So i'm in the process of buying the parts needed to remove the AFM/DOD from my 2006 LS4. I've picked up a LS6 intake, fuel rails/injectors and a ported TB. I plan to purchase a set of LS4 headers like these http://www.ls4store.com/pro...rs-exhaust-manifolds and I'm looking at these two cams. I've been reading about cam specs (intake/exhaust) and lobe separation and these two cams seem to be the best GM availible. https://www.summitracing.co...l-12565308/overview/ and https://www.summitracing.com/parts/nal-19355738 the hot cam is more expensive but also comes with the LS6 springs. Since I was going to buy the LS6 springs anyway, the price diff is not a big deal.

LS1/6 Hot cam: 219 int./228 exh 0.525 int./0.525 exh. 112 LSA
02-04 LS6 cam: 204 int./218 exh 0.550 int./0.550 exh. 117.5 LSA

While reading about cams, many times talk also included the torque converter. I hadn't thought about the converter with this swap. For those who have done it, did you swap out the stock GM converter for an aftermarket one? With these cams is will the stock one be OK? I'm only looking for about 400hp, not fuel economy and power in the lower RPM range, I have no plans to race this car, it will be a fun daily driver.

I know there are other parts needed, like lifters and guides, oil pan, head gaskets and several bolts/gaskets, but this thread is about the cam.

Thanks in advance.

Rob

[This message has been edited by qwikgta (edited 09-10-2018).]

Rob, I assume you are only looking for 400 hp at the flywheel and that us super easy. 400 at the wheels through an auto would be a little more of a challenge.

The LS4 shares the same head casting as the LS6 and LS2, and both of those engines are rate at 400 flywheel hp using the stock GM parts (intake, heads, camshaft, and exhaust manifolds). HP is about airflow, so you can swap over everything from the 5.7L LS6 and put it on a LS4 short block and you will get very close to the same power, but the power will be higher in the RPM range as the 5.3 has to spin faster to move the same amount of air/fuel as the 5.7 (or 6.0). So as long as you put a better exhaust than the LS6 setup, then you should be right at the 400 fwhp range. Then add a set of 1.8 rockers to get a little more lift.

However, since you are already spending $$$ to swap camshafts, I would get a better camshaft than either of your options (and not need the aftermarket rockers). The stock LS4 heads continue to gain flow to 0.600 valve lift, and we have the small bore that shrouds the valves slightly, so pick a camshaft that has close to 0.600" lift.

I would use one of these...
Comp Cams: 54-455-11 215/223 .604"/610"
Tick Performance Turbo Stage 1 Camshaft for 4.8L & 5.3L Engines 215/219 | .613"/.590" | LSA114+3
BTR TURBO STAGE I CAM 222/227 .602"/.598" 113+3

Don't get hung up on turbo vs. NA, the only difference is the turbo cams tends to have less overlap which is a good thing for drivability. I have had a custom cam spec'd for my LS4/f40 combo twice, once as a NA motor targeting 400 whp and once for the SXE369 turbo. The NA one was 222/226 and .59X lift. The turbo one was 221/225 and .59x lift.

I am not a fan of the doug thorley (or the OBX copy) headers for the LS4. If you look closely at the collector, the exhaust pretty much runs into a wall as the collector steps down from the 4 pipes to the crossover pipe. If you use them, cut the collectors off and use some better flowing ones.

I've not done a LS4 fiero yet .But i'm going to use the Elgin cam p/n 1840p [Sloppy stage 2].

Paul, thanks for the info, and yes, i'm looking for 400hp at the crank. I understand everything you wrote, and my concern was sticking close to stock b/c of the tuning. i'm still not sure who/where to get this tuned after I get it all done. Bolting on parts, making a harness, plumbing all the fuel/coolant is the easy part, but tuning is something I have not done. I figured if I went with a stock cam for the LS6, tuning it may be easy.

I've been reading all the LS4 posts and even reading others from the Grand Prix/Impala/Monte Carlo sites, and using the info for purchasing my parts. I've been trying to buy used stuff b/c there is so much used LS stuff out there. I got the LS6 intake/rail/injectors for $250 and got the valley cover the other day for $35. I have a line on a set of LS7 manifolds and only planned on the OBX style b/c it includes the crossover pipe. I AGREE ABOUT THE CRAPPY COLLECTOR's. I cannot look at those pic's w/out thinking the same thing. No way that crappy collector can be a good thing. But reading about them and finally seeing a pic of the inside, buyers seem to be happy with them. Funny you mention cutting off the collector, I already looked into buying collectors that would work better :-). My LS3 has a set of headers Archie had made up by Street and Performance. They are out of business now, but in their old catalog they sold them as LS "tight tuck" headers. They clear the manual axle but I doubt they would clear an auto trans. I checked the size of these headers and I think i'd have the same problem https://www.speedwaymotors.com/shoppingcart I'm thinking i could make these work but not sure its worth the effort. I also like these https://www.holley.com/prod.../parts/70301303-RHKR but they are pricey.

I've been looking into a LS2 style oil pan, oil pump, ARP bolts, head gaskets, LS6 lifters, springs, new guides, all this would be new. In your opinion other than the head gaskets/guides/lifters do I need all this stuff to convert the LS4 from DOD/AFM? I've got a lot of the small stuff on order, the cam, oil pan/pump and mounts are the last "big" things left.

Thanks again.

[This message has been edited by qwikgta (edited 09-10-2018).]

The beauty of the LS engine family is that nearly every tuning shop can tune it with HP Tuners, EFI Live or TunerCAT.

With the intake, injector, camshaft, and exhaust changes, it will need tuning and will run best when properly tuned. Don't skimp on this part...

Not sure if these would fit, but might be worth the $90 to find out. The collectors are too long, but you could cut them off and route the exhaust like the stock Fiero setup.
https://www.ebay.com/itm/Ge...a:g:tGwAAOSwRPhbjRnQ

As for all the parts to delete DOD. I wouldn't do anything below the block. Keep the stock oil pump and pan. Yes, the LS4 stock oil pump is a high pressure/high volume unit, and many other people use it as an upgrade for the other RWD engines. I would spend my money on the top side of the engine.

fieroguru, What are your thoughts on the Sloppy Mechanics Stage 2?

My plan is to go LS4 turbo.

Elgin Hydraulic Roller Camshaft - E1840P
Chev Gen III/IV (LS Series) 3-Bolt '97-Present
Adv. Duration: 283/286
Duration @ .050": 228/230
Lift: .585/.585
Lobe Separation: 112 LC
2200-7000, great mid range torque and power.

quote Originally posted by tampalinc: fieroguru, What are your thoughts on the Sloppy Mechanics Stage 2? My plan is to go LS4 turbo. Elgin Hydraulic Roller Camshaft - E1840P Chev Gen III/IV (LS Series) 3-Bolt '97-Present Adv. Duration: 283/286 Duration @ .050": 228/230 Lift: .585/.585 Lobe Separation: 112 LC 2200-7000, great mid range torque and power.

Way too large for the 5.3L. Probably a very good cam for a 6.2L