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Old 04-06-2022, 02:02 PM   #1
BlackFighter
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Default RCM High Grip Timing Belt Tensioner

Anyone use the new RCM High Grip Timing Belt Tensioner? Any great benefits vs just the new style OEM tensioner and the small idler bearing. What I can see is that its a side tensioner vs up/down newer style. How more reliable is it? Can I just replace the Subaru Belt Tension PN 13068AA051 when I need a new one on this kit?

How much longer do you think Subaru will be manufacturing and selling the OLD style tensioner and the timing tensioner pulley for? Don't want to buy one and then not be able to locate just the tensioner.

What I see is that to replace the older style tensioner and the Timing Tensioner Pulley, it will cost you a extra $100 then just getting the newer style tensioner.

https://www.flatironstuning.com/rcm-...belt-tensioner
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Last edited by BlackFighter; 04-06-2022 at 03:48 PM.
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Old 04-06-2022, 03:24 PM   #2
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of the millions and millions of cars with timing belts, I've never once heard of someone's tensioner failing in operation

That unit looks nice, but probably not necessary at all
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Old 04-06-2022, 04:01 PM   #3
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of the millions and millions of cars with timing belts, I've never once heard of someone's tensioner failing in operation
Really? There are at least two people that have posted in the past 2 weeks that have reported their Aisin tensioner failed on new build engines and skipped timing in less then 1000 miles.

I'm also sure that whoever skipped timing was due to a belt tensioner either going bad or went bad.
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Old 04-06-2022, 04:38 PM   #4
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I have had the new style fail loud, no skipped teeth but it was rattling on ej253
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Old 04-06-2022, 04:59 PM   #5
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Quote:
Originally Posted by BlackFighter View Post
Really? There are at least two people that have posted in the past 2 weeks that have reported their Aisin tensioner failed on new build engines and skipped timing in less then 1000 miles.

I'm also sure that whoever skipped timing was due to a belt tensioner either going bad or went bad.
2 people out of the **** ton of other people who don't use this and just use the Aisin style tensioner?
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Old 04-07-2022, 09:58 AM   #6
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Conversely I've seen multiple RCM or similar style tensioners fail. If you look at the total number of OEM Subaru vs total number of aftermarket, then hear about the failures....OEM is fine.
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Old 04-07-2022, 10:07 AM   #7
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If you look at the total number of OEM Subaru vs total number of aftermarket, then hear about the failures....OEM is fine.
If you look, they use a OEM Subaru old style tensioner in the kit. Its the bracket that is aftermarket, not the tensioner. If you look at the 3rd pic, it clearly has a "Japan" stamp on it and the "Lexus" icon I call it.

Quote:
Conversely I've seen multiple RCM or similar style tensioners fail.
I would not be surprised if the RCM tensioner is the same as Aisin just rebranded with their name. They clearly say "we are working closely with NTN, NSK, Koyo & Aisin to formulate our range."

Last edited by BlackFighter; 04-07-2022 at 11:51 AM.
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Old 04-07-2022, 03:51 PM   #8
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The “Lexus” icon is the symbol for Fuji industries

Aisin “style” tensioners are not aisin tensioners , or oem Subaru for that matter

Most tensioner failures are from improper install procedures , some are from blatant abuse or just full on crazy competition, not meaning some hard parking saggy pants flatbiller hanging at sonic drive with their vaping biz cards suck in the stretched tires beads that hangs it on the red limiter when his fav hip hop song comes on , I mean actual competition with purpose built cars that compete

The rcm unit looks very nice and it’s claims to better keep time in high rpm or while used with sequential boxes looks good to me , I have not heard of any failures other than improperly installed ones with the rcm unit

The blatant design ripoff of the rcm high grip tensioner by iag has had not so stellar result though

In my opinion use an oem Subaru or aisin and the right process to install , or the original rcm high grip , not a failure prone multi time revisioned rip off


Btw , Have you seen the solid exhaust gears from rcm paul ?
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Old 04-07-2022, 04:13 PM   #9
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Hey Mike, LOL you really hate car meets at sonic, don't you LMAO

Quote:
Btw , Have you seen the solid exhaust gears from rcm paul ?
I think so, might be a option since I'm not a fan of the OEM plastic ones. Got my heads back but have to put the project on hold for a little bit. Was hoping to get this car done before the baby comes, but now since I have to pay the IRS $9k+ the block has to wait a little, that was my block money HAHA. So close but so far away.

You talking about these?

https://rogerclarkmotorsport.co.uk/c...lley-kit-rh-lh

Quote:
The "Lexus" icon is the symbol for Fuji industries
Ya I know, just phrased it in a lazy way haha.

Quote:
The rcm unit looks very nice and it's claims to better keep time in high rpm
That is why I it could my eye with the engine we talked about.

Last edited by BlackFighter; 04-07-2022 at 04:26 PM.
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Old 04-07-2022, 04:21 PM   #10
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Yep. And the assclowns that do stupid ****e that ruin it for the real peeps

&

Yep, Flatirons has them
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Old 04-08-2022, 06:48 AM   #11
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Originally Posted by motorbykemike View Post
not meaning some hard parking saggy pants flatbiller hanging at sonic drive with their vaping biz cards suck in the stretched tires beads that hangs it on the red limiter when his fav hip hop song comes on
^this is the most descriptive statement about this type of car owner I've ever read.
awesome
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Old 04-08-2022, 08:36 AM   #12
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Really? There are at least two people that have posted in the past 2 weeks that have reported their Aisin tensioner failed on new build engines and skipped timing in less then 1000 miles.
I believe those were because they were not properly setup from the get-go.

Looks like that thread was deleted?
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Old 04-08-2022, 09:27 AM   #13
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I believe those were because they were not properly setup from the get-go.

Looks like that thread was deleted?
You can always rely on Chris to pitch in, thanks. Have you guys ever used this kind of a setup? Any thoughts on it?

Ya im not to concerned with Aisin, i still might go ahead and use it, my main question was, how much better is the older style tensioner, especially at high RPMS since that's where ill be running my engine at most of the time on the track.
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Old 04-08-2022, 07:14 PM   #14
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It’s not the old style tensioner

It’s the best of both worlds according to rcm
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Old 04-15-2022, 07:35 AM   #15
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Originally Posted by BlackFighter View Post
You can always rely on Chris to pitch in, thanks. Have you guys ever used this kind of a setup? Any thoughts on it?
Of course!

We don't build a ton of engines, but we're also not making crazy power. 760whp was the highest on a GD, and 600whp on a GR and VA. Stock belts, tensioners and guides were always used. The only deviation is that I like to use the LIC eccentric idlers to time the cams. Never had an issue using those, but have heard of newer variants causing issues.

We did use the 'Performance' or 'racing' Gates belt once. Noticed nothing different. I'm sure at some level they can be beneficial, but I think most fall prey to the perceived marketing 'need' for them.
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Old 04-15-2022, 10:05 AM   #16
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Originally Posted by KillerBMotorsport View Post
Of course!

We don't build a ton of engines, but we're also not making crazy power. 760whp was the highest on a GD, and 600whp on a GR and VA. Stock belts, tensioners and guides were always used. The only deviation is that I like to use the LIC eccentric idlers to time the cams. Never had an issue using those, but have heard of newer variants causing issues.

We did use the 'Performance' or 'racing' Gates belt once. Noticed nothing different. I'm sure at some level they can be beneficial, but I think most fall prey to the perceived marketing 'need' for them.
We cornered someone from Gates at PRI years ago to find out the difference between the normal belt and the racing belt. We were told that the difference is blue paint.
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Old 04-15-2022, 11:20 AM   #17
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We cornered someone from Gates at PRI years ago to find out the difference between the normal belt and the racing belt. We were told that the difference is blue paint.
LOL somehow I am not surprised.

Quote:
Of course!

We don't build a ton of engines, but we're also not making crazy power. 760whp was the highest on a GD, and 600whp on a GR and VA. Stock belts, tensioners and guides were always used. The only deviation is that I like to use the LIC eccentric idlers to time the cams. Never had an issue using those, but have heard of newer variants causing issues.

We did use the 'Performance' or 'racing' Gates belt once. Noticed nothing different. I'm sure at some level they can be beneficial, but I think most fall prey to the perceived marketing 'need' for them.
Were the engines high revving engines? Did you guys replace the tensioners after every season? I'm asking because I know my 500whp goal is not high like others are, so the OEM tensioner is fine, but my main concern is the high revving RPMS. The engine will be for the track mainly between 4000-9000 rpms driven hard.

I was fine with using the regular OEM tensioner but the RCM one caught my eye because they claim "An extremely worthwhile modification on all high revving engines". The EJ257 already come with small idler bearing, but they say "2 piece Subaru timing belt tensioner system as it is more reliable than the later single piece tensioner". So any one know how and why the 2 piece is more reliable?

I'm sure I'm splitting hairs here, but always willing to learn something new if I can.

Last edited by BlackFighter; 04-15-2022 at 11:29 AM.
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Old 04-15-2022, 01:39 PM   #18
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Originally Posted by BlackFighter View Post
Were the engines high revving engines? Did you guys replace the tensioners after every season? I'm asking because I know my 500whp goal is not high like others are, so the OEM tensioner is fine, but my main concern is the high revving RPMS. The engine will be for the track mainly between 4000-9000 rpms driven hard.
They were modest, 8-8,500. I don't recall how often we replaced them, but generally, I'm not a proponent of reusing wear components on engines at this level of cost. Seems like it's just asking for trouble.

Are you sure you're talking about an EJ engine? 5,000 RPM powerband is something I've never seen a Subaru come even remotely close to. If it's going to live on track, the RPM swing is going to be 2,500-3,000 RPMs max generally.
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Old 04-15-2022, 06:44 PM   #19
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Well maybe not as much as 9000 but definitely 8500+ rpms. It's a 2.35 de-stroker with a gt3582 turbo on e85 on a circuit track, not drag. Depending on the track, plan to keep the car in gear taking a turn, and then just floor it out of a turn. Hard to explain.
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Old 04-19-2022, 07:29 PM   #20
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Originally Posted by subydude View Post
Conversely I've seen multiple RCM or similar style tensioners fail. If you look at the total number of OEM Subaru vs total number of aftermarket, then hear about the failures....OEM is fine.
I've never heard of an RCM failure. IIRC IAG had a relatively low percentage failure but they also weren't on the market long.
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Old 04-19-2022, 08:08 PM   #21
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Hard to explain.
Sounds simple enough to me, but that turbo, de-stroked, on any fuel, isn't going to have and decent power at 4K RPMs. It would make much more sense to go into the turn in a lower gear, and make decent power when you get back into it.
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Old 04-19-2022, 09:24 PM   #22
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How many destroker 75mm crank 2-4mm rod , 99.5 - 101.6 bore motors have you played with Chris ?

You might like what you find there

It’s 2.34 Paul

The 2.35 is a 2.5 crank in a 2.2 case

Details
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Old 04-20-2022, 07:14 AM   #23
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Originally Posted by motorbykemike View Post
How many destroker 75mm crank 2-4mm rod , 99.5 - 101.6 bore motors have you played with Chris ?

You might like what you find there

It’s 2.34 Paul

The 2.35 is a 2.5 crank in a 2.2 case

Details
Few, but stroke or de-stroke the premise is straightforward, and at this point in time, plenty of plots detailing the effects on power.

I've never had a need personally, but tend to do things differently with the bigger power setups I've done, and they've always had a powerband wider than necessary for the job.
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Old 04-20-2022, 01:42 PM   #24
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Quote:
How many destroker 75mm crank 2-4mm rod , 99.5 - 101.6 bore motors have you played with Chris ?

You might like what you find there

It's 2.34 Paul

The 2.35 is a 2.5 crank in a 2.2 case

Details
Yes its going to be a 2.34 not 2.35 haha. Details are important.
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Old 04-22-2022, 03:10 PM   #25
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Quote:
Originally Posted by motorbykemike View Post
How many destroker 75mm crank 2-4mm rod , 99.5 - 101.6 bore motors have you played with Chris ?

You might like what you find there

It’s 2.34 Paul

The 2.35 is a 2.5 crank in a 2.2 case

Details
75mm and 101.6 is the ticket. Been saying that since 06 or 07
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