71 replies to this topic

[mdavis]

I know it has been discussed on FB as Tyler B thinks it's a safety issue. 

I got nailed in the back by Jim S at Topeka a couple of weeks ago when I stalled out.  Hadn't been an issue for me all weekend until that race but started happening a bunch that day.  

I hate FB for discussion like Steve S. so thought I'd start a thread here.

If timing is open at the crank why wouldn't we just allow open timing altogether?  Probably not that simple but as a collective we need to let the CRB know what we want in my opinion.

Here's a copy of the email I (along with hopefully everyone) got.

 

 

The Class Compliance Chief (CCC) has observed significant movement of the reluctor wheel on the intake cam of some VVT engines during compliance inspections at multiple Hoosier Super Tour Events.  Those that were discovered to have an altered reluctor wheel have been found non-compliant based on GCR section 9.1.7.G.1.

Some members have told us that the movement of the reluctor wheel is being moved specifically to make the ECU function as designed as it relates to cam crank correlation.  The SMAC is continuing to investigate the need for the reluctor wheel to be moved and have engaged Mazda to assist our team in understanding the relation between the reluctor wheel and the rest of the engine. 

It is important to note that the current rule does not allow for moving of the reluctor wheel.  Changes have been made to the official SCCA Camshaft Profile Data Sheet to show where that reluctor wheel is located and can be found in the May 2021 Fastrack. https://www.scca.com...data-1/download

As with any change or modification that may violate an existing rule, the SMAC would like to remind the community to please write a letter to request the approval of any modification that is not currently allowed prior to making the modification.  The SMAC will evaluate the request and recommend what they believe to be best for the community to the CRB for approval.  Requests may be submitted online at www.crbscca.com

SCCA Road Racing Department

[Jim Drago]

Matt, 

First, I am not convinced that most or maybe even many are effected by the reluctor wheel. My car has run 5 years without moving the reluctor wheel. So I can't imagine how or why this has become an issue since the VIR crash.  I will get to the bottom of my issue in the VERY near future.  Some are using this as an opportunity to take it to myself and Chris that we were "doing" something and why our cars have been better than theirs for years.  Wishful thinking. That coupled with the fact that the Compliance team and the SMAC have been on a two year witch hunt trying to find what we are "doing"  is not helping either as now they feel they have found the holy grail,  I cant tell you how completely wrong that is. 

 

So much so this weekend, the rumors and on FB turned to its only ESR cars, which is comical.  We are supposedly doing something inside the engine that is causing this and we had been moving the reluctor wheel for years to compensate and gain an advantage. To say that is stupid is an insult to stupid people

 

All that said,  it doesn't say we can move that ring, we have all tried it in attempt to help the situation, in hindsight we should have brought it up and asked. However, it was never my go to move as I have never seen that personally cure that problem. i have heard it has for others. However, I feel the result would be the same, they would not allow it.  Chris and Preston paid the price for it. 

 

So I will throw it out there for all the engine experts and those whose engines run so well and have never had this issue.  

 

Please call out specifically what we are doing inside the engine.. so tech can find it, some one can protest one of my cars and most importantly so we can address it and stop this once and for all

 

Beyond that, I have another one for you. If ANYONE can move that reluctor wheel in ANY position and prove a power gain outside the noise of the dyno I will pay you $5000.00.   I am going to tell anyone who says that it adds power, you are full of shit, stupid or a liar, you pick!  I will put up $5000.00 to prove it, all you have to do is show us how smart you are.  

 

I have also offered up to SCCA compliance team, a FREE full day on my dyno, with  a VVT car, a cut open valve cover for easy access to the ring and could move it all day and see what worked and what didn't. I also made adjustable VVT actuator pulleys that they could try as I did 8-9 years ago that didn't help either. 

 

Another problem we have is that all the members on the SMAC are either Anti VVT  or somewhat neutral. Their is NO ONE that speaks ion behalf of the VVT. The SMAC needs a knowledgeable VVT  representation. Preferably someone with knowledge and favors the cars as they are getting hammered with no one really there to counter.  Thats where all the compliance team witch hunting started. 

 

I also think it may be time to do away with the compliance team. It's time has come and gone imo.  This weekend three competitors had to remove their engines so the compliance team could verify their valves were open and closing in time with the crankshaft.  They did this so they could attach a big ass degree wheel to the crank.  Does anyone besides me think this is a colossal waste of time? If the cams pass on the cam doctor, which was there.. The crank key not indexed.. they valves MUST open in time. Nothing was checked for performance like bore, stroke or compression.. or the heads them-self.   No other class goes through all of this bullshit, just Sm. 

We do not need them, it you want to protest, protest, that's the way the system should be work, what re we "special' so the 40th place guy is satisfied the winners are cheating? well guess what, many still think they are cheating. 

 

I am going to send in two letters.. 

One asking for VVT representation on the SMAc

two: please do away with the Sm compliance team in 2021 moving forward

 

I hope a few of you will join me

Jim

[Steve Scheifler]

I can always use an extra $5k but I think it would be wasted effort. In 2017 there was a topic here about a VVT car that had a no-start problem that was first intermittent but became persistent. We went through extensive troubleshooting to no avail. It would seemingly fix itself only to return, particularly if it was spun and killed under load (it was a school/loaner at the time). Eventually I installed a MegaSquirt ECU and turned on logging for everything, which quickly revealed sync errors which proved to be the result of a moved reluctor wheel and a somewhat stretched timing belt. The belt alone would have been fine, as the reluctor wheel has been for years, but combined they were too much and the stock ECU refused to fire.

So that’s a little background, but of course it left me wondering whether moving the reluctor wheel made an appreciable difference. With the MegaSquirt it is possible to completely remap when and how much the VVT adjusts cam timing (within the physical limits of the actuator), which is FAR more than you can achieve by moving the reluctor wheel. I didn’t spend a great deal of time on it but quickly concluded that on an SM with intake restrictor plate there is little or no benefit from just messing with the VVT maps. The claims that reluctor wheels are being moved to address issues caused by the allowed ignition timing modification ring true, or are at least a better than average cover. A high RPM miss could easily be a milder form of the exact same problem we experienced on our VVT, Cam/Crank sync errors. If caused by the modified crank trigger wheel (and perhaps combined with decking block or head) then the logical solution is to move the reluctor by a similar amount. So I think Jim’s money is safe. I’m not sure enough to bet a similar amount that there’s absolutely nothing there, but I would be surprised if there is any verifiable performance benefit.

If anyone in my area has doubts or just has a VVT they would provide for testing of this, my chassis dyno is available absolutely free and it will even log all OBD data along with each run so we can see what changes as a result of a repositioned reluctor wheel.

[Jim Stevens]

Sorry about that. My plan, at that point, was to draft with you as long as I could and maybe catch the leaders. Wasn't expecting you to go dead at WOT. 

 

I got nailed in the back by Jim S at Topeka a couple of weeks ago when I stalled out.  

[Steve Scheifler]

One more thing about testing, unlike most used for SM tuning my Dynapack is a “hub type”/load dyno which allows for sustained testing at any combination of load and RPM rather than just “sweep” pulls like you typically see on inertia/drum types. That’s extremely useful during fine-tuning but also makes it possible to better simulate on-track conditions such as where the engine spends much longer at high RPM on long straights.

SMAC & Compliance, St. Louis is a nice place to visit. I’ll even supply the pizza & soft drinks.

[Jim Drago]

I can always use an extra $5k but I think it would be wasted effort. In 2017 there was a topic here about a VVT car that had a no-start problem that was first intermittent but became persistent. We went through extensive troubleshooting to no avail. It would seemingly fix itself only to return, particularly if it was spun and killed under load (it was a school/loaner at the time). Eventually I installed a MegaSquirt ECU and turned on logging for everything, which quickly revealed sync errors which proved to be the result of a moved reluctor wheel and a somewhat stretched timing belt. The belt alone would have been fine, as the reluctor wheel has been for years, but combined they were too much and the stock ECU refused to fire.

So that’s a little background, but of course it left me wondering whether moving the reluctor wheel made an appreciable difference. With the MegaSquirt it is possible to completely remap when and how much the VVT adjusts cam timing (within the physical limits of the actuator), which is FAR more than you can achieve by moving the reluctor wheel. I didn’t spend a great deal of time on it but quickly concluded that on an SM with intake restrictor plate there is little or no benefit from just messing with the VVT maps. The claims that reluctor wheels are being moved to address issues caused by the allowed ignition timing modification ring true, or are at least a better than average cover. A high RPM miss could easily be a milder form of the exact same problem we experienced on our VVT, Cam/Crank sync errors. If caused by the modified crank trigger wheel (and perhaps combined with decking block or head) then the logical solution is to move the reluctor by a similar amount. So I think Jim’s money is safe. I’m not sure enough to bet a similar amount that there’s absolutely nothing there, but I would be surprised if there is any verifiable performance benefit.

If anyone in my area has doubts or just has a VVT they would provide for testing of this, my chassis dyno is available absolutely free and it will even log all OBD data along with each run so we can see what changes as a result of a repositioned reluctor wheel.

I have a wedding in New Jersey this weekend.  If you promise not to hit the wall, you can run my car and put it on the dyno and check anything and everything you like. Isn't the st Louis race this weekend?

[Steve Scheifler]

I have a wedding in New Jersey this weekend. If you promise not to hit the wall, you can run my car and put it on the dyno and check anything and everything you like. Isn't the st Louis race this weekend?

Fortunately it is the following weekend, so I don’t even need to contemplate just how dumb that would be, for both of us!

If you haven’t solved it by then, or if you think you may have, come up for the test day that Friday and let’s try catching it again in OBD logs. Heck, by then I could have a MegaSquirt on hand. Send it up a few days early so I can install that with base maps and tune, then we’ll get mega logs to dig through.

[Tom Sager]

trying to understand.  Separating this recent reluctor spec from the reputation the VVT cars have for misfiring...is the new reluctor spec causing a problem? 

[Ron Alan]

trying to understand.  Separating this recent reluctor spec from the reputation the VVT cars have for misfiring...is the new reluctor spec causing a problem? 

This is my understanding...Jim or Chris or anyone can correct me if I'm not getting it!

 

First off...let me state I have seen 4 different VVT cars shut off or lose power on track. This is not like the 99 cam sensor misfire with a popping noise.

 

The VVT car computer is just a little bit smarter than the 99/00. It sees crank, cam and temperature(other?) and looks for these to be in some sort of phase or sync? When they are not it cuts something(limp mode)in an attempt to save motor? Basically when we put in the slotted timing wheel to advance timing(mechanically)...basically tricking the computer...it works on the 99/00.

But something about the VVT computer catches this. So to "trick" it...The relucter wheel(this is the cam timing trigger) is clocked from its factory location to match/stay in time with the crank timing we have already legally messed with. 

 

Again...not a mechanic...but when the reason for messing with this wheel was explained to me it made sense. Happily be corrected. But if in fact this is a solution to a car shutting down based on another aspect that we are allowed to do...I'm all for it! 

 

In the cases I have seen temperature seemed to play a role. A top VVT car in our area would have no problems running in clean air. When it would get in a draft and the temps went up it would shut off??

[Jim Drago]

trying to understand.  Separating this recent reluctor spec from the reputation the VVT cars have for misfiring...is the new reluctor spec causing a problem? 

You will have to sift through the bullshit.. 

The optics are since VIR and two cars were dq'ed for the reluctor wheel, I have started having chronic problems with my car shutting off after VIR.  Unfortunately I wrecked my car hard that weekend as well. I don't see what why or how the wreck would cause this either? Furthermore mine only shuts off with more than 10 degrees of timing( I have been up front with this, would not have shared if we were 'doing something" ) , which further helps sell the story that we have been moving this wheel for years and now I cant.  From the outside looking in, I could certainly see why some are selling that story and others believing it, if not me, I would probably feel the same way.   The only counter I have is that the following week another of our cars won with no issues on the cam at Pitt race and we have had more cams pass the silly reluctor wheel test than any other. 

 

So in short, we have not and did not move the reluctor wheel on my personal car or any other cars we build or engines we sell. One was moved in a last ditch effort at the track to solve a shut off issue. I have no ideas what happens to engines after they leave my control. But I know there will not be another reluctor moved on any engine that ran through here unless the customer moved it or had someone move it without my knowledge. I don't see how or why I would need to move it now, but first signs would point that way. I plan to do some serious testing next week and see what we find, I don't foresee the reluctor wheel being our issue.  I have personally never seen moving the reluctor wheel fix any of the VVt misfires, but others that i trust have used this method and say they have cured it that way. 

 

To answer your question the best I can..  I don't think the reluctor wheel is the issue, if it is, it may be in like 10% or less of the VVts.  In all the VVts we have built, well over 100. Right now i know of only 3 that are having issues. Two Chronic, mine and Kowalski and one more intermittent ( smith).  In all 100 plus they are running 15 degree of timing and no reluctor wheel realignment.   

Jim

[Jim Drago]

This is my understanding...Jim or Chris or anyone can correct me if I'm not getting it!

 

First off...let me state I have seen 4 different VVT cars shut off or lose power on track. This is not like the 99 cam sensor misfire with a popping noise.

 

The VVT car computer is just a little bit smarter than the 99/00. It sees crank, cam and temperature(other?) and looks for these to be in some sort of phase or sync? When they are not it cuts something(limp mode)in an attempt to save motor? Basically when we put in the slotted timing wheel to advance timing(mechanically)...basically tricking the computer...it works on the 99/00.

But something about the VVT computer catches this. So to "trick" it...The relucter wheel(this is the cam timing trigger) is clocked from its factory location to match/stay in time with the crank timing we have already legally messed with. 

 

Again...not a mechanic...but when the reason for messing with this wheel was explained to me it made sense. Happily be corrected. But if in fact this is a solution to a car shutting down based on another aspect that we are allowed to do...I'm all for it! 

 

In the cases I have seen temperature seemed to play a role. A top VVT car in our area would have no problems running in clean air. When it would get in a draft and the temps went up it would shut off??

just adding info.. 

I mentioned i tightened timing belt on mine.. went out Sunday and ran five laps no issues.. Previously it was shutting off lap one, every time, multiple times.. Which is why i was cautiously optimistic for Sundays race.  I didnt watch my video, but I would say it was lap 5-7 the first time it did this. I will check Sundays temps when I dig in. 

Mine has not been temp related so far though

[Chris Lefferdink]

My car, with a new motor, shut off numerous times this past weekend. The most common spot it happened was between the carousel and kink near the top end of 4th gear. It happened during early laps and late laps, running in a draft and running in clean air. The only thing that seemed constant was that it was near the upper end of the rpm range.

[Steve Scheifler]

My car, with a new motor, shut off numerous times this past weekend. The most common spot it happened was between the carousel and kink near the top end of 4th gear. It happened during early laps and late laps, running in a draft and running in clean air. The only thing that seemed constant was that it was near the upper end of the rpm range.

Are you running any data? Does the data or tach still show RPM (indicating ignition/spark still firing)?

[Chris Lefferdink]

Are you running any data? Does the data or tach still show RPM (indicating ignition/spark still firing)?

I am. It shows rpm only from the car's momentum, if I push the clutch in, then the RPMs drop.

[Jim Drago]

I am. It shows rpm only from the car's momentum, if I push the clutch in, then the RPMs drop.

Same

[Steve Scheifler]

OK, so RPM from ECU driven by crank sensor, but engine completely dead when clutch in, drops to zero? Makes it harder than the old days to know if there is spark, but the dominant theory/assumption is that there is not because the ECU is cutting it when critical sync errors occur. Would be nice to verify though. It does at least rule out power loss to the ECU, but probably not much else.

[Chris Lefferdink]

OK, so RPM from ECU driven by crank sensor, but engine completely dead when clutch in, drops to zero? Makes it harder than the old days to know if there is spark, but the dominant theory/assumption is that there is not because the ECU is cutting it when critical sync errors occur. Would be nice to verify though. It does at least rule out power loss to the ECU, but probably not much else.

I'm not an expert, but I believe the ECU is rebooting each time.

[Steve Scheifler]

I'm not an expert, but I believe the ECU is rebooting each time.

Not if RPM data log is uninterrupted.

[Ron Alan]

Some simple questions...data gathering. Lets assume all cars that have had a shut off problem are running a slotted wheel and nothing else.

 

1. Is the slotted wheel Mazda purchased or home ground(potentially more/less advance)?

2. Has anyone solved the problem by retarding the wheel or removing and putting in the unaltered stock trigger wheel?

3. If #2 is true for you...change in power? 

4. any specific model year popping up more than others?

5. Is the shut off momentary(less than 2 seconds)or longer?

6. Is the shut off predictable(speed, rpm, load, traffic)

 

For anyone who has had the problem and then clocked the reluctor wheel...did it 100% solve the problem? (post under an alias if you are a front runner )

If it did not...any specific thing that did?(Jim has mention timing belt)

[Tom Sager]

So is it felt that the lack of freedom to move the reluctor wheel is contributing to misfires?  Now that there's a spec for that more cars will not run correctly?