Running the flex plate AND a flywheel

[Jesus-Ninja]

I've dug up a few threads on this where people have talked about doing it, but then I've also not read any threads where the success or failure has been discussed. I guess no news is good news, and I didn't find the site littered with horror stories, so....

My plan is to run a flywheel to suit my needs and sandwich the stock 1UZ flex plate between my fly and the crank, but I just want to be sure that the flexplate, having no torque converter bolted to it, isn't going to wobble or be unstable at high revs. I'm sure it's fine, but I wanted that warm fuzzy feeling of experienced reassurance

On the subject, I have two ways to skin this particular cat. First i can do as above, bolt through both the fly and the flex with longer bolts. Alternatively there is an option to make up a flywheel to bolt onto the flexplate where the torque converter used to be bolted. In many respects this might be easier, but I'm conscious of the fact that the delivery of power to a torque converter is different to, say, a paddle clutch, and I'm not sure if the flexplate and bolts would be up to it.

Any thoughts on either approach?

 

[4U2QUIK]

are you talking about a tripple/double plate setup are are you talking about using the ring gear as a spacer behind a standard flywheel? (which would be a horrible idea for a number of reasons.

 

[markstoys]

I don't have experience with your exact situation, but as someone who has cobbled together more stuff than most I will give my opinion.

I am guessing you are trying to keep the flexplate for the ring gear, but want a particular clutch set up that is not the correct size for a 1UZ. I don't think what you are doing is a very good idea, mostly because of the loads put on a flywheel, which are very great. You must be very cautious making modifications in this area.

I think bolting through both flexplate and flywheel is probably better because I don't think the flexplate could handle the axial loads the throw out bearing would be putting on it in the area between the bolts for the flywheel and the bolts for the torque converter. Every time you push in the clutch pedal, you would be stressing that flexplate in a way it was not designed for. You wouldn't want the flexplate to eventually crack and have your flywheel come flying out. Bolting straight through puts no axial load on the flexplate. The remaining question is how much the additional material of the flexplate between the flywheel and crank affects things--I don't think it would be much, but I don't really know.

There is a possibility that without the structure of the torque converter to keep it straight, the flexplate will flex while the starter is engaged, causing problems while starting the car. I don't think flutter at high RPM would be a problem, though.

So to summarize: bolting the flywheel to the flexplate runs the risk of catastrophic failure, bolting through both runs a slight risk of starter engagement problems.

Hope this helps.

MArk

 

[Jesus-Ninja]

Ring gear behind a button type flywheel was the plan - something along these lines...

 

[Jesus-Ninja]

Mark - that's a cracking response. Many thanks for taking the time to put your ramblings down in words

What you've said aligns pretty well with my expectations, particularly the concerns around the extra loads on the flex plate by "replacing" the torque converter with the flywheel.

Thanks again.

I don't have experience with your exact situation, but as someone who has cobbled together more stuff than most I will give my opinion.

I am guessing you are trying to keep the flexplate for the ring gear, but want a particular clutch set up that is not the correct size for a 1UZ. I don't think what you are doing is a very good idea, mostly because of the loads put on a flywheel, which are very great. You must be very cautious making modifications in this area.

I think bolting through both flexplate and flywheel is probably better because I don't think the flexplate could handle the axial loads the throw out bearing would be putting on it in the area between the bolts for the flywheel and the bolts for the torque converter. Every time you push in the clutch pedal, you would be stressing that flexplate in a way it was not designed for. You wouldn't want the flexplate to eventually crack and have your flywheel come flying out. Bolting straight through puts no axial load on the flexplate. The remaining question is how much the additional material of the flexplate between the flywheel and crank affects things--I don't think it would be much, but I don't really know.

There is a possibility that without the structure of the torque converter to keep it straight, the flexplate will flex while the starter is engaged, causing problems while starting the car. I don't think flutter at high RPM would be a problem, though.

So to summarize: bolting the flywheel to the flexplate runs the risk of catastrophic failure, bolting through both runs a slight risk of starter engagement problems.

Hope this helps.

MArk

 

[4U2QUIK]

I believe steve Groenik the owner of ww.dorikaze.com has a similiar flywheel setup. He would probably be more than happy to tell you about it.

 

[stevieg]

Had no issues mechanically but it's a bit noisy on startup due to not having the mass of the torque converter to dampen some of the metal ringing during starting.


Worked fine tho

 

[4U2QUIK]

Guess steve found you!

 

[Jesus-Ninja]

Looks like he did! Thanks, Steve. Much appreciated

 

[fastdruid]

Bit of a late response but have you got a flywheel made up yet?

I'm putting a 1UZ-FE in front of a Audi 01E, basically using the design from http://guerillamotive.com/wordpress/?page_id=183 which uses the same idea flywheel. Indeed I'm not sure if it's close enough that you can use the same design if you've not had one made up yet?

Got to find someone to make a flywheel though (have a lathe but don't fancy that job myself), any suggestions in the UK?

If you haven't made one up I will add that by removing spacer from behind the flexplate you need shorter bolts and more engagement on the 'nose' of the crank at the expense of having to run the starter spaced back by the same amount (and running the flexplate very close to the block).