 lbs

The 1.5 liter flywheel, pressure plate and clutch + all bolts weigh 26 lbs

The topic was already discussed here: http://www.gassavers.org/showthread.php?t=5708

In the above thread, it was mentioned that the VX has a lighter than normal flywheel- I can see how that could help city mpg (easier to spin up the engine in stop and go driving).

But my car will do 95% of its driving on the interstate at 65-70 mph. Sometimes, the little 60hp 1.3 engine struggles on big hills (I already had the 1.3l engine and HF tranny combo in my 87 Civic for about 8K miles). For this reason, I am leaning toward using the heavier flywheel that may store a bit more energy to carry me over the big hills a little easier.

I would be happy to hear any opinions on the issue of best flywheel weight for highway driving.

[FrugalFloyd]

I agree with your reasoning, but have no personal experience with swapped flywheels. My bet's on your side, FWIW.

[theholycow]

I'll second SentraSE-R's opinion...and add that I don't think 1 pound (that's 1/25th) will make a difference anyway.

My flywheel is 53 pounds naked, 68 with pressure plate/clutch cover assembly and clutch disc (but no bolts)...getting it lightened would probably help my non-highway FE.

[VetteOwner]

yea i dont feel one pound is gonna be noticeable.

lighter flywheel will help acceleration and stop and go but heavier will prolyl help highway as it can "store" the energy and use it on slight hills BUT same is said for larger hills gonna take more oomph to spin it up to get up hills.

[slurp812]

Less power to the flywheel, more power to the ground. That is how I've always looked at it. As others said I dont think 1lb will make any measurable difference either way tho...

[GasSavers_Erik]

Update- thanks to all for their replies, but when I finally measured just the two flywheels without the pressure plates, disks and bolts, they weighed the same amount.

One clutch disk did have torsion springs, while the other had rubber torsion "bumpers" so that was part of the small difference in weights of the two sets.

I now have the engine installed and I hope to have it running today or tomorrow. It will be another week or two before I get it licensed and on the road.