What is so magical about turboing a stock 5.3 liter LM7??
10-31-2012, 05:02 PM
#21
Your not missing anything. Bigger cube motor with big turbo > smaller motor with smaller turbo. But if you size the turbo to small on the bigger motor the smaller motor will make more power more efficiently. People use the 4.8's and 5.3's because they are dirt cheap and anything bigger usually costs 2x+ the price. A bigger motor with a properly sized turbo will make the same power as the smaller motor with less boost. also, the pre ls2 rod motors (99-04.5) can be picked up for cheaper than the newer motors because they typically have more miles and they have the "weaker" ls1 rods. In all reality, detonation usually kills rods not horsepower. If the tune its healthy and your using good fuel, theirs no reason why you can't use the older motors. I posted this on another thread where an s10 on YouTube was running 25lbs boost plus a 125 shot nitrous on an older style 5.3. I ran 18lbs on mine to and i have a 2000 5.3. I picked up an lq4 for $400 and plan on making 500-600 rwhp on 9lbs boost. A well setup 6.0 will make more power EASIER than a well setup 5.3.
10-31-2012, 08:22 PM
#25
Being an actual member of the original "darkside" aka Grand National owner for the past 14yrs i am delighted to see the typical LS1 owner not have to spend ridiculous amounts of $$$$ ($1000 intake) to go fast(sorry 14hp increase)....just slapp a bigger turbo on for $260 ......everyone is having a wet dream all over again with the 5.3 craze...
10-31-2012, 08:50 PM
#26
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There is a guy by me with a 04 with 90k miles I can pick up I think for $400.
I heard the late 04s had the ls2 rods so I'm waiting for him to get back to me if its a yearly or late 04. I've been kinda hesitant to buying the older kinds afraid they won't hold the same power.
I will be running 110 turbo blue and have a air/water ic
I heard the late 04s had the ls2 rods so I'm waiting for him to get back to me if its a yearly or late 04. I've been kinda hesitant to buying the older kinds afraid they won't hold the same power.
I will be running 110 turbo blue and have a air/water ic
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CaptainArbitrage (04-01-2020)
11-01-2012, 11:46 AM
#31
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There is a guy by me with a 04 with 90k miles I can pick up I think for $400.
I heard the late 04s had the ls2 rods so I'm waiting for him to get back to me if its a yearly or late 04. I've been kinda hesitant to buying the older kinds afraid they won't hold the same power.
I will be running 110 turbo blue and have a air/water ic
I heard the late 04s had the ls2 rods so I'm waiting for him to get back to me if its a yearly or late 04. I've been kinda hesitant to buying the older kinds afraid they won't hold the same power.
I will be running 110 turbo blue and have a air/water ic
11-01-2012, 11:51 AM
#32
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11-01-2012, 04:20 PM
#33
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OP there was a single turbo 5.3 Impala SS at cecil county raceway who ran a 11.3 in the 1/4 mile. it was quite as a mouse and he drove it to the track. I also heard he went easy on that pass! no cage.. the turbo 5.3 setups sure can make power and be a DD. even in our boats.
11-01-2012, 04:31 PM
#34
Hot Rod mag did a test on a junkyard 5.3 on an engine dyno just to see how far it would go.. They opened up the ring gap, and got some ebay turbo power.. Think they finally quit at about 1200 flywheel HP, but it wasnt because it failed. Think they were having ignition issues... And after the testing, they realized it was actually a 4.8.
http://www.hotrod.com/techarticles/h...g_bang_theory/
http://www.hotrod.com/techarticles/h...g_bang_theory/
11-01-2012, 05:52 PM
#35
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I get the part about how the 5.3 and to an extent the 4.8 are way cheaper and easier to obtain from a junkyard than your typical 6.0 or 6.2 liter LSx. There more of them out there etc. etc.
But how do you explain those stratospheric RWHP AND RWTQ numbers that people post here on this forum about their boosted 5.3 liter budget builds?? You know 600 to 800 RWHP on little more than 1 bar of boost. Should there be at least typically 1000 FWHP from a boosted LS3/L92 stroker(408+ ci)???? After all the LS3/L92 based strokers have at 90 ci more displacement and way better heads than the 5.3 liter LM7???? Right??? Or am I missing something here???
But how do you explain those stratospheric RWHP AND RWTQ numbers that people post here on this forum about their boosted 5.3 liter budget builds?? You know 600 to 800 RWHP on little more than 1 bar of boost. Should there be at least typically 1000 FWHP from a boosted LS3/L92 stroker(408+ ci)???? After all the LS3/L92 based strokers have at 90 ci more displacement and way better heads than the 5.3 liter LM7???? Right??? Or am I missing something here???
I have seen lots of stock car motors make in the 500-600 HP range boosted, but it's because your limited at around 8-10 PSI, where as on the truck engines, guys are running 15-20 PSI, low timing, and pump gas and making huge HP. It's all in the combo, and obviously the truck motors just work better than the car motors stock for stock. Like was said above, you will always make more power all things equal with an LS2 or LS3 with boost over the truck motor, but not necessarily if it's completely original inside and you want lots of boost.
11-01-2012, 09:05 PM
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11-01-2012, 09:52 PM
#39
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FWIW. This was the first time I had ever attempted a turbo anything. I did almost all the fabrication and welding myself. I used twin PTE 62/62's on a junk yard LM7 5.3 and didn't do **** to it. I added arp rod bolts and chinese head studs and a cam that most people said wouldn't work. I also used patriot gold springs and LS9 gaskets. Other than that the engine wasn't touched. To tell you how awesome these things are, I have to tell a little story....
I was running a name brand 498 that I paid $8k for and my car was awesome and ran a best of 109mph in the 1/8th mile. I thought that was awesome. That engine had 3,000 miles on it and about 30 drag passes when it blew. It only lasted 7 months. There was no way I could afford to do that again. So, I tried what i had been reading on here. I dumped in a 5.3 with twin turbos, no intercooler, E85, factory pcm, factory wiring harness, 160lb injectors using $17 resistors instead of a $400 driver box, etc.. The end result was a daily driver that got 21mpg and went 118mph on nearly every pass in the 1/8th mile. This is a car that weighs nearly 4,000lbs, full factory interior, roll cage, 275's, Th400, sound system, full exhaust and 3.90 gears. The engine lasted 7 months also but by choice. On a night it was runnning well, I wanted the 5 second pass and turned the boost up to 23lbs but only had a 2 bar tune so I had to guess over that. The car blew up at the 330'ft, dropped 38mph and still ran a 6.40!
In less than a week I had another 5.3 in it with 180,000 miles on it but now I am trying the chinese turbos. I just put on the ON3 70mm turbo's with the .68 AR and fully expect this set up to run in the low 6's. That means I will have $500 into the engine, and $600 into brand new set of twin 70's.
By spring I should have the tune figured out and just plan on this engine being my test mule. Once I think I have it, I will push it til it blows and dump in another one. This last engine, I got over 15,000 miles on it and drove it everywhere with my kids jammin to the tunes.
These things are the real deal. Now we will find out if these knock off turbo's are the real deal. My precisions ran good but I had problems with the all the time.
I was running a name brand 498 that I paid $8k for and my car was awesome and ran a best of 109mph in the 1/8th mile. I thought that was awesome. That engine had 3,000 miles on it and about 30 drag passes when it blew. It only lasted 7 months. There was no way I could afford to do that again. So, I tried what i had been reading on here. I dumped in a 5.3 with twin turbos, no intercooler, E85, factory pcm, factory wiring harness, 160lb injectors using $17 resistors instead of a $400 driver box, etc.. The end result was a daily driver that got 21mpg and went 118mph on nearly every pass in the 1/8th mile. This is a car that weighs nearly 4,000lbs, full factory interior, roll cage, 275's, Th400, sound system, full exhaust and 3.90 gears. The engine lasted 7 months also but by choice. On a night it was runnning well, I wanted the 5 second pass and turned the boost up to 23lbs but only had a 2 bar tune so I had to guess over that. The car blew up at the 330'ft, dropped 38mph and still ran a 6.40!
In less than a week I had another 5.3 in it with 180,000 miles on it but now I am trying the chinese turbos. I just put on the ON3 70mm turbo's with the .68 AR and fully expect this set up to run in the low 6's. That means I will have $500 into the engine, and $600 into brand new set of twin 70's.
By spring I should have the tune figured out and just plan on this engine being my test mule. Once I think I have it, I will push it til it blows and dump in another one. This last engine, I got over 15,000 miles on it and drove it everywhere with my kids jammin to the tunes.
These things are the real deal. Now we will find out if these knock off turbo's are the real deal. My precisions ran good but I had problems with the all the time.