camz28arro

iTrader: (12)

Just get headers, there has to be something like 20rwhp hiding in your exhaust. Is there any ls1 headers out there that will fit in the 944 or would you need to fab them up?

If you want to get a cam though, definately get a 4-8* split. Something like a 222-230 EPS cam should be good on a 112 or 113lsa so the power comes in sooner.

docwyte

iTrader: (4)

I can't just get headers, no one makes a set of long tube headers for my car. The only two sets available are both shorty headers, one from S&P, (which I have) the other from Renegade Hybrids.

I'd love to have a bolt on set of long tubes, but unfortunately I'm stuck doing a lot of fab work to get a set to fit.

It's more cost effective to change cams then mess with the headers or even install the CNC ported 243 heads I have in my garage...

HAZ-Matt

iTrader: (8)

Here is a thread about a hotrod that had to keep stock exhaust manifolds and also had the LS6 intake manifold and stock 243 heads...
403 rwhp LS1 with stock exhaust manifolds and mild cam
It made 332RWHP/347RWLBFT with the tuned original 99 LS1. The cam was a 218/230 .595"/.600" 115LSA +4 on EPS lobes. If you don't want to get an EPS cam, there are plenty of other lobes that can work.

I bring this up because you should be able to hit that goal with the right cam and the 243 heads with your current exhaust, unless you assume your headers are the world's worst and in that case you could see if stock style manifolds fit... but I bet they would be about the same flow wise. You just need to spec the cam correctly for the power, rev range, and the other components. The CheaTR cam is somewhat similar to the one above and was designed for stock manifolds. All of the cams spec'd for stockish style exhaust have very wide splits... you are going to need a lot more than an 8* split most likely if you keep a decent intake duration. I agree with your assessment that the power is most likely exhaust side at this point. I wouldn't worry too much about the FAST. However, the heads are worth changing. Without knowing the exact specs of your cam, I would agree that you should consider changing it to something more along the lines of one designed for stock manifolds, like the onesmentioned above. Granted, this is without me knowing exactly what your cam specs are, do you know the full specs of that cam? There are a few different Comp Cams that have 224 @ 0.050 intake duration.

The idea of swapping out the heads and running higher ratio rockers, I assume with a stock cam, was an interesting idea. Darkman had some good info. If we assume the exhaust is about as good as it can get then I don't see the point of wringing hands over it... custom LT's I suppose are a solution but might be a bigger PITA than a cam with better valve events for the rest of the setup... which is what you are thinking.

Siciliano15

iTrader: (7)

i still say if u want 360-370 rear wheel then u install those heads u got and add a set of 1.8 or 1.85 rockers to them. u already have the heads all u need are the rockers and its not a big job at all. u will need a re-tune as well....

disc0monkey

iTrader: (10)

damian do you think thats a bit generous. been there with a 218/224 .551 which provides minor split barely saw 340rwhpSAE with better heads that him. his post is confusing if you skim through it he is still using stock 241s. with 243s I think he might see 355.

docwyte

iTrader: (4)

Yes, still have the stock 241's. I have a set of CNC ported 243's that I can install if needed, but I'd rather not.

I'd like to get what I need with a cam and sell the 243's...

Haz_Mat: Read that post, that's pretty much exactly what I need. By sticking with the 241's vs 243's I'd be down another 20ish hp, which still puts me in the range I want to be...

disc0monkey

iTrader: (10)

yeah not saying you should go with the heads imo without getting the car running better. how is the idle? any cam surge? does the motor run like its happy?

docwyte

iTrader: (4)

Idle is great, no cam surge, motor runs very well. Pulls great off idle on up, AFR's are nice, no issues.

HAZ-Matt

iTrader: (8)

That was one of the reasons I posted it... just because I didn't think it was unreasonable to get to your goal even with stock manifolds or shorty headers as long as you have a nice split for the exhaust, and don't do mess up with the amount and location of the overlap.

As far as the heads, I guess it is sort of academic: 243's with less cam v 241's with slightly more cam. The 241's do have the advantage of being on the car, and it would be perhaps be easier to keep from exceeding the power to weight ratio.

1fastlsx

tsp tor 2 v2

Darkman

iTrader: (2)

This was the very project I modeled my build after. I used essentially the same cam from PatrickG, had PatrickG tune it, and measured my results on the same dyno as was used for this project.

The difference is that my outcome was about 26 horsepower less. Some of this is attribuatble to additional parasitic losses in my setup and driveline (2005 CTSV). My point is that the results you get from this setup vary from car to car.


(I subsequently offset the "shortfall" and then some using Trick Flow 215s and a FAST 102/90 setup.)

docwyte

iTrader: (4)

I had PatrickG spec me a cam, he recommended a 226/230 .600/.602 115LSA +4 advance with EPS "endurance" lobes.

Since I'm a total noob to the LS motor, can someone explain all that gibberish to me?

HAZ-Matt

iTrader: (8)

Ah, I must not have read the thread quite closely enough... and didn't realize you had basically that same cam. I agree that different cars will certainly make different numbers on the chassis dyno... drivetrain is important as you say, even the specific dyno can be an overlooked factor.

The first set of numbers is the intake and exhaust valve duration in degrees of crank rotation, measured at 0.050" of valve lift. The next two numbers are the maximum valve lift for the intake and exhaust valve with 1.7 ratio rockers. The second to last number is the Lobe Separation Angle, which is the distance in camshaft degrees between the exhaust and intake lobe. The last number "+4" is sort of a short hand which means that the Intake Centerline (the middle of the intake lobe) is going to be at 111*.

These numbers are sort of a shorthand way to quickly compare cams. Obviously you don't see the effect of the shape of the lobe with just the lift at 0.050," which is why the manufacturers will often release the duration at 0.006 and 0.200 valve lift.

Comp has a decent area on their website just covering this sort of thing
http://www.compcams.com/Pages/416/va...-tutorial.aspx

Just out of curiosity, do you have those sort of specs (or the part #) for the current Comp cam in the car?

docwyte

iTrader: (4)

It's a 224/224 .563/.563, not sure on the lobe seperation...

HAZ-Matt

iTrader: (8)

Interesting, that seems like it would be a TR224 which is from Thunder Racing and ground for them by Comp... it typically comes in 112 or 114 LSA. If it was on a standard Comp lobe it should have slightly different lift.

I mainly just asked so I could see the exhaust duration to sort of get a better idea of what you were running right now. Although popular, not quite the right choice for stock style or shorty header exhaust.

docwyte

iTrader: (4)

It's an EPS spec'd cam, not sure beyond that what it is. I'm actually on the phone with EPS now to order my new cam and get the specs on what I have.

HAZ-Matt

iTrader: (8)

Well the reason I said that is because I thought earlier in the thread you originally tried to order a cam from EPS and it was delayed so he told you he would send you a Thunder Racing cam... also because there aren't any lobes with that duration and lift combo in the Comp catalog, but it is the duration and lift for the lobes they grind for Thunder. Comp grinds the TR224 for Thunder, but that cam (and the lobes) are not in their catalog because they are technically Thunder Racing cams. At any rate all that makes it sound like the TR224 cam to me. Obviously this is just idle speculation on my part

bayer-z28

iTrader: (14)

I was thinking that too.. A cam will put you WAY over your mark. Get it tuned and see where it is.. An LS6 intake with 241 heads is a NICE setup for a stock cam, stock cube motor. If you're still under, then look at the ported TB like was said before and maybe some P+P'd 243 heads and/or an underdrive pulley. That should do it.

There was a thread a WHILE ago from a guy that made like 395 or 400 RW on just a good tune, LS6 intake and 241 heads.

Darkman

iTrader: (2)

If the OPs car had, or could have LT headers I would agree with this statement. However, it has very small diameter shorty headers. Thus, all of the normal gains we assoicate with cams, heads, and the like go out the window. It is not unusal for a custom cam in this context to gain as little as 15 horsepower.

bayer-z28

iTrader: (14)

I'd like to see how this turns out......

My other question is: did he exhaust every other possibility, though? (no pun)