Good article on the Vipers cam in cam http://www.thehemi.com/news.php?id=20080211-1
http://www.youtube.com/watch?v=0uiDmcPEekc

 

I love mopar stuff too. The modern hemis seem to get similar results to LS engines with less cam, which could mean better flowing heads. Also could mean vvt might work better, because less cam means less spring, which means less hydraulic pressure for the phaser. You might be right about the viper only varying exhaust valve timing which has me scratching my head.




http://www.motivemag.com/pub/feature...xplained.shtml

 

Holy crap, that thing can vary exhaust and intake timing? I wonder if it has two phasers on the front or two independant chains??

 

sorry, Phaser(s)

I was thinking early vvt on single bank engines. The fact that 4 phasers are used in the 5.0 is interesting. I think some dual bank (V) engines only use two phasers.

 

GM's intention with VVT was to take a fairly small cam profile that they used and have a good bit of advance ground in, and retard the cam timing in higher VE conditions to have a broad powerband with something that gets good fuel economy. And, in mid range cruising throttle conditions, commanding 20+ degrees of cam timing retard is going to produce EGR (Exhaust Gas Recirculation) by hanging the exhaust valve open as the piston is going back down in lower VE conditions, will pull some exhaust gas back into the cylinder and reburn any unburned gas providing cleaner air for emissions, and it also reduces engine vaccum at part throttle which reduces engine load also improving emissions. In a nutshell, GM used VVT for emissions, not to make more power.
However, VVT can make more power globally with any cam, and even more with the right cam. But, more importantly, proper installation and calibration is the key. And, with our findings, if we sold our kit to someone and told them the way we do it, and what to do, anyone will have a hard time making sense of it at first, so we chose to keep it install only, plus the fact we have hundreds of hours of testing to come up with the solution in the way we did it, so if we announced what to do, it would be like throwing the money away for our R&D for someone else to just copy. With our method, any cam can be utilized to to have it's advantages with VVT, but we tested multiple thought out profiles and came up with one that was fairly universal making a lot of power and amazing drivability, so that is what we use, and what is still in my 2010 Camaro SS which has gone 11.41 @ 119.8mph, full weight with stock heavy rims. The VVT is worth about 2 tenths and 2 mph out of how fast my car is. And, I have all the data, especially the dyno data. Someone in this thread mentioned Darin Morgan, when his car was in our shop, we demonstrated it for him, showing him multiple install methods and what does what and why, but we have since then found a lot more power in the calibration, which I know he is aware of now as well.

 

Thanks Mike. I understand to duplicate this setup, you would have to install it and tune it. Very impressive results.

 

It is cool! Infininate possiblities. You can creat a lot of overlap at idle and make a stock cammed car sound like its has large cams.

Then when you get into performance, at the low end you advance the intake just like the GM VVT, but you keep the exhaust advanced too. This way your events are advanced and you have a tighter LSA, both good for low end. As you go through the RPM range, you retard the intake and retard the exhaust even faster. Now your events are retarded and the LSA wider at high RPM, again very good for power at high RPM.

The 3v Ford was SOHC with 2 phasers.

 

Mike@newera yes that was me that meantioned Mr. Morgan. It was through his posts that I heard about what you guys had discovered thru R&D. 11.4's is exceptional with a full weight car. What are your supporting mods?

I hope I can get my brother to take a road trip to NY lol

 

This is very true and why most shops dont bother with it. Its a lot easier to do a cut and paste then it is to R&D new tech and precisely why most shops are just parts swappers. Not everyone idolizes guys like Smokey Yunick and Rehr Morrison but someone has to lead the pack. I have to give kudos to New Era, Texas Speed, PatG, and especially EPS for designing a new lobe just for the L92/LS3 head and pushing VVT tech forward. You guys are on top of the heap



Really not a lot to add to that. All true ^


Your welcome for that. I went through over a month of HELL trying to sort out the gremlins with that freakin e38 pos. So far it looks like the doors are now open for VVT mods without restriction tuning with HPtuners. Enjoy fellas I know Im gonna


Keep your eyes peeled for this one.... I think it would already have been done if not for personal issues that arose with a guy who really knows his **** but it should still be in the works.

Dodge SUCKS nuff said

 

-New Era OTR Intake, 1 7/8" ARH (CATS), Stock castings ported via Darin Morgan, custom aluminum axle back, underdrive, NEP ported tb, intake. Stock suspension aside from pfadt springs.

Transmission and converter specs are currently in the experimental phase and are being changed / tested regularly, which is where a lot of our focus is right now.

 

Mike @ New Era thank you for the thought out response and great information. I appreciate you sharing your direct experience with LSx VVT along with the great tech.

Do you have any comments on the phaser control issue? Have you had any problems with the cam timing jumping around as SweetS10V8 described?

EGR is used to reduce combustion temperatures to prevent formation of NOx.

 

I believe that what he meant was that each phaser only has to control 1 set of valves...not that each cam isn't controlled...so they can independently control intake and exhaust valves, and each cam has less valves/springs following it meaning life is probably a little easier for each phaser...I guess my concern would come with changing to dual springs and seeing a lot more pressure on the cam from the lifters...is the GM phaser strong enough at that point, and if not what can we do to upgrade it?

 

Sorry to get off topic here, but I hadn't seen this before. Do you guys have any issues with MAF readings in your OTR intake? I ask because it looks to be situated very close to the throttle body and isn't located in a straight section.

 

At first we had some issues but we made a design change and fixed it, however it does effect the MAF transfer a little bit, as almost any aftermarket induction system does. We tested the MAF sensor in 25+ locations in 3 different prototype designs before we found the best location to measure airflow and make maximum power with a minimum effect on torque calculation. But, quite commonly the MAF sensors GM uses can read 10% off from the next one, which could require tuning if this is the case. We have installed and tuned upwards of 50 of them since 2009, never had a problem.

 

The phaser control stability is slightly effected above 6000 rpms with the components we use, maintaining +/- .2-.4 degrees of cam timing there which can be seen by simply logging Intake cam desired angle/Intake cam angle/Intake cam error for anyone that has VVT. This will create extremely small fluctuations in power on a dyno graph, because 1 degree of timing can be worth 8-12 rwhp, depending on your cam profile and engine rpm, but my car has over 10,000 miles on it, over 500 WOT dyno pulls, 150+ track passes, and was driven from Rochester, NY to Indianapolis, IN last October to race in 2 classes all weekend at the LSX shootout, without any issues.

 

I have a forged 402 LS2 in my '00 C5. I have been reading a lot on the VVT system and have been thinking if converting to it would be worthwhile. I am fairly certain that the stock '00 ECU won't be able to handle VVT and would need to upgrade the ECU. I know that mechanically I can fairly easily convert to VVT, but would you have any suggestions about what to do for controlling the VVT?

 

Thank you Mike. It's very interesting to get a feel for how much error there is in this system. I wonder how much of that is measurement error; for example if the phaser were locked mechanically so you knew there was zero fluctuation, I wonder if the ECM would still measure cam angles varying by that much at higher speeds. The sampling rate may not be fast enough or there may simply be error in the type of encoding being used.

If the timing really is fluctuating, I wonder if additional oil pressure or flow would be useful or if the control system just can't respond fast enough to spikes and pits in the cam drive torque that are experienced as the lobes actuate the valves.

 

I agree re the instability of the VVT although mine is not yet dyno tuned so we can verify my efforst beyond seat of the pants I have noticed that just from each romp to the next there is one in about 5 passes that SMOKE man lemme tell ya she FLIEEEES but there other 4/5 are just okay.

I think it comes down to how minute the phasers control is. Seriously your trying to control 20 plus degrees of cam timing with about 1/4" of valve plunger movement? Thats too small to control perfectly. If the phaser valve and servo were over an inch of throw and had a more solidified connection rather than the plunger/needle deal I think it would function a lot more accurately. Regardless its still fun as heck and the insane amount of bottom end GRUNT this thing has as a result of the VVT? I'll suffer with a little inconsistency over 6000 RPM so long as it goes faster I dont care so much.

My only worry is dropping a valve from the single beehives. Im old school and come from the camp of theres never too much valve spring, only not enough lol. But there are some compromises that must be made when running this system of VVT. If I get through this season without a catastrophic failure im going to try duals next year and compare results.

As for the MAF? LS7 maf card is the trick with LOTS of straight pipe before, and after the maf. Then it all comes down to the tuner if he can scale it properly and dial everything in as should be.

Im going to be playing a lot with my L92 swap this summer. Keep your eyes peeled

 

My kinda posts to read.

Thanks Mike

Mike do you have any links that offer your services?

Like cam packages?
Thanks
Zeke

 

See that? Keeping info tight is a losers game. Showing results and going open book brings in more customers every time. Good luck this year Mike