JakeL

Hey guys - this is sort of a corollary to my thread over in the internal tech section:

https://ls1tech.com/forums/showthrea...475#post957475

I'm interested in hearing your opinions on the suitability of the MTI stealth cams in a TT application:

Stealth 1: 220/220 on 115, .581 lift
Stealth 2: 224/220 on 116, .576/.581 lift.

I'm not really interested in other grinds for the moment, just curious about these two in particular as turbo cams. If neither is a great idea, there's always the GT2-3. (207/220 ~.580 on 118.5).

All three of these will suit my goals N/A (stockish/sleeper idle), and because of their wide LSA, should make decent FI (read: turbo) cams if I decide to continue on that path later. Keeping my options open and all that jazz.

I wouldn't ever want anything larger than one of these three cams due to the aforementioned idle smoothness considerations, so I'm not "limiting myself" in the N/A aspect just for the sake of turbo compatibility. Being an idle weenie has it's upsides sometimes, I guess.

The Stealth 2 has a pattern very similar to many suggested turbo grinds I've seen, so I'm pretty sure it would be an excellent turbo cam. The archives even has a post from Paul @ Thunder suggesting almost the exact same specs as a good conservative turbo grind. (he suggested 115lsa vs 116)

I'm curious what your impressions are of the Stealth I as a turbo stick though. No split, but on a fairly wide LSA, and presumably also low overlap like the 2 is. It shares the 220* exhaust duration with the other two cams, and just has a bit less on the intake side versus the II.

It is odd to consider that the LPE cam, with it's large split, and the Stealth II, with it's small reverse split - both from what I've seen to be well-regarded turbo cams or patterns, are so different. I suppose then that the Stealth I couldn't be all that bad...

Your thoughts?

-Jake

Pro Stock John

iTrader: (34)

I would do this one of the three you put forth:

Stealth 2: 224/220 on 116, .576/.581 lift.

Sure you don't have the lift backwards?

JakeL

That seems to be the best one to me too, I'm just a bit wary about the idle still. One good (Colonel) and one not so good (Cannibal), and the sample set size of two doesn't make it an easy decision! Subjectively, it's tough for me to convince myself that a 224 intake cam will idle smoothly. Still waiting for Colonel to make his sound clip of his car

I believe the lift numbers are correct - that's what's on MTI's site anyway.

Thanks again John,

-Jake

Pro Stock John

iTrader: (34)

224/220/116 will idle great.

CHRISPY

lift is backwards. The intake lobe on that cam XER .581 lift.

JakeL

http://www.motorsporttech.com/c5_engine01.asp

*shrug*

Doesn't make much difference to me - the first mentiones of the II in the archives state it as being a .581 on both lobes.

I admit it makes more sense this way though.

Now if I can just find some people with sound clips to help figure out which one of the three to go with!

-Jake

Pro Stock John

iTrader: (34)

I sure would not pick the cam from these three based on sound, only the reverse split cam listed is one that an actual cam company like Cam Motion would reccomend.

JakeL

John - the GT2-3 seems to be a very well performing cam for FI - there are a few vettes on CorvetteForum running over 550whp/600tq with that cam, with just 6.0L heads and around 10psi of boost. It seems to run quite strong. Other than the obvious fact of the traditional split design, is there something that is particularly odd about it for a turbo?

Kevin Sheridan (Shinobi) just did over 600 on his car with a definite non-turbo cam (at least so far as I'd been led to believe...) an XE-R 224 on 114, so I don't know what to think now...

I think I'll call MTI on Monday and see if I can get a bit more info about the idle luck they've had with their two stealth cams, since nobody seems to have any media clips of them.

-Jake

sr71

iTrader: (17)

after seeing Raymers numbers with a stock engine, I have started rethinking my cam choices. I already have ported heads with good springs and have been thinking about sliding the stock cam back in. Kevin has a killer engine, but Raymer is making incredible numbers with the stock set up.

VortechC5

iTrader: (6)

Does anyone know the intake and exhaust centerlines (or the specs off of the cam card if you have it) are for any of these cams? I have a Votech supercharger on my car and am going to be doing a forged bottom end for it. I am using Engine Analyzer Plus to try out different cams and would try these three out.

JakeL

I know the stealth I is straight up - no advance ground in. Don't know about the others. I suspect the II is the same, but don't know. PM Colonel, he might.

No idea on the GT2-3.

-Jake

stevieturbo

Im new here ( from the UK ), and dont actually have any real experience with the LS1 engine yet. But over the coming year I will be building a twin turbo LS6 motor for my own car.
I havent read up on too many profiles, but looking at the stock LS6 camshaft, which runs 218/204 0.550" lift, and 117.5 LSA, unless someone can offer a tried and tested turbo cam upgrapde, I will be using it.
As stock it offers factory idle, and driveability and emissions, yet a power band extending to 6500rpm. If it can make over 400bhp in N/A form, it cant be all bad. Id say it reads very well as a turbo cam.

Pro Stock John

iTrader: (34)

I would not do a traditional split camshaft for a turbo setup, after having talked to some cam companies. It's not what they would advocate. Doesn't mean that a 2002 LS6 cam won't be an improvement over stuck, it could be. But I don't see you guys looking at issues like midrange torque, driveability, etc.

I picked my blower cam based on a the following parameters:
-348ci, stock stroke
-Will not take the engine over 7200 rpms
-Want to run over 140 in the quarter
-Want to make 700-800 fwhp

I went with an FMS/Cam Motion 230/236//115. Terry wanted me to do a 114, but I pushed for 115 to mostly help the idle, but I had this idea that it would make a little less bottom end torque and pull harder up top. We'll see if that's the case.

If I had gone with a bigger grind, like 234/240/115, it would have had poor mid range torque, and would have peaked higher than my redline.

If I were to set up a turbo setup that i wanted to shift around 6500 at the track, I would say to myself, I will shift my setup 10% past peak HP. So peak on this setup would need to be around 6100-6200. My cam for example is set up to peak over 6600. So I would go smaller than me for a blower setup. Terry also said that turbo setups run less camshaft. I would be probably trying a 224/218//114 with a 6500 rpm redline for a turbo setup. I'd only run a traditional split cam if I got it for a $100.

Pro Stock John

iTrader: (34)

Steve, stock LS6 is not a reverse split like you have listed, it's the other way around, it's a traditional split cam.

sr71

iTrader: (17)

PSJ, you have some valid points, but can you explain to me how RR can make 600+hp with a stock engine on 11psi with a very safe tune and people like Kevin(Shinobi's Z) are only making 600hp with ported heads and bigger cams @ 15psi?...Jim Hall made 588hp with ported 6.0 heads and a stock zo6 camshaft @ 7.5psi. I am beginning to believe that a stock cam is the way to go with a turbo set-up. Even the highly regarded turbo book "maximum boost" says that nothing is better than the stock cam unless you are running 15 psi or more.

stevieturbo

I only quoted numbers from a ChevyLS1/LS6 book. I cannot actually verify the info.

But I do know from experience turbocharging other engines, that standard profile cams usually do work very well for turbocharging. Having said that, there is always room for improvement. But it can be expensive and time consuming for most people to experiment. Sometimes it isnt worth the risk.
If the valvetrain can handle it, a stock cam combined with high lift rockers, and a good pair of heads would be a safe bet.

Pro Stock John

iTrader: (34)

sr71 it would be nice to overlay the dyno graphs from all of these setups and see what can we can learn by comparing them.