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Got car back from dyno
Thread Starter
Instructor
Joined: Mar 2010
Posts: 125
Likes: 1
From: Dundalk MD
Got car back from dyno
Just put an A&A fuel system in it and got it re-tuned. It made 550 tq @ 5300 and 620rwhp @ 6500. Now here's the kicker. At 54k the afr hit 12.74, lost about 20hp and 30 lbft tq, and at 55k a crap ton of fuel hit and the afr went to 10.4, needless to say hp/tq rose up again. This was at 7.5 lbs of boost. It was a gradual leaning out of fuel, not a spike or anything. Gonna check the hobbs switch with a mityvac tomorrow but if that is working fine then it would be a FML situation. Mainly because I wouldn't know what to do. If the switch is jacked ill call up Mr.Steve or Mr.Andy and get me a switch. By the end of the pull it got 10.4 lbs of boost. Anyone else see that much boost with a stock ls6 motor, L/Ts. V3Si and 3.8 pulley?
Last edited by SuperSteve04Z; Jan 12, 2011 at 11:52 PM.
Tech Contributor
Joined: Apr 2007
Posts: 10,924
Likes: 78
From: Forney Texas
Just put an A&A fuel system in it and got it re-tuned. It made 550 tq @ 5300 and 620rwhp @ 6500. Now here's the kicker. At 54k the afr hit 12.74, lost about 20hp and 30 lbft tq, and at 55k a crap ton of fuel hit and the afr went to 10.4, needless to say hp/tq rose up again. This was at 7.5 lbs of boost. It was a gradual leaning out of fuel, not a spike or anything. Gonna check the hobbs switch with a mityvac tomorrow but if that is working fine then it would be a FML situation. Mainly because I wouldn't know what to do. If the switch is jacked ill call up Mr.Steve or Mr.Andy and get me a switch. By the end of the pull it got 10.4 lbs of boost. Anyone else see that much boost with a stock ls6 motor, L/Ts. V3Si and 3.8 pulley?
Thread Starter
Instructor
Joined: Mar 2010
Posts: 125
Likes: 1
From: Dundalk MD
Thanks for the help. Got questions. Is there a reason why the springs at that rpm get weak and then at an even higher rpm they seem ok? And I'm not planning on changing the cam at all just going to build a forged 346 later on but what should I get for valve springs?
Le Mans Master
Joined: Dec 2005
Posts: 6,460
Likes: 16
From: hamilton alabama
Thanks for the help. Got questions. Is there a reason why the springs at that rpm get weak and then at an even higher rpm they seem ok? And I'm not planning on changing the cam at all just going to build a forged 346 later on but what should I get for valve springs?
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Melting Slicks
Joined: Mar 2005
Posts: 2,225
Likes: 42
From: Okinawa
It made really good power up top. And it only had one dip in the graph and the AFR went fat and dropped power for 400 rpm then picked back up to 620. Maybe the maf got maxed and the tune was bad for a bit. Or maybe the hobs is screwing up? Thought the graph would be chopping up top along with the boost with bad springs. No expert though.
Last edited by SBCGENII; Jan 14, 2011 at 09:11 AM.
Thread Starter
Instructor
Joined: Mar 2010
Posts: 125
Likes: 1
From: Dundalk MD
I did road test the pump. Fuel pressure steadily increased as the boost increased but I didn't hear the pump come on, only went to 5 psi. Not gonna play around with it to much. Thank you for your input. Im going to order the patriot golds and schedule a tune at a different shop. Probably one that is a vendor of A&A. Might be a few weeks before I get results back but Ill revive this thread and let you all know what was going on. About the springs screwing up only for a little bit, no clue. But I consider the members that responded to be experts so Ill take their word for it. If it turns out to be wrong, hey, ill have nice springs
Last edited by SuperSteve04Z; Jan 25, 2011 at 08:45 PM.
Melting Slicks
Joined: Nov 2003
Posts: 3,011
Likes: 9
From: Dublin GA
Anyone else see that much boost with a stock ls6 motor, L/Ts. V3Si and 3.8 pulley
I have a procharger with a 3.7, so it's apples and oranges, but I'm a little over 10psi.
The high boost is because your engine is not as efficient as it would with better heads and cam.
I'll be in the minority here, but I wouldn't think of pushing my stock block to 6500 with that kind of power. I limit mine to 6150-6200 max.
I think it is a tune as well. It eases up to 12+ then back down. That may be where the MAF runs out, and the tune needs tweaking.
I have a procharger with a 3.7, so it's apples and oranges, but I'm a little over 10psi.
The high boost is because your engine is not as efficient as it would with better heads and cam.
I'll be in the minority here, but I wouldn't think of pushing my stock block to 6500 with that kind of power. I limit mine to 6150-6200 max.
I think it is a tune as well. It eases up to 12+ then back down. That may be where the MAF runs out, and the tune needs tweaking.
Tech Contributor
Joined: Apr 2007
Posts: 10,924
Likes: 78
From: Forney Texas
Anyone else see that much boost with a stock ls6 motor, L/Ts. V3Si and 3.8 pulley
I have a procharger with a 3.7, so it's apples and oranges, but I'm a little over 10psi.
The high boost is because your engine is not as efficient as it would with better heads and cam.
I'll be in the minority here, but I wouldn't think of pushing my stock block to 6500 with that kind of power. I limit mine to 6150-6200 max.
I think it is a tune as well. It eases up to 12+ then back down. That may be where the MAF runs out, and the tune needs tweaking.
I have a procharger with a 3.7, so it's apples and oranges, but I'm a little over 10psi.
The high boost is because your engine is not as efficient as it would with better heads and cam.
I'll be in the minority here, but I wouldn't think of pushing my stock block to 6500 with that kind of power. I limit mine to 6150-6200 max.
I think it is a tune as well. It eases up to 12+ then back down. That may be where the MAF runs out, and the tune needs tweaking.
Seems to be hit or miss with springs on these cars. I dunno.
Last edited by BLOWNBLUEZ06; Jan 14, 2011 at 05:38 PM.
Safety Car
Joined: Jan 2008
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From: Boise
Safety Car
Joined: Apr 2000
Posts: 4,326
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From: Weatherford, TX
Could've even been wheelspin or clutch slip?
Yeah I've seen posts from guys that broke a spring just pulling outta the driveway.
Not really, I know I'm pushing it and don't wanna pop the motor. What's funny is that it's street tuned with a wideband. On the road it runs about 1pt leaner, depending on conditions. If I tune for the dyno, it might be too lean at the track.
Yeah I've seen posts from guys that broke a spring just pulling outta the driveway.
Not really, I know I'm pushing it and don't wanna pop the motor. What's funny is that it's street tuned with a wideband. On the road it runs about 1pt leaner, depending on conditions. If I tune for the dyno, it might be too lean at the track.
Cruising
Joined: Sep 2008
Posts: 14
Likes: 0
Just for comparison, mine made 10.95 psi max from around 6500 rpm up to 6800 rpm. Same set up as you: bonestock LS6, V3-Si Trim. I honestly didn't think that head unit would make that much boost? Dyno sheet is in my profile, for what it's worth.