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BHR flywheel

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Old 12-11-2010 | 03:27 PM
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Thumbs up BHR flywheel

Hey guys I was wondering how many people have one of these and there thoughts as I plant to get one in the new year but ive been told if the fly wheel is to light it can compromise steering (not sure how) so id appreciate your opinions on this piece of kit.
Old 12-11-2010 | 05:53 PM
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from all i know if not engineered properly it will throw off the balancing of the rotary engine and cause big problems id go with sr motorsports i have there light flywheel i have no problems and i can feel a difference. there flywheel comes with a balance plate with there flywheels
Old 12-11-2010 | 05:56 PM
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Our flywheel is neutral balanced so it does require a counterweight for proper balancing. Charles Hill, MazdaManiac and myself all run this flywheel on our own RX8s.
Old 12-11-2010 | 06:56 PM
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From: Caput Mundi
I have it. It's balanced and machined better than 99.99999% of any other aftermarket flywheel and is just as light as you can go before compromising driving comfort at lower rpms.
Old 12-11-2010 | 07:00 PM
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I have their flywheel and the spec clutch to and I love it! Charles has always asked me about how I like it and I always say how I love it BHR will support this mod all the way, no worries.
Old 12-11-2010 | 09:15 PM
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Love love love my BHR flywheel. One of the best mods i've done other than short throw, and their midpipe
Old 12-11-2010 | 09:46 PM
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From: Y-cat-o NZ
Originally Posted by shifty
I plant to get one in the new year but ive been told if the fly wheel is to light it can compromise steering (not sure how) .
yes - what you heard is very true and it must have come from a very reliable source .















cough
Old 12-11-2010 | 10:25 PM
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I have one - love it!
Old 12-11-2010 | 11:23 PM
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steering.......someone is drunk
Old 12-12-2010 | 04:23 AM
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Ok cheers guys that's all I needed to know I'm glad your all pleased with the wheel and hopefully soon il be joining the ranks.
Old 12-12-2010 | 06:33 AM
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steering = streeting = streetability
Old 12-13-2010 | 03:30 PM
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I think SC-ed has banged the nail on the head mate.....

I've heard the stories it can affect streetability......

Also heard it requires a few more hundred RPM to get going and it helps deceleration quite a bit aswell.....

No real reviews on Acceleration? What are people thoughts on extra pull, butt Dyno? Actual dyno? (To show how much BHP is saved compared to the OEM item?)
Old 12-13-2010 | 03:50 PM
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I should just tell you to search but I'm in a good mood so :

Originally Posted by Elektix
I've heard the stories it can affect streetability......

Also heard it requires a few more hundred RPM to get going and it helps deceleration quite a bit aswell.....
Minimal effect - not worth worrying about

Originally Posted by Elektix
I
No real reviews on Acceleration? What are people thoughts on extra pull, butt Dyno? Actual dyno? (To show how much BHP is saved compared to the OEM item?)
good improvement in 1st less so in 2nd , fading away to nil improvement in 6th . As you would expect if you understand how this works.
No difference on a dyno because on a dyno the engine is not accelerating very quickly .
Old 12-13-2010 | 03:56 PM
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Originally Posted by Charles R. Hill
2) Potential engine bucking under 2,500 RPMs.
good point - been so long since I've driven a stock 8 that I'd started to think that this behaviour was normal .
Old 12-13-2010 | 04:06 PM
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Originally Posted by Elektix
I think SC-ed has banged the nail on the head mate.....

I've heard the stories it can affect streetability......

Also heard it requires a few more hundred RPM to get going and it helps deceleration quite a bit aswell.....

No real reviews on Acceleration? What are people thoughts on extra pull, butt Dyno? Actual dyno? (To show how much BHP is saved compared to the OEM item?)
Not many people have the money to buy the flywheel, dyno the car, spend 4(?) hours to replace the flywheel and then dyno the car with the new flywheel again. If they did, you would probably complain that the dyno's weren't done back to back so the data is invalid.
Sometimes you have to trust the butt dyno.
I installed a MS lightweight flywheel and I noticed a difference right a way.
Old 12-13-2010 | 04:28 PM
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From: Caput Mundi
Originally Posted by Brettus
good improvement in 1st less so in 2nd , fading away to nil improvement in 6th . As you would expect if you understand how this works.
No difference on a dyno because on a dyno the engine is not accelerating very quickly .
Talking in numbers i'd say that the flywheel is the single NA mod that yelds the best results.
0.2" as an average during 0-100km\h pulls per my telemetry, other users reported a 0.4" improvement but it seems just way too much for a streetable flywheel. Maybe with a 4.5inch clutch pack and flywheel
Old 12-27-2010 | 01:48 AM
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waiting for restock...
Old 12-27-2010 | 07:33 AM
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I want a flywheel badly.. I had a subaru that went from a 26lb stocker to an 11lb one. Then after an engine swap, I went to a 9lb Ultralight flywheel. Loved it. No problems in the street or snow.

No other mod makes an engine respond like a light flywheel.. but is this one going to be light enough?
Old 12-27-2010 | 09:09 AM
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Originally Posted by alnielsen
Not many people have the money to buy the flywheel, dyno the car, spend 4(?) hours to replace the flywheel and then dyno the car with the new flywheel again. If they did, you would probably complain that the dyno's weren't done back to back so the data is invalid.
Sometimes you have to trust the butt dyno.
I installed a MS lightweight flywheel and I noticed a difference right a way.
It makes sense to me... It wouldn't act any differently than an underdrive pulley, since the flywheel is just the other side of the e shaft.
Old 12-27-2010 | 09:25 AM
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From: Buddhist Monastery, High Himalaya Mtns. of Tibet
Originally Posted by Beodude
It makes sense to me... It wouldn't act any differently than an underdrive pulley, since the flywheel is just the other side of the e shaft.
The pulley doesn't weigh much to begin with, so changing it out will give you minimal gains. The underdrive pulley can lead to overheating on the street due to slowing of the water pump. Also, draining of the battery at idle. While it takes more work, a light weight flywheel is the way to make the greatest gains.
Old 12-28-2010 | 09:40 PM
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Hey guys,

I just got an ACT Extreme clutch and I am planning on ordering a flywheel as well since the clutch is going to be changed.

I have been thinking about either the ACT Prolite or the BHR.

Any thoughts on which of these might be the better flywheel since they're only about $120 difference including the counter weight?

Thanks.
Old 12-28-2010 | 11:09 PM
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Pretty sure everyone in this thread is going to tell you they love the BHR.

As Charles mentioned it's not just about weight, it's about inertia and where the weight is concentrated on the flywheel. The same flywheel weight with the center of mass further away from the center will take more power to spin.

Here's a simple experiment for you to figure out the effect of a lightweight flywheel.

Take a rock and tie a 12" string on it. Spin it over your head.

Now take a rock that is 1/2 the weight on the same string and spin it over your head. How much less effort does it take? That's the effect of reducing the weight of the flywheel. It frees up energy usually used to keep the wheel turning. No matter how fast you spin it or whatever gear your hand is in it's the same amount of energy freed up from your muscles.

Now here is how a well designed flywheel works:

Then take the same rock and tie a 6" string over it and spin it over your head. How much less effort does it take to spin the same rock?

That is what a well designed flywheel will try to do.
Old 12-28-2010 | 11:44 PM
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Do not use lightened fly wheels!

They don't fly any further than regular flywheels!

wait. whut?
Old 12-28-2010 | 11:46 PM
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RB is 12 lbs.

hey - is the flywheel to counterweight bolt torque 28 ft lbs? or is it based on bolt size and spec?
Old 12-28-2010 | 11:50 PM
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Originally Posted by Charles R. Hill
The Act


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