VVT Cams
12-15-2010, 08:44 AM
#81
spilling the beans Okay, I was going to wait until I got my chassis dyno numbers back, but here goes.
I placed several calls to Mast and talked to them about their new LY6 ss cam. I talked to the comp cams tech department a few times about their cams. I called TSP but did not get a call back. Bottom line: Mast and Comp produce excellent hardware, but do not support tuning unless, in the case of mast, you buy their ecm. The mast ecm, however, will not run my 2009 4L80e. Mast even tells me to find a reputable tuner in my area by checking out the forums. This leaves a crucial peice of the puzzle missing when purchasing vvt hardware. Also mail order tunes leave something to be desired over a custom chassis dyno tune.
Well, I live in Smyrna, GA on the north side of Atlanta and I take Mast's advice and search. Many users on here rave about Vengeance racing. I contact them, speak with Ron, and set up an appointment. So, I go in and sit down with Ron and we review the dyno charts from Mast's new 509hp ss ly6 cam and the chart from the L92 comp cam swap vvt magazine article where they dyno over 500hp. I expressed that I liked the benifits of vvt and that I wanted to keep this feature. After some further discussion, Ron said that he could beat the curve down low, build more bottom end torque and beat the curve all the way to the top with their cam and tune. Of course, Vengeance would have to tune the car. This is the package I was looking for. By the way, Vengeance has used some autokraft pans with great results, so we ordered one of those as well.
So I ended up ditching the vvt. I really like vvt. I have it in my Tundra 5.7 with a 6 speed auto and this truck is faster than a lot of sports cars. The new 5.0L mustang has it. But here's the thing. These engines have dual overhead cams, 4 valves per cylinder, and can independantly alter the valve timing on the intake and exhaust. I talked with Ron about this and it seems that these engines benefit more from vvt. The gm single cam push rod vvt, apparently was designed to enhance fuel economy more than engine output and because we comprimise by not independantly changing intake and exhasut valve timing, one of the issues we come up with is piston/valve clearance. So now we have to comprimise our cam. This is why I believe that for the sake of performance, in the case of gen 4 vvt, it may be better to do without. The proof will be in the pudding. Win or loose, I'm going to post my dyno results.
Another note. Alot of people on here confuse vvt with other systems that Toyota, Honda, BMW and Porsche use. Some of their systems change the valve lift and duration in different ways. This is a whole other benefit and does not compare to vvt. This is why some of these cars can scream to 8500 rpm and be street driven and get good fuel economy.
I placed several calls to Mast and talked to them about their new LY6 ss cam. I talked to the comp cams tech department a few times about their cams. I called TSP but did not get a call back. Bottom line: Mast and Comp produce excellent hardware, but do not support tuning unless, in the case of mast, you buy their ecm. The mast ecm, however, will not run my 2009 4L80e. Mast even tells me to find a reputable tuner in my area by checking out the forums. This leaves a crucial peice of the puzzle missing when purchasing vvt hardware. Also mail order tunes leave something to be desired over a custom chassis dyno tune.
Well, I live in Smyrna, GA on the north side of Atlanta and I take Mast's advice and search. Many users on here rave about Vengeance racing. I contact them, speak with Ron, and set up an appointment. So, I go in and sit down with Ron and we review the dyno charts from Mast's new 509hp ss ly6 cam and the chart from the L92 comp cam swap vvt magazine article where they dyno over 500hp. I expressed that I liked the benifits of vvt and that I wanted to keep this feature. After some further discussion, Ron said that he could beat the curve down low, build more bottom end torque and beat the curve all the way to the top with their cam and tune. Of course, Vengeance would have to tune the car. This is the package I was looking for. By the way, Vengeance has used some autokraft pans with great results, so we ordered one of those as well.
So I ended up ditching the vvt. I really like vvt. I have it in my Tundra 5.7 with a 6 speed auto and this truck is faster than a lot of sports cars. The new 5.0L mustang has it. But here's the thing. These engines have dual overhead cams, 4 valves per cylinder, and can independantly alter the valve timing on the intake and exhaust. I talked with Ron about this and it seems that these engines benefit more from vvt. The gm single cam push rod vvt, apparently was designed to enhance fuel economy more than engine output and because we comprimise by not independantly changing intake and exhasut valve timing, one of the issues we come up with is piston/valve clearance. So now we have to comprimise our cam. This is why I believe that for the sake of performance, in the case of gen 4 vvt, it may be better to do without. The proof will be in the pudding. Win or loose, I'm going to post my dyno results.
Another note. Alot of people on here confuse vvt with other systems that Toyota, Honda, BMW and Porsche use. Some of their systems change the valve lift and duration in different ways. This is a whole other benefit and does not compare to vvt. This is why some of these cars can scream to 8500 rpm and be street driven and get good fuel economy.
12-17-2010, 06:36 PM
#83
I emailed Mast about the LY6 SS cam and this is what they sent me:
If I'm reading that correctly, the specs are 220/234 @ 050 .573/.588 lift and no LSA given.
When I searched that part number on their site, I came up with this, which shows an LSA of 116:
http://www.mastmotorsports.com/2010/...ew.php?cat=VVT Cams&id=225
This seemed pretty mild for a 509hp engine. Maybe he just sent me the wrong specs.
We already have this cam available. Please see the specs below. The cam
made 509 hp on an otherwise stock LY6!
P/N 914-201 VVT 337R220 346R234 337 346 114 ATDC 118
BTDC 1.7 572.9 588.2
Thank You,
Chris Durrett
made 509 hp on an otherwise stock LY6!
P/N 914-201 VVT 337R220 346R234 337 346 114 ATDC 118
BTDC 1.7 572.9 588.2
Thank You,
Chris Durrett
When I searched that part number on their site, I came up with this, which shows an LSA of 116:
http://www.mastmotorsports.com/2010/...ew.php?cat=VVT Cams&id=225
This seemed pretty mild for a 509hp engine. Maybe he just sent me the wrong specs.
12-17-2010, 07:21 PM
#85
I emailed Mast about the LY6 SS cam and this is what they sent me:
If I'm reading that correctly, the specs are 220/234 @ 050 .573/.588 lift and no LSA given.
When I searched that part number on their site, I came up with this, which shows an LSA of 116:
http://www.mastmotorsports.com/2010/...ew.php?cat=VVT Cams&id=225
This seemed pretty mild for a 509hp engine. Maybe he just sent me the wrong specs.
If I'm reading that correctly, the specs are 220/234 @ 050 .573/.588 lift and no LSA given.
When I searched that part number on their site, I came up with this, which shows an LSA of 116:
http://www.mastmotorsports.com/2010/...ew.php?cat=VVT Cams&id=225
This seemed pretty mild for a 509hp engine. Maybe he just sent me the wrong specs.
Stage 0 - PN 914-201
Duration @ .050 218/230
Lift 564/578
LSA 116
Stage 1 - PN 914-202
Duration @ .050 220/234
Lift 573/588
LSA 116
Stage 2 - PN 914-102
Duration @ .050 224/238
Lift 578/593
LSA 115
Stage 3 - PN 914-103
Duration @ .050 230/237
Lift 588/607
LSA 111
The specs may have changed since I got the info though. The same PN has different specs depending on what part of their web page you look at.
12-17-2010, 07:49 PM
#86
Im looking for a SD, the wife has an SUV so no need for two in the family. I want AWD because I cant keep anything stock and 2wd just wont suffice in the traction department. I plan on putting a small circle D tripple disc converter in it(mainly for WOT lockup ability), with a 76mm turbo and a baby turbo cam. Ive done blowers, strokers and nitrous, time to try something different 
Even though I havent been able to find any info on people who have pulled the front shaft on the new tcases that are in the GMT900 denalis, the old NVG149 didnt care too much for not having the front shaft in it and puked shortly there-after if any decent amount of power was put through it. Im in the middle of trying research if the NVG149 can be retrofitted into the GMT900 as the borg warner tcase that comes standard apparently depends on the braking system to bias power and I dont like that at all. Ill modulate the power with my right foot not the left
Even though I havent been able to find any info on people who have pulled the front shaft on the new tcases that are in the GMT900 denalis, the old NVG149 didnt care too much for not having the front shaft in it and puked shortly there-after if any decent amount of power was put through it. Im in the middle of trying research if the NVG149 can be retrofitted into the GMT900 as the borg warner tcase that comes standard apparently depends on the braking system to bias power and I dont like that at all. Ill modulate the power with my right foot not the left
24's might've had something to do with that. Power is 48% front and 62% rear. The distribution % is not adjustable, but that is what the traction control button is for. Wheelhop can and is an issue when launching hard off the brakes....I have been beating on my Denali for 2 years now and only had the one yoke failure in the first year. I am looking at the VVT cams from Mast, since they are down the road. Last edited by midevil1; 12-17-2010 at 07:58 PM.
12-17-2010, 09:39 PM
#87
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Never had an issue with the front shaft, but I have twisted the rear shaft yoke in two... 24's might've had something to do with that. Power is 48% front and 62% rear. The distribution % is not adjustable, but that is what the traction control button is for. Wheelhop can and is an issue when launching hard off the brakes....I have been beating on my Denali for 2 years now and only had the one yoke failure in the first year. I am looking at the VVT cams from Mast, since they are down the road.
24's might've had something to do with that. Power is 48% front and 62% rear. The distribution % is not adjustable, but that is what the traction control button is for. Wheelhop can and is an issue when launching hard off the brakes....I have been beating on my Denali for 2 years now and only had the one yoke failure in the first year. I am looking at the VVT cams from Mast, since they are down the road.I wonder why the Mast cams are so exhaust biased compared to other VVT offerings?
12-18-2010, 09:57 AM
#88
Yeah wheelhop is not going to be a good thing. Not that Im going to put down that much power but Id like to get it up neart he 600rwhp mark with a small turbo. I cant see that being good. We'll see what happens though, right now there arent any high mileage cheaper denalis like what I want. I refuse to spend a bunch of money on a truck Im going to tear apart.
I wonder why the Mast cams are so exhaust biased compared to other VVT offerings?
I wonder why the Mast cams are so exhaust biased compared to other VVT offerings?
12-18-2010, 10:26 AM
#89
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L92/LS3 heads require more lift and exhaust duration than the intake due to major difference in flow. At least, this is what they have told me. A small turbo for a 6.2 is going to have to be atleast 70mm. I have seen several 90,000 to 100,000 mile Denali's in Houston area for 17,000 dollars. I dont know what cheapy is in your book...
Im going to run a 76mm to keep it right in the efficiency range and not have problems with IATs starting to creep up. A 70 is going to be gasping for air at 600rwhp. Ive found a few Denalis in the high teens but theyre 2wd and dont have rear dvd, nav and sunroof. Ive atleast got to have the nav(for backup camera) and rear dvd for my son. Im fine with waiting a little while longer, it will only give more time for the VVT stuff to be perfected.
12-18-2010, 01:01 PM
#90
Yeah but those cams have 12, 14, and 14 degrees exhaust biased, thats quite a bit even for an L92 head. I could understand if you were spraying a large shot, or blown possibly having the 12* but 14 seems to me like its getting on out there. I dont claim to be a cam guru but I know a little and Ive also watched closely what Pat G specs and they arent 14* degrees biased and they still run awesome. He has even said his VVT cams are much closer splits in the 4-6* range.
Im going to run a 76mm to keep it right in the efficiency range and not have problems with IATs starting to creep up. A 70 is going to be gasping for air at 600rwhp. Ive found a few Denalis in the high teens but theyre 2wd and dont have rear dvd, nav and sunroof. Ive atleast got to have the nav(for backup camera) and rear dvd for my son. Im fine with waiting a little while longer, it will only give more time for the VVT stuff to be perfected.
Im going to run a 76mm to keep it right in the efficiency range and not have problems with IATs starting to creep up. A 70 is going to be gasping for air at 600rwhp. Ive found a few Denalis in the high teens but theyre 2wd and dont have rear dvd, nav and sunroof. Ive atleast got to have the nav(for backup camera) and rear dvd for my son. Im fine with waiting a little while longer, it will only give more time for the VVT stuff to be perfected.
. Escalade's were the only thing around Houston that had all the options I wanted and I wasn't driving a caddy... Profiling....6.2L is a no brainer. Motor is a monster and comes alive at the littliest of mods. MPG's aren't bad either. on the 24's I get 17.2 on the hwy and on the 20's I get 20.7 on the highway. I have the LS Hot cam right now, but have been interested in putting the VVT back on and see what I could get...
12-26-2010, 12:54 PM
#91
Vvt This progress that TSP has made recently is what i've been waiting for. Almost time to drag my L92 out of the corner and start sending for parts. Nobody wanted to touch on the vvt topic a while ago, and how many hundreds were turfed to swap to an conventional cam out of fear of the unknown?
As a BMW tech, i've seen the benefits of vvt in an angine that makes 500+ hp, idles dead steady and almost silent (for those that are into that) and makes virtually no emissions. Most every manufacturer is using a version of this for both power and economy.
This is some awesome and very involved R+D, and using the phase tables are the only way to install a vvt cam, unlike stabbing a bigger cam in and running the phase as is.
Nice work dudes!
As a BMW tech, i've seen the benefits of vvt in an angine that makes 500+ hp, idles dead steady and almost silent (for those that are into that) and makes virtually no emissions. Most every manufacturer is using a version of this for both power and economy.
This is some awesome and very involved R+D, and using the phase tables are the only way to install a vvt cam, unlike stabbing a bigger cam in and running the phase as is.
Nice work dudes!
12-27-2010, 04:49 PM
#92
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Comp cant offer tunes, but they definitely could offer phaser tables as can MAST, if they dont TSP will continue to captalize on that niche market. I have a feeling as this stuff gets out there more and more it wont be a niche market anymore.
12-27-2010, 06:19 PM
#93
TECH Fanatic
GM VVT is not the same as others VVT they only adjust ICL so overlap stays the same, meaning emissions probably wont change much. Intake and exhaust lobes are fixed, the cam is just advanced or retarded.
Basically at lower rpm you can advance cam for more cranking pressure and at higher rpm retard it to take advantage of intake and exhaust tuning to increase VE.
Not sure why you need phaser tables, you should only be letting someone who knows how to tune near your ECU anyway. In which case, they are nice, but will need checking and tweaking for your combo in the same way that timing tables, maf tables etc are just a baseline.
Basically at lower rpm you can advance cam for more cranking pressure and at higher rpm retard it to take advantage of intake and exhaust tuning to increase VE.
Not sure why you need phaser tables, you should only be letting someone who knows how to tune near your ECU anyway. In which case, they are nice, but will need checking and tweaking for your combo in the same way that timing tables, maf tables etc are just a baseline.
01-04-2011, 10:08 AM
#94
you should only be letting someone who knows how to tune near your ECU anyway.
Anyways bumping for results? Anyone? Bueler...
01-07-2011, 07:10 PM
#95
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I have read that the phasers are capable of advancing and retarding the cam, but the tunes seem to only show retard. And per HPTuners range, you cannot put a negative number to advance the cam timing.
Also, does anyone know the specs on the stock L92 cam? Everything: Lift, Duration, LSA, and ground in advance...
Also, does anyone know the specs on the stock L92 cam? Everything: Lift, Duration, LSA, and ground in advance...
01-14-2011, 09:38 PM
#97
the real potential of these VVT motors has yet to be realized, I believe. Just from my mail-order tune I noticed a MASSIVE difference in the way the car behaves.
I have no dyno numbers to show it, there are no dyno shops within 60 miles of me, so whatever dyno numbers I eventually get will be with all the mods I've added (which is every bolt on imaginable).
I have no dyno numbers to show it, there are no dyno shops within 60 miles of me, so whatever dyno numbers I eventually get will be with all the mods I've added (which is every bolt on imaginable).
01-15-2011, 09:03 AM
#98
I personally wouldn't let a 60 trip to the tuner derail me from getting my car tuned. The closest tuner is about 60-63 miles. I just don't really have that much faith in him. His website doesn't show much of a difference (IMHO) in the tuned car. Maybe I am expecting too much, I don't know.
01-15-2011, 09:46 PM
#99
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Pulled the trigger I went to mast and talked to the folks there and the impression that I got was that. If your not runnung their ecm, which I will not comment one where that actually comes from. They really made me feel like they didnt have time to give any support or time to what I was doing..... So I called matt at texas speed and purchased thier cam springs cam phase limiter and I am very pleased with the customer service and pricing. MAST was 250$ higher and said that they couldnt sell me the phase limiter because it was a comp product?? Like they are grinding thier own cams ??? Any way i'm not here to bash anyone just not happy about making a two hour drive to be turned away with the feeling that my checkbook doesnt work here. I will have this setup running in the next two weeks, dyno numbers will follow. By the way cam specs came with the cam, but I will not share them since the guys at mast helped me out and I will be doing more business with these people. I went with thier vvt-2 cam and I am building an ly-6. Hope to shed some light soon!!!