1001 replies to this topic

[Tom Hampton]

 

1.6er's would you rather be an under-dog or over-dog.  If over-dog, plate and or weight.  

 

Well, neither.  However, as I said above I'd rather that the package err on the high side, and then use competition adjustments to fine tune.  Given the normal situation where rules changes only occur annually and competition adjustments can be conducted mid-year, this makes even more sense. 

 

Give it just a tick more than you think is needed, then play with min-weight / plate to rebalance. 

 

Disclaimer: I say all this knowing full-well that I'm unlikely to notice the difference in my own lap times or finishing positions.  So, don't mistake any of what I'm saying as salivating about the idea that I might suddenly go from 18/27 to 9th or even 17th.  Its just my normal approach to any search problem.

[davew]

IIRC Removing the entire ring from a 1.6 flywheel is about 4 pounds. So only half of it would need to be machined away.

 

Note to all 1.6ers; If the 1.6 becomes an overdog, you will see the price on some really nice NB cars drop. As their owners build $40k 1.6 cars for Mid Ohio next year. I just bought a 99 and a 1.6 donor car. It will be my first 1.6 build in a few years.

 

dave

[Caveman-kwebb99]

Please mandate the super charger for the double D's Denny and dewy for everyone else I think the blinker removal and wrapping intake and grinding welds in header along with their super flywheel will suffice. Still may be to much in the hands of a great driver....

[Bench Racer]

Kyle, post potential 1.6 changes you could procure my 1.6, sprinkle it with 5k of your magic dust and save yourself 20k from Wheeler's cost for a 1.6.

[FTodaro]

IIRC Removing the entire ring from a 1.6 flywheel is about 4 pounds. So only half of it would need to be machined away.

 

Note to all 1.6ers; If the 1.6 becomes an overdog, you will see the price on some really nice NB cars drop. As their owners build $40k 1.6 cars for Mid Ohio next year. I just bought a 99 and a 1.6 donor car. It will be my first 1.6 build in a few years.

 

dave

Dave you better Tell Tommy Brown to quit Ice racing his 1.6 and bring it back.

 

BTW tell him the next regional at Mid O is 10/10/15 he was asking.

[Caveman-kwebb99]

Kyle, post potential 1.6 changes you could procure my 1.6, sprinkle it with 5k of your magic dust and save yourself 20k from Wheeler's cost for a 1.6.

I already to asked to drive that devil and was ignored! Would have likes to see what times at road America between my black knight Tyrone and your 1.6 look like

[Todd Green]

Flywheel - Aftermarket lightweight flywheel would cost everyone something significant if we went that route.  I have not done the cost research myself, but I hear that a proper good quality aftermarket flywheel is $500+.

 

Obviously "good quality" is subjective, but these are 7.8 lbs, drop in, and fit my definition of "good quality" and are only $300.  We use them in our PTE cars and haven't had an issue with them yet.  Not saying that this should necessarily be the SM solution as I agree about issues with a single vendor.  Just saying that $500 seems high to me. One other thing to consider over raw performance gains is that those who are complaining they cannot make minimum weight just bought themselves 10 easy lbs.

 

Danny - I don't see your argument that we have to stay in the Mazda parts bin.  There are many items on our cars that are aftermarket even though Madza has parts (wheels, rotors, calipers, hoses, radiators, alternators, sway bars,  etc., etc., etc.)

[Bench Racer]

Point A. MazdaMotorSports sells the Fidanza aluminum flywheel................................. Didn't ask their Fidanza weight, number or cost.

 

Point B. A 9.5 pound SFI blessed Fidanza can be procured for $340.00...................... 

[jdmrrs]

Flywheel will reduce weight, but lightweight battery rule would do the same and be cheaper. If you believe that a lighter flywheel improves acceleration (data?) you also have to believe that there is a greater rpm drop when shifting.

[Sean - MiataCage]

Flywheel will reduce weight, but lightweight battery rule would do the same and be cheaper. If you believe that a lighter flywheel improves acceleration (data?) you also have to believe that there is a greater rpm drop when shifting.

 

The battery does not spin, nor is it connected to the drivetrain.  There are several who have done and Steve S is working on the acceleration data math to show what it does or does not do.  Hopefully it will be posted soon,

 

Sean

[mhiggins10]

IIRC Removing the entire ring from a 1.6 flywheel is about 4 pounds. So only half of it would need to be machined away.

 

Note to all 1.6ers; If the 1.6 becomes an overdog, you will see the price on some really nice NB cars drop. As their owners build $40k 1.6 cars for Mid Ohio next year. I just bought a 99 and a 1.6 donor car. It will be my first 1.6 build in a few years.

 

dave

Please make this a "top prep" car so we can finally put that part of the debate to rest.

[Tom OPM]

A little more insight on the 1.6 car I ran at Barber. This is a very good 1.6 car but not a top prep majors car. Not quite the prep we did to the Buras 1.6 but it is a rental after all. Paul Holton ran the car earlier this year at a Sebring regional in this form. Top 5-6 most of the wknd and all data was sent to Bauer.

 

Barber is a good 1.6 track, not the best not the worst. Very good field. Bolanos, Lamb, Brock 99 cars. Steyn, Clemments, Cross VVT cars.

 

My 1.6 rental with a cheap Chinese header and turn signal lens out. Legal built Nelson engine.

 

Car was very competitive. Would it win ? doubtful at least not with me wheeling it. Same issues, could turn good laps but in the race stacked up in braking zones and passed on the way out. But it was pretty close.

 

Did it fall off some in the race sure but not terrible.

 

I think what they are proposing will help a lot. It needs to be given slightly too much and then bump the weight up slightly. Most 1.6 cars were built for 2350 and 2275 is not attainable by many.

 

I really do not think the flywheel is an answer. I do not see the gains and from my old Sunbelt days I remember it might actually hurt top end. John Bennett ???

 

You have to drive it hard, lots of 2nd gear turns the 1.8 could do in 3rd. Needs more grunt not sure how to attain.

 

I for one am Happy they are doing something for it and hope to run mine a lot more next year.

[Bench Racer]

Not to argue with anyone. Not here to suggest a light weight flywheel is the end all to the 1.6 issue. For a learning process, the article below explains where a lighter flywheel makes it's gains. Suspect when/if Steve posts his calculation results the results will show improvements for lower gears and diminishing results for higher gears.  

 

http://www.uucmotorw...heel_works.htm 

 

How a lightweight flywheel works

How does a lightweight flywheel work?  Amongst the majority, there are two schools of thought concerning light flywheels. The first is that they do not contribute to power output. The second is that they do. Which thought is correct? In fact both, in a way, are correct. 

If we measured the power output of an engine first with light flywheel and then again with the standard part on an engine dyno, no change in power will be seen to occur. At first it appears that the light flywheel has done nothing and was a total waste of cash. This is not the case. A dyno that shows max power at constant revs does not demonstrate what happens to an engine's power output in real life situations - like acceleration. If an engine is accelerated on a dyno (we are talking about a rate of around 2000rpm a second ) it would show a power output of around 20%-25% less than at the constant rev state. 

The reason for this is that when accelerating a vehicle the engine not only has to push the total mass of the car but the internal components of the engine need to be accelerated also. This tends to absorb more power as the extra power is used accelerating the internal mass of the engine components and is why a motor accelerating on a dyno will produce less power than at constant revs. Also it must be remembered that the rate of acceleration on the engine internals is much greater that the rest of the car. This would then suggest that by lightening the flywheel, less power would be required to accelerate it and therefore more power would be available to push the car along. 

Now, it may seen unbelievable that by removing a few pounds from the flywheel a noticeable difference to a 3000lb+ car’s acceleration will be made. In fact the difference is quite noticeable and the secret behind this is hidden within the gearbox. Everyone knows that cars accelerate at a greater rate in low gears, this is because a car’s gear box basically a mechanical lever and just like when using a leaver to lift a heavy object, the gearbox reduces the mass of the car that the engine sees. For example, in first gear an engine will see the car's mass as only around say 250lbs but the engine internal mass would still remain around 45lbs.  

As for the "virtual" weight loss of a typical lightweight flywheel in the 3-series or M3, we've prepared the full mathematical analysis:

  Calculations for UUC flywheels showing exact "virtual" weight loss in each gear -

M3 / 3-series (E36 and E46, 1992-2004) click here to download Acrobat .pdf file

M5 / Z8 / 540i (1996-2003) click here to download Acrobat .pdf file

It is now easier to see were the extra performance comes from when you lighten a flywheel. You  effectively "lighten" a car by more than 10% in first gear just by removing mass from the flywheel. As the gear used increases this "lightening" effect is reduced. This is why car’s acceleration improvement reduces in higher gears, to very effect in top gear. Great for drags and tight race tracks but will not increase a car's top speed.

You will see the calculations include the diameter of the flywheel, weight lost (same overall rotating mass difference in UUC Stage1 or Stage2 due to pressure plate weight differences), gear ratios including 6-speed application, and typical diff ratio.

The effective "virtual" weight losses are:

 

GEAR M3 and 3-series "virtual"
weight lost: M5/Z8/540i "virtual"
weight lost:
1st gear  346.5 lbs.  394.4 lbs.
2nd gear  133.15 lbs.  151.7 lbs.
3rd gear  68.9 lbs.  75.4 lbs.
4th gear   46.18 lbs.  48.5 lbs.
5th gear  36.15 lbs.  37.6 lbs.
6th gear  30.04 lbs.  31.0 lbs.

A general rule of thumb for weight loss equivalence to "gained" power is approximately 10lbs/hp. That is for every 10lbs lost, the car gains the effective performance increase of 1hp.

With that in mind, the effective performance increase expressed in gained power can be expected to be the same as the "virtual" weight lost due to the flywheel in each gear divided by 10:

 

GEAR M3 and 3-series "virtual"
performance gain: M5/Z8/540i "virtual"
performance gain:
1st gear  34.6 hp 39.4 hp
2nd gear  13.3 hp 15.2 hp
3rd gear  6.9 hp  7.5 hp
4th gear   4.6 hp 4.9 hp
5th gear  3.6 hp 3.8 hp
6th gear  3 hp.  3.1 hp

 

This gear-dependent gain is also another reason why a typical 4th-gear dyno pull may not show a significant difference - the calculations show that little more than 4hp would be detected, yet a 4th-gear dyno run shows nothing of real-world acceleration through the gears.  Improvements in rev-matching and upgraded clutch clamping power remain regardless of gear.

Due to the nature of the "virtual" weight loss, typical 4th-gear dyno runs may show miniscule differences.  Real-world acceleration runs will show improvement equivalent to the "virtual" weight loss.

© 2003-2004 UUC Motorwerks • http://www.uucmotorwerks.com • 908-874-9092

[B(Kuch)Kucera45]

A little more insight on the 1.6 car I ran at Barber. This is a very good 1.6 car but not a top prep majors car. Not quite the prep we did to the Buras 1.6 but it is a rental after all. Paul Holton ran the car earlier this year at a Sebring regional in this form. Top 5-6 most of the wknd and all data was sent to Bauer.

Barber is a good 1.6 track, not the best not the worst. Very good field. Bolanos, Lamb, Brock 99 cars. Steyn, Clemments, Cross VVT cars.

My 1.6 rental with a cheap Chinese header and turn signal lens out. Legal built Nelson engine.

Car was very competitive. Would it win ? doubtful at least not with me wheeling it. Same issues, could turn good laps but in the race stacked up in braking zones and passed on the way out. But it was pretty close.

Did it fall off some in the race sure but not terrible.

I think what they are proposing will help a lot. It needs to be given slightly too much and then bump the weight up slightly. Most 1.6 cars were built for 2350 and 2275 is not attainable by many.

I really do not think the flywheel is an answer. I do not see the gains and from my old Sunbelt days I remember it might actually hurt top end. John Bennett ???

You have to drive it hard, lots of 2nd gear turns the 1.8 could do in 3rd. Needs more grunt not sure how to attain.

I for one am Happy they are doing something for it and hope to run mine a lot more next year.

Thanks for your opinion on the subject and that's the answer I was looking for your opinion.

Now I would like to hear Todd's opinion on this on track test.

Now remember I'm just looking for opinions from guys that ran close to this test car. I don't care what it looks like on paper just how it works on the track.

Please be honest with your answers like did your car come out of the corner better then his or did his car come out better then yours ect.......

[Steve Scheifler]

Bench, there has never been any question about where a lighter flywheel helps, I've made the point countless times. The text you quote is from someone selling flywheels and their assumptions and rules of thumb do not necessarily apply to our cars, which are not a lot like an M3 where it matters. For example,10lbs = 1hp is a good rule of thumb only if your engine makes about 1hp for every 10lbs total weight. (I'll let you do the math on that ) and frankly, their whole approach of equating it to weight reduction seems silly and less useful than sticking with the amount of power stored on the flywheel, which is what's really happening.

[Jim Drago]

Bench, there has never been any question about where a lighter flywheel helps, I've made the point countless times. The text you quote is from someone selling flywheels and their assumptions and rules of thumb do not necessarily apply to our cars, which are not a lot like an M3 where it matters. For example,10lbs = 1hp is a good rule of thumb only if your engine makes about 1hp for every 10lbs total weight. (I'll let you do the math on that ) and frankly, their whole approach of equating it to weight reduction seems silly and less useful than sticking with the amount of power stored on the flywheel, which is what's really happening.

agree on every word!

[Tom Hampton]

Bench, there has never been any question about where a lighter flywheel helps, I've made the point countless times. The text you quote is from someone selling flywheels and their assumptions and rules of thumb do not necessarily apply to our cars, which are not a lot like an M3 where it matters. For example,10lbs = 1hp is a good rule of thumb only if your engine makes about 1hp for every 10lbs total weight. (I'll let you do the math on that ) and frankly, their whole approach of equating it to weight reduction seems silly and less useful than sticking with the amount of power stored on the flywheel, which is what's really happening.

Yup.

 

I could have ignored the "rule of thumb" if the rest of the math held up for the "virtual mass equivalency". 

 

The whole analysis relies on the idea that rotational kinetic energy can be traded for translational kinetic energy in order to solve for Mass, at a particular linear velocity and gear ratio; and that accelerating one is the same as accelerating the other.  As I looked at the Ke = Kr line in the derivation, my first reaction was to attempt to prove (or disprove) that assertion by looking at the change in Kr under angular acceleration (ie, just work in the rotational domain). 

 

Thankfully, I stopped myself before getting out a pencil and piece of paper. 

[Bench Racer]

Steve, calm down, I never said anything about using a lighter flywheel for weight reduction. If I do anything to lighten my car I'll need to add weight to make the limit. These people selling stuff support what you've said many times, less flywheel rotating weight diminishes as engine rpm increases.

 

Jim, you in the mood to bust balls, bust the balls of the SMAC for their thought of decreasing the flywheel weight by two (2) pounds. There are guys on this site who talk about reducing their tire weigh and it isn't to have less un-sprung weight.

 

Tom H., when the moment of inertia of a flywheel decreases, the amount of torque required to rotate the flywheel to the same speed/same time (as the heavy flywheel) decreases correct. 

[Tom Hampton]

 

 

Tom H., when the moment of inertia of a flywheel decreases, the amount of torque required to rotate the flywheel to the same speed/same time (as the heavy flywheel) decreases correct. 

 

Shouldn't take long for a response, lurkers, Tom Hampton, chris haldeman, Jim Drago, Todd Lamb. 

I'm not arguing the basic physics.  That's the basic relationship of angular momentum, and angular acceleration.   
 

I'm not even arguing that the theory is wrong.  I'm only questioning the Kr = Ke basis of the theory.  Maybe it's true, but its not obvious to me.  I'd want to go back to first principals and derive the equivalency before making the assertion. 

[Johnny D]

I'm not arguing the basic physics.  That's the basic relationship of angular momentum, and angular acceleration.   
 
I'm not even arguing that the theory is wrong.  I'm only questioning the Kr = Ke basis of the theory.  Maybe it's true, but its not obvious to me.  I'd want to go back to first principals and derive the equivalency before making the assertion.

 

https://www.youtube....h?v=Jm-upHSP9KU

J~