It could, but they only play with the exhaust lobes in this application.

 

Yeah, and I bet your LS motor doesnt have vvt either. Right now, for all out horsepower, the LS motor is better off without vvt, because the ls motors make it at high rpm. It is high rpm that seems to be the limiting factor on the LS vvt system. So vvt in this application helps make horsepower, but at some point it starts to hurt. My guess is that point is around .625-.650 lift, over 6000rpm with appropriate valve springs.

 

I ran a L92 VVT with the Mast high lift cam and a T-56. Shifted it at 7000RPM and never had any issues whatsoever. It made for a very powerful combination in a 3000lb 240SX.

 

That must have been a fun car. I think Mast spins their LY6 to 7000 as well.

The question is could you have made more power with a non vvt cam with more lift. This is where there seems to be a lack of data.

 

The limitation on camshafts used with VVT is PTV clearance. Not many people have VVT and aftermarket pistons that will allow them to put in much larger cams.

 

I have no doubt it could have made bigger numbers with a non VVT cam with more lift. However the benefit with the VVT is that you get big hp numbers on the top end but tons of torque on the bottom end. So you might beat the peak hp numbers with the bigger cam but its going to have less torque on the bottom end than the VVT cam would. Mast Motorsports dyno graph for my combo made 530 peak hp, 5xx peak torque, but it made 400 lb/ft of torque at 2000rpm and was pretty flat up to the peak. It pulled like a freight train.

 

Here Is the Mast dyno graph for the SS vvt cam they have for the LY6 (engine dyno):





Here are my results LY6 with vengeance stage 2 cam and vvt deleted:





Like, Sierrac3, I probably make big torque at 2000. At 2500 I was definately making more torque than I would have with the Mast vvt cam. Considering my run was through an unlocked converter and a 4L80e, I think I made more torque and horsepower everywhere. Where could I have benefited with a vvt cam? We need to see results of some folks on here with tsp vvt2 and vvt3 cams. But after I looked at the tsp vvt dyno graphs on their websites, I don't think I would have done any better. Could I have gained more torque under 2500 rpm with vvt? I'm not sure. I hope more people post results.

 

Im confused, you counterdicted yourself. You think being able to move the cam will create more bottom end, but it will be weaker than a non-VVT cam at the top?

Ability to move the cam at any point will give the ability to optimize your engine at any RPM. Lift is not the issue with VVT cams, .570"-.600"(ish) lift is plenty to make a lot of power. These VVT cams are designed with less than optimal events because of the assumed lack of PTV from stock pistons.

Assuming PTV clearance, VVT will make more power everywhere! When designing a VVT cam with PTV opened up, the events would not only be optimized, but you can you also open up on lobe design and size!

 

L92 VVT with t56 here. Hit 7K many times I like it.

 

I have an LY6 with the TSP VVT-2 cam and related parts in a 92 camaro. I have missed a few shifts and regretfully done the 1st 2nd back to 1st shift with no issues. It makes 430 to the wheels @ 6000rpm. Car wieghts 3610 with me in it and has trapped at best 115mph. MPG on the highway with the t-56 is usually 23-24. Im very happy with this setup and I am also very glad that i stayed with the vvt against most opinions that I encountered during my build process.


Good luck.

 

What I was saying is that if you used a more radical cam than the VVT cam I used then yes you could make more power.

The benefit of VVT is that you don't have to set your cam timing for either max hp or max torque. You get both with the VVT. So if you had the same cam specs but had a non VVT cam setup for max hp then you would drop some torque. That same cam profile with VVT would make more torque down low and still make the same hp up high.

Hot Rod Magazine tested this very same thing. See there results HERE

I think there is still a lot of room for development in the aftermarket for VVT but there are a lot of misconceptions about it that it is A) too difficult to implement and B) that it doesn't make the power. While B maybe true right now it is only due to the fact that there aren't comparable cams in a VVT version as some of the bigger non-VVT cams.

I will add that I went with Mast's ECU because its already tuned. When I built mine they were the only ones building VVT cams and I had no one that had any experiences tuning the VVT motors. The cam phaser limiters weren't even out when I built my engine so I went with something that already had the bugs worked out.

If I had it all to do again I would do the same. I loved my VVT motor other than the fact it makes the engine longer due to the truck spacing on the engine accessories to clear the VVT cam cover. It was really tight in my 240SX.

 

Your results seem to be right in line with mine. Also your cam specs are very close to mine. Any chance you can post your dyno graph?

 

I would really like to see your dyno results also. What ET did you run with that setup? Did you tune it yourself or leave it to an expert? I am building a LY6 with a VVT-2 also. There are a handful of us - 85MikeTPI, tiresmokinv8 and you. Maybe others?

 

Ly6 here. With t-56 also. I am a technology junky, so I am intrigued by the vvt. Also, I am looking for torque more so than horsepower. I am building a cruiser, not a racer.

 

The Ly6 motors can make great torque with or without vvt. Check out this guys results with a stock vvt cam!

https://ls1tech.com/forums/conversio...wap-vvt-4.html

I gained lots of torque with an aftermarket LS3 cam, without vvt, but my dyno only started measuring full throttle at 2800. Also, my peak torque did not move up the powerband, it just made more everywhere.

Unfortunately, Until more data is posted this argument gets more convoluted...

 

Straight out of the hot rod article:

Ideally, the intake and exhaust lobes should be phased independently, which requires either a DOHC design or a trick cam-in-cam layout like in the '08-and-up Dodge Viper V-10. Fortunately, the other three valve events are so inconsequential compared with intake closing that it's nothing to split hairs over. For instance, exhaust opening is most commonly accepted as the second most important valve event, as it contributes to determining the lobe-separation angle of a camshaft.


So as you're adjusting the intake valve closing to be optimal, you can't simultaneously control the exhaust valve events to be optimal, like the exhaust valve opening, since they are slaved. This, the questionable phaser control at high rpm with high spring loads, and ptv clearances, lead me to question the merits of vvt on LS engines. I don't know for sure, but I believe the mast vvt stroker engine in the above mentioned article is practically neutered with it's smaller cam lobes.

 

I cant find my dyno sheet.........Still looking. The car wouldnt break into the
12s at the track, I was using street tires and a stock rear so it was very traction limited. Ill find the dyno sheet and get it on here. Rear end will be on order soon!! I think it will go mid 11s if itll hook on some drag radials.
My next venture is a TVS 2300, I am very curious to see how FI will react with the vvt??!!

 

Yep you should get into the 11s. I also ran 115 with my LY6. You will be a pioneer with the blower and vvt. Thanks for the efforts with regards to the dyno sheet. I think the LY6 could be a great blower motor with the reduced compression, but don't know for sure. I want to do a little forced air with mine too.

 

Finally found my dyno sheet!! Here goes.

 

Hey thanks for the help!!