Does a stock LT1 have a factory rev limiter built in or is an MSD still needed for safety? I just bought a 95 LT1 and am rebuilding it. Once it is finished I will start the swap. I already have a 6AL in my car, but could use it elsewhere if the LT1 has a rev limiter already.

Thanks

Mark

 

Yes. It's a fuel cuttoff at 5600 rpm. I would highly recommend the MSD rpm limiter since it's a spark retard and much easier on the engine.

You can raise the limit programmed into the computer to 6000 rpm and use the MSD to limit your engine speed.

 

I dont think all LT1's have that. I know for a fact mine doesnt. With the stock program, I had my shift light set at 5800 rpm with the MSD rev limiter set at 6K. After swapping heads, intake, and getting it programmed, I shifted at 5900 and hit the revlimiter with no fuel cutoff. So I dont know.

 

When you say you had it programmed, the person programming it for you most likely edited out the Rev limiter (or adjusted it a little higher).

 

possible, but I was going above 5600 before I had it programmed, so I dont know.

 

Mine is 6100, straight out of my 94' Z28

 

What kind of tach are all of you using? I know in the LT1 cars some tachs have been known to show as much as 300 rpms off around 6000. Not trying to flame but just figured I would ask.

 

my factory tach is off by over 500 rpm at 6000, I have an Autometer monster tach mounted under the center a/c ducts that is connected straight to my msd, so I know its accurate.

 

TexasLT1,

Did you have someone program the VATS out of PCM even when it was untuned? They may have bumped the limiter then.

 

nope, VATS has never been touched, it worked for a while after the swap, but then we ended up bypassing it some how. We guess one of the solder joints came loose or something on one of the VATS wires becuase we had to ground the fuel pump relay. going to sort that problem out when I get back home.

 

With my original '94 the PCM was set to 5800 like they said. At least, in the program it was. But then we bumped it. Maybe a 6500 limit on a junk LT1 was a bad idea........ I have the shrapnel to prove it Just kidding.

But I do run an MSD pill set to 6000 until I know I have a good tune on the engine. Once its set, the engine should pull past 6700.