LS3 Swap Cold Air Intake
#1
LS3 Swap Cold Air Intake
I recently finished doing an LS3 swap in to my 1999 C5. When I had the car tuned he told me that the intake is restrictive for the LS3. I'm looking for some suggestions on a cold air intake that will work in this setup.
The car currently has a aftermarket intake, although I'm not sure what brand it is, I can find nothing like it online. It's using the stock 75mm MAF. I can get all to hook up but because of the throttle body differences the air bridge doesn't attach correctly.
I was wondering if anyone else has done this type of swap and if they have suggestions on what pieces work together. I'd like to step up to a larger MAF, either an 85mm or a housing with a card style like the LS3's. I'm really open to any idea that will work.... and let the hood close properly.
I've seen pictures of people's setups for an LS3 in a C5. They all look like a cross between pieces from C5 & C6 intakes.
The car currently has a aftermarket intake, although I'm not sure what brand it is, I can find nothing like it online. It's using the stock 75mm MAF. I can get all to hook up but because of the throttle body differences the air bridge doesn't attach correctly.
I was wondering if anyone else has done this type of swap and if they have suggestions on what pieces work together. I'd like to step up to a larger MAF, either an 85mm or a housing with a card style like the LS3's. I'm really open to any idea that will work.... and let the hood close properly.
I've seen pictures of people's setups for an LS3 in a C5. They all look like a cross between pieces from C5 & C6 intakes.
#2
Burning Brakes
Before I went to an SC set up this year, I had the Vararam VRB2 with their Powerduct. I had used this before in another Corvette and really liked the throttle response and power gains. With this LS3 combo it worked pretty well even though it is really meant to be used on LS1/6. I had great throttle response and no issues with restrictions. I was using the stock MAF as well and had no issues just have to keep an eye on the location. As for the fitment-you really have to play with the fitment and try different angles and coupler combinations for the powerduct until you get it right. In my case I also had an after market hood so I did not have to worry about rubbing the liner.
Last edited by ezrider4u2; 05-31-2015 at 07:06 AM.
#4
Drifting
I just had a 418LS3 swap done and I got RID of the Vararam as it was the cause for the swap to begin with. Hydro lock. I went with a Halltech VenomII. During the tuning session, my tuner said ZERO restriction through the intake.
#5
Le Mans Master
Just asking for clarification... the cause of the Hydro Lock was the Vararam or bad judgement by the driver?
#6
Drifting
I was turning into where I was standing when I took this picture. So coming across the intersection. I was 6-7 cars back in that left lane and simply couldn't/didn't see the side I was about to enter and was looking at what you see on the right. That portion of our base gate/exit floods easy, but in the 3+years ive been here, ive never seen the right side(entering base) flood. By the time I thought I should stop and go in reverse, there was so much and too much traffic to stop. I was already halfway through going slow, so I continued.....then POW. I immediately knew what happened. I couldn't help myself and made it worse when I tried to start it again. that was the worst grinding sound ive ever heard. 12 months later, shes on the road again with a new motor, and more bad*** than ever. Sorry OP got a little carried away
#7
Thanks for the the suggestions. It gives me some ideas on how to go on this.
It looks like in your pics you have the passenger side valve cover vent hooked up to the power duck and drawing it's air before the MAF. It's was always my understanding that it should be drawing in MAF metered air. Am I incorrect in that and how does that work out for getting a good tune?
It looks like in your pics you have the passenger side valve cover vent hooked up to the power duck and drawing it's air before the MAF. It's was always my understanding that it should be drawing in MAF metered air. Am I incorrect in that and how does that work out for getting a good tune?
#8
Drifting
Thanks for the the suggestions. It gives me some ideas on how to go on this.
It looks like in your pics you have the passenger side valve cover vent hooked up to the power duck and drawing it's air before the MAF. It's was always my understanding that it should be drawing in MAF metered air. Am I incorrect in that and how does that work out for getting a good tune?
It looks like in your pics you have the passenger side valve cover vent hooked up to the power duck and drawing it's air before the MAF. It's was always my understanding that it should be drawing in MAF metered air. Am I incorrect in that and how does that work out for getting a good tune?
I think you're confused, though. Air doesn't go in the PCV and into the valve cover, the air comes out of the valve cover and into the intake.
#10
The PCV system should be plumbed between the air filter and the MAF. It needs the vacuum you'll get from the air filter and the engine needs to see any air brought into the engine (via the PCV) being metered.
I think you're confused, though. Air doesn't go in the PCV and into the valve cover, the air comes out of the valve cover and into the intake.
I think you're confused, though. Air doesn't go in the PCV and into the valve cover, the air comes out of the valve cover and into the intake.
Because this constant vacuum is applied through that connection the engine need fresh air for "make up". The make up air is supplied through the valve cover vents. Since that air is drawn through the valve covers in to the intake, it needs to be supplied from filtered air drawn from between the MAF and throttle body so it's measured as combustible air.
#11
Drifting
Perhaps I am confused, but the PCV system on the LS3 is through a metered orifice on the valley cover which connects directly to the intake manifold directly behind the throttle body (unless you have a catch can in the middle of that). It's this connection that supplies the vacuum to pull out the crank case gasses.
Because this constant vacuum is applied through that connection the engine need fresh air for "make up". The make up air is supplied through the valve cover vents. Since that air is drawn through the valve covers in to the intake, it needs to be supplied from filtered air drawn from between the MAF and throttle body so it's measured as combustible air.
Because this constant vacuum is applied through that connection the engine need fresh air for "make up". The make up air is supplied through the valve cover vents. Since that air is drawn through the valve covers in to the intake, it needs to be supplied from filtered air drawn from between the MAF and throttle body so it's measured as combustible air.
#12
If you draw the air out of the valve cover into a space between the MAF and throttle body, how does the MAF see it? At least on the LS1 system, the MAF is before the throttle body in the intake configuration. You need to draw the air into the intake between the MAF and the air filter, not the throttle body.
Here's a diagram of the LSx PCV system with the direction of flow. There are some variations on actual connection points depending on engine but the flow direction of air is the same. The valve cover is clean incoming air drawn in to the crank case, thus it needs to be metered by the MAF.
#13
Race Director
Member Since: Apr 2007
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If you draw the air out of the valve cover into a space between the MAF and throttle body, how does the MAF see it? At least on the LS1 system, the MAF is before the throttle body in the intake configuration. You need to draw the air into the intake between the MAF and the air filter, not the throttle body.
#14
Drifting
You've got the PVC system operation completely backwards. Air should be drawn into the engine from between the MAF and before the the throttle body blade where the intake has no vacuum so it gets metered by the MAF sensor as it enters the engine. Then, the air is drawn back out through the PVC valve (or valley orifice) into the intake after the throttle body blade where there is a vacuum to suck it out.
This system is considerably more complicated for achieving the same effect, though.
#15
Drifting
Bump. Gearing up to do an LS3/L92 swap in my 2000 C5 and need advice on an intake that won't be a restriction for the cam/bolt on 6.2, but also won't be a nightmare to tune.
Will the stock 2000 MAF and ducting restrict the engine that badly? Currently I have a dual cone intake in front of the stock MAF but can also use a Zip Tie modded stock duct if need be.
Will the stock 2000 MAF and ducting restrict the engine that badly? Currently I have a dual cone intake in front of the stock MAF but can also use a Zip Tie modded stock duct if need be.
#16
Melting Slicks
#17
Drifting
Gonna go with the stock LS1 airbridge and an 85mm Z06 MAF for my LS3 swap. I have a DCI or a zip tie mod panel I can use in front of it.