Upgrade flywheel on Alfa 155 Q4?

[S?r]

Hello!
Any idea where i could find a light flywheel for my Alfa 155 Q4?
Thanks!
/Jimmy S?r

[Brul(tm)]

Any idea where i could find a light flywheel for my Alfa 155 Q4?

Don't focus on the Alfa 155 Q4 in your search for parts. The engine ande the drive train are the same as te Delta Integrale or Fiat Coupe Turbo 16V. This way, you will find more parts.

Greetings,
Marc

[AlfaJack]

And Lancia Thema 2.0 16v Turbo....are there any more?

[djsly]

Lighten it for yourself.

OEM:



Lightened:

[AlfaJack]

Any implications in strength?

[jimnielsen]

I just got my Q4 flywheel back from the engineers today. I have had it refaced and lightened as well, but just a little....

www.nielsen.org/alfa155Q4/fw1.jpg

www.nielsen.org/alfa155Q4/fw2.jpg

and this one is a before shot..


www.nielsen.org/alfa155Q4/fw3.jpg

I have also have an alfa 116 type flywheel on my giulietta racecar that I have lightened using the same methods, and it is taken to 8200 RPM for every gear without a problem.

JimN

[AlfaJack]

Very nice too Jim!

[S?r]

Thanks to every one for the pictures and information!
Great to know what the rest of You have done!

Best regards from Sweden
/Jimmy S?r

[155-tbo]

I get this next week (the right one on the picture)
left one is standard Q4 flywheel and that right one is custom made flywheel. It is something special steel. It should last as standard, but I save some weight.

[AJ]

Here's mine from a fiat coupe 16vt:

Not quite as light as the others with the full dish effect but my engineer who does the engine tuning for the Integrale's said that by losing too much weight is not good for the engine as it will lose rotational mass, he said this is the best for a track day engine, unless you are only ever going to drive on flat tracks.
Also it makes a difference where the weight is taken from (the outer or the inner), with weight taken from the outer having a greater effect. There is a 4kg total difference in weight.

I combined it with balanced internals as well. Now when the engine goes on a hunting spree it fluctuates like a nutter, it also struggles to idle <~1100

So don't go too light, and also think of the safety of your passengers if it breaks!

[Steve Webb]

So don't go too light, and also think of the safety of your passengers if it breaks!

Actually, thinking of where the flywheel is situated on a Q4 (lhd only) its going to be the driver who gets bits of flywheel embedded in their legs if it breaks.

[AJ]

Ooh, good point there! It would also be worth getting the flywheel balanced with the crank.

[K.Kotkas]

Ooh, good point there! It would also be worth getting the flywheel balanced with the crank.

not just the crank. With pistons, rings etc. The whole 9 yards

[K.Kotkas]

btw, anyone seen real dyno results _after_ lightening the flywheel. I have some hard time beliving in this, although I know something about dynamic kinematics..

[AJ]

I had mine balanced with rods + new pistons + rings, but for road use just fly & crank *should* be enough I would think.

I have not seen the power curve after it has been done, one thing is idle is now very lumpy, and it needs a few more revs when pulling away from standstill!