How high can an LT1 spin?

[94 formula]

I have an internally stock LT1 with true duals, LT headers, and a CAI it feels like it still has a little uptop with the LT's on could I set my rev limiter up from the stock 5,700rpm to 6,000rpm or will this be too high for a stock engine? Also I am wondering if I am wrong in my theory does anyone have any dyno sheets of a similar setup to mine that could proove me right or wrong on thinking I'm making more hp higher?

[Craig 94 TA GT]

Depending on the mileage, I wouldn't take it past 6k. Do you still have the stock valvetrain too?
There are a lot of people on cz28.com who ended up with a spun bearing after a cam installation on a stock lower end. Some think it could be due to a bad or dirty installation, but others say it's because you're spinning the motor too high for its mileage.

[94 formula]

I'm at 111k on the bottom and top end. It is completely stock internally. I'm guessing that it is bad for it to spin it that high but I'm just checking. Also I'm not even sure where I'm making peak power at I've never had it dynoed it just feels like its breathing so much better after the LTs and CAI that it would do a little better shifting it higher.

[pennylessz28]

What about non stock valve train?

[wolfdogs]

your'e valves will float at 6k... you wont gain anything there.. my rev limiter in the compTA was set at 6200 by Ed Wright, and i thought that was too high so i lowered it to 6k.... and i had the lt4 hot cam, 1.6 rr's, and other internal gm hp parts..

[fastTa]

A dyno measurement would definitely help to show where you are making power, but roughly judging by your mods, I would say somewhere around 6k would be a good shift point.

The LT1 is hard limited by the PCM to 7,000 RPM, so it is up to you.

[95TransAm]

I believe my shift points at WOT are roughly around 6050 RPM....and my rev limiter is set at 6200. I never hit my limiter, but I haven't experienced any problems with my shift points...and i have around 114k on the clock

I can't wait 'til i go to school and the full tear down/rebuilding process begins bwah ha ha ha

[TraceZ]

A dyno measurement would definitely help to show where you are making power, but roughly judging by your mods, I would say somewhere around 6k would be a good shift point.

The LT1 is hard limited by the PCM to 7,000 RPM, so it is up to you.

7000? I could swear I've hit a rev limiter prior to 7000.

[Craig 94 TA GT]

I think what Kevin was trying to say (correct me if I'm wrong)...even with the rev limiter removed, it will not go past 7k.

[fastTa]

7000? I could swear I've hit a rev limiter prior to 7000.

Craig is correct.

The LT1 PCM can be be re-flashed to accept up to a 7,000 RPM limit. They call it a "hard limit" because the 7,000 RPM cutoff is not able to be erased or modified by means of PCM editing software. It is a PCM function that is hard encoded into ROM.

[95TransAm]

The sound of an LT1 spinning at 7 grand = me drooling

[94 formula]

The stock limiter is at 5700 right? Also if the stock valves will float at 6k will I be better off to just leave it where its at and not even mess with bumping it up to 5800 or 5900rpms.

[Jeff_in_Atl]

The stock limiter is at 5700 right? Also if the stock valves will float at 6k will I be better off to just leave it where its at and not even mess with bumping it up to 5800 or 5900rpms.

When my A4 was acting up, It wouldn't shift till after 6200. I don't know where it would shift because I left off at that point. I can say for sure that the limiter is higher than that and my valaves weren't floating that I am aware of. I've heard valve float before in my 85 GT and it didn't sound like that.

[HottestZ28]

Well with a basically stock LT1 it doesn't make any power after like 5700 so your basically wasting your time up there without valvetrain upgrade
I got my car dynoed with open exhaust and made power till 5600 and started to drop off so with your setup i couldn't see anymore then 100 rpm out of it

[MN6WS6]

That's kinda weird, because my car was still on a pretty good incline when my MSD kicked in at 5500 (still had stock PCM so it shut fuel at 5700, and you can't hit that on nitrous). I think mine probably wouldn't level until about 6k, so that's why I have a 6300 chip in the MSD now with the ECM set at 6500. I never hit it though. I think the highest I've ever taken mine was about 6100-6200, and that was a fluke.