I have this GTO, full weight, 3700lbs, built auto w/3500 stall, and stock 3.4x gearing.
Planning on a forged 347 w/oem ls6 heads, ls6 intake, with a 200-250 shot, single stage plate.
I drive it weekends only when I go out to the meets and the track.


I've been looking at the bigger cams: MS4, vindicator, Trex v2.

I don't see the point of getting a smaller 230ish cam because I'll be spraying the motor. So I won't have a lag down low when I launch and even though the stall is smaller, it should flash up higher because of the nitrous. Is there any reason why I should go with a smaller cam? Or am I missing the pros of the smaller cam for my application?

Also, how would it drive on motor? Driveability can be sacrificed but I don't want to get yanked by some gt stang on motor...that's the only fear I have with that big of a cam in my heavy gto on motor...on a big shot, it wont matter, but on motor it would.

 

Installation and tuning will greatly affect drivability of any of those cams. I'd get the cam that best matches your stall. I don't know which one that is. I'd call each of the sponsors to find out which fits your combo best.

Good luck stompin' those 'stangs.

 

if your just looking at those 3 cams and your talking bout just going all out, you might as well just slap the TREX on there. but i do like what ive seen from vengeance and there cams too.. i rode in my buddies 98SS thats untuned with a vindicator cam choked up with a ls1 intake and that car just rips..

 

I am looking for all out.
Just concerned with weight and gearing on motor. On bottle there won't be any issues that I can see. Just motor is what I'm concerned about. Don't want to go get food sat. night with an empty bottle and get yanked by something that makes a lot less power.

 

id talk to the cam experts here, like Patrick G. A custom cam is often better than an off the shelf grind. As for driveability, if you have a good tuner, it should have decent street manners, depending on the cam.

 

if your going all out, u might as well up the stall as well. if your going TREX i would just go with a 4k stall. look up "import slayer" hes running a TREX and a 4K stall.

 

from my experince i swap from TR224 to G5x3 and i was goin all out but then an issue raise up in the air wich is a Bigger cam need more air and so i had a vacuum issue our tiny Ls6 intake doesnt support on high end at all ,then i swap with FAST 90/90 then guess what the cam shine up there putting more 22hp just up there from 4800-7000 i was shocked then but think about it...it makes sence bigger cam need more air+more air needs more fuel so my stock injector was wide open at 116 duty cycle (another issue) the car was perfect as N/A but i have 150 dry shot to spray , so i swap with 38 lb injectors and just then i had the perfect night rider .
so calculate what you gonna invest in your car and treat the whoe engine as one peace putting big cam with stock heads stock bore stock injectors stock intake will buy you nothin...you need to look at these parts too . good luck

 

Unless this is a drag queen a big cam in your heavey car will make for a turd from light to light on the street. You will get yanked by a Honda.

Just concerned with weight and gearing on motor. On bottle there won't be any issues that I can see. Just motor is what I'm concerned about. Don't want to go get food sat. night with an empty bottle and get yanked by something that makes a lot less power.


heavy car big cam is not good for a street combination. Bigger gears and you will be ok at the track but 373's isnt going to do it.

 

So does the trex not make any power or tq at 3500rpm?
I don't see anything below 3500rpm w/the stall.

 

Big cams other dont make real power until 4000+ rpms. They start coming to life at 3500- rpms but you dont see *** kicking power until you hit the upper rpms. I would say from 4500-6600- rpms is where those cams really come to life.

Thats not good with a heavy car.


Do yourself a favor and have a cam speced for you. Cam size and compresion are not bragging rights, how fast the car is matters.

You will get a lot of misinformed opinions on here and hero worship from kids that do not know this difference.
Thats the best advice I can give.

 

Here's how I see it.

Here is a ls6 car w/ms4 cam (green line, blue line is stock ls1)


Here is a 224 cammed car (which is what I used to have)


I flash up to 3500rpm when I got WOT. MS4 car makes almost identical power at the 3500rpm-5000rpm....how is the big cam worse?

 

AT 3000 rpms you have 160 hp or 200 hp you tell me.

If all you do is drive at WOT then yes you have me there...LOL

 

160hp is what a stock ls1 does at 3000rpm also(close to it atleast), so then in theory that should lose to a honda also.
I don't see why 3000rpm is important when I race because I won't ever use that low of a rpm. So it wouldn't matter.
The only way I can hit 3000rpm is when I'm at partial throttle, once it downshifts w/more peddle mashing it jsut flashes up past it.

I'm not tyring to start arguments here, I'm just trying to understand with numbers and charts.
Everyone says the big cam and heavy car is bad, but I fail to see why. If I'm racing and these are the numbers i'd put down
I can't see why it would be a problem since I have a stall.
I don't know what I'm missing, but from these 2 charts, I don't see how I could be worse off with big cam.

 

LMAO! Look I'm not here to argue and personaly I could care less what cam you use.
I offered advice, you can take it or not.

I've been there and done that, I know the differences and I have many customers as well to draw from their experiences.

If you want to have to "flash" evertime to pass car thats your call.


Best of luck with your project.

 

I could care less that you could care less LOL

I never said "**** you, take your advice and shove it" I just want to know the reasoning.
I can see the moon comes out at night, but some people want to know why. I'm a Why kind of person.

I'm just responding because I want to hear your reasoning.
I'm not a "hear what everyone says and just take it as the truth" kind of person.
I like to know WHY! I don't think my discussion with numbers and graphs is wrong,
I think it's a good tool to prove and disprove a theory about big cams vs small cams.
You said big cam and heavy car would suck. I posted some charts comparing a
big cam and small cam and want to see what you're seeing. Because I'm not seeing the same thing,
but that's why I'm discussing this in this thread so I can LEARN....I don't see why you are acting the way you are.
You gave advice, and now I want to see what you're seeing, but it seems like you'd rather not show me
and just call it quits.

 

If anyone else can explain this to me differently feel free to post, I just don't see how
a ms4 in my big GTO would hurt me. I'm not interested in racing traffic at partial throttle.
I'm interested in WOT on the street and track. I run Hoosiers all the time, so traction is not an issue. I still fail to see how if I was say, rolling at 20mph and someone next to me jumps their car, and I hit it at the same time, how I'd be worse off w/the big cam when my car is setup to flash to 3500rpm.

If someone else can explain I'd like to hear. Don't just post and say "it won't work" or "it'll suck"....tell me WHY, show me using these dyno graphs. That's what I'm using as my reference point for this discussion.

 

No problem, it seemed like maybe you were arguing with me.

If you have to down shift everytime your on the road to pass a car or go up a hill I dont see that as being good. I like my cars to pull no matter what gear I'm in.

Now a racing situation is different. But you dont leave a stop light at 4000 rpms do you?

So I look at the street function more than the track function unless this is a dedicated race car or weekend special.

My downfall I guess, I look at it a little more practical.
Is your engine forged? Take a look around at all the spun bearings and broken rods.
Know how that all happens? Excessive rpms is a main culprit and guess what big cams like. Again I'm being more practical than most I guess but I see the adverse effects and think about them for people because there arent a whole lot of people talking about it. I dont mention it very offten but it goes into my line of thinking when answering questions like this.

 

I have a daily and I rarely drive this car, even when it was running, I rarely drove it. Saturday only, unless I was going to the track. Most of the time the car is on they highway heading to some place or going to the track.

So far as WOT, the downsides are fairly minimal in my book because on the chart, the ms4 cam makes a little less power from 3500-5000rpm (like 10-15less hp). But anything after the ms4 cam shines by significant amount.

But as just partial throttle driving, it's gonna suck going up hills and just giving it throttle to get it moving like it used to on the 224 cam.

That is what I'm getting as far as the pros and cons of each.


Now I've searched for trex charts but I can't hardly find any....will the trex make less power than the ms4 3500-5000rpm or should it be close to the same. I lean towards the trex because of the lower lift which would hopefully keep spring life a little longer. I'd like to even run a PAC beehive on the trex if it would make the valvetrain lighter and rev faster.

The motor will be forged with lightweight I beams and slightly higher compression. but stock ls6 heads and intake however.

 

Ahhhhh ok now we're getting somehere...LOL SO you have a definate need for the big cam.

Right on.
I would still go with a custom ground cam even if you went to TSP and said hey I was going to run the MS4 is there anything you can recommned that is inline with it that might better for my application and then give all the info you just listed. They're the same price from TSP, some guys charge extra for custom ground cams some guys dont... IIRC TSP does not. We charge 370 + shipping.

OR any of the sponsors can do that for you as well. Myself included.
The way I work it is we send you a questoinaire to fill out and we spec the cam from the info provided.

And I really did mean best best of luck, LOL I wasnt being a wise ***

 

you should contact one of our sponsers for help. I am sure they will be able to help you pick out the best one for your application.

P.S. I am running a big cam in my car [ 646 lift ] ,