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"Rate of RPM limiter" keeps getting triggered - clutching issue?

P
Dec 30, 2010
22
2
3
Nelson BC
Turboed XM @ 6-7PSI

I am wondering how I can build more "load" into the clutch system as the XM keeps triggering the what i assume is the "rate of RPM limiter" - if i punch the throttle (usually happens around 6000 - 7000 rpm - cuts right out).

The is no over rev displayed - as It is not over reving because if i slowly increase the throttle to full it lands around 7400RPM - no where close to 8300. If I put it on clicker one to decrease RPM I can then punch the throttle again but i cant get full rpm as it lands about 7000 RPM - but the rate of RPM limiter does not get triggered. If i try to increase the clicker - to get proper RPM (7900) I can't punch the throttle at all - it just triggers the rate of RPM limiter. I have to stay under 7400. If i try to increase RPM or increase boost from 6 to 7 - it immediately trigger rate of RPM limiter when i punch the throttle.


I tried stock secondary - way way worse!



Someone told me that a 43/47 Helix works well on the XM turbo to add more load to slow down the rev rate so the limiter is not triggered. I am not sure what the angle of the Cudney CR-8 is that i have in it.




Current specs:

2013 XM 800

mountain riding mostly @ 5000-6500 feet

21-51 gearing - 163 2.5 track
[FONT=&quot]200/290 primary spring[/FONT]
[FONT=&quot]441 ramps [/FONT]
[FONT=&quot]23 grams pin weight[/FONT]
[FONT=&quot]CR-8 Helix (cudney racing)
165-300 Secondary Spring (Dalton red)
[/FONT]
 
T

Turbo11T

Well-known member
Nov 26, 2007
3,062
751
113
Lake Crystal, MN
Im not sure what the CR-8 helix is exactly. But I will give you some thoughts.


You need to set your clickers on 3 and then adjust your pin weight to make 7900-8000 rpm. Clicker 3 is the best all around spot for revviness and load. Clickers are to fine tune your sled once you have it right where you want it. Preferably just overreving(8100) on the trail so that it will be right at 7900 in the powder.


I kind of doubt you are setting a safety for rpm increase. I have a lightweight primary and 1mm oversize rollers and my sled revs extremely fast with no issues. Others have ran the p85 which is light and revs quickly as well. Wells others still have ran the new pdrive which revs quickly as well and still not experienced what you think is happening.


I think you need to fix your WOT RPM first.


I will share what I am running for clutching and have been super happy with.


DJ mountain ramps 415/441 blend
200-290 spring
21.5 grams of pin weight
1mm oversize rollers(adds 2 grams, Makes it revvyer)
DJ qr11 Helix(no idea on the angle as he doesn't tell you)
225/330 spring


My buddy is running close to the same setup but he doesn't have the DJ helix he is running a 43/47 helix. His works ok but not as good as mine.
 
F
Nov 27, 2007
2,495
712
113
medicine hat
Explain what's your thoughts on what the clickers do on this pdrive, do they drop or increase top rpm or just make bottom revier?? ... When you increase clicker does it pull on motor harder pulling it down in rpm?? Thanks

Im not sure what the CR-8 helix is exactly. But I will give you some thoughts.


You need to set your clickers on 3 and then adjust your pin weight to make 7900-8000 rpm. Clicker 3 is the best all around spot for revviness and load. Clickers are to fine tune your sled once you have it right where you want it. Preferably just overreving(8100) on the trail so that it will be right at 7900 in the powder.


I kind of doubt you are setting a safety for rpm increase. I have a lightweight primary and 1mm oversize rollers and my sled revs extremely fast with no issues. Others have ran the p85 which is light and revs quickly as well. Wells others still have ran the new pdrive which revs quickly as well and still not experienced what you think is happening.


I think you need to fix your WOT RPM first.


I will share what I am running for clutching and have been super happy with.


DJ mountain ramps 415/441 blend
200-290 spring
21.5 grams of pin weight
1mm oversize rollers(adds 2 grams, Makes it revvyer)
DJ qr11 Helix(no idea on the angle as he doesn't tell you)
225/330 spring


My buddy is running close to the same setup but he doesn't have the DJ helix he is running a 43/47 helix. His works ok but not as good as mine.
 
T

Turbo11T

Well-known member
Nov 26, 2007
3,062
751
113
Lake Crystal, MN
Explain what's your thoughts on what the clickers do on this pdrive, do they drop or increase top rpm or just make bottom revier?? ... When you increase clicker does it pull on motor harder pulling it down in rpm?? Thanks



Fred,


No idear on the pdrive clickers. His post is on a XM so it has the TRA. I was making note of the fact that the pdrive is lighter so in turn it is faster revving and that many have ran it on the 800 etec without causing a "rate of RPM increase" safety in the ECU.
 
P
Dec 30, 2010
22
2
3
Nelson BC
That is the strange thing - if i try to raise my rpms to get them around 8000 it just cuts out when i pin it (around 6000). Gauge never says over rev. The only way i can get it to not cut out is when i set the clickers to keep the rpm below 7400 (then i can pin it). Or if i lower the boost i can get more rpm but then i am only at 5psi boost. That is why i was thinking it was the rate of RPM limiter.

Maybe there is some other issue going on?
 
T

Turbo11T

Well-known member
Nov 26, 2007
3,062
751
113
Lake Crystal, MN
That is the strange thing - if i try to raise my rpms to get them around 8000 it just cuts out when i pin it (around 6000). Gauge never says over rev. The only way i can get it to not cut out is when i set the clickers to keep the rpm below 7400 (then i can pin it). Or if i lower the boost i can get more rpm but then i am only at 5psi boost. That is why i was thinking it was the rate of RPM limiter.

Maybe there is some other issue going on?



You must have missed my point about setting the clickers on 3 and changing your pin weight until you get 8000 rpm. 3 is where you want to run the clickers. No matter turbo'ed or not.
 

winter brew

Premium Member
Lifetime Membership
Nov 26, 2007
10,016
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LakeTapps, Wa.
That is classic "rate of rpm" hesitation. It's from not loading hard enough in the low-mid.
The 200 primary spring start is where I would start....never could get a etec to consistently not trigger that annoying hesitation, even stock. I would drop to a 160 start, adjust weight as needed and run on clicker 3-4.
 

kfaz123

Member
Premium Member
Oct 3, 2012
7
5
3
B.C.
I`m with winterbrew totally rate of rpm hesitation. I run almost the same setup had to get all the way up to 25 grams pin weight with 2mm over sized rollers that pin weight includes the extra weight of the oversize rollers. this is on a impulse setup 7 psi. sled rips can pin it from a dead stop now no hesitation had to run a 320 finish cause my top end rpm was dropping off on a long pull with a 290 finish rate. 5000 too 7000+ feet elevation.

DJ mountain ramps 415/441 blend
160-320 spring
25 grams of pin weight
2mm oversize rollers
DJ qr11 Helix
225/330 spring
clicker 3
 
P
Dec 30, 2010
22
2
3
Nelson BC
Okay finally got the new primary spring in (160-290) plus I did the secondary - 43/47 helix and a 230-300 secondary spring. Good news is the rate of RPM limiter is solved - I can feel the sled being loaded more.

Now just have an RPM fade issue - hits 7900 and fades down to around 7400. @ 6psi boost. I guess I will try Kfaz123's advice and up the primary spring finish weight - I do have a 160-320 kicking around. Plus add more pin weight. OR should i try raising the finish rate of the secondary to a 330???
 
Last edited:

kfa670

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Lifetime Membership
Nov 29, 2007
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Okay finally got the new primary spring in (160-290) plus I did the secondary - 43/47 helix and a 230-300 secondary spring. Good news is the rate of RPM limiter is solved - I can feel the sled being loaded more.

Now just have an RPM fade issue - hits 7900 and fades down to around 7400. @ 6psi boost. I guess I will try Kfaz123's advice and up the primary spring finish weight - I do have a 160-320 kicking around. Plus add more pin weight. OR should i try raising the finish rate of the secondary to a 330???

What kind of turbo/kit are you running? I had the same rpm fade problem with my aero kit running 10 lbs. Aero stupidly draws air from under the hood... As soon as I switched to a cold air intake I saw almost 100 degree drop in intake temps... And no more rpm fade. I actually had to adjust my clutching because I started to over rev
 
P
Dec 30, 2010
22
2
3
Nelson BC
What kind of turbo/kit are you running? I had the same rpm fade problem with my aero kit running 10 lbs. Aero stupidly draws air from under the hood... As soon as I switched to a cold air intake I saw almost 100 degree drop in intake temps... And no more rpm fade. I actually had to adjust my clutching because I started to over rev

sounds like your cold intake helped alot!

Mine is a silber kit (with a Redline G3 fuel controller). It draws air from stock air box.
 

kfa670

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Nov 29, 2007
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sounds like your cold intake helped alot!

Mine is a silber kit (with a Redline G3 fuel controller). It draws air from stock air box.

Should be good to go on intake then.. what does your AFR do as it fades off?

Something I used to experiment with was taking out the muffler egt (not the pipe) and plugging it with a spark plug and just hanging that sensor up out of the way. This used to change the way the sled fueled as well as my AFRs and used to seem to hold rpm better. I'm not suggesting this as a fix but it's something you could try. I think my egts used to be so hot with that under hood air that it would start to retard the timing and by does that make a turbo start to suck haha. My cold air intake fixed all of that
 

winter brew

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Nov 26, 2007
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LakeTapps, Wa.
Maybe try a straight 42 or a Shockwave to see what angles work best at various shift ratios...then have a progressive cut to those optimum angles :face-icon-small-win
 

kfa670

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Nov 29, 2007
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Interestingly, a friend of mine called me last night with this same problem on his 15 aerocharged xm. Hitting the crank speed sensor or whatever it is. He was running a 260/400 primary spring... I don't know why...

Low and behold a 160/230 fixed his general issue. He just had that one laying around.

I run DJs clutch setup in mine and have been quite happy with it. Think I have a 200/320 in there currently.

Looking back I pretty much have the same setup as kfaz
 
Last edited:
P
Dec 30, 2010
22
2
3
Nelson BC
Now just have an RPM fade issue - hits 7900 and fades down to around 7400. @ 6psi boost. I guess I will try Kfaz123's advice and up the primary spring finish weight - I do have a 160-320 kicking around. Plus add more pin weight. OR should i try raising the finish rate of the secondary to a 330???

ok finally tried the 160-320 primary spring - with 25 grams pin weight - seems to hold RPM much better
 
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