Lightweight flywheel or headers?

[schnitzer325]

What would you recomend, lightweight flywheel or headers?

[Serious]

flywheel.

[Mad Dog 20/20]

Honestly? Neither. Both are a waste unless your car is a highly developed track car. 2 of the least pleasing mods I have done . . .

[slcook54]

Unless you are going with KK headers, I think headers are a total waste of money IMO from a hp/$ perspective. KK headers are extremely expensive also, but they actually seem to produce gains. Lightweight flywheel would be cool. What other mods do you have?

[wushucivic]

Honestly? Neither. Both are a waste unless your car is a highly developed track car. 2 of the least pleasing mods I have done . . .
what didn't you like about the flywheel?

[Mad Dog 20/20]

what didn't you like about the flywheel?

tranny rattle
vibration
low-end torque loss
driveability loss
marginal (if any) performance gain in gears 3-5

[slcook54]

How can a lighter flywheel create a torque loss?

[beatniks325]

http://www.uucmotorwerks.com/ says there is no torque loss either.

i'd say flywheel over headers.

[Mad Dog 20/20]

The torque loss issue has been debated for years. I'm not gonna rehash it. Reliable independent dyno testing has shown the low end torque loss with a LTW fly. Further, many users have claimed the "feeling" of lost low-end.

Here (http://www.europeancarweb.com/projectcars/0109ec_projbmw/) is the article/dynos.

[slcook54]

Link didn't work for me. I just don't understand scientifically how removing rotational mass can create a torque loss? I'm not saying you are wrong, I just don't understand. Also, we probably shouldn't take "feelings" as evidence, otherwise, I might have to start listening to Supabimma's claims of 50hp from switching to a K&N filter.

[Mad Dog 20/20]

Link didn't work for me. I just don't understand scientifically how removing rotational mass can create a torque loss? I'm not saying you are wrong, I just don't understand. Also, we probably shouldn't take "feelings" as evidence, otherwise, I might have to start listening to Supabimma's claims of 50hp from switching to a K&N filter.

I don't understand why, either.
I don't understand why a crank pulley makes power on a dyno and a LTW fly does not.

Just how it is . . .

When a number of people (non-supabimma people) have the same subjective feeling of low-end torque loss and objective dyno's demonstrate the losses . . . well, lets just say that its all consistent data.

[CarbonBlkE36]

yea, i think the only reason to get the "LTW" flywheel is cause its a single mass. only reason im going to be gettin one. don't blow ur money on headers either. might wanna get a diff if u want accelration.

[purepump]

from my experience, trading off slight low end loss with throttle response (heel&toe is addictive now), lesser power loss thru drivetrain, and that idle diesel tacktack....go for flywheel

[Serious]

I don't understand why, either.
I don't understand why a crank pulley makes power on a dyno and a LTW fly does not.

Just how it is . . .

When a number of people (non-supabimma people) have the same subjective feeling of low-end torque loss and objective dyno's demonstrate the losses . . . well, lets just say that its all consistent data.

crank pulley add hp because it decreases drag on the engine from the accessories. ltw flywheel jsut reduces rotational mass.

i dont know what dyno's your talking about losing low end torque, since ive never seen a dyno under 2,000rpms but whatever.

the flywheel has no affect on hp, it does have a huge affect on the delivery of power to the wheel as a gearing swap does.

its all a matter of what u want. honestly ltw flywheel is my favorite mod so far but mine hardly chatters and revs like crazy. when i drive my friends car with LTW flywheel it has horrible chatter and it makes the mod significantly less attractive.

headers are one of those last mods u do to gain that last little bit of top end HP. best for cammed cars.

[BMWg84]

What would you recomend, lightweight flywheel or headers?
Flywheel

[sac02]

My LTWfw was one of my favorite mods to my e30 and one of the first drivetrain mods I will do to the e36.

tranny rattleSome cars have it, some don't. Luck of the draw, it seems. Doesn't bother me much anyway.

vibrationNot noticed in my car

low-end torque losssee above

driveability lossMy definition of driveability must be different. A quick revving engine that is a joy to heel-and-toe is more driveable to me. Throttle response is a good thing.

Both are a waste unless your car is a highly developed track car. Again, disagree. Better throttle response, quicker revs and better rev-matching are things I appreciate on a daily basis.

However, I don't think this mod is something you should be looking at unless you already have the tranny out of the car for a clutch job or something, the time/labor involved quickly puts this in the "bad bang for the buck" category if it is done by itself.

Mac

[Bernanke]

When a number of people (non-supabimma people) have the same subjective feeling of low-end torque loss and objective dyno's demonstrate the losses . . . well, lets just say that its all consistent data.


:lol :lol :D ;)


btw i dont have LTW fly, i have crank pulley.

as far as the headers debate, short tube headers do not do much. Long tube headers however make a big difference. I made 18HP with crank pulley and long tube headers and that was over short tube headers so long tube headers (especially with a full exhaust system like AA's 3 peice exhaust system) makes a difference in both sound and top end power. but alot of it depends on what your setup is, some setups benefit more from it than others.

[m3mobbin]

What would you recomend, lightweight flywheel or headers?
I wouldn't reccomend both of those mods on a 325. After the install you are going to be pushing 1k for very insignificant performance gains, for the flywheel or headers. If you are going to get some headers, just settle with some used OBDII's or those 200 dollar ones of ebay(they are almost identical except for the polished finish), Jet Hots or any other expensive shorty headers aren't worth it for the gains...
If you haven't done chip, intake, crack pipe, cat-back, and pulleys take care of those first before you waste money on insignificant mods. When your done with all those bolt ons try cams :)

[SG_M3]

so you made 8 hp from headers?

I'd do the flywheel, headers are a waste, unless its the last thing you have to do.

[Bernanke]

ya headers is one of those last resort mods, my last two mods were headers and big bore throttle body, i like them both and the work well once you have a bunch of other mods but doing as your first mod... probably not, especially if you have ANY stock exhaust components at all (aka stock cat or exhaust)

[WytLytnyn]

If I had to start modding a new car I'd do the following in this order:

1. Premium tires- PS2's, So-3's, Eagle F1's
2. LTW flywheel
3. Suspension
4. Differential
5. Intake/Exhaust
6. Crown Royal Airfreshner

[Mad Dog 20/20]

i dont know what dyno's your talking about losing low end torque, since ive never seen a dyno under 2,000rpms but whatever.


You obviously did not read my post (LINK) then :rolleyes

http://europeancarweb.com/projectcars/0109ec_projbmw06_zoom.gif

http://europeancarweb.com/projectcars/0109ec_projbmw07_zoom.gif

[Serious]

ok theres no low end torque there. a little lost midrange

and peak numbers your down what 1 lb. ft. woohoo!!!!!!!!!!!!

those dynos are pure bullsh*t anyways. how would less rotating mass = less hp in the midrange then produce more on the top end???? its not like a flywheel is a breathing mod. if a dyno would show a difference it would be constant through the entire rev band.

lets see some acceleration times between flywheel equipped cars and non flywheel equipped cars. thats what really makes a difference not some BS dyno.

[Mad Dog 20/20]

My LTWfw was one of my favorite mods to my e30 and one of the first drivetrain mods I will do to the e36.
My definition of driveability must be different. A quick revving engine that is a joy to heel-and-toe is more driveable to me. Throttle response is a good thing. Better throttle response, quicker revs and better rev-matching are things I appreciate on a daily basis.

However, I don't think this mod is something you should be looking at unless you already have the tranny out of the car for a clutch job or something, the time/labor involved quickly puts this in the "bad bang for the buck" category if it is done by itself.

Mac

Mac. You misread my post. I was asked what I did not like about MY ltw fly. My post was responsive to that very narrow question. I never said that the LTW fly did not have positive attributes. Obviously, it certainly does, and I think most folks know what they are.

I think your definition of driveability IS different. A Honda S2000 or even an e36 race car with a 3lb flywheel have excellent quick revving engines, are a joy to heel-and-toe and offer great throttle response. However, such cars are NOT exactly praised for their street drivability . . .

[Mad Dog 20/20]

ok theres no low end torque there. a little lost midrange

and peak numbers your down what 1 lb. ft. woohoo!!!!!!!!!!!!

those dynos are pure bullsh*t anyways. how would less rotating mass = less hp in the midrange then produce more on the top end???? its not like a flywheel is a breathing mod. if a dyno would show a difference it would be constant through the entire rev band.

lets see some acceleration times between flywheel equipped cars and non flywheel equipped cars. thats what really makes a difference not some BS dyno.

I take it you still beg to differ? :stickoutt Whatever . . .

Please read the article in the link.

The author states that there was a loss of torque down low. The LTW fly gave the M3 a maximum loss of 8.2 lb-ft of torque and 5.7 bhp at 3660 rpm. The gap was not made-up until 5500 rpm.
PM VaderM3 (Pablo). He posts on BF.com. It was his car, his article, etc. Tell him you think he and his dyno's are full of BS :rolleyes

But before you do that, do me (and yourself) a favor and post something, anything, that shows an OBJECTIVE gain in hp/trq and/or acceleration due to a LTW fly on an e36 M3. Please do not post theory, physics, explanations of why or how it SHOULD provide a gain, etc., and please do not post anectdotal subjective claims. I'm very familiar with all of that, as it is what led me to put a LTW fly on my car.

[Serious]

I take it you still beg to differ? :stickoutt Whatever . . .

Please read the article in the link.

The author states that there was a loss of torque down low. The LTW fly gave the M3 a maximum loss of 8.2 lb-ft of torque and 5.7 bhp at 3660 rpm. The gap was not made-up until 5500 rpm.
PM VaderM3 (Pablo). He posts on BF.com. It was his car, his article, etc. Tell him you think he and his dyno's are full of BS :rolleyes

But before you do that, do me (and yourself) a favor and post something, anything, that shows an OBJECTIVE gain in hp/trq and/or acceleration due to a LTW fly on an e36 M3. Please do not post theory, physics, explanations of why or how it SHOULD provide a gain, etc., and please do not post anectdotal subjective claims. I'm very familiar with all of that, as it is what led me to put a LTW fly on my car.


those dynos arent accurate at all.

apparently the car made an extra 50lb feet of torque and 50hp jsut by changing gears????? with accurate dynos like that im sure it can accurately measure a mod that makes no difference in HP numbers.

honestly i could do 3 runs back to back and the change just between those three runs could be as different as the runs in that dyno. its not representive of the flywheel at all.

i know a flywheel equipped car is faster, ive driven m3's with and without a flywheel. first 1-2-3 gears are quicker. enough to notice.

i understand what your saying about the low end torque loss but my take on the flywheel is that the m3 shouldve come with a 10lb flywheel stock, the dual mass was one of those keep the bmw customers happy parts so they didnt complain about noise. and it was cheaper to use the flywheel from 325/8.

the quick revving nature the flywheel adds just fits the m3. quick revving top end power, easier heel and toeing, insane throttle response.

[Bernanke]

well actually... my third and forth gear runs were identical and I switched back and forth (two 3rd, two 4th) back to back and entire powerband was 100% identical, that is on a dyno dynamics dyno though which is much more accurate, dunno about dynojet and etc.

[sac02]

Please do not post theory, physics, explanations of why or how it SHOULD provide a gain, etc., and please do not post anectdotal subjective claims. I'm very familiar with all of that, as it is what led me to put a LTW fly on my car.
Sounds like you are not impressed with your LTW fly... give it to me, then. :devillook

wanna trade + cash?

Mac

[GotBHP?]

well actually... my third and forth gear runs were identical and I switched back and forth (two 3rd, two 4th) back to back and entire powerband was 100% identical, that is on a dyno dynamics dyno though which is much more accurate, dunno about dynojet and etc.

Any properly setup dyno machine will take into account/factor in gearing...regardless of what gear ratios or what diff you have on there. Of course a car's engine will transfer more torque through the wheels in first gear when compared to 5th. That has nothing to do with how much torque at a given rpm your motor is producing (unless you are trying to come up with what gears would work best in your car).

I personally dont see how reducing the rotating mass of your flywheel/clutch assembly could possibly reduce the amount of torque you produce. I dont recall ever seeing an equation in any physics or mechanics class where more mass can produce any "favorable" (as far as we are concerned) effects on acceleration, angular or not.

[Jean-Claude]

Hot Rod magazine had a article on ltw flywheels and the suposed loss of tq that some claim. What they had to say might surprise you. Iirc their final verdict was that all pro drag racers prefer to have a lighter flywheel than a heavier one due to the fact that the benefits outweigh the cons. Let me look for it and see if I can't find a link....


I take it you still beg to differ? :stickoutt Whatever . . .

Please read the article in the link.

The author states that there was a loss of torque down low. The LTW fly gave the M3 a maximum loss of 8.2 lb-ft of torque and 5.7 bhp at 3660 rpm. The gap was not made-up until 5500 rpm.
PM VaderM3 (Pablo). He posts on BF.com. It was his car, his article, etc. Tell him you think he and his dyno's are full of BS :rolleyes

But before you do that, do me (and yourself) a favor and post something, anything, that shows an OBJECTIVE gain in hp/trq and/or acceleration due to a LTW fly on an e36 M3. Please do not post theory, physics, explanations of why or how it SHOULD provide a gain, etc., and please do not post anectdotal subjective claims. I'm very familiar with all of that, as it is what led me to put a LTW fly on my car.

[Serious]

drag racing is an entirely different thing.

the launch is everything in drag racing, you want to have some weight in the flywheel to make the car launch hard and not bog (espically with drag slicks).

[///M3///M5]

I am kinda in this same debate over what to get, but I am leaning toward SS Headers and Midpipe. Do you guys think I will get any kind of gain with my car? I have basically every bolt on mod except for the flywheel and BB TB. I also have the Eurosport Cam Kit. I am also considering a 3.38 (this will happen either way eventually).

[Serious]

3.38>flywheel/clutch>headers/midpipe>BBTB.

[xdr driftx]

headers are nothing but engine bling for e 36 m3's.

i would go with a ch ch ch ch ch flywheel

[Serious]

nah if hes got a cam kit.

SS headers and mid pipe youll get 10-15whp.

how can u argue with how fast it revs with the ltw flywheel though? roast the tires in 1st and 2nd :buttrock

[GotBHP?]

I am kinda in this same debate over what to get, but I am leaning toward SS Headers and Midpipe. Do you guys think I will get any kind of gain with my car? I have basically every bolt on mod except for the flywheel and BB TB. I also have the Eurosport Cam Kit. I am also considering a 3.38 (this will happen either way eventually).

My car is loving the cams and headers together ;)

[///M3///M5]

nah if hes got a cam kit.

SS headers and mid pipe youll get 10-15whp.

how can u argue with how fast it revs with the ltw flywheel though? roast the tires in 1st and 2nd :buttrock

Ok then...new plan

SS Headers + Midpipe----->Grad present from parents

3.38------>Grad Money

LTW Flywheel------->When I need a new clutch

[///M3///M5]

My car is loving the cams and headers together ;)

How did you do the Euro exhaust. I email TurnerMS and they told me that Euro had a different exhaust port diameter and could not mate with a US spec engine.

Also, what SS midpipe are you running, and are you running O2 sims. If so, how is your A/F?

[Serious]

How did you do the Euro exhaust. I email TurnerMS and they told me that Euro had a different exhaust port diameter and could not mate with a US spec engine.

Also, what SS midpipe are you running, and are you running O2 sims. If so, how is your A/F?

BS. euro headers fit fine.

[///M3///M5]

BS. euro headers fit fine.


That is what I thought, but here is the email:

> -----Original Message-----
> From: Thomas [mailto:Thomas614@comcast.net]
> Sent: Monday, May 02, 2005 12:08 AM
> To: Doug Mahar
> Subject: Exhaust Question
>
> I just had a quick question about the exhaust system I am
> trying to build for my car. I have a 99 M3 with a Cam Kit
> and have been wanting to open up the exhaust end for a while.
> I have been considering the SS Midpipe/Resonator section.
> Now if think I also want the TMS Shorty Headers.
> My question is, will these two mate properly or will I have
> to get the SS Headers to mate with SS Midpipe. Also, is
> there a major difference between the Euro and US S Midpipes?
>
> Thanks,
> Thomas


The shorty headers are designed to bolt right up to a stock center
section (Cat.)
So there should be no problem with the combo you are thinking about
doing.

The Euro M3 exhaust will not fit a US M3 as the diameter of the pipe is
larger the entire length.

-Doug

<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>

Douglas Mahar
Turner Motorsport
dugmar@turnermotorsport.com
www.turnermotorsport.com
www.turnerMINIsport.com
www.tmsracing.com (New LIVE Webcam!)
www.allshocks.com

- 2003 & 2004 Speed Touring Car Champions -

[GotBHP?]

How did you do the Euro exhaust. I email TurnerMS and they told me that Euro had a different exhaust port diameter and could not mate with a US spec engine.

Also, what SS midpipe are you running, and are you running O2 sims. If so, how is your A/F?

The euro's exhaust has larget primaries, collectors and overall piping. Perhaps thats what Doug was trying to say. You will need the euro SS headers, or just euro headers, and the appropriate euro sized mid-pipe and muffler. You just cant mix and match US spec and euro spec parts, unless you want a shop to chop things up and weld them back together.

[///M3///M5]

The euro's exhaust has larget primaries, collectors and overall piping. Perhaps thats what Doug was trying to say. You will need the euro SS headers, or just euro headers, and the appropriate euro sized mid-pipe and muffler. You just cant mix and match US spec and euro spec parts, unless you want a shop to chop things up and weld them back together.

Where did you buy your full Euro SS exhaust? Also, are you running O2 sims?

[Serious]

ya what he is trying to say is that the long tube euro headers are too long to mate up with teh stock mid pipes so you have to buy euro mid pipes in conjunction to headers to make it bolt up. or just hack your stock mid pipes off a foot or so and re weld the flanges.

[eXpLiCiT]

Hmmm well Im in need for a new clutch pretty soon. For the moment I have CAI, Trackpipe, Stromung exhaust, and uuc pulleys. I plan on going FI within the next 3 years. I once considered the UUC stg2 flywheel with m5 clutch but would this mod do anything for a FI'ed car?

[///M3///M5]

ya what he is trying to say is that the long tube euro headers are too long to mate up with teh stock mid pipes so you have to buy euro mid pipes in conjunction to headers to make it bolt up. or just hack your stock mid pipes off a foot or so and re weld the flanges.

Will I still be able to keep my AA Gen III or is the midpipe shortened as to allow for a regular length exhaust?

[GotBHP?]

Where did you buy your full Euro SS exhaust? Also, are you running O2 sims?

I got everything from Evosport, call them up, they know their $hit.

I run with magnaflow cats welded into the midpipe, so I can run O2 sims or with the stock sensors, works either way. You will need AA's air injection sim however.

[///M3///M5]

I got everything from Evosport, call them up, they know their $hit.

I run with magnaflow cats welded into the midpipe, so I can run O2 sims or with the stock sensors, works either way. You will need AA's air injection sim however.


Cool, so I could just buy the Euro Midpipe and Headers w/ AA's Sims and everything will bolt right up? Do you run the cats for emission testing?

[GotBHP?]

Will I still be able to keep my AA Gen III or is the midpipe shortened as to allow for a regular length exhaust?

The header-midpipe junction is a different length between the 2, the midpipe-exhaust junction is in the same exact spot. So long as you get the headers to mate with your stock mid-pipe, the rest will fit fine.

HOWEVER, the piping diameters of the euro pipes are so much larger than the US stuff that it would most likely do more harm than good to have such a large and abrupt step-down in piping diameters. Either do it all or save your money for somthing else.

BTW, for those of you who say headers wont give any gains, the SS Euro headers have given slightly greater gains on US motors than the KK setup.

[Serious]

Will I still be able to keep my AA Gen III or is the midpipe shortened as to allow for a regular length exhaust?

jsut shorten the front of the mid pipes to accomadate the longer headers. cat back isthe same.

[GotBHP?]

Cool, so I could just buy the Euro Midpipe and Headers w/ AA's Sims and everything will bolt right up? Do you run the cats for emission testing?

You would need a euro muffler as well for it to bolt up perfectly. I run the stock US cats for emmisions testing (had them welded up on a separate pipe). Getting harder all the time here in Cali to pass....

[///M3///M5]

GotBHP?,

Is your midpipe the SS Euro staight pipe or the resinator section?

[GotBHP?]

GotBHP?,

Is your midpipe the SS Euro staight pipe or the resinator section?

Their straight pipe with mag. cats in it. The resonator section is the same thing with resonators in it. If you search for my screen name and euro headers, you will probably find a gigantic thread about my euro headers, which probably has more clear info than I am typing up right now, cuz I am tired right now :stickoutt

[Serious]

from what ive heard any cat back will bolt up just fine to the euro mid pipes.

[GotBHP?]

from what ive heard any cat back will bolt up just fine to the euro mid pipes.

Nope, ive tried it. Pipes are completely different diameters, and the euro pipes use a compression fitting/gasket, the US versions do not.