Questions on running VVT with Boost?
#1
On The Tree
Thread Starter
Questions on running VVT with Boost?
I'm wanting to put 10 psi on a 70 mm turbo into a mostly stock 5.3L (cast block). My co-worker owns a Silverado that has VVT, and I really like the way his truck feels off the line. Besides another way to control boost, I figure VVT will give my set up some nice off the line performance before the boost kicks in.
The Mast guys say that lower Valve spring pressures are needed to run VVT, but boost guys say you need stronger ones to insure valve seating.
My questions are...
1. Would stiffer intake valve springs really hurt a VVT set-up that much?
2. Is anyone even trying VVT and Boost, what are they doing?
3. Is there a "Turbo Rule" that makes running VVT with it a bad idea?
The Mast guys say that lower Valve spring pressures are needed to run VVT, but boost guys say you need stronger ones to insure valve seating.
My questions are...
1. Would stiffer intake valve springs really hurt a VVT set-up that much?
2. Is anyone even trying VVT and Boost, what are they doing?
3. Is there a "Turbo Rule" that makes running VVT with it a bad idea?
#6
On The Tree
Thread Starter
Everything I read on boost says the intake valve springs need to be stiff to seat under boost, and that the exhaust valves need to be able to withstand heat. So I think if I just use the stiffer intake valve springs, and use the softer ones recommended for VVT just on exhaust side, I shouldn't be as hard on the phaser. Then all I need are higher temp valves.
The Mast HO L99 cam has 1 degree of overlap, is that about right for boost? I'm also reading cam overlap is bad for boost, but some is needed to spool the turbine.
Am I at least on the right track? I would like to try a VVT Turbo combo in my build.
#8
On The Tree
Thread Starter
I just returned from over seas and I'm still very interested in boosting a VVT equiped 5.3L. The basic set-up I'm thinking of running is an aluminum block, LS6 heads, Truck manifolds, LS4 cam, custom pistons with deep valve reliefs, and a Mast PCM to control it all. I think 10 psi should net me about 550hp & tq, and I'm building the rest of the car to be a streetable auto-cross car.
Am I on the right track? Any ideas to add to my basic set-up I am open too, looking to just build the engine once and tune as I go.
Am I on the right track? Any ideas to add to my basic set-up I am open too, looking to just build the engine once and tune as I go.
#9
On The Tree
Thread Starter
My build has already started, my car is under the knife as I type. I have an LS1 in my garage that will be getting a rebuild, and I would still like to boost it with VVT.
I'm still looking for alittle info to help me be succesful. I've read quite a bit of info on both topics, but am still finding nothing on LS engines with both.
Anyone.....
I'm still looking for alittle info to help me be succesful. I've read quite a bit of info on both topics, but am still finding nothing on LS engines with both.
Anyone.....
#10
On The Tree
Thread Starter
......Anyone? Guess not
Oh well, for the same kind of $$$ I would invest in a turbo, I can sink it into the block and have 434ci. Gonna stay n/a & vvt.
Oh well, for the same kind of $$$ I would invest in a turbo, I can sink it into the block and have 434ci. Gonna stay n/a & vvt.