experts needed: LS3 Safe Boost
Thread Starter
Instructor
Joined: Apr 2009
Posts: 205
Likes: 19
From: Denver Colorado
St. Jude Donor '09
Alex Trebec - "The answer is, a safe level of boost for an LS3".
Ding - "What is KABOOM -1 Alex?"
Jez, I don't want to be the Grinch who stole Christmas here but am I the only one who's going to call BS? 620 RW with 6.5 PSI, 91 octane, no meth? With a P1 no less?
Either the boost gauge is lying or the dyno is. I'm a little short on cubes but I have a similar setup and I need to push ~11.5 PSI to get my numers.
Ding - "What is KABOOM -1 Alex?"
Jez, I don't want to be the Grinch who stole Christmas here but am I the only one who's going to call BS? 620 RW with 6.5 PSI, 91 octane, no meth? With a P1 no less?
Either the boost gauge is lying or the dyno is. I'm a little short on cubes but I have a similar setup and I need to push ~11.5 PSI to get my numers.
a P1 only makes 200CFM less than a D1
I have a pretty big cam in my car - not a blower cam but a torque cam
I have headers / no cats / BB exhaust
I have a Dallas big mouth air intake
4.5 pulley good for 6.5 lbs at 6700rpm
the numbers are what they are - pre blower I was at 460 = so the blower added 160 HP...nothing surprising about that.
there are a lot of negative folks on this forum - dont understand it.
anyway - I ordered a 4 inch pulley yesterday and will have it installed next week along with my new blowoff valve. I would let everyone know what type of numbers I get with a conservative retune...but no one will believe me anyway
-Ryan
Le Mans Master
Joined: Dec 2005
Posts: 7,002
Likes: 1,687
From: Southeast TX
you can call what you want...but I own the car
a P1 only makes 200CFM less than a D1
I have a pretty big cam in my car - not a blower cam but a torque cam
I have headers / no cats / BB exhaust
I have a Dallas big mouth air intake
4.5 pulley good for 6.5 lbs at 6700rpm
the numbers are what they are - pre blower I was at 460 = so the blower added 160 HP...nothing surprising about that.
there are a lot of negative folks on this forum - dont understand it.
anyway - I ordered a 4 inch pulley yesterday and will have it installed next week along with my new blowoff valve. I would let everyone know what type of numbers I get with a conservative retune...but no one will believe me anyway
-Ryan
a P1 only makes 200CFM less than a D1
I have a pretty big cam in my car - not a blower cam but a torque cam
I have headers / no cats / BB exhaust
I have a Dallas big mouth air intake
4.5 pulley good for 6.5 lbs at 6700rpm
the numbers are what they are - pre blower I was at 460 = so the blower added 160 HP...nothing surprising about that.
there are a lot of negative folks on this forum - dont understand it.
anyway - I ordered a 4 inch pulley yesterday and will have it installed next week along with my new blowoff valve. I would let everyone know what type of numbers I get with a conservative retune...but no one will believe me anyway
-Ryan
If you want to see a bunch of F/I LS3 builds, the camaro5 forum is a good spot. All of those builds start with the LS3 (manual trann) or L99 (auto tranny). 600+ on mild boost is pretty common there.
Life Time NCM #2196
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From: Converse TX
Pro
Joined: Apr 2008
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From: DFW 942whp/938tq
I have an LS3.. I went from a P1 to a D1 and went from a 3.3 pulley on the P1 to a 4.0 pulley on the D1, and I'm making the same boost.. So there is a BIG difference in the P1 to the D1 in my personal experience.. When I had the P1 on my car, it took meth and a 3.85 pulley @ 10-11psi to make 620...
Last edited by Slvr08Z51; Dec 24, 2009 at 12:58 PM.
Pro
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From: DFW 942whp/938tq
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Michael S. Palmer
Pro
Joined: Feb 2003
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From: Detroit MI
While I can't give first hand comment on the P1sc, I made my power with a pair of GT30r's. I'm pretty confident in my 600rw numbers since they came from a calibrated (by me) MD1100 dyno and my airflow numbers also jive with the power level. Logging shows 67lb/min airflow, which is roughly 670flywheel HP. Since my fuel delivery numbers are right and the delivered AFR matches the target AFR; this means the airflow number is right too. So... 670flywheel minus about 70hp of drivetrain loss leave us at about 600rw, very reasonable. As a very efficient engine, the LS3 loves boost, within reason.
Burning Brakes
Joined: May 2007
Posts: 887
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From: Dallas TX
I am putting a pair of gt35r's on my bone stock ls3 A6 vette and will be looking for just over 600rw on 93 only no meth. Then add meth to get it up to 700+rw and only plan on upgrading the fuel system and valve springs. For the final stage to find the limits of a stock ls3 I plan on tuning it for race gas and meth and see what it can put down.
Former Vendor
Joined: Jun 2006
Posts: 1,622
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From: Dallas TX
I am putting a pair of gt35r's on my bone stock ls3 A6 vette and will be looking for just over 600rw on 93 only no meth. Then add meth to get it up to 700+rw and only plan on upgrading the fuel system and valve springs. For the final stage to find the limits of a stock ls3 I plan on tuning it for race gas and meth and see what it can put down.
Don't lie Adam, those snails are never going on your vette!
Instructor
Joined: Jul 2008
Posts: 112
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I am getting a Procharger race valve installed and I was thinking of getting a smaller pulley installed at the same time.
here are my specs:
P1SC with a 4.25 pulley for 6.5 lbs of boost = 620 RWHP 543 lb on
91 octane pump gas only - no meth
I have a upgraded springs and push rods along with a cam and headers.
what is a safe level of boost for an LS3 - I was thinking of going to a 4 inch pulley...
experience please
ryan
here are my specs:
P1SC with a 4.25 pulley for 6.5 lbs of boost = 620 RWHP 543 lb on
91 octane pump gas only - no meth
I have a upgraded springs and push rods along with a cam and headers.
what is a safe level of boost for an LS3 - I was thinking of going to a 4 inch pulley...
experience please
ryan
I can't help ya you here but I have a 08 LS3 making 405 rwhp with no cats, BB bullets, tune and halltech CAI, with a 150 NOS shot I am just under 520 rwhp, results posted
i have to think with the cam and blower 620 is possible for whatever it's worth but holding it should be interesting
It appears you are not losing as much as I am motor to tire, what type of cam - heads are you running, I am thinking about that very same add on( H/C) very soon
I will stayed tuned, good luck with that mod man, !!
Ron
Burning Brakes
Joined: May 2007
Posts: 887
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From: Dallas TX
And just hope no one calls me out. lol
Thread Starter
Instructor
Joined: Apr 2009
Posts: 205
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From: Denver Colorado
St. Jude Donor '09
FYI... I talked to ATI today and they said that they know of many many LS3's that take 10-14 psi with no problems on the a stock bottom end
just wanted to pass on what I learned...
I will be tuning mine tomorrow with the addition of a 4 inch pulley and race valve - all good for another 3 lbs of boost according to ATI
wish me luck
just wanted to pass on what I learned...
I will be tuning mine tomorrow with the addition of a 4 inch pulley and race valve - all good for another 3 lbs of boost according to ATI
wish me luck
Former Vendor
Joined: Jun 2006
Posts: 1,622
Likes: 3
From: Dallas TX
FYI... I talked to ATI today and they said that they know of many many LS3's that take 10-14 psi with no problems on the a stock bottom end
just wanted to pass on what I learned...
I will be tuning mine tomorrow with the addition of a 4 inch pulley and race valve - all good for another 3 lbs of boost according to ATI
wish me luck
just wanted to pass on what I learned...
I will be tuning mine tomorrow with the addition of a 4 inch pulley and race valve - all good for another 3 lbs of boost according to ATI
wish me luck
No luck needed, good cal file and you'll be fine!
Thread Starter
Instructor
Joined: Apr 2009
Posts: 205
Likes: 19
From: Denver Colorado
St. Jude Donor '09
thanks taylor! I am excited to see what type of reliable numbers I get with a few more pounds of boost!
also - your big mouth intake is the best 350 bucks I have EVER spent...kudo to you for offering it! it really is worth 40HP...tested it myself on the dyno.
-ryan
also - your big mouth intake is the best 350 bucks I have EVER spent...kudo to you for offering it! it really is worth 40HP...tested it myself on the dyno.
-ryan
Racer
Joined: Jun 2006
Posts: 327
Likes: 12
From: Carlsbad California
I have run both the P1 and D1. Big difference. More of a difference than I was expecting. I was running a 3.85" pulley on my P1 with milled AFR 205 62cc heads. With meth, I was low 600 RWPH and mid/high 500 TQ. That combo seemed to work well, although the compression was too high due to the milled heads. I upgraded to LS3 heads, lowered the compression to 9.6, and upgraded to a D1 with a 4.15" pulley. Had to lose the boost-a-pump in favor of an A&A fuel system to handle the job. Baby Stage 2 cam from A&A, and I'm just over 700 RWHP and 630 TQ @ 12 PSI. I'm supposed to be able to pass the California sniff test with the baby cam. Time will tell...
Last edited by thomas walters; Dec 30, 2009 at 11:42 PM.
3rd Gear
Joined: Dec 2009
Posts: 3
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Connecting Rods
The Ls3 motor are a new style motor that can handle certain amount of power safetly, after trying to make over 700rwhp the rods gives up, some may think it is safe until it goes into pressure, dyno Queens and searching for numbers are quite safe but that is where it stops.
I can safely say, the connecting rods will not handle over 700rwhp under heavy pressure(high RPM constantly) or constant racing. Don't ask me how I know, its a secret.
I can safely say, the connecting rods will not handle over 700rwhp under heavy pressure(high RPM constantly) or constant racing.
Don't ask me how I know, its a secret.
Former Vendor
Joined: Jun 2006
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From: Dallas TX