15 Hellcat, hitting some sort of limiter at 4500

[Jay@HAP]

I've had no luck trying to figure out what limiter I am hitting at 4500. At 4300 the bypass valve starts to open and at 4500 it closes the throttle.

I've raised the limits in the Engine Diag section with regards to the Airflow RPM Max tables and the P0068 Airflow table but that didn't change anything.

[curt@injected]

need more info on vehicle and the tune file please

[Jay@HAP]

Sorry. I didn't realize I didn't attach the tune file. I added it to the first post.

mods are; ATI 10% OD balancer, metco 2.4 upper pulley, bwoody extra idler, headers, full exhaust, K&N CAI, ID1700's, return style fuel system, triple pumps, 110 octane, Brisk racing spark plugs.


I'm definitely exceeding the 2 bar MAP on this car, ended up with more boost than I expected. I havent been able to spin it high enough yet to see if I'm going to max out the blower.

[Jay@HAP]

I rescaled the supercharger airflow table up to 2.24 and added about 28% to it and it still does it. I don't know if there is a table that I can see in the tune that's the problem or what.

[curt@injected]

I would say you are over spinning the blower. I know with a 2.55 and 10 % lower we made around 21-22 pounds and were having some really high iats.

[Jay@HAP]

I would say you are over spinning the blower. I know with a 2.55 and 10 % lower we made around 21-22 pounds and were having some really high iats.

Do you mean the RPM limit is due to the supercharger?

[curt@injected]

Is this a stick or auto?

[curt@injected]

Do you mean the RPM limit is due to the supercharger?

No I was just saying that you are probably out of the efficiency rang of the blower

[curt@injected]

Unless you changed the hardware configs this is a stick car? If so you've got the p/n limiter set at 4500 which is where it is shutting you down and what the throttle torque source is showing. On a stick car the drive limiters are not used the p/n limiter is used. Raise the p/n limiter to where you want your rev limit

[Jay@HAP]

Unless you changed the hardware configs this is a stick car? If so you've got the p/n limiter set at 4500 which is where it is shutting you down and what the throttle torque source is showing. On a stick car the drive limiters are not used the p/n limiter is used. Raise the p/n limiter to where you want your rev limit

It's a stick.

[curt@injected]

You also have the knock sensors disabled. I would highly advise against this. With how hard you are spinning the blower and you have added spark in peak torque plus disabling the sensors you are creating a recipe for disaster.


Edit: the hellcats are not bullet proof. There are a bunch of blown up ones out there. Be sensible they do not like a ton of spark in peak torque when you are spinning the blower this hard.

I hope this helps, not trying to beat ya up just don't want you to make a costly mistake

[Jay@HAP]

Unless you changed the hardware configs this is a stick car? If so you've got the p/n limiter set at 4500 which is where it is shutting you down and what the throttle torque source is showing. On a stick car the drive limiters are not used the p/n limiter is used. Raise the p/n limiter to where you want your rev limit

son of a bitch. I did not know that.

[Jay@HAP]

You also have the knock sensors disabled. I would highly advise against this. With how hard you are spinning the blower and you have added spark in peak torque plus disabling the sensors you are creating a recipe for disaster.

They are disable because I'm using a PLEX knock monitor.

[curt@injected]

son of a bitch. I did not know that.

all good man. Glad I could help.

[curt@injected]

They are disable because I'm using a PLEX knock monitor.

never used one. I would still advise being cautious. Even if it doesn't rattle I'm sure you can imagine what cylinder pressures are like at peak torque in that thing.

[Jay@HAP]

never used one. I would still advise being cautious. Even if it doesn't rattle I'm sure you can imagine what cylinder pressures are like at peak torque in that thing.

I agree 100%.

[curt@injected]

I agree 100%.

Alright man good luck.

[Jay@HAP]

Yup, that was the problem. It was nice to see 5500rpm.

I can't tell you how happy I am. Thank you very much.

[Jay@HAP]

You also have the knock sensors disabled. I would highly advise against this. With how hard you are spinning the blower and you have added spark in peak torque plus disabling the sensors you are creating a recipe for disaster.


Edit: the hellcats are not bullet proof. There are a bunch of blown up ones out there. Be sensible they do not like a ton of spark in peak torque when you are spinning the blower this hard.

I hope this helps, not trying to beat ya up just don't want you to make a costly mistake

No worries. I appreciate the input.