Z06X

As a long time engine builder, fabricator, etc. I've built many platforms over the years. As I move and learn more about these LSx engines, I have tried to establish what's been done and what's yet to be done.

Like many other genres I have experience with, the Corvette crowd has a pretty typical upgrade path that 95% follow to get to "x" hp and what not. What I haven't seen much of are those who try to break the path.

One would be, who's explored the limits of the car while maintaining stock heads/cam. Combinations with headwork, intake mani work, etc. C6Z whp with a C5Z combination that is mildly mannered is the ticket IMO. Has anyone pumped up the c/r a tad, worked the heads/intake and kept the stock cam to see how much power can be made while being able to lug 6th gear at 40mph like a stock cam car will?

This feels to me to be the path I'd like to go with this car. I'm just wondering if there are any others out there. Any aftermarket companies on here ever really explore what you can do on a stock grind?

Post it up...

AU N EGL

stock LS6 block, LTs, open exhaust and a good CAI, great tune NASA ST2 cars are running 385-388 RWHP

Z06X

That's the common approach and is well documented. I'm looking for someone who went further than intake/header/exhaust/tune....

Who's worked the head/intake/bottom end, along with those mods and kept the stock cam?

zeevette

You're not going to get near C6Z RWHP with those restrictions. The only way a stock cammed Z is getting in that range, (and beyond) is to use a power adder. Touch nothing else on the motor, and you can have a stock driving Z with more than enough juice to take on C6Zs. Besides, the number game is played on a crooked field. Dynos/operators are very inconsistent.

winters97gt

+1.

Dyno's are really a tuning tool. You won't be able to hang with a c6Z NA without a cam. They will completely destroy you when they are stock, and then if they only have an intake and tune, it's game over. The LS7 is a beast. You will need heads/cam to keep up with LS7 cars since they usually have an intake and tune at the least. They just make so much power under the curve and keep pulling hard.

Z06X

1) I've built 2.0 liter engines that made 298chp n/a (I'll provide engine dyno sheets...VE way beyond 100%), I will not believe that an LS6 can't make 505chp with that cam. This is a production motor with 405chp, built on a mass scale. There are inherent losses just due to that fact. It's clear people are able to find an additional 50-60hp with just basic breathing mods. There are still plenty of avenues to go beyond that. Headwork/intake manifold modifications are a piece of that equation that can yield a lot of additional power.

2) I understand dyno's are tuning tools...I own one (Land and Sea dynomite). It's as simple as running a C6Z on the dyno to establish a comparison.

3) If noone has done it, then how can you guys come in with some confidence to say "no, not possible". It's 100% possible, it just comes down to how much one would spend to avoid putting in a cam.

I am not going to make theoretical conclusions until I find that someone has done intake/header/exhaust/headwork/intake mani/tb/tune and shown some figures. If noone has done it that can be located, then I guess I get to find out.

Every genre I've ever been involved in had people who just wanted to either stick to stock bottom ends, stock turbo's, stock trannies or some other guideline. I feel someone here has to have "been that guy" but maybe not. I like to push boundaries, and when people say something can't be done, it honestly just makes me want to find out more.

You have a right to your own opinion though. If we load up this thread with "no's" then I guess it'll make for an interesting finale.

jake07Z06

03 z with lg headers, b&b catback, vararam intake, ported tb, maf, and a tune put down 395 rwhp.

on the same dyno an 07 z put down 474 rwhp with lg headers, b&b catback, cai (hurricane), and tune.

hope that helps

btw the 07 z was making about 446 ftlbs. I dont remember what the 03 made for torque but I think it was in the 380 range.

jake07Z06

You probably wont find very many people with that kind of setup because most people dont want to spend 3-5 grand on those mods when you could spend under a grand on a cam swap and get huge results. Another reason is, and im sure you are aware, most people build an engine around the cam. Heads, valve train, intake/tb size change, usualy all come after or with the cam swap. Thats how we do it in the bike world anyway.

AU N EGL

Then again, we see stock LS6 NASA ST2 cars faster then LS7 NASA ST1 cars.

~Josh

The highest hp "stock cam LS6" has a supercharger attached to it.

zeevette

To the OP... You're the big engine builder; go for it. Just because you say it's possible, doesn't make it so. Besides, what's the point? Why would you limit ONLY the camshaft? Not really how the world works. From backyard gearheads, to professional shops, the method is the same; use the most efficient/effective components to achieve a goal. In the case of a 2 valve, single in-block camshaft w/o phasing, a bigger cam is the center piece to add power. You seem to be suffering from some form of wishful thinking. As far a "following this path", you're going to be the only one drinking the juice.

robz

Just to add Gary went 10.89 with a bolton ls6. Not sure of the hp but I think with the newer stuff out today and some additional knowledge he could run around 10.60.

ctusser

The highest Bolt-on LS6 dyno's I've seen were around 390whp range with no cats. I'm somewhat curious about a stock cammed car's potential. I don't think I've ever seen results posted on a car with worked heads and a stock cam. I suppose you could really shave down the heads and run a Cometic .040 gasket to bump compression way up and run race gas or meth injection to keep detonation at bay.

A half point bump in compression ratio tends to be worth around 8hp at the wheels, so there is some to be gained there, and probably a few gained by cleaning up the head ports and port matching components. You could run a higher ratio rocker arm which tends to be worth around 7-9 hp. An electric water pump and underdrive pulley set will attribute to less parasitic loss and show up as a gain. Also lighter drivetrain components, flywheel, clutch, wheels and tires will show more hp on a dyno jet. Just My fidanza aluminum flywheel showed an increase of 7hp on a dyno jet over stock flywheel.

Trying to get C6Z power on stock cam is a tall order, I doubt you'll be able to hit that target but I admit I am curious what the max potential is with the stock cam. I think you'll be breaking new ground here and wish you luck.

95wht6spd

The cam will be the limiting factor, your better off asking what most do, how much with stock heads (also costs a lot more than a cam for modded heads) and changing cam to work better (pump more air) through the other mods.

Z06X

I feel there is a demand for more potential to be explored while maintaining ENTIRELY stock manners. I think there is a sector of individuals that would spend an additional cost beyond that of cam swap in order to maintain BONE stock style streetability.

Zeevette...I'm not claiming that because I say it, it is so. What I AM saying though, is that 390whp has been done with bolt ons and NO headwork or intake mani work. No reduction is parasitic losses, no increase in compression, no reduction in bottom end frictional losses, etc. There is TONS more potential in the motor, with the stock grind beyond 390whp...that's a FACT. How much more is the question.

I think the motor has 500chp in it on the stock cam....that's my feeling. Whether or not that becomes the fact who knows, but so far noone has provided any proof it's not possible....only speculation.

Saying that the cam is the easiest and cheapest means to achieve that power is false. There's always easier and cheaper, but there's reasons people don't do it...choice. If everyone who wanted more power wanted the easiest/cheapest method they'd use nitrous. There are downsides though, so some people choose not. Some people choose to supercharge, some people choose n/a/...all their own reasons. I simply feel going with a huge stumblin grind is something people don't want. Some people want it to feel STOCK...bone STOCK in it's manners, yet lay down more power...that's why you see so many intake/header/exhaust/intake/tune people.

To each his own. I like doing what others say isn't possible...I've spent plenty of years doing that. Maybe I'm wrong, maybe I'm not...we'll see I guess.

zeevette

You make it sound like any aftermarket cam will ruin/change the stock driving manners. That's one of your preconceived notions that needs to be set aside. Many people have achieved nice power gains from an aftermarket grind that doesn't have any negative affects on drivability, myself included. Another point; you seem to have chosen 390 as the number everybody hits with basic bolt-ons. My Z, with a CAI, and LG pro headers, only did 370 on it's first dyno trip. That's a long way from 500 BHP. Just because you "feel" that it's doable isn't very scientific, and again, what's the point? Lots of guys choose a cam based on sound, not overall performance, but you don't need a big loper to make your car faster. If you place an emphasis on "bone stock" like street manners, you can get that with a cam that also increases power.

Z06X

Listen, I've dealt with people like you for years. You sound like someone who just wants to argue because you think you know it all. I heard your opinion....I disagree with it.

The fact you conclude that it's not possible based upon...nothing... is interesting. My "feeling" based upon my experience is that it's certainly possible. My desire is to do it on a stock grind. I agree that some increase in duration, lift and ramp rate can still be manageable in terms of driveability, my point is though, what is possible without a cam change...period.

I've now found an LS6 with stock cam making 414whp peak on a dyno that shows C6Z's at 438whp stock. His mods still leave room to go further, but he's the highest I've found thus far. I believe it can be done...at least in terms of PEAK whp.

In addition, I own a dyno and have tuned EMS for years. I can commit MUCH more time to extracting as much power as possible with no worries about the bill that needs paid. I've also built custom headers for nearly a decade. I can commit much more time to building a one off set that is built specifically for the application. There are many things that are possible that can be improved on the LS6 without going straight to a cam change. It just comes down to money and desire to find out. I feel some people would be interested in the option were it proven possible.

PRE-Z06

I know you don't want a cam, but my 218/230 116 cam will pick-up ~35hp and literally will sound like stock through cats at 725rpm and not buck under a 1000 with a good tune. You could swap 1.85:1 rockers and springs, but will gain less than half that. FWIW my set-up makes ~417rwhp and will slowly pull away from a stock c6z, but I also have a vararam which doesn't show on the dyno...

Z06X

Enough with the pictures and inflamatory crap. I'm trying to have a discussion. I hear the opinion, the end. Delete your stupid pic please.

Pre-Z06....good info. I'd considered 1.85:1's, but realized I didn't want any alteration of lift/duration whatsoever. Were I to go some lengths and not achieve the desired goal, good to know your cam is out there.

In addition, the company I now run builds many GTM variations, SLC's and other kit based products using the LSx platform. Your product is definitely noted.

SoDiezl350

I think it's definitely possible to go above and beyond on stock cam simply by building the valvetrain to allow the motor to rev to a higher RPM. I'm not sure what kind of speeds the stock rods can handle but it's pretty obvious that you are going to output more power if you can increase the flowrate. I imagine this was the way that you were able to get big gains on those 2.0L 4cyls you were talking about?

I imagine the limitation to this approach would lie in the flow capabilities of the stock heads, the valve lift and duration(cam), the strength of the rods, and the stiffness of the valve springs being high enough to prevent valve float. I'm surprised that more tuners don't raise the redline of the motor, but I am not familiar enough with the specifics to question why they don't. I would imagine an 5.7L 8 cyl motor with so much more rotating/reciprocating mass approaches the limits of the rod strength as well as valve float a lot quicker than say a 2.0 4 cyl. Don't forget the valves have mass as well, and most likely need much stiffer springs than those of a 4cyl.

The bottom line is there is a difference in how most people make power on these motors, but there isn't anything inherently different about them than any other combustion motor. To the defense of the other posters here though, I've never heard of building a motor and leaving the stock valve lift and duration(cam). If you are going to try and raise the redline of the motor, it would seem pretty silly to keep a cam that won't allow you to flow at those higher RPMs.