Hitting Rev limit 7000 rpm on GM PCM

Dan Fahey · 11-07-2021, 09:05 PM

Have run into the Rev limiter on the GM ODB1 PCM.
Cannot exceed 6950 rpm.
How do you fix it?

Reset the Rev limit to 7200 rpm with no implact.

Rob Petrie E395 · 11-08-2021, 04:36 PM

I have the same problem on my bracket car at some 1/4 mile races. But mine will get to about 7200 before it does it. I’ts geared where on an average day. It just barely ticks it if you drive it all the way to the finish line. But in good air it’ll do it a lot sooner. Only way to fix it is to change something to get RPM”s down (taller tire, less gear). Or change fuel injection systems. Some guys do what i think is called a 411 pcm swap. You might look into that. If you don’t want to spend the money on a aftermarket FI system. I was going to take the old Holley system out of my stocker. And put it in my bracket car. Then put a newer up to date system in my stocker. But there is no more 1/4 mi bracket racing here anymore. So I just left it as 1/8 mile it’s fine. You could try different PCM’s of the same part number. As some do get a tick more rpm before the quad drivers lock up. But you could spend a lot of money and not find one.

Dan Fahey · 11-08-2021, 05:24 PM

Quote:

Originally Posted by Rob Petrie E395

I have the same problem on my bracket car at some 1/4 mile races. But mine will get to about 7200 before it does it. I’ts geared where on an average day. It just barely ticks it if you drive it all the way to the finish line. But in good air it’ll do it a lot sooner. Only way to fix it is to change something to get RPM”s down (taller tire, less gear). Or change fuel injection systems. Some guys do what i think is called a 411 pcm swap. You might look into that. If you don’t want to spend the money on a aftermarket FI system. I was going to take the old Holley system out of my stocker. And put it in my bracket car. Then put a newer up to date system in my stocker. But there is no more 1/4 mi bracket racing here anymore. So I just left it as 1/8 mile it’s fine. You could try different PCM’s of the same part number. As some do get a tick more rpm before the quad drivers lock up. But you could spend a lot of money and not find one.

Learned that ODB1 limited to 7000rpm
LT1 ODB2 Limited to 7200 rpm

Trying to find out if the TorqueHead is a legal replacement?

Dan

11-07-2021, 09:05 PM	#1
Dan Fahey VIP Member Join Date: Oct 2008 Posts: 2,128 Likes: 1,084 Liked 184 Times in 113 Posts	Hitting Rev limit 7000 rpm on GM PCM Have run into the Rev limiter on the GM ODB1 PCM. Cannot exceed 6950 rpm. How do you fix it? Reset the Rev limit to 7200 rpm with no implact.

11-08-2021, 04:36 PM	#2
Rob Petrie E395 VIP Member Join Date: Dec 2007 Location: Woodlawn IL Posts: 1,092 Likes: 162 Liked 216 Times in 77 Posts	Re: Hitting Rev limit 7000 rpm on GM PCM I have the same problem on my bracket car at some 1/4 mile races. But mine will get to about 7200 before it does it. I’ts geared where on an average day. It just barely ticks it if you drive it all the way to the finish line. But in good air it’ll do it a lot sooner. Only way to fix it is to change something to get RPM”s down (taller tire, less gear). Or change fuel injection systems. Some guys do what i think is called a 411 pcm swap. You might look into that. If you don’t want to spend the money on a aftermarket FI system. I was going to take the old Holley system out of my stocker. And put it in my bracket car. Then put a newer up to date system in my stocker. But there is no more 1/4 mi bracket racing here anymore. So I just left it as 1/8 mile it’s fine. You could try different PCM’s of the same part number. As some do get a tick more rpm before the quad drivers lock up. But you could spend a lot of money and not find one. Last edited by Rob Petrie E395; 11-08-2021 at 04:42 PM.