M44 Dual Mass to Single Mass and Beyond

[zedonist]

Now i know the arguments, why bother modifying a 1.9 get a 2.8 etc etc, well for me its not about just getting a bigger engine with more power and extra cylinders, i like to tinker, i like to look at something and say what if? Well i chose the 1.9 because i can work on it, i can change things or fix them, normally fix them........

I have been on a journey (still travelling), i have modified the body to wide rear format like the 2.8, i have lowered it and stiffened the springs and ARB's, and uprated the brakes to 3.0 vented discs and callipers, this has bought a lot of smiles to my face whilst driving the back roads. but the thing that has niggled me has been it just needs that 5% more from the engine department, yes a stainless exhaust and induction kit made it sound like 5% more but it was just those few instances when you just new if just slightly tweaked it would be the perfect roadster.

Well i researched this in detail, i have looked at Turbo's, and DASC, but just too much modification required and then you have a real frankenstein and it has cost you an arm and a leg, so as i have a limited hobby budget, i have had to say no. The search has lead me to 3 options, remap, diff change and flywheel modification, so which one, well i have ruled out the diff change as they are like hens teeth, and people covet them so much the cost nearly as much as a DASC, so option binned for the moment, plus i think the trade off of cruising speed v acceleration is just too much for a road car (Good for a 1/4 miler). So remap and flywheel, well the clutch judders when cold, so i have opted to go this route first and then the remap as the icing on the cake.

So Flywheels and clutches, The M44 has a DMF (Dual Mass Flywheel) they are very heavy, help with torque but are parasitic to draining the engine power, how much you say, well its to the tune that if you shaved 10lb off one you would gain 34BHP (virtual) in first gear, 28 in second, 18 in third, 10 in fourth and 5 in 5th. This sounds good, and in theory it is very good and backed up by calculation, we should all do it yes? well the problem is the DMF it cannot be modified, its a very intricate and heavily engineered component, and nobody has the skill to do it. The option therefore is to fit a single mass fly wheel, they are available in various expensive forms from the states, you can even put in an M3 flywheel and clutch or a Valeo conversion kit, problem is these are the same weight as the DMF so that you do not notice any difference in driving, so no point in just swapping these out. Answer therefore get one modified, have the fly wheel lightened and balanced, well that is my solution, but today ended up in a fortunate twist.

Having broken up for xmas break, decided to get my recent Valeo purchase down to a highly recommended engine builder MJA Automotive Engineering, owned by Martin Adams, i had gotten a price and lead time over the phone and was going to post it, however i was not quite convinced it had enough meat to allow it to be lightened, and certainly not enough to reduce by 10lbs. Today i took a drive to see Martin, we looked at the flywheel together, and with Martins experience and witness to a few exploding flywheels agreed it was not worth doing, especially if it could not be done safely, after a brief batting of ideas Martin said "Why don't i make you one from Aluminium", this seems the perfect idea, it can be made to the same dimensions and saves the weight without any loss of integrity. So we agreed the price, had a tour of his work shop including engine dyno and race cars and confirmed i would collect it at the end of January.

Once i have the flywheels back i will do some weight comparisons, and then some logged driving runs on the existing DMF prior to changing over to the new one. I will update this thread as i go along.

 

[t-tony]

Very interesting Rich. Hope all goes well for your modification mate. I will be looking forwards to hearing how it works out.

Tony.

 

[zedonist]

Me too Tony, my main worry is about drivability in traffic, but as the Aluminium one will be the same dimensions as the valeo one and not a light weight race item, Martin has said it will be fine, so fingers crossed, other wise i will only be able to drive it between midnight and 4 in the morning on a sunday! lol

 

[GazHyde]

Now that was a good read Rich, can't wait to see how this develops!

 

[hard top]

Second that, good read Rich and this is going to be interesting.

 

[Ashbandicoot]

Very interesting, I'm all for tinkering over the 'get the bigger engine' mantra . If you had the 2.8 some people will simply say get the M, but even that can be improved

Ash

 

[t-tony]

In the end it comes down to placing your own mark on a mass produced item which makes it an individual, your very own car.
Also with the satisfaction that you did it yourself too.

Tony.

 

[Cooper]

Great story and I look forward to the reports in the future.

 

[Lee]

I like the way this is heading. My only concern would be "How much lighter is the flywheel over standard" the reason i ask this is it could make the initial pulling away tricky going round town situations also the flywheel itself stores energy(inertia/moment vs friction) so when tackling hills you don't really notice drop in speed/torque but you may with a lighter flywheel and the same with overtaking on motorways. One things for sure though she will rev much more freely. I look forward to the end result.

Lee

 

[zedonist]

You have read my mind Lee, it is the reason we are not looking at a racing flywheel, the truth is the DMF is designed to be heavy to prevent stalling amongst other things and sorry to say this to assist women in driving, its the reason why most modern cars will pull away just on idle speed alone, the benefit is you have a very smooth clutch action for very little effort and the majority of people will be used to this now and have forgotten how a a lighter solid flywheel felt and having to keep the revs up to pull away. So i really expect this to just behave how my MK2 escort was when modified, in essence its just going back to the way things used to be before the DMF was conceived and not doing something that could be detrimental.

I don't expect acceleration to be a problem especially from low speeds or on the motorway to be honest due to the theoretical power added to the car by the reduction in rotational mass, it wont hold the revs like a DMF as you say on hills it may struggle and fuel economy will be a bit down due to applying gas to keep it spinning rather than momentum. Again as in the first paragraph above one of the DMF design features is to increase fuel efficiency by adding sufficient weight allowing the engine to keep spinning when you come off the gas, you probably notice you are hardly on the pedal at cruising speeds or it does not slow down as rapidly as older cars used too, remember when you used to engine brake a car? Its also one of the reasons modern cars have to have extra BHP just to keep up with the same performance figures as similar simpler cars in the day. So in essence this modification just takes the car back to 70' / 80's design and style of driving, so i don't anticipate the car behaving as a pig, but i will have to drive it like a 70' / 80's car, most classic car owners will know what i mean

The key benefit of this mod will be the pick up in the lower gears (the 20 - 30 virtual bhp gain area), which will be especially welcome when coming off tight slow bends etc, i very rarely use it on the motorway, and if i do i keep in the slow lane because it is so low and the lorries scare me (wuss).

I am not expecting miracles either, just a more exciting drivers car, if your interested you can be part of my before and after testing regime, to give that independent review at the end of this little project?

 

[Lee]

@zedonist It would be my pleasure to be a part of it. The more i think about the pro's and cons the more i tie my head up trying to give it an accurate outcome. It will have to be down to how the finish product proforms.

Lee

 

[zedonist]

Thanks Lee, just need to think up some tests to do to provide some data, things like weight, time between gear changes, and then driving impressions, the latter one from two people's persoective will help give a balanced view I think.

 

[TaffZee]

Mmmm, me thinks that this could be a problem, I am sure that I will be corrected, but my main concern would be the longivity of an alloy flywheel, the very nature of the beast could prove wear problems to the mechanics of the flywheel? Am I wrong or am I right?

 

[zedonist]

Of course your right, it could be a problem, but it's not a daily driver and the cost is low enough not to worry about replacement. I've taken all this plus more into account as a Metallurgist and I am not overly concerned. But as part of the write up and diary, I will keep it up to date as the miles progress, whatever the outcome it will be good information for others thinking along the same lines.

 

[Lee]

Originally my concern @TaffZee but seeing as Zedonsit is going to a reputable company i would assume they would use high quality grades of aluminium.

Lee

 

[t-tony]

I had the same concern and I wondered if, although it would increase weight, about the possibility of a steel face insert was possible as a compromise?

Tony.

 

[Lee]

@t-tony then would you not face a balancing issue? But an option i would consider!

 

[t-tony]

I wouldn't have thought so Lee if a piece of steel was machined to an interference fit into a housing machined into the alloy block of the flywheel, it might need pinning as well. I have seen this used on smaller engines in the past but really can't see why it shouldn't work in a car engine. It might make a better compromise between DMS and all alloy? Obviously it has to be machined to accept the starter ring gear as well, also interference fit.

Tony.

 

[zedonist]

Sorry guys, looks like I have taken a bit of the technology for granted and assumed you guys knew, you can't use the aluminium as a friction surface, it will have a hardened steel plate for the friction surface, which is why I am not concerned about wear as it can be replaced when required, but should last as long as a normal one depending on use, obviously continuous drag starts will wear it quicker, but this is not its intended use so will be ok.

It's standard practice on alloy flywheels to have this friction plate which bolts in place.

My response earlier was generalising over the strength properties of aluminium v steel, too which I don't see a problem as I am not uprating the engine in power, if it were a 400bhp monster I don't think I would go this route.

 

[oldcarman]

Great reading guys! I'm leaning more toward the types of clutch linings available now as opposed to the 70-80s. Or am I completely out of the park with that. Would not having the proper compounds, etc make launching easier and still give the performance needed for acceleration for passing and hills. Please correct me as this is not an area I exel in. JIM