454 LSX, need some help with the graphs
#1
454 LSX, need some help with the graphs
UPDATE: Took the car back to the same dyno with hot tires and strapped the crap out of it. It took a couple pulls for it to hook. I added a little to much fuel to the last pass up top but here are the results:
So I built a guy a LSX 454 for his 06' Z06 after the exhaust valve decided to vacate the motor out of the side of the block. The first graph is over MPH and shows the problem. The second graph is another Z06 I am doing with H/C to really show the problem. I tuned both of them less than 30 minutes apart. I expected the 454 to make 620/560rw. The thing makes 460rwtq at the hit and doesn't get any better till the end of the run which makes no sense to me. I designed the motor not to exceed 6,500 rpm since the SS intake valves and springs coupled with the FAST just won't allow power to be made much above that on this size motor. Just for perspective, a 15' Z06 with full exhaust, pullies, CAI and tune only put down 630rw on this dyno. I think he said 15lbs of boost but don't quote me. Runs started at 2,750 and ended at 6,750.
Does this look like clutch slip, spinning on the dyno, something in the drive train? The 454 was run second and there is nothing in the logs to indicate anything is wrong at the motor. KPA is good 101-98, DynCyl follows on both although the 454 only peaks at 1.11 like the 427 but doesn't drop off like the 427. The 427 ends at .94 at 6,800. I am not sure if an exhaust restriction would show in the logs though. I am not sure where to go with this. Any suggestions would be greatly appreciated.
454 mod list: 600 miles on motor
TEA/TFS 260 heads
BTR STG IV cam 246/254 111
8.75 DCR
Lunati lifters - 3/8" push rods .0030" preload
Haltech 108
Ported FAST 102 and NW tb
OBX 1 7/8" catted LT's with stock cat back
60lb injectors
Monster LT1 Twin
427 mod list:
FRH ported LS7 heads
bullet 242/248 114
8.5 DCR
3/8" push rods
Vararam
Ported FAST 102 and NW TB
TSP 1 7/8" headers with stock cat back
stock injectors
McLeod RXT Twin
So I built a guy a LSX 454 for his 06' Z06 after the exhaust valve decided to vacate the motor out of the side of the block. The first graph is over MPH and shows the problem. The second graph is another Z06 I am doing with H/C to really show the problem. I tuned both of them less than 30 minutes apart. I expected the 454 to make 620/560rw. The thing makes 460rwtq at the hit and doesn't get any better till the end of the run which makes no sense to me. I designed the motor not to exceed 6,500 rpm since the SS intake valves and springs coupled with the FAST just won't allow power to be made much above that on this size motor. Just for perspective, a 15' Z06 with full exhaust, pullies, CAI and tune only put down 630rw on this dyno. I think he said 15lbs of boost but don't quote me. Runs started at 2,750 and ended at 6,750.
Does this look like clutch slip, spinning on the dyno, something in the drive train? The 454 was run second and there is nothing in the logs to indicate anything is wrong at the motor. KPA is good 101-98, DynCyl follows on both although the 454 only peaks at 1.11 like the 427 but doesn't drop off like the 427. The 427 ends at .94 at 6,800. I am not sure if an exhaust restriction would show in the logs though. I am not sure where to go with this. Any suggestions would be greatly appreciated.
454 mod list: 600 miles on motor
TEA/TFS 260 heads
BTR STG IV cam 246/254 111
8.75 DCR
Lunati lifters - 3/8" push rods .0030" preload
Haltech 108
Ported FAST 102 and NW tb
OBX 1 7/8" catted LT's with stock cat back
60lb injectors
Monster LT1 Twin
427 mod list:
FRH ported LS7 heads
bullet 242/248 114
8.5 DCR
3/8" push rods
Vararam
Ported FAST 102 and NW TB
TSP 1 7/8" headers with stock cat back
stock injectors
McLeod RXT Twin
Last edited by Pray; 12-15-2015 at 05:28 PM.
#4
Super Hulk Smash
iTrader: (7)
That's not all that weird with the rectangle port stuff. They don't "come on" the same as the cathedrals and have a flatter torque curve typically. But the curve should be higher.
Hell, Brian Tooley had a 416 with stock LS3 heads do 600/560 on an engine dyno... which translates into something close to 530/490 on a dynojet.
Hell, Brian Tooley had a 416 with stock LS3 heads do 600/560 on an engine dyno... which translates into something close to 530/490 on a dynojet.
#5
FormerVendor
iTrader: (13)
We just back to back tested a pair of AI CNC LS7 heads against the TFS 260's and the AI heads made 20 rwhp more power. It was our LS7 Stg III cam and the car went from 580 rwhp to 600 rwhp.
With that said, I think the bearings on the dyno need greased or something, it doesn't look right.
With that said, I think the bearings on the dyno need greased or something, it doesn't look right.
#7
Super Hulk Smash
iTrader: (7)
We just back to back tested a pair of AI CNC LS7 heads against the TFS 260's and the AI heads made 20 rwhp more power. It was our LS7 Stg III cam and the car went from 580 rwhp to 600 rwhp.
With that said, I think the bearings on the dyno need greased or something, it doesn't look right.
With that said, I think the bearings on the dyno need greased or something, it doesn't look right.
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#8
TECH Veteran
We just back to back tested a pair of AI CNC LS7 heads against the TFS 260's and the AI heads made 20 rwhp more power. It was our LS7 Stg III cam and the car went from 580 rwhp to 600 rwhp.
With that said, I think the bearings on the dyno need greased or something, it doesn't look right.
With that said, I think the bearings on the dyno need greased or something, it doesn't look right.
#9
It is the way the graphs loaded on here for some reason. I tried messing with it but it didn't change. The dyno owner laid it over MPH to see if it changed the graph in anyway. We were also trying to see if the mph would show clutch slip or tire spin. The problem being that it makes peak tq at 6K and only makes 10 more than at 2,700. The MPH graph is the one I accidently printed since it was up. The only RPM graph I have is the one comparing the two cars. Hence the reason both are on there. Just look at the second one if the first one hurts your eyes. I don't think anyone on here has seen a tq curve look like this.
#10
We just back to back tested a pair of AI CNC LS7 heads against the TFS 260's and the AI heads made 20 rwhp more power. It was our LS7 Stg III cam and the car went from 580 rwhp to 600 rwhp.
With that said, I think the bearings on the dyno need greased or something, it doesn't look right.
With that said, I think the bearings on the dyno need greased or something, it doesn't look right.
#11
I would have a close look at the valve train, especially the lifters.
I recall a motor with a similar problem last year and it ended up being the lifters that were preventing the motor from making power and having a weird power curve.
They swapped in another brand and the thing ran strong
I recall a motor with a similar problem last year and it ended up being the lifters that were preventing the motor from making power and having a weird power curve.
They swapped in another brand and the thing ran strong
#12
I would have a close look at the valve train, especially the lifters.
I recall a motor with a similar problem last year and it ended up being the lifters that were preventing the motor from making power and having a weird power curve.
They swapped in another brand and the thing ran strong
I recall a motor with a similar problem last year and it ended up being the lifters that were preventing the motor from making power and having a weird power curve.
They swapped in another brand and the thing ran strong
#14
FormerVendor
iTrader: (13)
I had some 260's on my supercharged C6 Z06 and it made less power than a car almost identical to mine with stock LS7 heads, except it had a smaller cam. However my shortblock wasn't healthy so it was apples and oranges.
I did build a new shortblock, changed to the smaller cam that made more power, hand ported the heads, changed the boost juice to M1, gutted the cats and it picked up 130 rwhp and 110 rwtq, so who knows...
I brought the short turn height down to be like stock LS7, rounded it over, deshrouded the chamber with a 1/2 round burr like I normally do.
It looks like they were trying to get high lift airflow by leaving the chamber shrouded, and trying to get mid lift airflow by leaving the short turn tall and square, which is the opposite of how I used to develop heads.
I did build a new shortblock, changed to the smaller cam that made more power, hand ported the heads, changed the boost juice to M1, gutted the cats and it picked up 130 rwhp and 110 rwtq, so who knows...
I brought the short turn height down to be like stock LS7, rounded it over, deshrouded the chamber with a 1/2 round burr like I normally do.
It looks like they were trying to get high lift airflow by leaving the chamber shrouded, and trying to get mid lift airflow by leaving the short turn tall and square, which is the opposite of how I used to develop heads.
#15
I am going to give the car a once over and take it to another dyno before I really dig into it.
#16
I had some 260's on my supercharged C6 Z06 and it made less power than a car almost identical to mine with stock LS7 heads, except it had a smaller cam. However my shortblock wasn't healthy so it was apples and oranges.
I did build a new shortblock, changed to the smaller cam that made more power, hand ported the heads, changed the boost juice to M1, gutted the cats and it picked up 130 rwhp and 110 rwtq, so who knows...
I brought the short turn height down to be like stock LS7, rounded it over, deshrouded the chamber with a 1/2 round burr like I normally do.
It looks like they were trying to get high lift airflow by leaving the chamber shrouded, and trying to get mid lift airflow by leaving the short turn tall and square, which is the opposite of how I used to develop heads.
I did build a new shortblock, changed to the smaller cam that made more power, hand ported the heads, changed the boost juice to M1, gutted the cats and it picked up 130 rwhp and 110 rwtq, so who knows...
I brought the short turn height down to be like stock LS7, rounded it over, deshrouded the chamber with a 1/2 round burr like I normally do.
It looks like they were trying to get high lift airflow by leaving the chamber shrouded, and trying to get mid lift airflow by leaving the short turn tall and square, which is the opposite of how I used to develop heads.
In your opinion, what should this combo make?
#18
Another thought. Is the dyno brake dragging?
Last week I did a 2012 Camaro:
Ported stock heads
Low 230's intake mid 240's exhaust
Fast 102 with a ported stock t/b
1 7/8" long tubes
Stock h pipe with muffler deletes
This made 490 whp@6500 and 450wtq@5200. The 454 is only making 25 more lb/ft than a h/c/i ls3.
Last week I did a 2012 Camaro:
Ported stock heads
Low 230's intake mid 240's exhaust
Fast 102 with a ported stock t/b
1 7/8" long tubes
Stock h pipe with muffler deletes
This made 490 whp@6500 and 450wtq@5200. The 454 is only making 25 more lb/ft than a h/c/i ls3.
#19
Another thought. Is the dyno brake dragging?
Last week I did a 2012 Camaro:
Ported stock heads
Low 230's intake mid 240's exhaust
Fast 102 with a ported stock t/b
1 7/8" long tubes
Stock h pipe with muffler deletes
This made 490 whp@6500 and 450wtq@5200. The 454 is only making 25 more lb/ft than a h/c/i ls3.
Last week I did a 2012 Camaro:
Ported stock heads
Low 230's intake mid 240's exhaust
Fast 102 with a ported stock t/b
1 7/8" long tubes
Stock h pipe with muffler deletes
This made 490 whp@6500 and 450wtq@5200. The 454 is only making 25 more lb/ft than a h/c/i ls3.