Carbureted LSX forum - where should I set the rev limiter?

My LS-1 is now runnjing great, but since I put the 4.10:1 gears & the 3800 stall, it revs really fast & I'v seen over 7000 rpm on the tach a couple times, I'm worried that the stock bottom end will only do that a limited number of times. It's got a Predator Z cam & the right springs,so I don't think valve float is a problem, but I'm not sure where I should be trying to shift or where the rev limiter should be set? How many rpm's is the stock bottom end good for on these things? The Edlbrock controller that's in it doesnt have a rev limiter, but I have a 6010 on order.

Safe: 6800

Not scared: 7000

Me: 7200

Safe: 6800

Not scared: 7000

Me: 7200
:werd:

How many people really run them that high with a stock bottom end?

I keep seeing these numbers from Zones but man, that sure is a lot higher than GM set them from the factory. That is higher then they set the LS7 motors.

that sure is a lot higher than GM set them from the factory. That is higher then they set the LS7 motors.

thats because they have to last the customer 100k miles or GM is eating it... they don't like buying motors.

Six bolt mains and a stout crank. The LQ9 rods are beefy too.

I hit the rev limiter at 7200 in my Trans am and RS every time I drive them, the TA for a year and the RS for 3 years, not all survive though, my friends have great luck but some after a year or so have lost a rod, so it is safest at 6800 supposedly, so beyond that it is a risk that I don't mind taking.

I bang my 6.0 off the 7600 rpm limiter all the time.

Nothing like a 7000+ shift on a ls with a t56 and a suspensionn that bites down hard.:headbang

Thanks for the input everyone! I think I'm gonna takes Zones advice & set it 6800, I don't think I'm making anymore power past that anyway. And just out of curiosity, I'd like to know if Tenners got a stock bottom end going to 7600??

No idea, but a friend tried 7500 and it fell apart, but had he used ARP bolts after rebuilding, instead of stock bolts, who knows? I never re use stock bolts.

thats because they have to last the customer 100k miles or GM is eating it... they don't like buying motors.

EXACTLY! I mean.....it isn't exactly good for them, but as long as it's controlled and not sustained, the damage done is minimal.

I shift my stock bottom end 99 LS1 at 7K and have done so for years. The limiter is set at 7300 on that car.

The LY6 in my Camaro also gets shifted at 7K but that's only because I tried it at 7200 with no signficant gains with my current combo and 6800 showed a slight loss. This motor has Katech rod bolts as an added insurance policy. Limiter is set to 7500 on this one cause once I start to spray it I may be stretching it's legs a little bit at the stripe (TH400/4.10 gears/28inch Tires).

I have the limiter at 6300 RPM but with the carb intake the LS2 is still pulling strong at that RPM. The first couple of gears hits the limiter so quickly that the additional revs will be useful.

I guess the way to look at it is if I blow something up I will have an excuse to get a stroker kit.

i always set it at the moon lol, or when it hits the red line , or when the rev limiter tells me to stop lol

I raced a 5.0 Ford for a long time, so that was what I was used to.

The first time I ran this LS car (was manually shifting my auto) my eyes got really big :eek::eek: when I saw that tach hovering right around 7,000!

Doesn't seem to have hurt it, like GC99TA says, it is not sustained

If you know your SBC history and then look at the gen iii and IV, the lighter valve train and other technology in these engines makes it easy, piston speed is increased over the old 5.7 with a 5.3 on up due to the larger stroke crank, but everything else is better with it, not a biggie. In fact, the lil ol 4.8 having a shorter stroke can go to 7700 or so without hesitation with the right cam(any cam in general with a little duration).

I have buzzed mine to 7200 on every shift for aprox 70 passes down the quarter, and aprox 500 street miles of abuse. I then installed ARP rod bolts and it has since survived more than a dozen engine dyno pulls with peak power arriving at 7500. It will be shifted at 7700 this season, we shall see if it stays together.........

I have buzzed mine to 7200 on every shift for aprox 70 passes down the quarter, and aprox 500 street miles of abuse. I then installed ARP rod bolts and it has since survived more than a dozen engine dyno pulls with peak power arriving at 7500. It will be shifted at 7700 this season, we shall see if it stays together.........

I should be able to remember your combo by now, but I'm old. :emb: Refresh my memory, is that a hydraulic cam? And if so, are you using the short-travel Comp lifters?

my current engine setup : hydraulic , oem lifters
http://ls1tech.com/forums/carbureted-lsx-forum/1514719-just-home-engine-dyno.html

Hey S-10, I think you were asking me? I don't know what lifters they are, I bought the long block already finished from a friend. It's an 02 ls-1 w/ TEA stage 1.5 heads off a 5.3 & a Predator Z cam Hydraulic roller. 230/230 612/591 111+2 on a 109 ICL. Vic Jr w/ a Holley 750 DP.

when i ran 26" tires and a 4.10 gear i use to cross the line at 7400 in the qtr with a stock bottom end motor...and yes,i was gritting my teeth the whole time.

How many people really run them that high with a stock bottom end?

I keep seeing these numbers from Zones but man, that sure is a lot higher than GM set them from the factory. That is higher then they set the LS7 motors.

I have my limited set to 7400. I see 7-7200 everytime at the track. This is on a stock bottom end minus arp rod bolts. I literally flipped the motor over and put the rod bolts in the day I got it from the scrapyard.

My rev limiter is at 6800 on a stock LQ9 bottom end. It used to be at 6600, but even with my small cam it wanted more rpm.

My rev limiter is at 6800 on a stock LQ9 bottom end. It used to be at 6600, but even with my small cam it wanted more rpm.

If your limiter is at 6800, where are you shifting it? 6700ish? Just for grins I would try shifting it at 7000 at least once at the track. I say this because your relatively tight converter is probably going to be much more sensative to shift RPM (tight converter affecting how far back it drops in RPM between shifts) than a much looser converter would be. So even if power is starting to drop off by 7K with your smaller cam, the time you spend at that high RPM is much shorter than the time you spend climbing back up into power. Just my $.02. What do you think?

Just for grins I would try shifting it at 7000

You are a bad influence.........

You are a bad influence.........

I do what I can......:devil: :secret2:

Now go spin that bitch to the moon and report back..........:drive:

I guess I should also add a little evidence for context. For what it's worth, on my particular combo in my Camaro, a 7200RPM shift was worth a .5mph gain over my typical 7000RPM shifts and a 6800 shift was worth a .5mph loss. So over all, a gain of 1 full mph in shifting at 7200 vs. 6800. Granted......this was just my combo, but I suspect my 8 inch 5000 stall converter isn't nearly as shift-RPM sensative as a tighter converter would be. For example, if I had a 3000 stall in this car, I think the gains/losses would have been mulitplied. I see this all the time with my six-speed car since it has a further "climb", if you will, to recover back into maximum power. Again, this window of best average power will be different with each combo and centered mostly around the camshaft profile, but it's probably still a safe generalization to say that these are high RPM oriented motors in most cases.

Absolutely, great to have some technical data, it is another statement further backing that a automatic will usually be a significant amount of ET gain with the right converter ect.

my current engine setup : hydraulic , oem lifters
http://ls1tech.com/forums/carbureted-lsx-forum/1514719-just-home-engine-dyno.html

Thanks for the refresher, still cannot believe the power from that combo, I hope it stays together!

Hey S-10, I think you were asking me? I don't know what lifters they are, I bought the long block already finished from a friend. It's an 02 ls-1 w/ TEA stage 1.5 heads off a 5.3 & a Predator Z cam Hydraulic roller. 230/230 612/591 111+2 on a 109 ICL. Vic Jr w/ a Holley 750 DP.

Tommy, the purpose of the quote button is so peeps know who we are replying to, hence the quote block from 3pedals...

Thanks for the refresher, still cannot believe the power from that combo, I hope it stays together!



Tommy, the purpose of the quote button is so peeps know who we are replying to, hence the quote block from 3pedals...

Thanks S-10, I never picked up on that!