91_rs-teal

iTrader: (13)

Hello all. I am also a GXP owner and looking to do a little somethin around tax time. I have holes in the top of both my mufflers and was wondering if purchasing the magnaflow cat back is truly worth the money. or just buy replacement mufflers? In addition the catless DP. I also can not find stock ls4 cam specs for the life of me. Is anyone driving a GXP with a cam swap that has retained the DOD feature? I was looking at getting a stock 2001 LS1 cam to bump up exhaust duration for a little more sound, keeping in mind I wouldnt need new valve springs. (cheap also) I also was looking at a K&N CAI and the price is rediculous for a slight gain. Also trans coolers... is there any out there that retain the stock press in clip style fitting? I have a soft shift while putsin around and was wondering if a mild pressure bump up would be best? I'm right around 80k and I am full aware the trans isnt goin to last forever.

I have seen guys do 1.7 rockers(spring hassle), clamp style trans cooler, ls6 intake(fuel rail hassle,TB hassle,oil pressure sensor hassle, and rear port hassle).
This car is not somthing I wanna do a complete ordeal on. I would like to keep as a daily driver but its nice to have a little more passing gear

Overall the question is.....

What is worth doing????????????????

I ran 14.2 - 1/4 mi. three times in Michigan hot humid weather on 93 octane.

Whats gonna get me to were?

2005gxp

could do a ported intake. headers, catless and magnaflow catback and put a cutout in the downpipe before where the cat would be. tune, cai, shift kit. or go turbo lol

i have a k&n for sale also if your interested. boxed up ready to ship

monte_with_a_LS4

iTrader: (4)

haha. blah blah blah..... or just go turbo

AlabamaGuy

iTrader: (5)

So you want to remove the motor to do a cam but the intake swap is a hassle?

TiredGXP

iTrader: (2)

All things considered, turbo and beefed up transmission. Pricey, but I don't think any combination of other mods will put as big a smile on your face.

91_rs-teal

iTrader: (13)

Right a cam isnt a modified piece and of cource it would be when I would need a new trans.

AlabamaGuy

iTrader: (5)

You'd have to do new lifters unless it's a DoD cam. Which means you'd be pulling the motor out, intake off, and heads off. Or you can get the same gains (possibly more) by modifying a few pieces to make an off the shelf intake fit, and you can do it in a couple afternoons. Not telling you what to do, but if a cam was worth it in these cars, there would be cam swap guys running faster times than intake swap guys.

91_rs-teal

iTrader: (13)

the Dod lifters wouldnt work with the slight more lift of a ls1 cam? (still under .500") (.467" / 0.479" in a 2001-LS1) with the same push rods and lifters it wont do the same kinda "bleeding out" of the lifters? ls1 cams have the same LSA right?

theres 0.466" / 0.457" in a LM7 how much less lift does the ls4 have

AlabamaGuy

iTrader: (5)

No one knows the specs on the LS4 cam for sure. It's believed we have a DoD truck grind. Here's a question though. Why spend the money on a cam that might give you 7 or 8 hp?

LS1 Racing

iTrader: (15)

QFT. I've been told by a Chevy parts counter person that we got the 5.3 (RPO LMG) grind from the 2007-up Tahoe/Suburban.

And it's ture...A cam swap is a colossal waste of time with our crappy intake and exhaust manifold systems.

AlabamaGuy

iTrader: (5)

And to clarify, I'm not trying to come across as a dick. But you asked, and there are certain things that work and certain things that are considered a waste of time and money. A camshaft on an otherwise stock motor is a waste. Especially with the compression you'll lose with the added overlap to add "sound".

91_rs-teal

iTrader: (13)

stock apeal, cheaper upgrades. Say 310 HP at flywheel with cam, add CAI and full open exhaust and cam gives you that 3% or more on top of everything you do. I just see it as a slight or mild upgrate from front to back. slight difference on cam lift, little more duration.

I take it you have done a ls1/2/6 intake swap. Idealy a ls1 would be the way to go $75-$100 intake and $30-$40 cam for 20+ HP gains thats huge! It seems with these cars HP gains are at high costs. I would "guess" with ls1 intake, ls1 cam you could make the same power as a ls6 intake and stock ls4 cam for half the money into it. Keeping in mind mild mods.

if i were to decide to go with 1.8 ratio rockers after swaping cam
intake lift is basicly the same on both cams minus the duration


stock LM7 cam 190/191 - 0.466" / 0.457"
Exhaust:
1.7 - .7769
1.8 - .8226

stock LS1 cam 197/207 - 0.467" / 0.479"
Exhaust:
1.7 - .8143
1.8 - .8622

.0396 difference in lift between cams with the 1.8's
again its not huge but its not expensive

the extra exhaust wouldnt help turbo guys?
what have you gained with what youve done?
what have you spent to gain what you have?
I am new to this, this my first nice DD, more power with same driveability is my overall goal

AlabamaGuy

iTrader: (5)

You are going to gain 20hp easy with just an intake swap and a good tune. I dropped nearly 3 tenths and picked up 3 mph going this route. Fact is, the tiny bore makes these motors react much differently than the rest of the more popular lsx motors, it's hard to make the power. We can't even rev high enough to flow with the stock heads...If anything I would go with 1.8rr and full bolt-ons. You're going to come out better but the lifters are going to limit the power because you can only rev so high. I pull HARD right into the shift point which is set at 6k rpm. I don't feel like causing a lot of damage with the POS lifters GM put in these motors so I don't rev higher. I have stock valvetrain, so I can't see the logic in moving the powerband even further right when you're not going to be able to use it. (unless you change the lifters) Sorry if I'm rambling but I'm getting tired, lol.

If you're wanting to keep the DD nice, just go full bolt-ons and be done with it. You'll have a low 13 sec car if it's done right and it will hang right with mid-high 12 sec cars on the street. Plenty to play with.

nmp0098

There is a post in this forum with the stock specs by JDMC5, and it has since been backed up by fieroguru who degreed the cam. The stocker is:

193/193 (non-DOD) 197/197 (DOD) 114-2

The New Era DOD cam that I installed has been measured by a couple people now. They will only tell you the lift (.570/.575) and LSA (113). In my install thread I pointed to thread that put the specs at 224/232, which was backed up by another set of measurements. The kick in the nuts for me is the 20 degrees of retard ground into the sucker. So:

224/232 113-20

Sittingmongoose installed a 224/224 (I believe) and had good results. However, others have tried stock like cams and found very little difference in actual vehicle performance. I'd say you need to get to at least 210 degrees on the intake side for the cam swap to be worth the effort, with 220 being about ideal based on the truck guys experiences.

From my own experience, my car was faster overall with just the LS6 intake manifold and gear change. I was faster from 0-60 with the old setup (consistently well under 5 seconds before to around 5.5 seconds now), although the cam takes over up top (from a 40mph roll I'm about 2s quicker to 100mph). The retard in the cam makes it a bad match with the stock transmission gear ratios. With a 6-speed and different gearing, the car would be a monster so I'm not knocking the grind for the G8 application. Since I've opened up the intake tract a little more, I don't hit peak injector duty cycle (which correlates pretty well to peak power RPM) at 7000RPM (although it is pretty flat there, so it's right around peak power). The cam is just too big with the retard.



If I had to pick from the cam, the intake, the gear change, and the headers, I would take the intake first, the gear change second, the cam third (with about 2 degrees of advance ground in, or advanced 22 degrees from the as delivered grind), and then the headers. I don't think the headers buy you much over the downpipes for the money without the rest of the mods. If you want to go turbo, save your money and trade your car in for an N/A V6. They run 12s all day for a fraction of the cost. Those are just my opinions.

707chance

iTrader: (2)

Questions that need to be answere is how much money are you willing to spend? how much of this work can you do on your own? what are your performance goals? street or strip? I have done a cam swap along with alot of other stuff, but I haven't found the time to get the motor back in the car and get it to the tuners. Would I do it again? Hell no!!!! but ask me again after I get it tuned.
IMO: I would def. get a trans cooler, shift kit and polymount/dogbone, this should be your first mod!!
Inproving the intake side of the motor is a good idea...a CAI, a intake swap is a "easy" mod for the money, rocker/rods/springs is good esp if you can get them used. The exhaust issue can be addressed with a set of headers and a electric cut. A magnaflo provides very little performance for the cost.
The cheapest mod for the dollar? install a small shot!
don't forget to get it tuned!!!

JDMC5

iTrader: (3)

I just tuned a guys car on this forum and with just 1.8 rockers, CAI and flowmaster mufflers that car hauled ***! I can imagine an LS6 intake and some headers or maybe a downpipe making his car plenty fast.

evil 5.3

ok guys alot of good info in this thread but there is alot of dod cam out there i just cam from an o7 gmc (will post pic) but there were several cams for it for almost were every you want the power to be so i can see a cam swap beeing a pain but i dont understand the lack of gain example 04 gto stock 302hp to the wheels , called cartek made it a head and cam car ported intake and headers bam 430hp wheel so if we had a good cam for the car it would be worth it by the way the cam in the gto was 224/224 112lsa 597/597

Bryan921SS

Evil you need to research more on how engines make power.

An LS4 is a small bore small stroke engine...which limits power outputs and gains from conventional n/a modifications.

The LS2 might as well be on another planet in comparison to the LS4.

If you want to make high hp numbers, north of 400fwhp, you need boost.


Edit: Or you would need to spin this little 5.3 up into the clouds...ie the 60's Z28

707chance

iTrader: (2)

I agree with Bryan921SS. If you check out the Dyno section or other sites you won't find those numbers coming from 5.3s unless they are boosted. I think Sittingmongoose is the only guy who has spent the time and money to come close to those numbers.

91_rs-teal

iTrader: (13)

has anyone tried

http://store.katechengines.com/oil-p...take-p148.aspx

it seems you can cut the neck off the OPS and itll fit right up the the stock holes

more so able to fit with the ls1 swap but still

just wondering..............