Hard Rev Limit Around 7700.

[schaid]

Somewhere between 7700-7800 I'm hitting a hard limit. I've set every available limiter up to 8k, but it still hits around the aforementioned range. Are we missing some parameters? I've tried comparing to a boss that revs easily to 8k with no avail at seeing a parameter that I missed.

[redline5.0]

This is what Eric told me before.

"Something in the code prevents the Gts from spinning to 8000... around 7700 or so there is a limit. I have never looked for it, but I can probably fix it"

[Eric@HPTuners]

Yep..... there is not any cal limit that causes there, but there may be something in the code. I will poke around.

[wbt]

Messed around with this for years on the autos. I was able to get my car up to 7,900 with the CJ pulse ring and an ATI dampner. Not sure there is a way around that. The manuals should be able to go higher once Eric is able to find the underlying code. It would be neat if the auto's could also do the same.

[Eric@HPTuners]

Messed around with this for years on the autos. I was able to get my car up to 7,900 with the CJ pulse ring and an ATI dampner. Not sure there is a way around that. The manuals should be able to go higher once Eric is able to find the underlying code. It would be neat if the auto's could also do the same.

The debate has always been that it isn't the PCM, that its hardware (pulse ring related). I never looked into it myself.

[redline5.0]

Mine has been to 7950 with the manual and a sct tune which I think was using a boss strategy and the stock pulse ring. Even then I still think the boss strategy is still hard limited to 8200.

[TobyG]

I have a gt that spins to 8300-8400 with the Cj pulse ring although it is a manual car. Also a road race car that is all stock we spin to 8k on the stock ring.

I'm sure you will figure it out Eric!

[wbt]

The debate has always been that it isn't the PCM, that its hardware (pulse ring related). I never looked into it myself.

I honestly don't think the pulse ring will gain you anything. It is more for making sure the resolution is good at higher RPM's.

IMO the limits are in the underlying code base.

[schaid]

I know it's underlying code related. I had to switch the strategy on the same boss that I mentioned that ran to 8 easily and now it hits rev limit at 7780 or so. I know when I was tuned by someone not Eric I could run to 8 and that person changed the strategy. I had made mention to it to Eric when he was tuning my car before HPT and we never got it above the 7700ish mark. Of course that was about 2 years ago at this point. So...it's strategy related.

[Eric@HPTuners]

I know it's underlying code related. I had to switch the strategy on the same boss that I mentioned that ran to 8 easily and now it hits rev limit at 7780 or so. I know when I was tuned by someone not Eric I could run to 8 and that person changed the strategy. I had made mention to it to Eric when he was tuning my car before HPT and we never got it above the 7700ish mark. Of course that was about 2 years ago at this point. So...it's strategy related.

Its on the list, but I won't be looking until I get all the scanner stuff taken care of.

PS: 2015 Mustangs can spin VERY high. Haven't hit a limit on them yet.

[Eric@HPTuners]

I dug around further in the rev/limiter section of the calibration, so maybe it is code related. Even so, the Boss code will only go to about 8100

[wbt]

I dug around further in the rev/limiter section of the calibration, so maybe it is code related. Even so, the Boss code will only go to about 8100

Makes sense. Mechanical inertia of the engine may show 1-200 more RPM in a log.

I think the trick would be to find out what limits the auto past ~7,700.

[schaid]

8100 would be fine. The boss that I'm working with has a cobra jet intake monoblade throttle body jba's and a spec 3+ clutch with dss driveshaft on the way. This car likes to RUN up top and hitting the limiter when trying to hit 7750 shift points when the limiter comes in at 7780 is rough lol. Prior to having to switch the strategy I had the limiter set at 8100 so...back to opening statement...8100 would be just fine lol.

[Kevin@JPCRacing]

This issue started for us with the 3V. Tried everything and had a lot of people above me give input, look at our files etc.. and nothing would get us past it. FRPP even tried to help and had a Ford engineer look at the file. They said we had everything right and it should rev to the moon. Even tried a different PCM. We slowed the dyno way down and logged it, everything is good up to 7800, all the source values are mint but it starts banging like a limiter. Long story short, it was in the PCM manufacturers hard code and there wasn't anything we could do at the time. They said that problem would be gone with the Coyote. I guess it is and it isn't unless you use a Boss strategy. With some time digging around in the code, I'm sure someone could figure it out. I do know the 2015 PCM is happy up to at least 8500

Also, don't be fooled by over revs and shift flares. I've seen 87-8800 before on a lot of logs from cars that will never get past 7800/8200 under load. The PCM has no problem reading the RPM and displaying it.

[wbt]

This issue started for us with the 3V. Tried everything and had a lot of people above me give input, look at our files etc.. and nothing would get us past it. FRPP even tried to help and had a Ford engineer look at the file. They said we had everything right and it should rev to the moon. Even tried a different PCM. We slowed the dyno way down and logged it, everything is good up to 7800, all the source values are mint but it starts banging like a limiter. Long story short, it was in the PCM manufacturers hard code and there wasn't anything we could do at the time. They said that problem would be gone with the Coyote. I guess it is and it isn't unless you use a Boss strategy. With some time digging around in the code, I'm sure someone could figure it out. I do know the 2015 PCM is happy up to at least 8500

Also, don't be fooled by over revs and shift flares. I've seen 87-8800 before on a lot of logs from cars that will never get past 7800/8200 under load. The PCM has no problem reading the RPM and displaying it.

+1

[schaid]

is there a way to know what the hard limit is before licensing a strategy?

[schaid]

Reviewing an sct log I've got of an older tune...hit 7915 with strategy FPRD1F5.

This tune was done using sct pro racer software I'm assuming. It was done by another tuner, not Eric.

If this strategy is not for a boss, then by what's stated here it shouldn't be able to go past the aforementioned 7700ish. So...can anyone tell me what this strategy goes to?

[wbt]

Reviewing an sct log I've got of an older tune...hit 7915 with strategy FPRD1F5.

This tune was done using sct pro racer software I'm assuming. It was done by another tuner, not Eric.

If this strategy is not for a boss, then by what's stated here it shouldn't be able to go past the aforementioned 7700ish. So...can anyone tell me what this strategy goes to?

My car has strategy FSDL5A8 and will go slightly above 7,900. It was stuck at ~7,700 until I put an ATI balancer and CJ trigger wheel on it. There was no noticeable difference with the CJ trigger wheel however the balancer made a difference.

Another car using the same strategy with a Boss engine, same trigger wheel and balancer wouldn't go above 7,700.

[schaid]

Ok, great. I have a car that is exactly the same hardware wise that went from revving to 8200 to hitting at 7700. Not a single piece of hardware changed. Only the strategy.

I am absolutely convinced this has NOTHING to do with hardware.

By changing hardware, what I think is happening is a "trick" of the pcm.

[wbt]

Ok, great. I have a car that is exactly the same hardware wise that went from revving to 8200 to hitting at 7700. Not a single piece of hardware changed. Only the strategy.

I am absolutely convinced this has NOTHING to do with hardware.

By changing hardware, what I think is happening is a "trick" of the pcm.

I agree this is something in the code.