edhardley 0 Report post Posted March 1, 2009 Lots of americans whinge about this and I agree - the thing with british tuners is they show you the estimate flywheel figure which can often be hyperinflated and inaccurate.Yea agreed, a piece of paper with some numbers only means so much, hp definatly doesn't always equate to speed/ acceleration, there are lots of things one can do that will make a car quicker but wont change horsepower one bit. You have to drive it/ take on other similar cars to see the results. But there cool for bragging rights, and like a certificate for all the hard work you done. Quote Share this post Link to post Share on other sites
*Glenn* 854 Report post Posted March 1, 2009 I'm not convinced that the M50 manifold is the way to go though after doing quite alot of research. I like the torque the M52B28 produces. So I'm going down another track which I'm posting under projects. I'm going to reduce the wasted energy the mass flywheel obsorbes. Doing the manual conversion on my car, I'm going to install the UUC flywheel with appropriate clutch assembly. The lighter flywheel allows the engine to spin up faster, producing better road acceloration. Going the M50 manifold might give slightly better top end HP, however engine torque and reducing the wasted energy that the mass flywheel absorbes, I feel will give me better driveability gains. Will have to see what the results are like. Have a read of this: http://www.uucmotorwerks.com/ Go to BMW, lightened flywheels, How a lightened flywheel works. Alot of good info on this website Quote Share this post Link to post Share on other sites
*Glenn* 854 Report post Posted March 1, 2009 Meh, Westys M50 manifolded car goes like f**k, much harder than other 2.8 beamers I have owned/driven. It simply walked away from another 328i at a recent track day. I have no doubt at all the M50 works well. Would love to see a drag race. My car had issues though Graham. One of them was me...inexperience on a race track...first time for me. Once I had things sorted my problems were... Sick auto trans... with unpredictable changes...especially in the twisties. I didnt know half the time what gear the car was in. I was using manual select, however it wouldnt change when I wanted it to and sometimes changed down half way through a friggen corner. It also kept hitting the rev limiter, dropping power, then changing up... I think that would account for the black puff of smoke you were seeing when it was changing up a gear...it just kept hitting the rev limiter before it would change up to the next gear even though I had selected a higher gear. Anyway its "3 pedal" time and LSD... next time I'll have a bit more fun and wont need to drive so conservitavely. It was quite scarey with cars around you in the twisty bits, not knowing or being able to predict what the car was going to do. It finally died (trans) and I ended up going home in limp mode. Quote Share this post Link to post Share on other sites
westy 614 Report post Posted March 1, 2009 My car gets more from the short ratio LSD and lightened flywheel then the m50 manifold. I never claimed to believe the manifold conversion was a magic bullet that made the m52 a powerhouse, only that it made a nice change to the character of the engine. The point I was always trying relay was that it didn't create a torqueless mess with driveability issues, as some exaggerated statements would lead you to believe. At the same time, exaggerated claims as to its benefit arnt helpfull either. As for headers, I'm happy to accept there are nice gains to be had. I have no personal experience to assume otherwise. I'm bored with this argument. Quote Share this post Link to post Share on other sites
*Glenn* 854 Report post Posted March 1, 2009 What flywheel did you use Tony.. I thought you were still running dual mass Quote Share this post Link to post Share on other sites
westy 614 Report post Posted March 1, 2009 Lightened M20. Good write up in the earlier link. Quote Share this post Link to post Share on other sites
*Glenn* 854 Report post Posted March 1, 2009 Lightened M20. Good write up in the earlier link. Which link ?? Quote Share this post Link to post Share on other sites
Silver Fox 43 Report post Posted March 1, 2009 More info on his site In here Glenn, you need to reg and login to get to the article. Quote Share this post Link to post Share on other sites
*Glenn* 854 Report post Posted March 1, 2009 In here Glenn, you need to reg and login to get to the article. Thanks Dave Quote Share this post Link to post Share on other sites
CamB 48 Report post Posted March 1, 2009 My car gets more from the short ratio LSD and lightened flywheel then the m50 manifold. ... I'm bored with this argument. I suspect that changing to a shorter diff makes any loss of lower end torque from the M50 manifold irrelevant --> you have to rev the engine harder etc but it wants to. My M3 is screaming for a shorter diff. I do not need 2200rpm at 100kph and gearing for a 300kph+ top speed. It also needs a lighter flywheel. Quote Share this post Link to post Share on other sites
*Glenn* 854 Report post Posted March 1, 2009 I might be sticking to the 3.64:1 at the moment...havent really decided.. more research needed Quote Share this post Link to post Share on other sites
Silver Fox 43 Report post Posted March 1, 2009 Good write up here Glenn. http://www.metricmechanic.com/pdfs/metric-...ial-booklet.pdf Quote Share this post Link to post Share on other sites
martyyn 2 Report post Posted March 1, 2009 Glenn, it would be great if you mentioned these links in your project write up so all the information is in one place. Im really looking forward to seeing how this goes. Quote Share this post Link to post Share on other sites
CamB 48 Report post Posted March 1, 2009 Would be good for the track, but top speed not much over 210kph (I think, did it quickly). Would be over 3000rpm at 100kph. It might be worth deciding on a ratio if you are pulling the diff apart to put an LSD in anyway. Quote Share this post Link to post Share on other sites
*Glenn* 854 Report post Posted March 1, 2009 Glenn, it would be great if you mentioned these links in your project write up so all the information is in one place. Im really looking forward to seeing how this goes. I have saved all these links now Martyn... I'll post up a link thread in my project as it proceeds Quote Share this post Link to post Share on other sites
westy 614 Report post Posted March 2, 2009 Would be good for the track, but top speed not much over 210kph (I think, did it quickly). Would be over 3000rpm at 100kph. Spot on. Tis the ratio I am using. Hardly suitable for a daily driver but good fun. Also a usefull multiplication of the engines torque dont forget. Sorry Glenn, had to shot off to work. How inconsiderate of them. One thing to be aware of with the lightened flywheel is that they can have a tendency to rattle. Mine is the same setup as the one in the link and rattles like a bastid, although he claims his doesn't. Have heard similar conflicting reports about all kits including the UUC. Seems some rattle, some don't. Quote Share this post Link to post Share on other sites
*Glenn* 854 Report post Posted March 3, 2009 Would be good for the track, but top speed not much over 210kph (I think, did it quickly). Would be over 3000rpm at 100kph. It might be worth deciding on a ratio if you are pulling the diff apart to put an LSD in anyway. Was this reply intended for Me or Westy Cam ?? I'm still unsure about ratio at the moment.... what would you suggest ?? The auto was 1900rpm @ 100kph in top lock up Quote Share this post Link to post Share on other sites
*Glenn* 854 Report post Posted March 3, 2009 Spot on. Tis the ratio I am using. Hardly suitable for a daily driver but good fun. Also a usefull multiplication of the engines torque dont forget. Sorry Glenn, had to shot off to work. How inconsiderate of them. One thing to be aware of with the lightened flywheel is that they can have a tendency to rattle. Mine is the same setup as the one in the link and rattles like a bastid, although he claims his doesn't. Have heard similar conflicting reports about all kits including the UUC. Seems some rattle, some don't. I'm aware of the backlash rattle in the gearbox at idle in nuetral.. most manuals make a little noise. I'm not too concerned about it...if it does or doesnt, doesnt worry me Quote Share this post Link to post Share on other sites
CamB 48 Report post Posted March 3, 2009 Glenn - it was for you, but Westy has confirmed my maths is close enough. It really depends what you want from the car - if it really is primarily for track, that 3.64 diff ratio would be good as you'll probably about run out of revs at the end of the straight - I would guess you have enough power vs frontal area to hit 210kph. Ask Westy. Alternatively, you could decide what the maximum rpm at motorway speed you are happy with in 5th, and go with that. A shorter diff (within reason) really helps acceleration, but it does get a little tiring. A 3.46 might be a good compromise. If I can find it, I will send you a spreadsheet later on. I have your email somewhere. Alternatively you can plug # in here: http://www.unixnerd.demon.co.uk/revs.html Quote Share this post Link to post Share on other sites
