5.3 is lazy
Thread Starter
Teching In
Joined: Jun 2020
Posts: 33
Likes: 17
From: North alabama
5.3 is lazy Any input would be so appreciated! Having turbo issues or backpressure woes.
GenIII Sbe 5.3
Rings gapped .028 & .030
stock truck intake and 862s
Pac1218s
elgin 1840p 228/230
BR7EF gapped .022
80lb injectors
walboro 400
Innovate scg-1 wideband/controller
Gen1 cast vs 7875
80e w/ stock converter
3/4 ton ext cab silverado
pump93
2.25” crossover
3” downpipe to a five foot Straight tailpipe turned down under cab.
Log manifold
The first setup was a 6L with stock cam but had the same supporting mods as now. It would spool almost instant and was a blast to drive. Made 498 on 12 psi. Blew it up so I bought this 5.3 from a junkyard, had the block cleaned up and honed, new rings and bearings.
when the old engine came apart it sent metal through the exhaust housing, and dinged the wheel up a little. Nothing major (I thought). So I put it all back together as I had it. On the dyno it falls on its face over 5k rpms. It takes forever to spool it now and will barely turn the tire over. Soft timing until I get this methanol kit installed. Made low 400s on 10psi
I currently don’t know how to operate hp tuners so haven’t data logged anything. But could this be a bad backpressure issue or the wheel of the exhaust housing ? Hard to believe that this setup is having issues spooling this turbo and 3” downpipe especially seeing as how popular it is. This is my first turbo setup so any help or insight on how to verify would be welcome. I’m currently looking for a rebuild kit for this unit. Or probably just buy the billet 78
GenIII Sbe 5.3
Rings gapped .028 & .030
stock truck intake and 862s
Pac1218s
elgin 1840p 228/230
BR7EF gapped .022
80lb injectors
walboro 400
Innovate scg-1 wideband/controller
Gen1 cast vs 7875
80e w/ stock converter
3/4 ton ext cab silverado
pump93
2.25” crossover
3” downpipe to a five foot Straight tailpipe turned down under cab.
Log manifold
The first setup was a 6L with stock cam but had the same supporting mods as now. It would spool almost instant and was a blast to drive. Made 498 on 12 psi. Blew it up so I bought this 5.3 from a junkyard, had the block cleaned up and honed, new rings and bearings.
when the old engine came apart it sent metal through the exhaust housing, and dinged the wheel up a little. Nothing major (I thought). So I put it all back together as I had it. On the dyno it falls on its face over 5k rpms. It takes forever to spool it now and will barely turn the tire over. Soft timing until I get this methanol kit installed. Made low 400s on 10psi
I currently don’t know how to operate hp tuners so haven’t data logged anything. But could this be a bad backpressure issue or the wheel of the exhaust housing ? Hard to believe that this setup is having issues spooling this turbo and 3” downpipe especially seeing as how popular it is. This is my first turbo setup so any help or insight on how to verify would be welcome. I’m currently looking for a rebuild kit for this unit. Or probably just buy the billet 78
GenIII Sbe 5.3
elgin 1840p 228/230
Gen1 cast vs 7875
80e w/ stock converter
3/4 ton ext cab silverado
.
.
.
.
.
None of that combo is going to spool QUICK
First thing I would do is put the stock cam back in or more of a truck cam, thats a heavy truck for a 5.3 with a cam that big.
Main reason I say that is I highly doubt you want to put a high stall in a 3/4 ton truck, or wannt to be revving it to 7,000rpm I know I wouldnt.
Not sure why its falling on its face at 10psi above 5000 though, you would need a data log
elgin 1840p 228/230
Gen1 cast vs 7875
80e w/ stock converter
3/4 ton ext cab silverado
.
.
.
.
.
None of that combo is going to spool QUICK
First thing I would do is put the stock cam back in or more of a truck cam, thats a heavy truck for a 5.3 with a cam that big.
Main reason I say that is I highly doubt you want to put a high stall in a 3/4 ton truck, or wannt to be revving it to 7,000rpm I know I wouldnt.
Not sure why its falling on its face at 10psi above 5000 though, you would need a data log
Thread Starter
Teching In
Joined: Jun 2020
Posts: 33
Likes: 17
From: North alabama
GenIII Sbe 5.3
elgin 1840p 228/230
Gen1 cast vs 7875
80e w/ stock converter
3/4 ton ext cab silverado
.
.
.
.
.
None of that combo is going to spool QUICK
First thing I would do is put the stock cam back in or more of a truck cam, thats a heavy truck for a 5.3 with a cam that big.
Main reason I say that is I highly doubt you want to put a high stall in a 3/4 ton truck, or wannt to be revving it to 7,000rpm I know I wouldnt.
Not sure why its falling on its face at 10psi above 5000 though, you would need a data log
elgin 1840p 228/230
Gen1 cast vs 7875
80e w/ stock converter
3/4 ton ext cab silverado
.
.
.
.
.
None of that combo is going to spool QUICK
First thing I would do is put the stock cam back in or more of a truck cam, thats a heavy truck for a 5.3 with a cam that big.
Main reason I say that is I highly doubt you want to put a high stall in a 3/4 ton truck, or wannt to be revving it to 7,000rpm I know I wouldnt.
Not sure why its falling on its face at 10psi above 5000 though, you would need a data log
I didn’t want to half *** and put a single disc converter in it, and the billet triples are $1000+. I’m gonna pull the turbo off and swap in a buddies billet78 just to see if there is a difference.
Smaller turbo would help for sure, but I would still do the stock cam or maybe a stage 1 truck cam, especially if your just looking for 500hp.
The stock cam with a little smaller turbo would do more torque than Hp and make that beast move without having to spin the engine so high.
The stock cam with a little smaller turbo would do more torque than Hp and make that beast move without having to spin the engine so high.
Thread Starter
Teching In
Joined: Jun 2020
Posts: 33
Likes: 17
From: North alabama
Smaller turbo would help for sure, but I would still do the stock cam or maybe a stage 1 truck cam, especially if your just looking for 500hp.
The stock cam with a little smaller turbo would do more torque than Hp and make that beast move without having to spin the engine so high.
The stock cam with a little smaller turbo would do more torque than Hp and make that beast move without having to spin the engine so high.
TECH Fanatic
Joined: Feb 2015
Posts: 1,080
Likes: 178
As Ls7 stated, the combination is not right. What's the goal for your rig? A triple 12 cam for that weight and converter would be the max I'd go? Tune (timing) can be optimized to get motor/turbo to respond better. Why did previous motor fail? Understanding the details will keep you from making the same mistake and help move your plans forward. With data, you'll be able to better understand why it's falling off at 5K.
Thread Starter
Teching In
Joined: Jun 2020
Posts: 33
Likes: 17
From: North alabama
As Ls7 stated, the combination is not right. What's the goal for your rig? A triple 12 cam for that weight and converter would be the max I'd go? Tune (timing) can be optimized to get motor/turbo to respond better. Why did previous motor fail? Understanding the details will keep you from making the same mistake and help move your plans forward. With data, you'll be able to better understand why it's falling off at 5K.
I ran this cam on another setup I had and it worked fine with stock converter. However it was NA.
previous motor went because of a stuck wastegate. Dusted 3 rods etc.
ive since swapped to a turbosmart gate and added the innovate controller. Water meth kit is about to be installed too.
I will be pulling turbo off this weekend, will post pics of the exhaust wheel. It had some damage, but to my untrained eye didn’t seem horrible.
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That cam is huge for a 5.3 and will shift everything way up in the rpm, but a 6.0 would love that cam.
A smaller turbo would help but in my opinion that's backwards.
Camming it properly and keeping a decent size turbo will be having your cake and eating it too. I'd also try to get a little more stall converter in there.
A smaller turbo would help but in my opinion that's backwards.
Camming it properly and keeping a decent size turbo will be having your cake and eating it too. I'd also try to get a little more stall converter in there.
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Verdad Gallardo Thread Starter
Teching In
Joined: Jun 2020
Posts: 33
Likes: 17
From: North alabama
That cam is huge for a 5.3 and will shift everything way up in the rpm, but a 6.0 would love that cam.
A smaller turbo would help but in my opinion that's backwards.
Camming it properly and keeping a decent size turbo will be having your cake and eating it too. I'd also try to get a little more stall converter in there.
A smaller turbo would help but in my opinion that's backwards.
Camming it properly and keeping a decent size turbo will be having your cake and eating it too. I'd also try to get a little more stall converter in there.
Thread Starter
Teching In
Joined: Jun 2020
Posts: 33
Likes: 17
From: North alabama
That cam is huge for a 5.3 and will shift everything way up in the rpm, but a 6.0 would love that cam.
A smaller turbo would help but in my opinion that's backwards.
Camming it properly and keeping a decent size turbo will be having your cake and eating it too. I'd also try to get a little more stall converter in there.
A smaller turbo would help but in my opinion that's backwards.
Camming it properly and keeping a decent size turbo will be having your cake and eating it too. I'd also try to get a little more stall converter in there.
TECH Fanatic
Joined: Feb 2015
Posts: 1,080
Likes: 178
Goal 500-600whp. How is it going to be used? towing, tire burning, street racing, etc. The more details you can provide on goal the more someone can help build a combo that works to achieve goal. As a reference, a stock 5.3 and smaller turbo (builds boost at 2k) can achieve whp goal but maybe more importantly have > 600 ft lbs of low end tq for towing with stock converter.
Thread Starter
Teching In
Joined: Jun 2020
Posts: 33
Likes: 17
From: North alabama
im swapping cams next few days.
i really want to keep to the stock converter. I don’t pull a ton of weight, occasional car and my bass boat.
TECH Fanatic
Joined: Feb 2015
Posts: 1,080
Likes: 178
A 5.3 is 12% smaller than 6.0. For simplicity sake, if you want the 5.3 to operate similar to the 6.0 with 228/230 cam, you need a cam 12% smaller 201/203. A cam to operate in a 5.3 at 1500 to 5000 is much different than 3500 to 7K or 6K to 8500K. Hope this make sense.
TECH Fanatic
Joined: Dec 2019
Posts: 1,129
Likes: 478
A 5.3 is 12% smaller than 6.0. For simplicity sake, if you want the 5.3 to operate similar to the 6.0 with 228/230 cam, you need a cam 12% smaller 201/203. A cam to operate in a 5.3 at 1500 to 5000 is much different than 3500 to 7K or 6K to 8500K. Hope this make sense.
