Great N/A - Now want boost
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On The Tree
Joined: Dec 2011
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From: Colorado Springs, CO
Great N/A - Now want boost I've got a 99 Z28 with just about every N/A upgrade I can think of. I want to boost it in the not too distant future, but have no idea how much boost I can actually handle. I've asked some local shops, but I get a lot of different answers so I figured I'd look here and ask some people who've done it. a [mostly] complete list of my mods is below:
standard LS1 block bored to 3.903
SCAT rotating assembly (4340 forged)
-4.000" stroke crank
-6.125" I Beam rods
CP Carrillo bullet series flat top pistons with 3cc valve reliefs
-supposed to be 11.5:1 SCR (actually closer to 11.1:1)
TFS 215 heads
-Harland Sharp SLS17 rockers
-Cheverolet Performance LS1/LS6 head gaskets
-P/N #12498544
TFS-21407500 Chromoly pushrods
TFS-30602003 Cam
-283/286 .585/.585 112
CompCams hydraulic roller lifters
FAST LSxR 102 Intake
FAST Big Mouth 102mm TB
FAST Precision flow LS2 style 46lb/hr injectors
FAST billet aluminum fuel rails
100mm MAF from Texas Speed
104mm air box lid (can't remember brand, maybe SLP)
Fast Toys Ram Air System
PHAT full exhaust (can't find company anymore)
-1 7/8" L/T headers and 3" all the way back
Melling oil pump
-started with a high volume, but the engine blew up once and idk if the shop changed to high pressure or not. I just know they stayed with melling (if they replaced it at all)
Upgraded fuel pump (can't remember specs or details)
I believe my weak link as far as boost will be my high compression and possibly blowing head gaskets right? Just looking to see what I can accomplish safely without another full rebuild. Thanks for any help.
standard LS1 block bored to 3.903
SCAT rotating assembly (4340 forged)
-4.000" stroke crank
-6.125" I Beam rods
CP Carrillo bullet series flat top pistons with 3cc valve reliefs
-supposed to be 11.5:1 SCR (actually closer to 11.1:1)
TFS 215 heads
-Harland Sharp SLS17 rockers
-Cheverolet Performance LS1/LS6 head gaskets
-P/N #12498544
TFS-21407500 Chromoly pushrods
TFS-30602003 Cam
-283/286 .585/.585 112
CompCams hydraulic roller lifters
FAST LSxR 102 Intake
FAST Big Mouth 102mm TB
FAST Precision flow LS2 style 46lb/hr injectors
FAST billet aluminum fuel rails
100mm MAF from Texas Speed
104mm air box lid (can't remember brand, maybe SLP)
Fast Toys Ram Air System
PHAT full exhaust (can't find company anymore)
-1 7/8" L/T headers and 3" all the way back
Melling oil pump
-started with a high volume, but the engine blew up once and idk if the shop changed to high pressure or not. I just know they stayed with melling (if they replaced it at all)
Upgraded fuel pump (can't remember specs or details)
I believe my weak link as far as boost will be my high compression and possibly blowing head gaskets right? Just looking to see what I can accomplish safely without another full rebuild. Thanks for any help.
Last edited by shadowfirep; Mar 26, 2016 at 06:57 PM.
Thread Starter
On The Tree
Joined: Dec 2011
Posts: 118
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From: Colorado Springs, CO
What if I go with a water/meth kit? I might get to the point where I need to run race gas. but I'm not concerned with the pre ignition because I will ensure my fuel is proper for that. Will my heads and head gasket handle a good amount of boost? (20-30psi)
Restricted User
Joined: Mar 2014
Posts: 7,192
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From: Ohio
I would really hate to replace my heads after spending 2300 on my H/C kit lol if I need to lower compression I will just replace pistons and do the full rebuild.
What if I go with a water/meth kit? I might get to the point where I need to run race gas. but I'm not concerned with the pre ignition because I will ensure my fuel is proper for that. Will my heads and head gasket handle a good amount of boost? (20-30psi)
What if I go with a water/meth kit? I might get to the point where I need to run race gas. but I'm not concerned with the pre ignition because I will ensure my fuel is proper for that. Will my heads and head gasket handle a good amount of boost? (20-30psi)
Lol. The N/A guys spend five times as much to make half of the power.
Replace the pistons. The heads and gaskets will be fine.
TECH Addict
Joined: Jul 2013
Posts: 2,189
Likes: 123
From: Portland, Oregon
Your weak link is your overbored LS1/6 block. Those cylinder sleeves are useless with boost. You could probably cram enough boost to grenade your Fast intake into the setup you have now with an iron block, even with 11.1:1 compression. Have a really good intercooler, some meth, and optimally burn corn, but that compression can be boosted with a little preparation. You do not need new pistons or heads, and choose your head gasket thickness for optimal quench, not to change your compression.
Awesome setup, though. Stick it in an overbored iron block and get a custom cam, feed it 18psi all day long.
Awesome setup, though. Stick it in an overbored iron block and get a custom cam, feed it 18psi all day long.
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Thread Starter
On The Tree
Joined: Dec 2011
Posts: 118
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From: Colorado Springs, CO
As for going with an iron block, the sleeves have only been thinned out by .004" (so 2 thousandths on each side). This doesn't seem like all that much to scrap an entire block. Aren't others running boost on the aluminum blocks with good success?
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Verdad Gallardo TECH Addict
Joined: Jul 2013
Posts: 2,189
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From: Portland, Oregon
Others are boosting aluminum 5.3L blocks with great success due to their thicker cylinder sleeves. Lots of LS2 and LS3 aluminum blocks being boosted and surviving due to their thicker cylinder sleeves. It's literally just the LS1/6 blocks that do not appreciate boost. Paper thin cylinder sleeves just can't take the abuse.
You could pick up an iron block for pretty cheap, even an LQx block and some 4" pistons, make your 383 into a 402 and boost the **** out of it.
But boosting a LS1 block is just setting yourself up for failure.
You could pick up an iron block for pretty cheap, even an LQx block and some 4" pistons, make your 383 into a 402 and boost the **** out of it.
But boosting a LS1 block is just setting yourself up for failure.
The aluminum LS1 blocks aren't the greatest platform for boost, and your block has been bored, making the cylinder walls even thinner. That is the point he's trying to make. Are you wanting to go with a turbo or Procharger? I would opt to go the Procharger route and run e85. You honestly wouldn't need to change much, and even on low boost, it will makea lot of power.
You mentioned being worried about the compression ratio and the cam needs to be changed. You don't need a big fast intake for boost so there's an all new top end. With the power that a striker turbo engine can make I would be worried about I-beam rods. So there you are changing rods as well. Do at that point I figure it would be easier and possibly more money in your pocket to sell the engine as a running pull out and go with something more tailored to what you want to do.
That's what I was trying to say. He would literally not have to change anything if he can run e85. 
On The Tree
Joined: Jun 2014
Posts: 132
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From: Kansas City MO
I'm running stock bottom LS1 with 317 heads. Running 9-12psi. I did accidentally hit 25! Man was it stupid fast! I had PRC 2.5 heads and had to change those while I kept my torquer v3 cam. NOT a good boost cam. No low end power at all but when it hits it's stupid power. Get a Mighty Mouse catch can also.
Thread Starter
On The Tree
Joined: Dec 2011
Posts: 118
Likes: 0
From: Colorado Springs, CO
I'm wanting to do autocross racing on weekends and not so much drag racing. that's why I would like to stay with the aluminum block to keep the front weight down. I appreciate all the advise!
Great N/A - Now want boost In your case, no. You'd need to change a lot with your existing setup if you plan to go turbo, but with a Procharger, you add meth and a good tune, and you're golden. Plus, the instant power you get with a Procharger is perfect for autocross.