What RPM are you guys turning?

[lazerlemonta]

I have a 2015 1LE with 1.85 rockers, PSI1511 Springs and Titanium Retainers along with 1 7/8 ARH 3" x pipe, Z28 CAI and home ported intake with rod mod and self tuned. I just bumped the limiter up to 7300 to go through the traps next time in 3rd gear. I trapped 115 shifting to 4th I had my limiter set at 7000 and it would only trap high 112 in third. my best pass on stock tires was 12.52 @ 115.24 MPH

[willhe64]

Aftermarket cam? The stock cam falls off at that high rpm.

[lazerlemonta]

Originally Posted by willhe64

Aftermarket cam? The stock cam falls off at that high rpm.

You want to pull a gear keeping you in the most optimal power band. I shift 1st and 2nd at 68-6900 and will ride third out to 7300.

[Russell James]

7300 is way too high for a stock LS3. If you've upgraded the valve springs 6700/6800 max. Stock cam... no reason to go above 6600.

To build a motor that can reliably spin higher than 7000... it will have some really nice pistons/rods/rod bolts/shaft mount rockers... high dollar stuff.

Spinning a stock bottom end LS3 over 7000... one day the pins will rip right out of the pistons. Seen it happen. And seen engineers comment... oh yeah, can't do that with those pistons.

Reset limiter to 6600, shift to 4th in the qtr.

Nobody ever takes that advice, so good luck.

[Russell James]

Originally Posted by lazerlemonta

You want to pull a gear keeping you in the most optimal power band. I shift 1st and 2nd at 68-6900 and will ride third out to 7300.

Only problem there is...you don't have a 7300 rpm capable motor.

Have it pro tuned. Self tuning is a recipe for disaster...especially if you think it can spin 7300.

Pro build a $30 - 40K race motor... then spin it to the moon.

[zz430camaro]

I don't drag race but I would never go to 7300.

[Unreal]

7500rpm, self tuned.

Only 24k miles like that, and 100+ 1/2 mile passes and 1000+ street pulls.

[JusticePete]

Originally Posted by lazerlemonta

I have a 2015 1LE with 1.85 rockers, PSI1511 Springs and Titanium Retainers along with 1 7/8 ARH 3" x pipe, Z28 CAI and home ported intake with rod mod and self tuned. I just bumped the limiter up to 7300 to go through the traps next time in 3rd gear. I trapped 115 shifting to 4th I had my limiter set at 7000 and it would only trap high 112 in third. my best pass on stock tires was 12.52 @ 115.24 MPH

Titanium keepers and retainers are well suited to a race motor. Race motors are routinely inspected or torn down completely after a race. They change out the titanium keepers and retainers to ovoid failure, before they fatigue and crack.

In a street / track motor, use Tool Steel keepers and retainers for greater reliability.

Originally Posted by Unreal

7500rpm, self tuned.

Only 24k miles like that, and 100+ 1/2 mile passes and 1000+ street pulls.

The plastic trays in your stock motor are not designed to keep the lifters correctly oriented to the cam at RPMs in the 7k range. Be happy you have not incurred a failure and dial that baby down or tear it down to install link bar style lifters and toss the plastic trays, shaft mounted rockers and more.

[Bo White]

Many of the top drag guys shift 7000+
Got to have the valvetrain to support it.

[lazerlemonta]

Thanks guys for all your input.

[JusticePete]

Originally Posted by Bo White

Many of the top drag guys shift 7000+
Got to have the valvetrain to support it.

Exactly, they don't run 7k+ on stock engines.

[Unreal]

Originally Posted by JusticePete

Titanium keepers and retainers are well suited to a race motor. Race motors are routinely inspected or torn down completely after a race. They change out the titanium keepers and retainers to ovoid failure, before they fatigue and crack.

In a street / track motor, use Tool Steel keepers and retainers for greater reliability.



The plastic trays in your stock motor are not designed to keep the lifters correctly oriented to the cam at RPMs in the 7k range. Be happy you have not incurred a failure and dial that baby down or tear it down to install link bar style lifters and toss the plastic trays.

Disagree on the plastic tray. Ls7s rev factory to 7k+ and run plastic trays. I know atleast 50 cammed ls7 cars with zero issues on stock plastic trays. The trays are not an issue. Valve control is far before plastic trays.

My car runs amazing, so not going to tear it down to fix a non-issue.

[JusticePete]

Originally Posted by Unreal

Disagree on the plastic tray. Ls7s rev factory to 7k+ and run plastic trays. I know atleast 50 cammed ls7 cars with zero issues on stock plastic trays. The trays are not an issue. Valve control is far before plastic trays.

My car runs amazing, so not going to tear it down to fix a non-issue.

I am happy to hear it is running well.

You won't find a single full race motor running with plastic trays. The plastic trays are an inexpensive way to build a production motor. Search the forum and look for cam failures. Count how many are directly related to a turned lifter. Some are poor installation, some are cracked trays, some are over-revved, but if it is your motor, it is one too many and very expensive.

As for the LS7, they are a really nice limited production motor, that still has weak points.

To put this in perspective, a Chevy non-current SB2 NASCAR motor have an $18,000 billet steel crank. The pushrods are as big as thick as some cigars. New they were over $120K. All this to be able to run one 500 mile race. In that light, what we get out of a LS3 or an LS7 is the bargain of the century.

We keep them a bargain by not breaking with up graded components. Link bar lifters, shaft mounted rockers and helicoils for the stands.

[acammer]

Originally Posted by lazerlemonta

I have a 2015 1LE with 1.85 rockers, PSI1511 Springs and Titanium Retainers along with 1 7/8 ARH 3" x pipe, Z28 CAI and home ported intake with rod mod and self tuned. I just bumped the limiter up to 7300 to go through the traps next time in 3rd gear. I trapped 115 shifting to 4th I had my limiter set at 7000 and it would only trap high 112 in third. my best pass on stock tires was 12.52 @ 115.24 MPH

What size tire? It may be worth it to add some tire height if you're trying to finish in third gear. I'm having the same line of thought after my last track outing and having to go to fourth just before the beams. I'm contemplating a 295/40/20 for the rear instead of the 275/40/20 there now. That half inch in tire height is 2.2%, 2.5mph more in 3rd - should get me to 115-ish without 4th gear (fuel cut is around 112-113 right now @6600rpm).

I realize 3rd is a touch shorter in the MM6/3.91 setup - a 315/40/20 would get you there in third at a reasonable 6600rpm @ 115mph.

I'm with these guys, 7300, even 7000, is too much. I'll stay with the factory 6600 for my fuel cut - I certainly understand the value of running third out, but it's not worth the risk. If I can't get there on tire size then I'll keep on shifting or running her out on the limiter, at 6600pm.