Another L99 cam question....VVT!

[IConnection]

The VVT is not a bad thing..
It can give u an advantage in both hp and tq threw the whole rpm band..
It just needs the correct valvetrain and camshaft design along with proper tuning...

[SS-screamer]

Originally Posted by Late Model Racecraft

Here ya go guys, here is a dyno vid of our VVT cam shaft for you L99 guys. Please feel free to give me a ring at the shop with any questions you might have.

What gains would you expect on a car with 1 7/8 kooks with high flow cats, roto fab cai and painted stripes (don't forget the stripes) coupled with your cam? Also what about heads?

Also, how is the driveability?

[Ject]

I think i'll be keeping VVT but doing a DoD Delete.. and save me a ton of money instead of doing the full LS3 conversion.

[IConnection]

I believe DOD can be turned off per gear and throttle angle so u can still keep it for 5 and 6 but not worry about it down low threw 1 to 4...Good fuel economy on the hwy with killer power, U CAN HAVE YOUR CAKE AND EAST IT TOOOOO WITH A L99

I will do the VVT setup with LT's and Cats along with a mild 2800 stall
I believe this will make for a nice setup :o)

Stay tuned for final testing

[SS-screamer]

Originally Posted by Ject

I think i'll be keeping VVT but doing a DoD Delete.. and save me a ton of money instead of doing the full LS3 conversion.

I think I've decided to go this route as well. Less expensive and sounds like it might be a little more fun being able to get in the torque curve earlier.

[firengnred]

I will do the VVT setup with LT's and Cats along with a mild 2800 stall
I believe this will make for a nice setup :o)

Stay tuned for final testing

[StlRomAniaN]

Originally Posted by SS-screamer

I think I've decided to go this route as well. Less expensive and sounds like it might be a little more fun being able to get in the torque curve earlier.

Think about TAPshift then. 1st gear - all rubber, 2nd gear - all rubber, 3rd gear - *chirp* haha

[Supercharged SS]

After doing the costs vs gains on my l99 cam swap I decided that it would just be better to do a s/c. While retaining the stock vvt cam,actually never opening the motor, we were still able to make 550/553 to the wheels on a nice safe tune. To this day the car retains all the stock valve train components.

[Ject]

Originally Posted by StlRomAniaN

Think about TAPshift then. 1st gear - all rubber, 2nd gear - all rubber, 3rd gear - *chirp* haha

I already do this with just a Vararam CAI, NoWeeds, and Tune..... tho I have to shift into 2nd at like 5800 RPM to roast all of 2nd.

Im all for power but I love the sound of a mild - big cam over a supercharger, plus i kinda like naturally aspired. So i honestly believe keeping VVT and going with a mild Cam and DoD delete will do it for me. Now just to figure out how much labor is and what I need to buy.

[trudawg660]

some cars are making close to supercharger numbers but with a N/A engine. there are a couple cam and bolt on cars making 460 at the wheels. i said i will stay with N/A for a while but like the saying goes "to each his own"

[PatrickfromMD]

Originally Posted by InjectionConnection

I believe DOD can be turned off per gear and throttle angle so u can still keep it for 5 and 6 but not worry about it down low threw 1 to 4...Good fuel economy on the hwy with killer power, U CAN HAVE YOUR CAKE AND EAST IT TOOOOO WITH A L99

I will do the VVT setup with LT's and Cats along with a mild 2800 stall
I believe this will make for a nice setup :o)

Stay tuned for final testing

My tuner tuned out the DOD/AFM (what ever you want to call it) in all but 5th and 6th. In 5th and 6th we restricted the RPM range so it would not come on at too a low of RPM.
This helped a lot, but still with my LTs and 3inch exhaust, it was annoying when it dod come on (even though I have 2 pairs of mufflers).
The EFI live was easily enough to figure out, so I used my EFI live to turn off 5th as well, and restrict the range in 6th.
I will more than likely turn it off all together, as any time it comes on, I feel it.

Like some of you out there, I’m lookin to get a VVT cam, but delete the AFM/DOD. There was a time I wanted to retain the AFM, but with 22k miles of having to deal with it, there is no use in having it, if I’m going to tune it out. I want the increased reliability of running std lifters and extending my RPM band.

Horace at Mast spec’d out a nice VVT grind that was mellow enough to do FI in the future (he is a pioneer). Still, it’s based on the stock VVT phasing (using a phase limiter of course), and I’m looking to see if there is anything else out there that comes with a phasing tables that complement each other. Until such time, the Mast is still my 1st choice.
I would love to add a Whipple in the future, so right now I want to focus on cams that would be compatible with that future path.
A Vararam is also high on the list, and that requires special tuning as well.

[cam-]

it’s based on the stock VVT phasing (using a phase limiter of course), and I’m looking to see if there is anything else out there that comes with a phasing tables that complement each other.

Yeah this is the main VVT issue. Tuning.

The real problem is you cannot ( as of yet ) adjust the cam phase without having that affect ign timing and fueling as well so it adds a real mountain of complexity vs a conventional non VVT tune. Mast runs a phase limiter but they still retain both advance AND retard features of the VVT. COMP on the otherhand also sells a phase limiter but theirs locks out all advance so the cam sits in a zero position and only allows retard phasing. Both MAST and COMP phasers limit total cam retard phasing to 20 degrees but MAST also offers 20 degrees of phase advance for 40 total degrees whereas COMP only offers 20 degrees of retardation as the phaser limiter prevents all advance. The unfortunate reality we all live with is piston to valve clearance so there is no perfect way BUT....

What Im seeing so far is this. The L92 heads really seem appreciate lift and the MAST cams are all around .560 which is about as much as one can safely run and still allow the phaser so much room to operate without bif'ing pistons into valves. If you run the COMP phase limiter with its 20 degrees of phase movement then you can safely run .600 lift cams and gain the advantages of the L92 heads a bit more. Plus you can order a cam with as much advance in it as you can possibly clear on ptv concerns.

So this is the route that i am going and I will post results. Initially I was a little confused as to what the limitations were and why but after a couple of three months of digesting these thoughts and the limitations at hand I feel that this route should net both more peak hp than a MAST cam plus it will be a lot easier to tune as I have less phasing to deal with AND less duration to smooth out. So my strategy at this point is to leave the cam phasing tables stock and let the phaser do its job and just tune the a/f in a conventional way. Once I have that done I will dyno and post results. Then Im going to take the rest of the season to play around with the phasing tables and see if I cant squeak more out of it which I'll also post up about. Of course i have to get the car together first. Anyways this is probably a bunch of jibber jabber but I hope it makes sense to you guys.

Sooner or later we'll have enough if us guinea pigs that test out this stuff and find what works out best. Wish someone had done all this homework for me before I started LOL

[SS-screamer]

So let me see if I get this right. If I change out my heads to L92 then I can run a Comp cam/phaser combo which allows more lift and better potential performance over the Mast cam/phaser and may be easier to tune?

"Wish someone had done all this homework for me before I started LOL " That's what I'm banking on you for.

[third1]

The L99, already has L92 heads.

I need to see more guinea pigs before I make a cam decision.