ACT Prolite vs. Streetlite Lightweight Flywheel Performance Review and Comparison

[@madmiata1887]

3.5yrs later still relevant. You have both street and racing experience on these flywheels, awesome man. Can't get better then that. Went with a street lite. Thanks for the video.

[@RacerDave]

Thanks Mad Miata!

[@ask-Jack]

Very nice review. Lots of good information for anyone thinking of upgrading their flywheel.

[@RacerDave]

Thanks OM jack!!

[@Wolverine05]

Permanent smile lol good job

[@mackchannel6348]

Old content is still good content. Super great information here, thank you for the time and effort put into sharing your thoughts! Helping me to consider my choices--because of your video I'll avoid making a wrong decision that would have me suffering on the streets.

[@RacerDave]

Thanks! Glad I could help.

[@0ut0fafricaa]

An informative and engaging product comparison! Something most other reviewers can't do 👊

[@RacerDave]

Thanks Shaun!!

[@WickedCrispy]

I have a 2006 2.5i Impreza with 196,000 miles on it and the clutch is all but gone. There are no mods other than a free flow exhaust, and no tuning changes on the ECU. I've hated the stock 25 lb. flywheel since I've owned the car and I want to lighten the flywheel. I've researched the heck out of all the potential issues and I'm leaning towards the ACT Streetlight ~12 lb. flywheel because I don't want to throw any codes by confusing the knock sensors. The stock 25 lb. flywheel is horrible for rev matching, and I definitely agree with you when you say it feels like slow motion. The engine does what it wants and it's so unresponsive. Because I want to lower the flywheel weight I'm worried replacing the clutch with an OEM clutch will just burn the clutch up again so I want to upgrade to a minimal "Stage 1" aftermarket clutch. I don't race or launch the car. It's my daily driver. My BIGGEST issue is I can't get a straight answer on mixing and matching aftermarket flywheels with aftermarket clutches. All the websites just say I should use the same brands together, but because of this either the clutch is expensive and the flywheel is cheap, or vice-versa. ANY help would be hugely appreciated! Glad I found your channel today!

[@RacerDave]

These flywheels are designed to work with a stock clutch so it must be stock geometry right? And the clutches you're looking at are just stock replacement clutches so they must also be stock geometry right? I'm not a clutch expert or mechanic but I would feel plenty confident mixing and matching in my own car.

[@qleap99]

FYI for anyone, I've had the same ACT Streetlite flywheel in my Integra for, jeez, 20 years now (bought in 2004, I just added it up!), first with an Exedy stage 1 clutch for 4 yrs, now with an Exedy stage 2 clutch for 16 yrs. The stage 2 clutch is just giving up the ghost as of last week (which is why I'm researching) but the mixed combos have been excellent.

[@l.zhang_]

I got the Streetlite for my '09 Impreza 2.5i and it was a NIGHT AND DAY difference. Shifting from 1st to 2nd was atrociously slow before. Now I'm just banging through the gears. The increase in low end torque out of corners was very noticeable. 5th gear is more usable in the city and I can actually go uphill in 5th now 🤣 Thanks for the vid, Dave. This was very informative and helped me with my LWFW purchase 🤙🏼

[@RacerDave]

Excellent! Thanks for the feedback and I'm glad I could help!

[@angelis745]

Since I take my 2018 Forester off road alot (which I built it for) I prefer a heavy fly wheel to help keep the momentum up on these n.a. low hp/low torque 2.5i engines

[@RacerDave]

That's exactly what I would recommend too! Similar to my example of creeping up an on ramp in stop and go traffic. You definitely wouldn't want to go light weight. Thanks for the good input!

[@franciscocruz6726]

So I have the streetlite flywheel but my engine revs relatively slow anywhere below 3500 rpms. I have FBO, GSC S2 and I'm on e85 making 430whp on stock block. I'm contemplating on getting the prolite flywheel to improve bottom end responsiveness and shifts. How much would it help in your opinion. My Evo is not a DD.

[@RacerDave]

I’m not familiar with your exact setup but I will say that the changes you noticed going from stock to Streetlite will be significantly more noticeable with the prolite because not only is it lighter but most of the weight is taken off the outer portion of the flywheel which has the greatest affect on momentum. In my car it allowed the revs to climb and fall very quickly.

[@michaelbieber4502]

Awesome video.... Your very well spoken👍.

[@RacerDave]

Thanks dude!!

[@doraexplora9046]

I think lightening the flywheel is the best mod you can do to car once you've done the exhaust and intake. It's a cheap mod, especially if you get it done at a machine shop. And you can dial in the performance, by changing the amount you take off or keep on. Obviously you will lose torque, but a fast car is all about the power.

[@vzda123]

Nice, I'll probably get the streetlite for my frs/86. Still a daily but track 4+ times a year.

[@RacerDave]

Awesome, I’m glad this video helped!

[@MultiEd34]

How is the chatter on both flywheels?

[@willmoua1]

@3:35 no one's noticed your 7 fingers clutching that flywheel? I mean no disrespect, Just found this channel because I love racing too. Been mostly track and autox, but would love to try rally one day. Keep up the good work.

[@RacerDave]

Thank you! Not sure what you're seeing with 7 fingers. My gloved palm through the lightening holes?

[@FastPaull]

Looks like he's holding back a laugh the whole time haha. Solid info for people inquiring about a LWFW.

[@nwbklr]

If you close your eyes it feels like you’re listening to Ray Romano.

[@Rockerrobin]

Whats the opposite direction im building my 05 forester xt for off-road driving. 3" lift and 225 70r15 tire setup throughout bearing is going so looking into a clutch kit and flywheel upgrade while its getting replaced.

[@RacerDave]

For off-roading and slow speed stuff I would definitely go the other direction and put on the heaviest flywheel available to help carry the car through all the little things that try to stall out momentum.

[@Rockerrobin]

@@RacerDave my issue ended up being the drive shaft is wearing out

[@turbskibrz6594]

What a mint and detailed review thx so much

[@RacerDave]

You're very welcome!

[@buddybestor]

Nice review! What are your thoughts on lightweight crankshaft pulleys? I hear a lot of mixed opinions on that....some say to stick with the factory because it reduces engine noise vibrations, others ay with boxer engines they're already balanced well as they are so go as light as possible. I'm not sure.

[@RacerDave]

I recommend running a stock pulley. You'll keep the maximum protection for your engine plus you'll get the most performance out of a lighter flywheel anyway.

[@arsenal557]

I want expert advice, please. I own a 2000 Jeep Grand Cherokee and would like to change the new flywheel with less weight, knowing that the engine is 4.0-6 cylinders, how much do I lose from the weight of the old flywheel?? Do I need to change anything else???

[@RacerDave]

I’m definitely not an expert, especially on your particular vehicle. I suggest talking to a local shop or club that specializes in it to get the best information.

[@arsenal557]

@@RacerDave thanks

[@jaekdel34]

Just checking I just got the act heavy duty street clutch kit, there is a ton of clutch chatter in first and reverse, if this normal? Have driven about 200 miles on it

[@RacerDave]

I had no chatter with my setup but I know there are some setups that are more prone to it than others. What car are you driving? What flywheel are you running? Does having the air conditioning on or off change it?

[@jaekdel34]

@@RacerDave I have a 2017 wrx, with the light weight fly wheel. Not the racing one, wanted to keep it as a daily driver and thought this would be it but it chatters a shit ton.

[@jaekdel34]

@@RacerDave ac is off I haven’t tried running with it on but could try that, just hopping s couple hundred more miles will fix it but I don’t have high hopes. Thank you for the reply

[@RacerDave]

That’s a bummer for sure. I really don’t have any experience with the newer cars but definitely call ACT and do some research on that body style. I’d like to hope that combination would work just fine since it’s not extreme at all but some cars are just more sensitive to that stuff. It’s also possible one of the parts is just bad if no one else is having that issue. I asked about the A/C because one other guy mentioned the load from the compressor made his car worse. I wish I had a more specific answer for you but I wish you luck and hope that it’s a relatively straight forward fix for you.

[@RacerDave]

One other thought: if there’s nothing apparently “wrong” after you do your research and you are the type drive that generally starts with low rpms and almost no slip of the clutch you could try adjusting your technique to bring the rpms up a bit and slip the clutch a little more. This will give the engine a little more inertia at the slowest speeds to help combat that chatter. Good luck again and if I think of anything else I’ll let you know.

[@rayleal2109]

Thanks. Huge huge help

[@RacerDave]

You're very welcome!

[@edoubleist]

Excellent explanation, thank you

[@RacerDave]

You're welcome! Glad I can help.

[@Gunzaly]

Would the streetlite flywheel work with a exedy stage 1 clutch or is this strict to the act set up?

[@RacerDave]

It is an OEM replacement flywheel so as long as you're running a factory replacement / factory form factor clutch that will work on the OEM flywheel it will bolt right up no problem.

[@Gunzaly]

Racer Dave thank you for the fast reply! Was very hesitant, but you just confirmed my thought process. Looking forward to getting this. Great review by the way!

[@RacerDave]

You're welcome! And Thank You!!

[@leohughes6921]

Are your flywheels NA motor specific or are they WRX ones, I see part number differences for the WRX vs regular impreza. Been wondering about switching to a prolite from my streetlight on my own stage rally car.

[@leohughes6921]

I know they're technically interchangeable but I'm not sure about differences in clutch diameter.

[@RacerDave]

They are specific to certain years and models. I think there is a lot of overlap in Subarus but I couldn't tell you what is what. You'll have to check with ACTs website. Especially if you have the stock pulleys I recommend the prolite for racing. It makes the car feel very snappy.

[@ireneguerin6769]

Are these lighter flywheels beneficial on an EJ257 or other turbo motors?

[@RacerDave]

Irene Guerin, Absolutely! In fact these same effects will apply to all motors but to varying degrees depending on how the motor is designed and what the power curve is like. For any given car, if it has a more powerful motor, it will accelerate and go through the rpm's quicker, so a lighter flywheel will free up even more power than a less powerful motor in the same car. Also, on the other end, if a motor has more bottom end torque, it will be less affected on the starts than a motor with less bottom end torque in the same car.

[@patonbike]

Would you run a 12# flywheel on a street car or stick with stock weight?

[@RacerDave]

If I wanted the sportier feel and/or I drove a little more aggressively then I would totally run a lighter flywheel. The Steetlite with stock weight pulleys will drive just fine on the street and you should get used to the drawbacks I described in the video pretty quickly. Now if I had a lazy/casual driving style and/or always kept the rpms really low then I'd stay stock for sure.

[@patonbike]

@@RacerDave Thanks! It is going to be a "street ripper" probably will have to end up with a 6 puck clutch for the power. I will be putting on a Fluidampr soon which is actually heavier than stock. I've read that 6 puck and lightweight flywheel don't go all that well together but I'm not sure. Car is definitely sluggish in the low RPMs because it's a centrifugal supercharger so I thought the lightweight flywheel could help get it through those low RPMS. Sorry for the essay!!!

[@RacerDave]

I run a 6 puck with a fluid dampr and a prolite flywheel. Works great! The 6 puck just has a very short engagement window so if you're not slow and smooth on the clutch with some extra rpms then it can seem "bad".

[@patonbike]

@@RacerDave Thanks!!!!

[@jimvines5589]

debating on going with the act race sprung he clutch and prolite flywheel on my cammed mustang. what is a good slave cylinder/ throw out bearing to go with this?

[@RacerDave]

My ACT clutch kits always come with throw out bearings so I'd assume yours would too but check out their website or give them a call to be sure. As for Mustang parts, I have no clue there. On my Subaru I run the stock setup.

[@thanakislupusthesaltywolve7208]

I'm building my Mazda Protege5 right now and wondering should I install this flywheel it is a daily driver but I'm putting a lot of work into the motor and spensha is already completely coilover lowered with Wilwood brakes trying to make a rally car escs theme would you recommend putting this in my car

[@RacerDave]

Only you can decide that. My video tells my experience with these two flywheels and what I think the trade offs are. I'd suggest asking for more people's experiences and if possible drive someone's car that has a light flywheel so you can feel it for yourself. Good luck!

[@DrRockso419]

Hey Dave, big fan... I have an EJ253, and am looking into Lightened flywheels... Are you running a stock ecu? I hear that lightened flywheels cause timing issues... What input can you give?

[@RacerDave]

Thank you! All of last year I raced on the original stock 2.5L motor with the stock 2.5 RS computer. I first removed the A/C compressor which removes some rotational inertia even when it's not engaged. Then I added a complete light weight underdrive pulley set and had no issues at all. I then went to ACT's Streetlite flywheel because I also heard rumors of issues and didn't want to go straight to lightest flywheel. Still no issues at all. For Rally Colorado I swapped to ACT's Prolite flywheel to save even more rotational weight. The car still ran fine but I started to notice random times when the car didn't run perfectly smooth at low rpms or at idle. Still no check engine lights but I could tell the computer wasn't totally happy. I highly doubt you'd have any issues if you ran a Streetlite with stock pulleys. I even really doubt you'd have issues with a Prolite and stock pulleys. Especially if you still have to A/C compressor. It's possible that people who have had issues with light weight pulleys already had other issues developing that made it worse so who knows. I can't guarantee anything but if your motor is anything like mine you should be good. Have fun and let me know how it goes!

[@DrRockso419]

Thanks so much for the reply, Dave! I am actually interested in the Fidanza 110001 for 5MT NA offered by your friends over there at Flat Irons Tuning. I will be replacing my clutch in the next 6 months-ish, and figure if I'm going to be in there anyway, I'd like to make some upgrades. Is there anything else in that area you might suggest? Thanks again for hitting me back, and good luck in the coming season! Looking forward to many more great upgrade, install, review, and race videos!

[@RacerDave]

As long as they're similar in weight and design I think you'll have the same result. Your clutch kit should come with a new throw out bearing and pilot bearing. If not, make sure you replace those too. The Flatirons guys will definitely know this so I'm sure they've already made sure you've got the right stuff. There's not much else down there but if you've ever thought of changing out motor and transmission mounts or shifter bushings, now would be a convenient time. The next video is in work as we speak and should be out this week!

[@BP-fx3qc]

Dave, i know this is unrelated to the video but what are your thoughts on oil consumption on a 19k mile car. I got a fully routed catch can which is empty. Got an oil change yesterday on oil that only had 2k miles on it and i was 1/2 a quart low. I think its too soon to be loosing that much you know

[@RacerDave]

I just saw this comment and I'm sorry that I didn't respond sooner. A car that new shouldn't be losing any oil. I'd start by checking the oil level myself so you can check it more consistently and accurately to confirm that it is actually going through oil.

[@MrNiceGuyGTL]

I just had my stage 1+ subaru 2015 wrx clutch kit put on. (Act II street friendly) by a mechanic my car is making a tick tick tick tick tick tick noise while driving... and the engine has no power past 4500 RPM’s whats wrong with my car?

[@RacerDave]

Hard to say but that's definitely going to need a mechanic to look at it in person. I'd take it back right away if it wasn't doing that before the clutch job.

[@rayleal2109]

That happend to my car too when I press the pedal itd go away. It was the clutch cylinder loose. Ziptied and stop the noise

[@penguinpie5056]

the first thing you should always do after a serious crash is get more performance out of the car. 4:32 ...and it crashes faster.

[@RacerDave]

Hahaha, yep!! That crash was because of several factors but the car being too fast wasn't one of them. Normally I'd agree with you though.

[@Floatworld]

Great info... great video

[@RacerDave]

Thanks Robert!

[@miamimotogroup5371]

I purchased the HD with streetlite fly wheel for frs. And with AC it sounds like rocks are in my transmission. If your going to daily YOU WILL HATE IT. The noise makes your car sound like trash

[@RacerDave]

Oh no! That's no good. This is the first I've heard of an issue like this, especially on a Subaru. Have you found any stories that this has happened to others? Also, do you have any other mods like lightweight pulleys?

[@miamimotogroup5371]

Racer Dave yes it’s on KZbin people have posted videos of clutch rattling when ac is on. With this specific kit. I would do exedy. Which is what I will be doing next time

[@RacerDave]

That's great to know! Thanks for adding the info for everyone I really appreciate it! One thing to look out for is the brand shouldn't really matter but the combination of the rotating weight (flywheel and/or pulleys) and whether you have a sprung or unsprung clutch disk so whether you switch up the brand or not just make sure not to duplicate the specific combination that's giving you trouble. If you happen to think about it when you make the swap let us all know what combo you switched to and what the outcome was. Thanks again!

[@miamimotogroup5371]

Racer Dave the only issue of going light on the fly wheel. Because it is so light the way the stock engine was built for the oem weight which now increase rotation mass and causes that rattle. I can drive the car real hard and the shifts are amazing but at lights and idle with ac on the car is very bad. I will post a video on my channel to show you what I mean. I upgraded the clutch fork to verus and billet pivot ball as well retainer clips to

[@jonntischnabel4918]

Lightweight flywheel has everything to do with rotational mass and inertia. the difference in kerb weight will be negligible. 🤣 however , it's still lighter I guess. A gain can be made by lightening all the pulleys also.

[@RacerDave]

Of course that’s the biggest benefit but consider that racers spend hundreds or thousands of dollars on carbon and other high end materials just to save a couple pounds here and there on non-moving parts so they can shave tenths of seconds of their lap times. Also consider that rotating mass savings only helps with acceleration where as any generic mass savings helps with acceleration, braking and turning. You can see that getting 10 to 20 pounds off of the car anywhere is a pretty big deal in general. Now add in the rotational effects and this is an awesome mod. If you search my videos I also did a video on light weight pulleys and one on the potential down sides to installing them. Thanks for your input and hopefully I helped clarify some things!

[@Ed-vi4rx]

Well i got the streetlite installed. Engine sounds like a diesel from 900 till 3000 revs. if your not racing dont do it. (NA engine with hfc and catback exhaust)

[@RacerDave]

That hasn't happened with any flywheel I've ever run and I've never heard of this being an issue and I know a lot of people that run it. Something else could be wrong so definitely check everything over. Exhaust leak? Hose or intake not hooked up correctly?

[@Ed-vi4rx]

@@RacerDave It is definetely chatter in the more extreme way. Think ill change it to JWT or light dual mass. Iam with a large club of 350z enthousiast. Comparrison is here

[@RacerDave]

@@Ed-vi4rxummer. Sorry to hear that. Good to know that 350Zs shouldn't run light flywheels at all. Thanks for sharing.

[@allgripnoslip]

@@Ed-vi4rx I am about to buy the streetlite flywheel with the street/race use clutch kit. Can you please give me some feedback? I am a little worried. My car is a 2003 350Z. Thank you so much.

[@altimatic2183]

great video, but you look like youre trying your best not to laugh hahaha

[@RacerDave]

haha... ok. Not sure what to say about that one but thank you!

[@jsallerson]

It’s kinda funny how your voice gets lower at end of phrases when you’re getting low on oxygen.

[@Cullinane2010]

kind of creepy watching you try and maintain a smile the whole time. maybe try editing in some extra footage pertaining to what youre talking about on your car or some examples, and maybe try different camera angles while talking about an object so i dont feel like im just awkwardly standing in front of you while you recite a script with a permanent smile.

[@deluxsound123]

Your a fuckin asshole!

[@NWkush024]

U need to smile more

[@Sedona_FD3S]

You’re a flywheel

[@williamcapps8914]

This guy is just smiling WAY too much which keeps me wondering what is he smiling about? Does he think it’s funny cuz he’s recommending me a dumb product? Or is he really just that happy about a truly simple upgrade on his car but still I don’t see how just this flywheel is like the greatest thing ever and can’t stop smiling about it. The fact I was so distracted by that creepy smile made listening to the video even harder like, why must you do that? What is SO FUNNY? Idk. For sure get more serious and ditch that smile man its just not necessary