Out of the loop - need opinions
Out of the loop - need opinions Hey guys, I am out of the loop on everything and wanted some opinions from you guys on what the current setups are. The last time I was here is 2015. Work, life and everything else gets in the way of fun, but now I am trying to get back into it.
What I have for a project.
1994 Z28. Wanting something somewhat reliable and making around 700rwhp. Years ago, the common route was a 5.3 with some boost and all was well. With the different options available now, what's best to use? Intake manifolds have been tested more and more options as well. What cylinder heads work best? What are the good brands now for rotating assembly? I see that CP is still up there on the lists. Fuel? Headers/manifolds?
The car currently has all of the LT1 stuff still in it, but I have a harness, computer, k member, etc. The body wiring has already been converted to a 99+ car.
My guess from digging around some is a gen 4 5.3 block, stock crank, some good forged pistons and rods, somewhere around a 90mm snail (unless there's something decent making that much that's smaller), sheet metal intake. But that's about where I'm at. I do have a gen 3 6.0 sitting around too.
What I have for a project.
1994 Z28. Wanting something somewhat reliable and making around 700rwhp. Years ago, the common route was a 5.3 with some boost and all was well. With the different options available now, what's best to use? Intake manifolds have been tested more and more options as well. What cylinder heads work best? What are the good brands now for rotating assembly? I see that CP is still up there on the lists. Fuel? Headers/manifolds?
The car currently has all of the LT1 stuff still in it, but I have a harness, computer, k member, etc. The body wiring has already been converted to a 99+ car.
My guess from digging around some is a gen 4 5.3 block, stock crank, some good forged pistons and rods, somewhere around a 90mm snail (unless there's something decent making that much that's smaller), sheet metal intake. But that's about where I'm at. I do have a gen 3 6.0 sitting around too.
A Gen III 6.0 with 317's would be my choice if planning on boost. If doing an NA with NOS build I'd look for some 799/243's and If I wanted to bore and stroke then start looking at the LS3 top end.
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Joined: Jan 2022
Posts: 1,034
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From: Seattle
If you want boost, you can go with a 5.3, you don't really need those extra cubes to get to 700 with the 5.3. You're pretty much on the money, Stock Crank, forged rods and pistons, stock cylinder heads will flow plenty for a turbo setup. Nothing wrong upgrading to a set of Trick Flow 225 or AFR 230s though, just be mindful of your compression ratio for a turbo build!
As for intake manifold, the FAST composites have proven to be the best that money can buy. It can depend on what you want the car to be, for a drag car, you want all the top end power you can muster, so a taller hi ram type manifold shines best there, where the composite intakes make better power in the lower RPM ranges.
Upgrade the heads to a dual spring with stock rockers arms with a trunnion upgrade, pick out a turbo cam, keep it in the 220-230 duration range and .600 lift or so, pair that to a good converter for an auto, and you'll have a beastly street machine.
As for a well mannered street turbo, you could go with a 75mm and get to your 700 easy. Anything you go over 650/700HP gets pretty expensive to put through to the rear wheels transmission wise.
All that said, if you have the 6.0, Go for it! Won't be a bad choice at all!
The general rule of thumb for a turbo build is, build the best NA motor you can, and the turbo is just the icing on the cake. There are a lot of turbo exhaust/crossover manifold options out there too, which can save a ton of headache when you're plumbing everything. Pay close attention to Wastegate size and routing as well, as that can really be a headache.
Cheers!
As for intake manifold, the FAST composites have proven to be the best that money can buy. It can depend on what you want the car to be, for a drag car, you want all the top end power you can muster, so a taller hi ram type manifold shines best there, where the composite intakes make better power in the lower RPM ranges.
Upgrade the heads to a dual spring with stock rockers arms with a trunnion upgrade, pick out a turbo cam, keep it in the 220-230 duration range and .600 lift or so, pair that to a good converter for an auto, and you'll have a beastly street machine.
As for a well mannered street turbo, you could go with a 75mm and get to your 700 easy. Anything you go over 650/700HP gets pretty expensive to put through to the rear wheels transmission wise.
All that said, if you have the 6.0, Go for it! Won't be a bad choice at all!
The general rule of thumb for a turbo build is, build the best NA motor you can, and the turbo is just the icing on the cake. There are a lot of turbo exhaust/crossover manifold options out there too, which can save a ton of headache when you're plumbing everything. Pay close attention to Wastegate size and routing as well, as that can really be a headache.
Cheers!
Last edited by theunderlord; Feb 25, 2022 at 04:42 PM.
I actually have some 317s laying around from years ago for this purpose. As far as the 6.0 I have, it’s a 99-20 block so that crank has that offset or something if I remember right. Will a newer gen 3 crank work or should I just pick up something else?
Going the boosted route is new to me. I’ve always done NA builds in the past so solid roller, hi-revving was my thing. Building one of those gets to be too much money in the grand scheme of things, hence why I said somewhat reliable. Lol Not wanting to dump $20k on just an engine again!
Tranny is a T56. The car had a 12 bolt years ago, but I moved that to my WS6. For now it has a 3.42 10 bolt. I’ll worry about the rear later.
What about fuel? The car has a Walbro 255 in tank still there, but guessing I’ll need a booster unless there’s a way better in tank pump now.
Cooling still has a stock radiator, dual fans. I’d prefer to keep the AC, but can ditch the ABS block and the battery is already in the back. The history of the car is it WAS a drag car 20 years ago when I first bought it. I’ve since put it all back to mostly stock, minus the cage that’s still in it.
Going the boosted route is new to me. I’ve always done NA builds in the past so solid roller, hi-revving was my thing. Building one of those gets to be too much money in the grand scheme of things, hence why I said somewhat reliable. Lol Not wanting to dump $20k on just an engine again!
Tranny is a T56. The car had a 12 bolt years ago, but I moved that to my WS6. For now it has a 3.42 10 bolt. I’ll worry about the rear later.
What about fuel? The car has a Walbro 255 in tank still there, but guessing I’ll need a booster unless there’s a way better in tank pump now.
Cooling still has a stock radiator, dual fans. I’d prefer to keep the AC, but can ditch the ABS block and the battery is already in the back. The history of the car is it WAS a drag car 20 years ago when I first bought it. I’ve since put it all back to mostly stock, minus the cage that’s still in it.
TECH Fanatic
Joined: Jan 2022
Posts: 1,034
Likes: 468
From: Seattle
Everything I've read and seen says and shows they can take whatever is thrown at them. Now that said, let's assume these are street legal cars seeing relatively sane levels of boost here. The FAST Manifold @ 10 PSI on a twin S475 6.0 makes north of 930HP.
Last edited by theunderlord; Feb 25, 2022 at 04:42 PM.
TECH Fanatic
Joined: Jan 2022
Posts: 1,034
Likes: 468
From: Seattle
Don't be afraid to look at Vaporworx's PWM fuel module, really can make life a bit easier on your pumps using PWM and duty cycle.
Last edited by theunderlord; Feb 25, 2022 at 04:45 PM.
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TECH Junkie
Joined: May 2012
Posts: 3,047
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From: Poplarville, MS
Cool, they just look like they would blow apart where the hafts came together. Thanks.
Last edited by bbond105; Feb 26, 2022 at 12:19 PM.
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Shoot, this is easy peasy. Junkyard $300 5.3. A 78/75 turbo. An inter cooler. Trailblazer SS intake. 88lb injectors. Twin 450’s with -10 lines to and fro. 750 wheel through a 4l60. Just helped a buddy build this in his truck. Tune needs to be spot on. Don’t skimp with tune. Also, don’t skimp with tune. 😜