gsxrred1000

iTrader: (3)

Have a ljms stage 3 turbo cam in stock 5.3 with flat tops and stock 799 heads. See below my whole setup in signature. Think I popped a ring land and pulling out to replace piston. While it’s out I was considering trying the sloppy stage 2 over the ljms stage 3. I realize stage 3 is to big but at time of build I wanted a rougher idle so that’s why I choose this cam. I have sloppy stage 2 sitting on the shelf. What would I be giving up or gaining with this cam swap ? 90% street car. Want it fairly max effort as I push up to 25+ psi every now and than. Attempting for an 8sec pass this year. Go ahead give it to me square my feelings won’t get hurt.

JoeNova

It'll be easier on the valvetrain because the lobes are insanely lazy.
It'll still make power. Stock cam will make power with boost.
You can reach into the bag of any 22x/22x cam out there and run an 8-second pass with enough boost.

panda240ss

wait...you dont even have springs?

gsxrred1000

iTrader: (3)

Yes 660 btr springs are already in and have been for 3years

gsxrred1000

iTrader: (3)

3 years now beating on it I can deal with a valvetrain failure if it happens got 3 spare engine. Will I be giving up power ? Or will I have to run 30 psi to make same power as I did on 25psi. If I would gain better In the low and mid range and not give up to much power I would consider switching. Guess that’s my main ?

V8sounds

iTrader: (1)

I think you would be giving up power by changing the setup. Going from a larger cam with valve events set up for a turbo to a smaller more N/A style cam.

Only way you may not is if you have a high back pressure, just my 2cents.

stevieturbo

With no real info...who knows.

"too big" of a cam....usually in terms of overlap etc often just pushes the power band higher in the rpm, hurts spool...and if EGBP is high, will probably make the car slower all round.

but it's all relative. Rarely does a slightly smaller cam hurt anything though.

Although different scenario/era, it still rings true. Vizard once wrote to pick the cam you want, and then buy the next stage down or next smaller cam.

bortous

Roasted already

94heritage

You will be giving up a lot of rpm capability and probably quite a bit of top end power. I have ran the ss2 and its done on power about 6200-6500 rpm and in another car I have run the ljms st2 turbo cam and it would make power out to 7200 easy. Both cars were as close to identical set ups as you can ask for other than cam and springs. Turbo, heads, hotside all the same on sbe 5.3s.

jayyyw

How much power did you make on the setup, as-is? I run the same turbo with a BTR stage 2 turbo cam. I've been thinking about going to the Stage 3 cam to get some more upper RPM power but I don't want to sacrifice spool.

gsxrred1000

iTrader: (3)

I’m fine with being roasted. That’s how we get answers round here. Lol. I kept stage 3 ljms turbo cam in it. Threw a new slug in it and ready to fire up tonite. Thanks for all the advice. I think a stage 2 turbo or stage 1 turbo cam would do better for me but I agree that ss2 would be giving up power and higher rpm for sure.

yenkomike

iTrader: (2)

what turbine is in that 476r? if it is a 87 or 92 you are getting back pressure's pretty high. if it is 96mm turbine get rid of the t4 and build a devided 2 1/4 t6 and it will come alive.

gsxrred1000

iTrader: (3)

92 turbine /2” hot side merges to 2.5” a few inches before t4 flange. Guess I need to setup back pressure Gauge or sensor

yenkomike

iTrader: (2)

that turbine and hotside should work fairly well. but im sure the backpressure is getting up there and a better match for a smaller cam . if you go 2 1/4 devided to a t6 96 mm wheel it will make a huge difference in power with as good as spool as it is now. did this to my nova and picked up 6 mph in the 1/8 mile at 2 lbs less boost.

gsxrred1000

iTrader: (3)

Good to know. I’ll see how long this turbo lives before I upgrade probly.