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Discussion Starter #461
I love my Kegerator! A 1960's model Frigidaire made by GM. The logo on the door is GM with Frigidaire in the middle of it.

Back on topic.... :
Jim, thanks for the ideas! That sounds amazing...I might look into that situation.
 

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Discussion Starter #462
@Rubber Duck – Without knowing the specific valve events, I’m not sure if this question can even be answered, but in my being a little lazy, I don’t feel like pulling a cam at the moment and I’ll be running my blower cam from Thompson Motorsports in my Turbocharged 427 for a bit. Here’s the basic cam profile: 233/249 .630/.600 120+4 LSA

I watched a cool video of a turbocharged LS3 going through different cams comparing them to their NA output and turbocharged output. What was interesting was the HP and TQ curve……it stayed the same no matter what cam, NA, Blower, NOS and Turbo. Different cams made different NA baseline numbers, but when they were given boos from a single turbo, of course they made more power, but the HP and TQ curves were similar in shape.

This leads me to believe my blower cam will do just fine with the twin T6262s. Lots of exhaust duration and minimal overlap.

Do you have any thoughts?

Spring time, it’s coming out for a custom cam that I’m hoping to have spec’d by a builder on the forum. I have to do valve springs soon anyway as I’m approaching the 20K mile mark.

Anybody else, feel free to chime in.
 

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@Rubber Duck – Without knowing the specific valve events, I’m not sure if this question can even be answered, but in my being a little lazy, I don’t feel like pulling a cam at the moment and I’ll be running my blower cam from Thompson Motorsports in my Turbocharged 427 for a bit. Here’s the basic cam profile: 233/249 .630/.600 120+4 LSA

I watched a cool video of a turbocharged LS3 going through different cams comparing them to their NA output and turbocharged output. What was interesting was the HP and TQ curve……it stayed the same no matter what cam, NA, Blower, NOS and Turbo. Different cams made different NA baseline numbers, but when they were given boos from a single turbo, of course they made more power, but the HP and TQ curves were similar in shape.

This leads me to believe my blower cam will do just fine with the twin T6262s. Lots of exhaust duration and minimal overlap.

Do you have any thoughts?

Spring time, it’s coming out for a custom cam that I’m hoping to have spec’d by a builder on the forum. I have to do valve springs soon anyway as I’m approaching the 20K mile mark.

Anybody else, feel free to chime in.
I don't have an immense amount of experience with Turbos.
But here are some general comments I have that might help you.

For best power, the turbos are going to require a different camshaft.

Supercharged / Blower engines require more exhaust duration than
they do intake duration, so we now have a dual pattern cam.

But many times a turbocharged engine, will run a single pattern cam.

And I have seen turbo cams, that use less duration on the exhaust side,
than on the intake side, in order to enhance throttle response.

The exhaust port size, shape and velocity plays a large part in all of this.
The better the exhaust port, the less the exhaust lobe duration can be.

Cheers,
RD
 
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And I have seen turbo cams, that use less duration on the exhaust side,
than on the intake side, in order to enhance throttle response.
Duck,

I understand turbo lag, but how does what you wrote, improve that?
 
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Duck,

I understand turbo lag, but how does what you wrote, improve that?
Less efficient exhaust means higher exhaust pressure (to spool up the blower)?

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Discussion Starter #466
I don't have an immense amount of experience with Turbos.
But here are some general comments I have that might help you.

For best power, the turbos are going to require a different camshaft.

Supercharged / Blower engines require more exhaust duration than
they do intake duration, so we now have a dual pattern cam.

But many times a turbocharged engine, will run a single pattern cam.

And I have seen turbo cams, that use less duration on the exhaust side,
than on the intake side, in order to enhance throttle response.

The exhaust port size, shape and velocity plays a large part in all of this.
The better the exhaust port, the less the exhaust lobe duration can be.

Cheers,
RD
Thanks Bruce,

I figured as much. Did a little research on valve events on PDS cams and turbo cams. Looks like the PDS blower cams tend to do well with turbo applications, but there are some preferences with the valve events that are a bit different. Looks like no matter what I'm going to be pulling the cam this spring.
 
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Thanks Bruce,

I figured as much. Did a little research on valve events on PDS cams and turbo cams. Looks like the PDS blower cams tend to do well with turbo applications, but there are some preferences with the valve events that are a bit different. Looks like no matter what I'm going to be pulling the cam this spring.
I am sure that either Matt / GP Tuning or Pat G. can help you.

If you want to go further than that let me know I can refer you
to others (much more cranky people though..lol), but it also costs more.

They will want 'Absolute' flow numbers on your heads and 'Exactly'
how much fwHP you want to make.

Problem again with our engine platform is the 'Crappy' exhaust port,
which plays a large part in selecting a cam, especially for a turbo.

Cheers,
Bruce
 
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Thanks Bruce,

I figured as much. Did a little research on valve events on PDS cams and turbo cams. Looks like the PDS blower cams tend to do well with turbo applications, but there are some preferences with the valve events that are a bit different. Looks like no matter what I'm going to be pulling the cam this spring.
I can tell you that our Turbo and Twin Turbo cams are quite a bit different from our PD blower cams even on the same long block.
 

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Discussion Starter #469
I can tell you that our Turbo and Twin Turbo cams are quite a bit different from our PD blower cams even on the same long block.
Matt, do you mind if I email you specifics and get a cam from you then. I had your 2.5 blower cam at one point in my life and it was good to me :).
 
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Thanks Bruce,

I figured as much. Did a little research on valve events on PDS cams and turbo cams. Looks like the PDS blower cams tend to do well with turbo applications, but there are some preferences with the valve events that are a bit different. Looks like no matter what I'm going to be pulling the cam this spring.
JA. . .
Curiosity. . .

Where are these Huron Twin Turbo 6262 kits placing the turbos?
How far from the exhaust port?

Do they require different headers, are the primary pipes shorter, versus a roots blower?
Are the primary and / or secondary pipes smaller than for the roots blower engines?

Anyone have any performance stats on these kits?

Cheers,
Bruce
 

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Duck,

I understand turbo lag, but how does what you wrote, improve that?
The better the exhaust port flows, the less exhaust lobe duration you can run.

From what I have been told; back in the day when Indy Cars
ran turbos, some of the heads had such good exhaust ports,
that they actually ran less exhaust duration, then they did
intake duration.

Today, on some highly refined drag cars, the exhaust ports
are of much smaller size, dimension and volume, than they
were just 10-years ago.

The exhaust side of an engine is exactly the opposite of the intake side.

On the intake side, you need to wait for the piston to move downward,
in order generate a 'Negative' depression, in order to get the intake charge
(mass charge) to flow into the cylinder

That takes time, and for the most part the mass charge is
lagging in time behind the piston crown as the piston moves
downward during the entire intake stroke.

On the exhaust side, you have a 'Positive' pressure existing, which
amounts to at 'Least' 4-BAR, which immediately begins to move
the unburnt portion of the mass charge out of the cylinder, as soon
as the exhaust valve is cracked open.

First you want an efficient burn. This then reduces the quantity
of the mass charge (air and fuel) that is required to be moved
out of the cylinder. <= Think E85 for our needs here!

Then, you want the fastest exhaust port you can design.

This then reduces the need for an exhaust port with a large
flow area, which then can move the unburnt portion of the
mass charge out of the cylinder very, very fast.

Consider this; the faster you spin the engine, the less time
you have to burn the mass charge.

You also have less time to move the mass charge in,
as well as out of the cylinder.

I can't remember the rpm number, but at some of the higher
engine rpm the Formula 1 engines are spinning, they consider
it to be a 'Constant Burn' science.

Cheers,
Bruce
 
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Just watched Engine Masters last week where they tested this on a stroker Ford on a dyno. They had a regulat street cam and tested it with and without a big Vortech supercharger, then they changed to a "blower" cam and dynoed that with and without the supercharger. The power curves were the same. They gained less than 20hp if I remember correctly.
 

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Just watched Engine Masters last week where they tested this on a stroker Ford on a dyno. They had a regulat street cam and tested it with and without a big Vortech supercharger, then they changed to a "blower" cam and dynoed that with and without the supercharger. The power curves were the same. They gained less than 20hp if I remember correctly.
Then in 'Both' cases. . .
The engines 'Supply' side, was meeting the engines piston CFM 'Demand' side.

Cam duration 'Required' is related to Piston CFM Demand,
generated by 'Piston Speed', given in Feet Per Minute (FPM).

Cam lift is related to the CFM 'Required' to fill the cylinder,
versus the area of the bore, versus the area of the valve.

The CFM required to fill the cylinder, is also related to VE%.
As VE% rises, the engine 'Effectively' becomes larger.

If the VE% is 135%, then the pressure in the cylinder, when
the piston is at BDC will be equal to. . .
=> (14.7 * 1.35)= 19.85 psi.

Cheers,
RD
 
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Discussion Starter #474
JA. . .
Curiosity. . .

Where are these Huron Twin Turbo 6262 kits placing the turbos?
How far from the exhaust port?

Do they require different headers, are the primary pipes shorter, versus a roots blower?
Are the primary and / or secondary pipes smaller than for the roots blower engines?

Anyone have any performance stats on these kits?

Cheers,
Bruce
Pretty far from the port Bruce. I'd say right where long tubes connect to the rest of the exhaust. They don't look like tuned headers at all, they look like logs with pipes, lol.
 
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Discussion Starter #475
I've chatted with Matt and ordered a cam designed for my goals and for the new power adder, thanks Matt, don't hold back on the chop chop....lol...J/K.

Updates:
147923


I got the FMIC installed. Just need to make a trip to Lowes for some grade 8 hardware and spacers. Crash bar just barley clears the FMIC with it spaced away from all the radiator mount parts. PS cooler gets zip tie love to the crash bar.....after I chopped it up a bit.

I have to make new sub-frame connectors....since this kit didn't come with the gen II updates, I have to fab some shit and make it happen in my garage. I'll not be showing you all my welds, for the sake of losing respect.

New 90deg intake coupler will be here today. I had to flip the 102 TB in order for it to not hit the belt tensioner and that created a problem with the TB and maf. The new coupler puts the tube away from the TB a bit more and should clear.

Waiting on new LS3 manifold bolts....I ordered black bolts. Billet rails will be here soon and I'll be able to work on the fuel system. New fuel system consists of nothing new, except I'm running the DSX Aux all the way up to a Y fitting that will join the stock fuel line with the aux line and run them like this: 6AN stock line into Y with DSX Aux - 8AN out into 8AN filter - 8AN outlet into Y fitting - 6AN to each rail.

147924


I have to port the LS3 intake a bit to work with the 102mm TB and then the runners a little to transition them to my ported heads. Not going crazy here....just blending.

147925


Not looking for earth shattering performance, so these teriyaki tornados with billet wheels will do. Next summer I'll buy some nice BB 6262s and upgrade. I also want to upgrade the converter stall to 3,000 and the heads at some point. I really want a 6 bolt head.

Does anybody know what the hell I'm supposed to do with the other two map looking sensors? One is a baro sensor that was on the snout. I believe I can tune that out. The other is another map? I know the red 3 bar map sensor goes on my LS3 manifold. Any info on this would be great. Thanks
 

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There’s only two MAP sensors on the stock blower right? One is ambient pressure and the other is pressure in the manifold. The ambient one can be mounted anywhere it is open to the air pressure in the engine bay. The other one should have a spot on the LS3 manifold for boost reference.


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Discussion Starter #477
There’s only two MAP sensors on the stock blower right? One is ambient pressure and the other is pressure in the manifold. The ambient one can be mounted anywhere it is open to the air pressure in the engine bay. The other one should have a spot on the LS3 manifold for boost reference.


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There are three. One is barometric pressure, one is a three bar map sensor and the other is another map....not three bar. No idea if it's needed. It's on the lid forward of the red three bar sensor. It's referencing boost and vac. Will have to figure that one out.

147926
 

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If you look where that one mounts, I believe it is open to atmosphere and not to the inside of the lid.

As far as function in the map references, I’m not sure where it is used though. I’d imagine DMS could help though.




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Pretty far from the port Bruce. I'd say right where long tubes connect to the rest of the exhaust. They don't look like tuned headers at all, they look like logs with pipes, lol.
Just out of curiosity;
How does this group feel about using a Turbocharger, which is installed so far away from the exhaust port?

Pressure, or a pressure differential moves the air. The pressure differential generates the flow rate. And the flow rate also has a velocity component associated with it.

-with the above in mind-
Should we be concerned about heat, or simply mass flow to move the turbine(s)?
Would the mass flow requirement be increased, as the exhaust temperature is reduced?

Is one of the two variables above more important than the other?

Cheers
 

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I've seen a few Corvettes with turbos mounted close to the rear axle that made lots of power and were very fast.
 
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