114 LSA, .600" lift, split duration 235-242
This is the cam my tuner recommended what do you guys think?
Anyone have any experience with a similar cam and an E-force/roots?
Im at about 9.5 to 13.7 psi on an all stock LS2 except exhaust and Id like to get that back down some. will this cam bleed off much boost?

 

it will work but I would do something in the high 220s/mid 230s on a 115 for that setup.

 

I agree, you can go that route since its an LS2 and PVT isn't really an issue should make good power, and with cathedral ports you drivability should still be decent. Going from stock to that you may regret the surging issues you may encounter. Going 22x/23x on 115lsa I think you'll be happier with boost.

That cam profile you commonly see on a standard SBC, or LT1 head, not so much with LS for the average street car.

 

Do yourself a favor. Sure, that cam will work. It will shake, rattle, and roll......and, at the end of the day, it won't make any more power than a much milder grind. Get you a 222/234 116lsa with Comp's LXL lobes. Your motor will make just as much power as it would with the bigger cam. You'll enjoy driving it a whole lot more. If it matters, it will still sound good. Just not with the big cam lope. You'll pass a few fuel stops that the big cam guys won't

 

I mostly auto-x the car (in 2nd gear) so what will help smooth out the 2 - 4k range, the split or the duration?

 

More duration and overlap makes for rough running. Also, makes more power. Totally not necessary dealing with a TVS blower though. You're comparing a cam with -4 degrees of overlap to one that has +10.5 degrees. Big difference. If you're worried about it being strong and smooth between 2 and 4K, the big cam isn't the ticket.

Install the big cam and you'll like the cam...for a little while. Then you'll hate your car. Install the smaller one, and you'll love your car no matter what you're doing with it. Street, track, long trips. All good.

What size blower pulley do you have? With that info, I can tell you about where your boost will be with the smaller cam.

 

3.5 with an innovators west 10%OD. It makes about 13.5 to 13.7 up top witch is too much or my liking. Maybe this winter ill get the blower ported.

 

That's like having a 3.15" blower pulley with a stock balancer. That's really spinning the 2300 hard. The cam that I mentioned should lower your boost at least a #. Hard to tell without seeing a boost curve. If your exhaust isn't real good, it can cause the boost to go up on the top end. Might be some restriction in the intake runners that could push boost up a little too. Your boost "curve" shouldn't be a curve at all. It should peak quick (2500 to 3000 rpm) and hold roughly that boost level to red line.

 

I can post the dyno pic when I get home but it definitely curves. Should I ditch the cats? I'm also running stock 2.1/2" axle back with 1.7/8" kooks headders. The min boost was around 9 or 9.5. Ill post that picture to be sure.

 

The only change made was the OD pulley and tune. The final tune only has 5* timing and a max of -4*






10psi@4400
10.5psi@4900
11psi@5400
12psi@5700
13.7psi@6400

 

Black line is boost, right? Not sure what to make of that. You've got restriction somewhere. Here's a Maggie TVS at similar boost. Post #115:http://forums.corvetteforum.com/c6-f...und-3-a-6.html.

I'm pretty sure his exhaust is causing the slight rise in boost at the end of the run on that one. At lower boost levels, I'd bet your boost curve would look similar. Seems like yours should be higher at 3500 and lower up top. My boost curve (Maggie TVS2300) peaks at 9.5psi at 3500 and settles to 9.25 for the rest of the run. That's with a 3.3" blower pulley. ZR1 TVS2300 boost curves look similar to mine....even at 15+psi.

At WOT, a p/d blower should have similar boost, no matter the RPM. It's blowing a fixed amount of air per revolution into the motor. As rpm rises, the amount pushed by the blower goes up by a like amount. At least that's my dumb a$$ farmer way of trying to understand it

 

That is a typical E-Force boost curve, the boost rises in the higher RPM's due to long runners. The Maggie, ZR1 etc... do not have runners so they won't rise.

 

My question is do the cylinders see that rise in boost or just the plenum/runners

 

I don't think the cylinders see the extra air. I believe the air "stacks up" (that's one hell of an engineering term) in front of the intake mani at high air flow rates. Those runners that help the bottom end hurt a little on the top. Here's an interesting read. The Behan guy knows his stuff just a little. I argued with him a few times on that forum before I knew to shut the hell up and learn. http://www.camaro5.com/forums/showth...ck+boost+curve

 

Future plans include ported 243's and a ported blower, that said what (in a cam) would help the boost not rise so much up top and still have a nice smooth 2-4k curve? Low duration and some moderate overlap like -2 to +2? The opposite maybe?
I realize the cam you mentioned earlier has been tried and tested but I auto-x and almost never drag race

 

You might be better off playing to the EForce's strengths. Maybe concentrate on a more moderate boost level and be able to run some more timing. There's not much out there (probably nothing) that will match it from 2 to 4k rpm.

I ran a 222/230 116+1 cam in my TVS blown truck (6.0L with ported 243 heads) for 40K miles. Always thought that it was just a hair too big for a 5K# truck. Also thought it would be perfect in a 3200 lb vette if it had 4 more degrees on the exhaust side. It would still be in there except for a cam bearing taking a crap. Never had that happen before.

New motor will have a 218/230 118. Lift with LXL lobes is either side of .600 in/ex. Either of those cams would work well in your LS2. I don't think a bigger cam is the answer to lowering your boost. The main restriction you have is before the air ever gets to the valves. Maybe go to a 3.75" pulley. Lower the boost a little and be able to run more timing. IAT's will go down too.

My thoughts on it anyway.

 

Just the plenum/runners. If you are still looking for a cam, the Lingenfelter GT9 works quite well with the E-Force.

 

Ive thought of using that cam but it seems too mild on the intake and way too hot on the exhaust side.
I think I need to learn about lobes to better chose something that works for me/auto-x
Any auto-x guys out there with blowers?
Probably not

 

Has anyone lost boost by removing cats?
Do aftermarket cams typically like catless X's?

 

I am far from a cam expert but will share my experience in choosing. I am running an eforce, 1 7/8 headers, cats, npp exhaust. My pulley is 3 inch and an 8% OD damper. Things are different from there as I have an LS402 and ported heads. Your boost curve on the graph doesnt say much because I cant see the scale but the numbers you posted seem in line. At 4000 rpm I am at 8lbs and steadily increase to a max of about 12.6 at peak. I know I am pushing that poor little blower but its what I have to work with for now. I guess your boost is a bit higher because of less cubes.
Now, about the cam. I had my cam spec'ed by Pat G. and what I told him I wanted was simply the following.
Good power through out, although low end was already insane so not a priority.
I plan to shift by 6500 rpm (due to my A6) and redline would be 6800.
Something easy on the valvetrain, the less issues the better in my book.
I want to know the car has a cam, but nothing very choppy, I guess a "mild chop"
Since I know little about cam choice, I went with exactly what he suggested, even though some other people told me I could go bigger. To be perfectly honest, I couldnt be happier. It idles perfectly at 750 rpm, has a nice sound, and makes great power.
Specs.... 226/246 .610/.637 119+3 XE lobes. I know.... XE lobes are old school, and I can get a few more ponies with something more aggressive, but they work for me.
Not suggesting this is right for you as the engines and needs are different. I am saying I think it pays to have someone (and there are others than Pat G. also) who knows cams spec one out. It is not expensive and pays off. They should ask a lot of details and you should be very honest with them and yourself about what you want. They take into account, engine, trans, stall, shift points, boost, heads, compression, etc etc etc.
It pays to try and make the right choice the first time. I have more than one friend who wanted..."super lumpy" and now regret that move.

Sound at idle..


Power band...