lq9
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Teching In
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lq9 sorry if this isn't the right section, couldn't find anything that seemed to be the "right" place.
I am new to LS engines and chevy in general. I am looking to build an LQ9, wanting at least 500rwhp but the more the better. Original plan was boosted LM7 which might still happen depending on how this thread goes. Car is not going to be daily driven, probably backed with a 4l80e or th400
Anyways, i was thinking LQ9 short block, ported LS3 heads, matched LS3 intake, not sure on camshaft, probably mill the heads and try to get in the 12:1 compresson range and run E85. What kind of power should i see (depending on the cam of course)
I am new to LS engines and chevy in general. I am looking to build an LQ9, wanting at least 500rwhp but the more the better. Original plan was boosted LM7 which might still happen depending on how this thread goes. Car is not going to be daily driven, probably backed with a 4l80e or th400
Anyways, i was thinking LQ9 short block, ported LS3 heads, matched LS3 intake, not sure on camshaft, probably mill the heads and try to get in the 12:1 compresson range and run E85. What kind of power should i see (depending on the cam of course)
I was at 410rwhp with an LQ9, CNC LS3 heads, FAST intake, and a small cam (219 @ .050). Your 4L80/TH400 is going to eat up some power.
You wont be able to mill the heads to 12:1. I milled .030" off my heads on my LQ9 and was only at 10.5:1. Plus with the monster 2.160" intake valve in the LS3 head, as soon as you mill you loose PTV clearance very quickly!
Are you planning on adding pistons?
You wont be able to mill the heads to 12:1. I milled .030" off my heads on my LQ9 and was only at 10.5:1. Plus with the monster 2.160" intake valve in the LS3 head, as soon as you mill you loose PTV clearance very quickly!
Are you planning on adding pistons?
Man i have ported unmilled LS3 heads with a stock L76 intake and a 228/242 futral cam on a stock bottom end LQ9 in my camaro. It made 463rwhp 430rwtq corrected and 475rwhp 450rwtq uncorrected with a M6 and a S60 with 4.10 gears. I think with a ported fast 102mm, 1-7/8" long tubes and true duals my car should hit the 500rwhp mark. With a 4L80 in the same setup as i have with the addition to the optional mods i listed i think your goal is close to doable!!
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i am reallly hoping not to touvh the bottom end. I have found low mileage (50k or so) LQ9's in the $600 range and wouldn't want to touch the bottom end. I am hoping to keep it all H/C/I, i wont be running A/C, will have full length headers, dual 3" pipes etc...
Didn't know about the head milling thing, just figured i will be running E85 so higher compression would be safe and an easy way to make a little more power. Glad i posted here, some very useful information on this place!
Didn't know about the head milling thing, just figured i will be running E85 so higher compression would be safe and an easy way to make a little more power. Glad i posted here, some very useful information on this place!
On The Tree
Joined: Oct 2011
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From: Dirty South
I was at 410rwhp with an LQ9, CNC LS3 heads, FAST intake, and a small cam (219 @ .050). Your 4L80/TH400 is going to eat up some power.
You wont be able to mill the heads to 12:1. I milled .030" off my heads on my LQ9 and was only at 10.5:1. Plus with the monster 2.160" intake valve in the LS3 head, as soon as you mill you loose PTV clearance very quickly!
Are you planning on adding pistons?
You wont be able to mill the heads to 12:1. I milled .030" off my heads on my LQ9 and was only at 10.5:1. Plus with the monster 2.160" intake valve in the LS3 head, as soon as you mill you loose PTV clearance very quickly!
Are you planning on adding pistons?
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With the right cam and bolt ons it's doable. I run a ls1 with all bolt ons a cam and no accessories except alt. and it made 433/409 to the wheels through a stalled auto and 12 bolt so a 6.0 with ls3 heads should get the job done or be really close
On The Tree
Joined: Oct 2011
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From: Dirty South
I had originally thought a 8 to 10 degrees was ideal but I see alot of guys using splits of 15 degrees and more. Why would you tighted it up, if you were to do it again.
I had Lingenfelter CNC heads, so I didnt need so much exhaust duration. Plus I like smaller cams. The intake lobe makes more of a difference. Smaller exhaust lobe would mean less overlap, which is up my ally as well...
Thread Starter
Teching In
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so, ported ls3 heads, matched intake, long tube headers, 3" duals, no A/C, E85, what cam would be suggested? Also, the automatic is not a MUST, i could still go T56, just not 100% sure yet.
The other option is a bone stock long block LQ4/9 or LM7 with a turbo slapped on it running E85. I just want to stay N/A if it is a reasonable goal. Seems like everyone is doing a boosted LS these days...
The other option is a bone stock long block LQ4/9 or LM7 with a turbo slapped on it running E85. I just want to stay N/A if it is a reasonable goal. Seems like everyone is doing a boosted LS these days...
TECH Enthusiast
Joined: Jun 2010
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From: Illinois
what's your budget for the build? Also is this car going to be a weekend street bruiser, or mainly a strip car? Give some more info about the car and your goals. Everyone chases the 500rwhp mark, but the car might run way better with a lower power output to the wheels. But the ls3 heads, from the research I have done, like 8 degrees+ of duration separation for the cam. I hope pat g or one of the serious engine builders gets in here and talks about the cam selection for those heads.
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no real budget, just as cheap as possible, buying used parts when/where i can. Mainly wanting a track car but i will be driving it around town, car shows, stuff like that a lot. The car is a Chrysler Conquest/Mitsubishi Starion.
The more i think about it, the more i am thinking of just going turbo. To fit a T56 is going to be a huge PITA redoing the trans tunnel/floor so i am just going to go with the 4l80e or th400. Wont be so worried about losing power through he auto if i go turbo.
The more i think about it, the more i am thinking of just going turbo. To fit a T56 is going to be a huge PITA redoing the trans tunnel/floor so i am just going to go with the 4l80e or th400. Wont be so worried about losing power through he auto if i go turbo.
Last edited by Unknown User; Feb 6, 2012 at 07:28 PM.
Thread Starter
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i have a 76mm turbo laying around, intercooler, piping,along with an A1000 and fuel lines etc... Really wouldn't cost much to just got turbo LM7, keep low boost for now then crank it when i get the cage and 8.8"/4-link done.
Only things i would really have to buy would be injectors, piping for the exhaust crossover, cam, better intake/tb and some small misc stuff. Probably about $500-$700 more to have everything i need to turbo.
Only things i would really have to buy would be injectors, piping for the exhaust crossover, cam, better intake/tb and some small misc stuff. Probably about $500-$700 more to have everything i need to turbo.
Thread Starter
Teching In
Joined: Jul 2011
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let's put a $2k budget on this to start with. That doesn't include the engine/trans/wiring etc... That's how much i can spend on "performance" parts for it. Really thinking turbo might be the way to go.
