Hey guys, I am in the middle of putting a supercharger onto my forged LT1. It’s not an “ideal” build for FI, but I want some opinions on my supporting mods. I just want to make sure I have crossed all my “T’s” prior to taking the car to be tuned. If anyone sees something I am missing feel free to let me know! Thanks!!


Here is a break down of my set up:

LT1 Engine - 1993 Block

Short Block
Bored .030 over = 355ci
Mahle Forged 5CC Dished Pistons
Eagle 6” H Beam Rods with ARP Bolts
Stock Crank cut and polished
Melling High Volume Oil Pump​

Heads/Cam/Intake
Lloyd Elliot Custom Grind Cam
223/230 .565 Lift 112LSA
LS7 Lifters
Cloyes Timing Set
Comp Pushrods
AFR 190cc (Ported Flow 294/208 CFM)
60cc - 2.05/1.60 @.600
Crane 99893 Double Valve Springs
ARP 7/16” Rocker Studs
ISKU Adjustable Guide Plates
Comp 1.6rr NSA 7/16”
Ported Intake
58mm Throttle Body
60 LB Siemens Drake Injectors
340 Fuel Pump
Aeromotive adjustable fuel pressure regulator
ATI Super damper Balancer and Hub
Pace Setter Long Tube Headers with Off Road Y pipe
NGK TR6 4177 plugs gapped at 0.035”
24x ignition conversion

Supercharger Set up
Procharger D1SC with twin intercoolers
12 Rib pulleys (4.50” blower pulley and 7.65” crank pulley) which should land me around 8lbs of boost
Innovate AFR Gauge
Autometer Electic boost and fuel pressure gauge

Other
Tuned for 91 Octane – PCM tuned as 2000 Trans am (LS1 PCM)
10.3:1 Static Compression


Rear End – Moser 12 Bolt 3 Channel
Motive 4.11 Gears – G888411X
Fidanza flywheel
Power Grip HD clutch

As shown I’m only going to run 8lbs of boost. Any foreseen issues with the set up?

I measured my MAF and it’s 3.5” do I need to upgrade it?

Will a walboro 340 fuel pump be enough?

Aeromotive AFPR be ok?

24x ignition system be sufficient?

Thanks for the help!

Greg

 

What do you mean tuned as a 2000 LS1? its still and LT1, If its tuned as an LS1 then its way off. Stock MAF is fine, Mine is stock and the motor makes 806 HP..

 

Great looking build, that car is going to be a beast.

LS1 computer has a lot of benefits, but the motor is still an LT1...AKA the timing and firing order are different and they take different approaches to tuning. Might be just a wording mix-up, but like Moe said you can't tune an LT1 like an LS1 and expect good results since they react differently to changes in the tune.

 

Doesnt look horrible...but some comments:

-Where did the cam specs come from?
-Twin IC's are junk... put a single front mount IC on there
-10.3 static CR isnt too bad... but on 91 octane the timing will be way down...unless you add meth
-Might need a BAP
-24X and LS1 PMC should be great
-I used to run an Aero AFPR... I liked it.

 

Sorry guys, that “tune as an 2000 LS1” was put in there for the future reference I think. I totally realize it’s still an lt1 and NOT an Ls1!

 

Cam is a custom grind by Lloyd Elliott ... (basically putting a blower on my current set up) so might not be the best for FI but hopefully it work. (I have to etest)

I have thought about meth but don’t know if I want to get into that! I guess I’ll see how the timing will be!

I’m going to tune two different PCM one for Etest and one for no etest! I currently have a y pipe with high flo cats. Will I benefit a lot from an off road y pipe with the none etest tune? And just swap out the pipes and PCM with the different tunes?

What do you think I’ll expect to see with 8lbs as far as horsepower and torque (safe tune)

 

2 weeks after your driving it you'll be swapping the pulley for 12psi... I guarantee it, and do the trap door lol that's all. That car will be nice!

 

500-550rwhp

 

Hahaha thanks! Would def need a meth kit I think if I went up to 12lbs but well see! Thanks for the positive words!

 

Are there any specific meth kits that are better than others?? Not entirely sure how they work?

Also this is maybe a noob questions but is the car safe enough to start and move (low RPM) with the old tune? (Different plugs and injectors?). I would def keep it out of the boost!!

 

If you're confident in the tuner, let them be your guide ha. I think you'll be pleasantly surprised with the results you yield if they're good. I don't think you'll need meth honestly. Here are some basic specs from a build I did a while back.

1997 Camaro SS ~9k original miles
10.7:1CR LT1
stock bottom end w/ Melling pump
AI ported heads/PCM spec'd cam/AI ported intake/58mm TB
24x conversion
Kooks 1 3/4" headers w/catted Y with cutout
Lonnie's Performance in tank dual pump
Griffin Radiator with custom dual fan shroud
D1SC with twin intercooler piping @ ~10psi

Zero meth

Car made ~640/600 if I remember correctly.

This was via a T56 with monster clutch and 10 bolt with 4.10s, has since been changed for a Moser 12 with 3.73s.

I'd get a start up file from your tuner before you start the car honestly, otherwise you'll wash the cylinders with a different fuel setup.

 

My advice would be to take a different approach to these parts you have listed:

Rear End – Moser 12 Bolt 3 Channel
Motive 4.11 Gears – G888411X
Fidanza flywheel
Power Grip HD clutch

I've built/owned many supercharged LT1 combinations. My favorite of all of them was a similar build to yours (355ci/Procharger F1A). However, I had a McLeod Street Twin with steel flywheel and 3.42 gears in a Strange 12 bolt. Personally, I hate lightweight flywheels in supercharged setups (albeit, personal decision). That Fidanza is too light. The PowerGrip HD clutch is not going to be happy if you decide to up the boost and probably marginal at best in the "low boost" setup you are discussing.

Also, I dislike deep (4.11) gears in a FI car. With boost, you just don't need that deep of gearing in a street car for multiple reasons. Traction will be an issue with 3.42's as it is.

Again, this is just my opinion with having many different FI LT1 combos over the years. But, a lightweight flywheel and 4.11 gears in a setup like this would make me sell the car if it were mine

 

I have a very similar build. Lower compression and just last week had to pull the oil pan over the oil pump pick up falling off. Make sure it's properly secured. Might as well do poly motor mounts. All that power is gonna strain rubber...

 

Wow!! That’s very very impressive. I’m hoping my lone 340 will hold up for fuel supply, but we’ll see! Here’s to my fingers crossed!! Thanks

 

I appreciate your opinions Jason! I’m going to run this set up for a year and see what happens! Maybe by then you’ll have some gently used parts I can snag!! Would a Spec 3+ clutch be a better option maybe?

Unfortunately I already have the 411 sitting in the rear end and don’t wanna get into changing them as they legit have 0 miles on them. About 10 years ago I had a P600b on a stock motor and I found the 411s in my 10 bolt to be to short of a gear as well. But I’ve sunk enough $$$ into this machine this year I’ll see what happens next! Thanks Jason!

 

I just the pan off about a week ago because of oil leak issues. Everything appears to be good now!!

I already have all poly mounts and just bought a BMR cross member relocation bracket for the torque arm. Ordered it Nov 20th and it still hasn’t even shipped!! Starting to get frusterated!! Thanks for the input!

 

In my experience, yes. The Spec 3+ is the only Spec clutch that I even remotely liked. I've always been a McLeod Street Twin guy, but I've driven a few Spec 3+ cars (forced induction) and they've driven quite well and held 600rwhp.

 

I would get more fuel pump and potentially go 80# injectors. You will want more boost, now or later.

Another vote for getting rid of the steep gears, I have 3.73s and want 3,54s in mine. Let it eat and pull through the gears.

 

But really how much boost can this engine with 10.3/1 SCR hold!?

 

The last part of my “to get” list is a bypass valve. What are your guys suggestions?? I want to vent into the atmosphere.

Stand Proflow valve? AV008A-001

The proflow bullet valve (open) AV006A-004

Or a red race valve? Not even sure which one would be the best