What do folk recommend as per title, for an STI5 wagon with about 350bhp?
I'm posting on behalf of a mate, so any advice will be passed on.

Thanks,
Alcazar

 

Skim the O/E down to about 8kg. Use an automotive machine shop who will do this sort of work regularly. Cost will be £30-50.

 

Been toying with this one myself (if you've seen my posts about my feckin box you'll know I may need to do this anyway )
Any how when you ask the machine shop boys to do it, what are they likely to take it from? Would I need to give them more detail (or do I just say make this 8Kg please mate, how heavy is it any how?) Also how more juddery (is that a word?) will it be? Any how noticable will it be on a normal MY97 turbo?

Cheers,

Mike

 

The O/E flywheel will be in the region of 12 kg.
It needs to go to a competant automotive machine shop who will be doing this sort of work all the time. Do not give it to anybody who needs to be told what to do. That would be a recipe for disaster.
Ask them to aim for 8kg minimum but to go to whatever they are happy with above 8kg. There should be no more judder at 8 kg ish than on the o/e providing the face of the flywhelel is in good condition without high spots.
Hope that helps but come back if you want more info.
If you were closer it could be done in a couple of hours but carriage charges each way sort of put the block on that.

 

If you get it machined make sure you get it balanced before putting it back, I put a 5Kg billet in my RA very quick pick up but it will now has a lumpy idle especially when all the electric bits are on.!!!!!

 

5kg is quite light and so engine settings need to be that more accurate for a smooth tick-over. The lumpiness in idle is not related to balance.
Having tried a range of flywheels down to 4.2kg, I think 8kg is a good all round choice and that is what is on my new engine. The WRX is at 4.6kg and I may change it for something heavier when I do the clutch.

 

Harvey

Is it OK to use a paddle clutch with the standard clutch face or does it need to be a billet flywheel?

Also would you still opt for an 8kg flywheel with a paddle clutch

Mark A

 

Mark : I have e-mail probs. You get my info from yesterday?

Paddle will work with an O/E flywheel, skimmed or otherwise.
There are sprung and unsprung clutches. IMHO you stick with a sprung clutch whatever else you do as this transmits less shock to the transmission which to me is important.
I do not have a lot of paddle clutch experience but I would certainly not go lower than 8KG with a paddle that is lighter than an O/E IF you want to retain ease of drag launch. If that is not a priority then go lower by all means but it is a bit like try it and see to find out what suits you and my experience is with 2.0 litre units.
Skimmed O/E = Not a lot of money.
Fancy billet = Lots of money.
Performance difference apart from placebo effect from having spent £hundreds?

 

just to jump in here

who makes aftermarket flywheels which are around 7 - 8 kg ?
i need a new 1 and dont want mine skimming .
cheers
daz

 

With regard to OE flywheel, and paddle clutches, yes they will work, but the paddle clutch material will eat the OE flywheel quite quickly.

I have been warned that this can shorten the overall life of the clutch, due to a premature reduction in clamping pressure.

Mark.

 

my flywheel is a skimmed down one as harvey suggests, curtessy of alyn at AS performance, and i think it is one of the better mods i have done, it feels noticeably better for such a small amount of cash

 

Skimmed/lightened OE flywheel, with organic clutch, is a very good,cost effective option.

Mark.

 

Yeah I have a skimmed flywheel but when the box comes out I'm thinking of putting a paddle clutch in. The last thing I want to have to do is replace a sha**ed flywheel in two months.

Cheers Harvey & Mark

Mark A

 

?? not sure how you think the "paddle" will shorten life or damage the O.E. flywheel..............run a variation of our own flywheel (O.E. own to 7kgs) with an AP 4paddle in the rally/track car and have done for the last 2yrs with no issues............

alyn

 

I would have thought the friction properties where different, and therefore the paddle was more "abrasive"

Mark A

 

I have the unsprung paddle clutch plate out of Tristan Pye's rally car. It has done a full season at the top of the championship with an O/E flywheel and the clutch is almost as new.
I think the paddle clutch does generate more heat but that has not been an issue.

 

Alyn,

I assume it varies on the pad material, but it's similar to the effect an aggressive brake pad has on a disk.

I'm not certain that rally/track use is a good comparison. There's little driving in traffic, slipping the clutch, etc'. Plus, how many miles does the average rally car rack up in two years ?

It's not so much the plate wearing, but the actual flywheel, the plate would possibly last longer.

Mark.

 

definately agree "slipping" a paddle causes all kinds of problems because they are designed not to....................also have a couple of guys with them in road cars and can't say i've ever noticed any issues with the flywheels.................
only the paddle wears much quicker

even in an evo7 (notorious for replacing flywheels), we never had any greater issues with a paddle fitted, if anything it was better than with the O.E. plate
alyn

 

Perhaps I can clear up a few misconceptions.
The wear on the flywheel and for that matter the pressure plate, will substantially depend upon the hardness of the friction plate material.
The material can range from relatively soft up to VERY hard ceramic based. These are capable of damaging O/E flywheels and pressure plates along with many after market lightened flywheels.

Here is what AP Racing have to say on the subject and it is possible this has been taken out of context.
"CERAMETALLIC (PADDLE)DRIVEN PLATES
recommended for COMPETITION ONLY.
If used in road applications it can induce judderon take up and promote higher wear on flywheel and pressure plate surfaces"

"For Road Applications AP Racing recommend the use of an organic type friction material"

Furthermore, relating to flywheels, I think lightened after market flywheels are greatly overrated. They get far hotter, far quicker than the heavier O/E item and once the clutch start slipping and a critical temperature is exceeded, things only go down hill from there on.