ChevyThunder17

iTrader: (45)

I think it pulls timing before the shift as well. I would definitely tell you to try removing TM entirely until you get it figured out. With your timing going up and down like that, you won't get a good idea of whether or not you've gained anything.

yurs78

Have you talked to MAST yet? I've seen the dyno graph of the L92 truck intake, it's pretty stout. I think there's a lot more to tuning it, made my head spin a little after reading this article.

http://www.gmhightechperformance.com.../photo_23.html

I'm sure someone out there knows the trick to these VVT engines. I think it's worth the grief for the low end boost in TQ. Good luck getting it ironed out.

Russ

Daryn

iTrader: (19)

yeah its called DONT GET ONE!

norris_83

iTrader: (4)

sorry to hear this happened with you.. i was one the same page, in the end i just removed the vvt for peace of mind! should be going with a CTS-V cam or LS3 cam to keep my SC happy

CI DENALI

No, I haven't talked to Mast yet. I've been really swamped with work this week, but will try to call them tomorrow and report back with what they say.
I did read that GM High Tech article. It was what convinced me that these things work, until I saw a more recent article where they were testing cams on the LS3 and I realized that the LS3 w/out the VVT still has a comparably shaped torque curve!
iwas actually going to buty the Comp VVTcam, but since no one seemed to have it in stock and I figured Mast would be more experienced and promised to be helpful with the tune, I would go with the Mast instead.
This cam should make at least a little more power than the stock cam, even if it stays parked at full advance or retards to 10 degrees ATDC! I will check carefully this weekend to see if its a vacuum leak, because this MAP sensor DTC and the power loss may very well be a sign of that.
Thanks everyone for your input.

CI DENALI

I called Mast on Friday and they told me again to call back on Monday to speak to Horace, as he is their tuning guy. So I called today and the first time Horace was at lunch and when I called back he was too busy to speak with me, so they put some guy named Brian on, who really tried to be helpful. However, I have now learned that Mast doesn't have any kind of tune, nor can they offer any tuning advice on this cam. I pointed out that their website says that for the cam package for the L99 (2010 Camaro auto) they offer as an option, an EFI Live Auto Cal and/or custom calibration. Given that my cam is a similar spec grind with the VVT as well, they should have something for me that could work. They said that EFI Live hasn't come out with the Auto Cal yet and that's the problem. But they must be able to at least give someone an idea of how to tune for the VVT. They also offer their own M-90 ECU's and a bunch of L92 VVT crate engine's so obviously someone has to be doing the calibration for them. The thing is, I remember talking to them at the manufacturers midway at the LSX race in Memphis in 2007 and they were bragging about how they were doing all sorts of wonderful things with VVT, so one way or the other, they've been blowing smoke up my ***, and I'm not a very happy customer right now. They gave me the name of a "dealer" - Fastlane Manufacturing and told me to speak to a guy there named Nick who should be able to help me!? Felt like a big ****** brushoff to me. Meanwhile, I gotta live with a truck that can't idle properly, throws a DTC every now and again and simply doesn't run any faster than it did before the cam swap. I guess I should consider myself lucky that they didn't tell me I have to now buy one of their $1800 ECU's to get it to run, but if they did, I would have told them where to shove that for sure. Well, I can tell you all, after spending over $800.00 bucks with those ****** for nothing, they won't be selling me any **** anymore. I was waiting for their rockers to come out in January and was seriously considering installing one of their 427 LSX motors in my truck next year, but they can **** off with that.
My advice to all of you considering a VVT cam swap; Do like daryn c said and get rid of it.
It's like having a stripper for a girlfriend, really cool to show off and talk about, but a lot more trouble than it's worth!

GONEB4U

iTrader: (125)

Sorry to hear about your vvt issues. I think that the vvt is more of a marketing tool for GM to say that they can get better gas mileage but I think that it is a big piece of . These trucks get no better gas mileage than a truck without vvt. If I ever get around to swapping out my cam, I def will be installing a non vvt type cam and throwing that vvt in the garbage. As for Mast, I think they are a bunch of butt holes. I've been going to SEMA for the last 4 years. I seen their booth last year and stopped to ask them a couple of questions regarding their products. I got the deer in headlights look from their crew. I could have got better answers from a crack head. They are just marketing the hell out of themselves but have no idea of what they are doing.

yurs78

That's a bunch of ****, it's some of the worst crap I've heard. I bet that they have no clue on how to tune that thing. They brought someone else in to do it.

As a last resort I'd try to call Comp Cams. They've got someone to do the tuning obviously because they've got the screen shots in the article. I know it sounds like a long shot but I dont' think a company as big as Comp Cams would sell a VVT cam that requires tuning and then not back it up with any.

There is an answer someone out there know how to do it, they're just being a bunch of greedy asses and not telling yet.

Good luck.

CI DENALI

Thanks. My sentiments exactly. I honestly would've gone with the Comp, but I couldn't find anyone that had their cam in stock. I have been experimenting with the phaser curve and have it now set to retard progressively to 5 degrees at 4000 to a total of 9 degrees @ 5500 RPM - which should be about 1 degree ATDC, since the phaser is "parked" at 8 degrees advanced. It seems to be working, but I haven't had a chance to test it at the track yet, and I still have some other fueling issues that we are sorting out. I will keep you all posted. If I figure this out, I'll post the results and the tune for the phaser.

Iraq Sucks

iTrader: (1)

Don't understand that CI, I picked up 43hp and 27lbs. ft. after tuning the same cam. Picked up respectively at the track. Only issue we had was valvetrain noise between 2800-3200rpm under the right conditions, inspection of problem proved it's not affesting anything though.