L99 cam question.

[Milkman20]

Originally Posted by mlee

Since you have an L99 you would need to swap out the DOD (displacement on demand) lifters with that cam. There are cams specifically made for keeping your lifters called VVT (variable valve timing). This would save pulling your heads. There are pros and cons to both... just do a search on VVT and you will find lots of info... my preference is to get rid if the lifters it's the weak point even in a stock L99.

As with any cam install, springs and pushrods are an easy swap also

Thanks a Bunch!! i really appreciate it. these L99 and LS3 engines confuse me so much cause its the same car and engine but different in so many ways. anyway, i am probably gonna do a VVT and DOD delete, get a 3200 stall torque converter, i found a couple of VVT/DOD kits and found people that have used them and said there good kits. I really highly appreciate it.

Originally Posted by Jeffs_SS

This might help you some. I also have the L99

http://www.camaro5.com/forums/showthread.php?t=123470

thanks this helped a bunch!!

[mike@newera]

If you change the cam and leave the converter stock, you will lose acceleration from a dead stop, due to the fact that any aftermarket camshaft will be increasing power more so in the higher rpm range, the trade off will be a slight power loss down low depending on what the camshaft profile is. This also makes the idle less stable, which generally will require the idel to be raised, ignition timing to be raised as well. When you do this on the stock torque converter, especially with the 6l80e transmission which has a very tight stall converter (so you can't feel the converter lock up), your car will want to lunge forward a bit when you are at a stop. There are camshaft profiles that can be used with the stock torque converter, we have a couple of profiles that work well, but even with those cams, a properly stalled converter will not just make your car faster from a stop, but will have better street driveability. From my experience with the 2010+ camaro DOD/AFM lifters, get rid of them if you change the cam.

If you have a roots blower, which produces instant torque gains off idle, a custom camshaft can be designed to be used with the stock converter that has negative overlap to give a tame idle and make great power with a roots blower, but will not perform very will naturally aspirated. The reason a stock converter will work well with this particular application is due to the fact that the roots blower increases torque so much off idle, that it raises the stall speed because of the increase in power.

Basically, naturally aspirated, if you don't match the converter stall speed to your camshaft profile power band, your combination wil not be efficient. Take this information as you will.

[Milkman20]

Originally Posted by mike@newera

If you change the cam and leave the converter stock, you will lose acceleration from a dead stop, due to the fact that any aftermarket camshaft will be increasing power more so in the higher rpm range, the trade off will be a slight power loss down low depending on what the camshaft profile is. This also makes the idle less stable, which generally will require the idel to be raised, ignition timing to be raised as well. When you do this on the stock torque converter, especially with the 6l80e transmission which has a very tight stall converter (so you can't feel the converter lock up), your car will want to lunge forward a bit when you are at a stop. There are camshaft profiles that can be used with the stock torque converter, we have a couple of profiles that work well, but even with those cams, a properly stalled converter will not just make your car faster from a stop, but will have better street driveability. From my experience with the 2010+ camaro DOD/AFM lifters, get rid of them if you change the cam.

If you have a roots blower, which produces instant torque gains off idle, a custom camshaft can be designed to be used with the stock converter that has negative overlap to give a tame idle and make great power with a roots blower, but will not perform very will naturally aspirated. The reason a stock converter will work well with this particular application is due to the fact that the roots blower increases torque so much off idle, that it raises the stall speed because of the increase in power.

Basically, naturally aspirated, if you don't match the converter stall speed to your camshaft profile power band, your combination wil not be efficient. Take this information as you will.

ok, so say i were to buy a 3200 stall torque converter, with DOD and VVT delete, and a bigger cam, but keep it naturally aspirated could i still buy a roots blower like a few months later or would i have to put the stock converter back on.

[mike@newera]

In that case, I would say to have the converter closer to 2800rpm.

[mlee]

Originally Posted by Milkman20

ok, so say i were to buy a 3200 stall torque converter, with DOD and VVT delete, and a bigger cam, but keep it naturally aspirated could i still buy a roots blower like a few months later or would i have to put the stock converter back on.

You would also need to buy a blower cam with more lobe separation, if you're thinking of going that route in the future...

...or just change cam again when doing the blower, would be a pretty easy job at that point.

[Milkman20]

ok thanks everyone!!

[CAP'N B]

The converter has a lot of variables involved with it, the person you get your converter from will ask about the cam, the rear end gearing and also the weight of the car, the will want to know if it is Naturally aspirated (N/A), Forced Induction (turbo/supercharged) or Nitrous oxide injected. This will all be taken into account for the torque converter. For a cam with lots of overlap and Low Lobe separation angle(110*-113*) you will need higher stall. What it does is also allow the engine to freely climb into the power band of the cam so the engine doesn't lug or bog down at low RPM's. In other words a torque converter will be custom ordered for your application. You may also have to change the ecm/tcm tune if you add a converter for the lock up speed. Also depending on the lift of the cam you may also need to change the valve springs.

[Milkman20]

Originally Posted by CAP'N B

The converter has a lot of variables involved with it, the person you get your converter from will ask about the cam, the rear end gearing and also the weight of the car, the will want to know if it is Naturally aspirated (N/A), Forced Induction (turbo/supercharged) or Nitrous oxide injected. This will all be taken into account for the torque converter. For a cam with lots of overlap and Low Lobe separation angle(110*-113*) you will need higher stall. What it does is also allow the engine to freely climb into the power band of the cam so the engine doesn't lug or bog down at low RPM's. In other words a torque converter will be custom ordered for your application. You may also have to change the ecm/tcm tune if you add a converter for the lock up speed. Also depending on the lift of the cam you may also need to change the valve springs.

yea i was planning on getting duel valve springs.

[CAP'N B]

Precision Industries makes a great torque converter but it is a little pricey. Read up on how they make it that was what made up my mind.

[Darth_Emma]

My shop recommended a Precision Industries TC for my L99 car when the cam goes in. I told them I want to make sure my car remains well behaved on the street and I don't want it to surge and buck when stopped at a red light. They told me to get a torque converter when they do the cam. (My car also has a maggie, btw.) I will be getting a blower cam and torque converter in March.

[jsharp]

I too will have a precison 2400 with my blower/cam.