Ls3 safe power up to 7000 rpms

[icemanrd19]

Currently have a ls3 hot cam that I would slowly start upgrading. Car already has a hot cam and stainless works headers. I would like to have the ability to run the e fine up to 7000 rpms and still be able to make power.

What does everyone suggest or is it not doable? Just trying to add some more power and fun till I eventually start messing with the short block and stroke the motor or forge for boost. Again I do not want to mess with the short block now.

[65 drop top]

The hot cam LS3 peaks around 5750 rpm. Spinning it much more than a couple hundred rpm's past that won't do you any good. Actually you'll float the valves and trash the engine.

If you are set on 7000 rpm's you need to look at a cam and springs that'll operate in that rpm range. And at that point the LS3 components are getting close to their limits.

Tell us more about your goals. What kind of torque and horsepower do you want to make? With a well selected cam and springs you could make a lot more power and at less rpm's. If your engine makes say 480+ hp now, a simple cam swap could get you ~550 or so.

Not sure if you consider a cam messing with the short block though.

[65 drop top]

Or a small nitrous kit

[slimjim]

Any sort of budget in mind? A new cam (and supporting mods) will get you closer, porting your heads to 280cc or similar would be a good idea also. I pick up my engine today with all of this done, unfortunately it won't be dyno'd straight away

[AU Doc]

A question for the group. I thought the point of spinning a motor higher is to generate more horsepower. That is,

HP = RPM*T/5252

So for an engine that produces a given amount of torque, you spin it faster to make more horsepower. I know there are a lot of variables there and the torque an engine makes varies over its powerband, but the example that always comes to mind is a small displacement motor that doesn't make a lot or torque, you rev it higher to make horsepower. Like the engines in IndyCars. Larger displacement engines generally make more torque, and they generally make more horsepower at a lower RPM.

I say all that to ask, if you can make the same horsepower at a lower RPM, why would you still want to rev an engine to 7,000 RPM? As far as I'm concerned, "it's just cool" is a full-credit answer. I'm just wondering if there's another reason to want to rev an LS3 that high.

[slimjim]

I Couldn't agree more. RPM was never a concern of mine with this build, coming from a rotary engine past it never will be. But RPM is damn cool all the same.

[icemanrd19]

RPM is damn cool. Loved hearing those ford gt350s revving high.

No nitrous or anything is in my future

Springs would be fine and easy to upgrade.

Currently enjoy the hot cam that is currently in it but if i can make alot more power and not sacrifice drive ability im perfectly fine with upgrading the cam

My end goal for this car is a nice 525 - 550 RWHP. Now if that isnt possible with a ls3 376 ill end up stroking it. I dont want to do anything twice really.

[slimjim]

RPM is damn cool. Loved hearing those ford gt350s revving high.

No nitrous or anything is in my future

Springs would be fine and easy to upgrade.

Currently enjoy the hot cam that is currently in it but if i can make alot more power and not sacrifice drive ability im perfectly fine with upgrading the cam

My end goal for this car is a nice 525 - 550 RWHP. Now if that isnt possible with a ls3 376 ill end up stroking it. I dont want to do anything twice really.

Same goal as me then, which is right at the limits of the stock bottom end and the entry level fuel system for a pro tourer.

I ran with this cam below, and they seem to frequent those exact figures you're chasing without sacrificing much drivability at all.
http://www.pcmofnc.com/product/pcm-of-nc-ls3-phoenix-cam-231-246-61x-61x-050-113-lsa/

To improve from here will mean bigger fuel pumps, injectors and bottom end, I'll wait until this power gets boring first.

[badazz81z28]

I feel 525-550 at the tires NA on a LS3 is not realistic. You can probably get close to 550 with a max effort cam and supporting mods, but it would be a horrible driver and be nothing but a peak HP dyno queen.

A realistic number for a healthy LS3 is closer to high 400s and barely 500 Rwhp at best.

[65 drop top]

Keep in mind that many of the aftermarket cams run minimal piston to valve clearance and if you get any valve float your engine is done. Also replacing valve springs will need to be done regularly.

The LS3 525 ASA cam will get you up into the higher rpm range. It's budget friendly and easier on the valve train than some of the aftermarket cams. Trade off is a little less bottom end torque.

[icemanrd19]

Same goal as me then, which is right at the limits of the stock bottom end and the entry level fuel system for a pro tourer.

I ran with this cam below, and they seem to frequent those exact figures you're chasing without sacrificing much drivability at all.
http://www.pcmofnc.com/product/pcm-of-nc-ls3-phoenix-cam-231-246-61x-61x-050-113-lsa/

To improve from here will mean bigger fuel pumps, injectors and bottom end, I'll wait until this power gets boring first.

what did your car end up putting down? i have a few things from PCM of NC. i like what they put out.

[icemanrd19]

Keep in mind that many of the aftermarket cams run minimal piston to valve clearance and if you get any valve float your engine is done. Also replacing valve springs will need to be done regularly.

The LS3 525 ASA cam will get you up into the higher rpm range. It's budget friendly and easier on the valve train than some of the aftermarket cams. Trade off is a little less bottom end torque.

Local guy has the 525 package. Maybe ill take a spin in his car to see the difference.

Now if i can go with the PCM of NC package and eventually stroke the motor and still use the same heads, cam, springs etc im all for it. Best way to sum it up is that im looking for the most usable, reliable, safe, power now only working with the heads and cam that would then be able to work with stroking the motor

[badazz81z28]

The 525hp LS3 is only going to put down around 470hp to the tires. Also “regularly” is a but extreme. You change your oil regularly, not your valve springs. There is a reccomend interval but it’s like 20-30k Miles depending on the set-up. I suggest this reccomendation comes from the cam and spring manufacture

[slimjim]

what did your car end up putting down? i have a few things from PCM of NC. i like what they put out.

They only have a chassis dyno so unfortunately I couldn't get it tested just yet. I walked in, told them what I wanted(basically exactly what you want plus L99 conversion and DOD delete etc) and they put the package together with what seems to be their most popular cam, I have another friend putting this exact setup into a C10 currently. PM if you want the specifics.

[icemanrd19]

For those that were wondering the difference. The hotcam dynoed higher than the location I had the tsp cam dynoed. Car rips with the new package

https://www.facebook.com/48502792/po...1688281926766/

[pro86tourn]

RPM is damn cool. Loved hearing those ford gt350s revving high.

No nitrous or anything is in my future

Springs would be fine and easy to upgrade.

Currently enjoy the hot cam that is currently in it but if i can make alot more power and not sacrifice drive ability im perfectly fine with upgrading the cam

My end goal for this car is a nice 525 - 550 RWHP. Now if that isnt possible with a ls3 376 ill end up stroking it. I dont want to do anything twice really.

Take it from a gt350 owner as much as i love the car and its a road course monster the car makes its power up high and suffers on the street. all depends on how you wish to make your power...

[badazz81z28]

Take it from a gt350 owner as much as i love the car and its a road course monster the car makes its power up high and suffers on the street. all depends on how you wish to make your power...

This is definitely the cost for max effort cams. This is why you don’t look at peak horsepower to judge a camshaft. It may give you only that peak power. One cam may make more peak power than another, but driveability is horrible. TSP makes good cams. Their goal is performing cams, not who can get the most peak power ignoring all the other factors.

[icemanrd19]

Completely agreed. Absolutely love the way the car drives now with the additional power and rpms. Maybe some new heads will be in my future but I doubt it. Most likely I’ll enjoy this motor till I build another and and just swap it out. Tsp customer service was top notch as welll


This is definitely the cost for max effort cams. This is why you don’t look at peak horsepower to judge a camshaft. It may give you only that peak power. One cam may make more peak power than another, but driveability is horrible. TSP makes good cams. Their goal is performing cams, not who can get the most peak power ignoring all the other factors.

[andrewb70]

I have a LS7 cam in my GTO...Redline is set to 6800rpm and it pulls hard there. I use dual valve springs and titanium retainers.

Andrew

[DualQuadDave]

Wow, so much misinformation out there. Ok, let me help some.

- LS3 is fine to 7000rpm, over and over again. The limitation on LS's and RPM is the connecting rods(primarily the bolts) and the valve springs. Stock springs will run to 7000rpm, but sustaining is another issue. Just an example, I ran my LS2 from new to 227k spinning 7000rpm everyday at least once and many topend 150mph runs sustained on stock springs.

- Buy better springs, any of the .660 lift spring packs will work great and give you room to upgrade cam in the future.

- Hot Cam is decent, but not great. There are way better cams out there, but reality is the cam should be matched to the car and driving style. Everybody shoots for big #'s and says "That's the one!", but overall use and purpose are more important.

- Don't port the heads. Porting LS3 821 or 823 heads is a waste, the port velocity is really slow with them. Best thing you can do is cam it and shave them .020-.030 and pick up compression, maybe a regular 3 angle valve job. That's it. They love that like I love whiskey.

- Valve lift is power, don't believe the "low lift lives forever" BS on the net. Let those guys keep being slow. Valve to piston needs to be checked with really big cams, though.