I have heard that you can't turn an LT1 over 7000 for some reason. I am wanting to build aLT1 with some good heads and a solid roller cam but am curious as to why you can't turn one over 7000 and what you can do to fix that.

 

You can turn the engine as high as the rotating assembly and valve train are designed for. Problem with the stock PCM is that the tables only go up to 7,000rpm. But you can turn more than 7,000rpm on the stock PCM... it just runs on the 7,000rpm values. Means the 7,000rpm table values/programming have to take into consideration that the engine will actually be turning more than that. It may also put a bit of a strain on the distributor rotor. For vey high RPM, something like the LTCC ignition, which uses only the optical sensor in the distributor might provide better results.

Or, go to an aftermarket ECU and the sky is the limit.

 

I think 7k is where you hit fuel cutoff (not sure, never hit it), but you wouldn't be making power at 7k anyway, even with a new cam. I've seen shift points from 6200-6800 for new cams, should be no reason to go over 7k.

 

Fuel does not cut off at 7,000rpm unless that's where you happen to have the rev limiter set. With the right heads and cam, its possible to make power above 7,000rpm.

 

I didn't know that, how far above 7K? I'm assuming this is with an upgraded bottom end?

 

Yes very upgraded. I just didn't want to put something together that may or may not turn that high and take a chance that it does and the computer will not support it. Can you simply fix this when you have the computer tuned or is this something seperate?? If so what does it usually run??

 

Like Injuneer has said if you want to go over 7000 rpms, you need an aftermarket PCM and possibly some adjustments to the opti unless you go with a LTCC or other coil-pack igntion.

This thread has some information in it: https://www.camaroz28.com/forums/sho...=579997&page=2

Ken95z28 talks about a LT1 that is spinning 8800 rpms with a pop rivet modification on the opti that he has pictures of.

 

I'm turning 7k rpm at the trap

Not very upgraded.. just rods and pistons.

Stock opti, not sure how long it will last but we'll see.

 

I shift mine at 7k on a very similar set-up to Javiers also a stock opti....so far so good

 

You guys are CRAZY LOL

You got any sound clips of the car spinning up that high, i bet it sound MEAN!

 

i usually shift around 6600-6700 but i have slipped up and went to at least 6850 on a stock 100k opti with a msd cap and rotor in it

no, i dont have a good camera, but yeah it sounds real mean, it kinda changes around 6200, it sounds weird in like 3rd when your pulling for a few seconds up that high

 

colins sounds like a honda at 7k... :P

 

I've never heard it from the outside

But when I raced Dustin and Alex last week, one of the by-standers was asking how high I shifted...they all said it sounded like I was revin it to the moon

 

http://www.zmydust.com/videos/1126_022708.wmv

 

That's just your connecting rod bolts crying for mercy.