Generation IV Internal Engine - Perfect Driveability LS3 Cam?

Hi guys,

I'm thinking about putting a more daily driver friendly cam in my LS3 with the following mods.
1 3/4" extractors
twin 2.5" cat back exhaust
fast lsxr 102mm intake manifold
nick williams 102mm throttle body
comp dual valve springs, comp pushrods 7.4" and currently has a comp 227/243 cam.

I rarely rev the car over 6000-6500rpm, so power above this point is of no concern.
I would like it to have perfect or close to perfect street manners.

I also have 4.11:1 diff gears so don't really need heaps of torque down really low in the rev range.

What sort of cams would people recommend with the above requirements?

I'm currently looking at something like a Vengeance Racing stage 1 cam (223/231 115+3) or maybe a thunder racing TruTorq Level 1 cam (219/224 115)

Probably leaning against the smaller cam at this stage, as I don't see the need to give up torque at lower revs to gain a little over 6000rpm?

Thanks for the help
Benno

Here is cam test that may help you, I would suggest having a look @ Lingefelter's spec'd camshaft.

I've always run Cathedral heads so I've no camshaft LS3 experience, seems that LS3 heads make the cam choice very fussy as you are describing.

http://www.gmhightechperformance.com/tech/lsx_engine/0911gmhtp_chevy_ls3_engine_camshaft_comparison/index.html

get a 220/232* 116LSA+4* with no more than .600" lift.

you will be happy then!

whats wrong with the current cam?
Maybe you need to check the tune out first?
Though it might be a tad too big. I like gto_ua spec cam.

Here is cam test that may help you, I would suggest having a look @ Lingefelter's spec'd camshaft.

I've always run Cathedral heads so I've no camshaft LS3 experience, seems that LS3 heads make the cam choice very fussy as you are describing.

http://www.gmhightechperformance.com/tech/lsx_engine/0911gmhtp_chevy_ls3_engine_camshaft_comparison/index.html
i have a brand new lingenfelter gt11 cam in the box forsale. it's the same cam in the test that did very well. pm me if your interested

whats wrong with the current cam?
Maybe you need to check the tune out first?
Though it might be a tad too big. I like gto_ua spec cam.

The current cam bucks and surges a lot, especially around 1600rpm and coupled with a shuddery clutch, makes it annoying to drive in traffic. This was never such an issue previously, however the car is now my daily drive, so I would prefer better driveability. I must just be getting old perhaps?! lol.

I am going to spend some time on the tune and see if it can be settled down a bit, so I will probably decide from there. I do really enjoy the current cam when going for a drive on the weekend or entering in motorkana's etc, however even then, I rarely rev it over 6000rpm much, so tend to think I may be better off with a smaller cam anyway?

Cheers
Benno

If you are HPT & want to forward a log of the surge & buck as well as the tune file maybe I can see something. Shoot over a PM & will send you my email.

What is the LSA of your existing cam? Or do you know the overlap?

If you are HPT & want to forward a log of the surge & buck as well as the tune file maybe I can see something. Shoot over a PM & will send you my email.

What is the LSA of your existing cam? Or do you know the overlap?

I already have a tuner looking at it, I just need to spend some time over the weekend trying a few things. Thanks for the offer though.

Cam is 113lsa by the way. Its a comp lsr grind. Not sure of the overlap?

Cheers
Benno

Hopefully your tuner can sort out the kinks, I swapped out my cam as the buck & surge under 1800 rpm in lower gears was brutal. To many compromise's in the tuning for my liking.

I've a very good link that gets into some pretty good detail why the LS3's don't need big cams & what happens technically.

i have a brand new lingenfelter gt11 cam in the box forsale. it's the same cam in the test that did very well. pm me if your interested

I have that cam. It really does drive like stock. With the 4.11 gears it would drive even better than stock.

Sounds more like a tune issue than anything!

I currently daily drive an LS3 in our Monaro with a Comp Cam, 231 239 .617 .624 113.:)

Sounds more like a tune issue than anything!

I currently daily drive an LS3 in our Monaro with a Comp Cam, 231 239 .617 .624 113.:)

:stupid:

FWIW: The best cam I ran in my 403 with WCCH Stage 2 heads was a 230-240 111+0. It made 530/480 and drove prefectly thanks to the spot on tune by Ed Hutchings.

The cam I run in the 427 now is not much different and either is the drivability. I can leave it in 6th gear on the highway and pull cleanly from 600RPM (yes, six hundred) when I get in traffic. Also thanks to the tune by Ed. That's even with a heavily modified FAST 102mm matched to a NW 107mm TB.

http://i54.photobucket.com/albums/g93/WKMCD/VSEngine5.jpg

This must be almost perfect tune
My car is 4.0845" bore with 3.622" stroke with milled L92 heads (0.010"), stock LS3 intake and TB 102mm & LT headers (1 3/4") & cam of 227 / 239 LSA 114 + 0; after tuning it still surge at 1500 ~ 1800 rpm, but after that it suddenly jumps with a power that my tire start spining hard which i do not like it espically in town between trafic lights.

Your cam is very powerfull to get over 500 rwhp & 480 rwtq

"currently has a comp 227/243 cam"

IMHO that 16 degree split between the intake and exhaust duration is the reason it does not drive all that well. I would knock some duration off the exhaust side and I bet the driveability will increase quite abit and make it easier to tune.

This must be almost perfect tune

after tuning it still surge at 1500 ~ 1800 rpm, but after that it suddenly jumps with a power that my tire start spining hard which i do not like it espically in town between trafic lights.



Your serious?

I'm planning to travel to a tuner who is good and dyno the car, to fine tune the engine. The vaccum for the braks is very poor which affect the breaking, i think it is from cam

I'm planning to travel to a tuner who is good and dyno the car, to fine tune the engine. The vaccum for the braks is very poor which affect the breaking, i think it is from cam

Something is wrong there!

However I don't think it is the cam.
Your cam is similar to mine if not a little smaller.
In fact I was very surprised, if not a little disappointed, how smooth our LS3 drove. I expected it to be a lot lumpier at idle than our old LS1 fitted with a Speed Inc Comp Cam 228 228 .588 .588 13, however it was almost identical.

I have that cam. It really does drive like stock. With the 4.11 gears it would drive even better than stock.

I also have the Lingenfelter GT11 cam on my LS2. It was originally designed for the LS1 which has a smaller bore so the high lift gets the valve out the way.

For the LS3, I believe there are better choices available today. Something in the range of ~220° intake and ~230° with lift in the .600" range and 111° + 3°. You don't need a big overlap cam anymore to have a fast car. A big overlap cam usually is the cause of surging at 1600 rpm. Who wants that?

Sure, the big overlap cams will show nice peak dyno numbers everybody likes to brag about but if you look closely at the torque curves, most of these cams suck in the 3500-5500 rpm range where you spend 90% of the time during WOT acceleration runs. What this means you can jump out to a comfortable lead and hold it over a car that makes more peak HP at 6500 rpm. A big, flat torque curve is preferred over one that peaks at a high RPM.

Peak HP means nothing in my book.

I'm running the Vengeance stage 2 with great success. Very nice street manners, it can lope along at 1200rpm, idle 850. Big flat torque curve with no dips and peak hp by 6000. With this cam they made 470 to the wheels in a setup like yours without the fast.

My engine broke
The tuner discovered that the tuning was made in very bad way. The A/F ratio was made 11.1 till 1600rpm, then after 1600rpm it is 12.8.
Also, when trying to tune it, the engine started very unusual way, after that cooling water start to go low level and heat start raising very dramatically, however there is no leak observed. It was decided to teardown the engine after detailed inspection that didn't revealed any source of leak.
We discovered that the cylinder wall thickness between two sleeves observed of cracks in three location that water cooling is leaking to the oiling system. The tuner says it is knocking the engine expirenced.
It is very bad. Now im looking for new iron block.

Pictures for elaboration

I see the damage, but it's hard to imagine the tune alone caused that. Either way the block is scrap

As for cam, most of Lingenfelters offerings will drive nice and smoothly. And as for your clutch being nasty to drive with. Buy a proper clutch. There is little reason to have a clutch that isnt smooth to drive with these days.

The case of this damage was investegated and the following cases came at the same time that made the block to crack:

1.The tunning was not that best, where the tunning was found it is a copy of SD from another car and not optimized with the new combination I have.

2.The engine block is LS1, where the bore was overbored to install new sleeves to acomodate piston size of 4.0845" bore. The recommended interference fit shall be 0.002" per the recommended sleeve (Aluminum to Iron), but the shop made the interference fit of 0.006".

3.The overboring of the block wasn't made at each of the cylinder center point (found offset of almost 3mm).

The block is crap now

Didnt realise it had been re-linered.

I know everyone has different views, but I wouldnt trust any re-linered block. Factory installs only as far as liners are concerned for me.