low ms3 numbers
This isn't a 4.6l mod motor that makes 420hp and 353 torque. By spinning it higher, it's not going to make any more torque than it did at 4800-5000 rpm. By 6200 rpm, the torque is going down. Something is not right with that massive of a cam and heads. I made over 400ft/lbs of torque with handported heads and a tr224 cam back in 2002. Granted, it put down 438 hp, but that's because the tr224 cam on a 112 with 4 degrees of advance ground in was peaking by 6000rpm.
Without seeing the graph and seeing what happens with both the HP & TQ lines it is really a guessing game at this point. Once we see this we can see if the HP numbers are still climbing at 6,200 or falling off. Is the TQ truly falling off or is it staying more flat across the 6,000 range?
Yeah, we really need to see the dyno graph. If it's just falling on it's face in the upper RPM's you should look into a valvetrain issue. What springs are on those heads and how many miles? Clutch or converter slipping? Were you on a Mustang dyno? They tend do dyno a bit lower. Are your numbers corrected? Actual numbers for elevation maybe? How does the car feel when driven?
This isn't a 4.6l mod motor that makes 420hp and 353 torque. By spinning it higher, it's not going to make any more torque than it did at 4800-5000 rpm. By 6200 rpm, the torque is going down. Something is not right with that massive of a cam and heads. I made over 400ft/lbs of torque with handported heads and a tr224 cam back in 2002. Granted, it put down 438 hp, but that's because the tr224 cam on a 112 with 4 degrees of advance ground in was peaking by 6000rpm.
Intake was out of the budget and I needed to tune it before anything else. Had some other gm maf sensor on when i bought it along with a mail order tune and the driveability suffered as one can imagine. They swapped that out with a stocker when I got up there. A new intake/tb is next on the list unless someone else thinks there is still a mechanical problem with the motor?
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Whether he pulls it to 6000 or 9000, the point at which he made max torque has already been exceeded. Low torque is an indicator or low cylinder pressure during combustion. THE MOTOR IS NOT HEALTHY IF IT MAKES LESS 360 FT/LBS of TORQUE WITH PORTED HEADS, LARGE CAM, 6 SPEED, LONG TUBES, AND EVEN WITH AN LS1 INTAKE.
An LS6 intake might bump him up to 370, maybe 380 torque, but that's still pretty low in my opinion. With that low torque, it's probably a dog under 4000 rpm.
An LS6 intake might bump him up to 370, maybe 380 torque, but that's still pretty low in my opinion. With that low torque, it's probably a dog under 4000 rpm.
I'm not sure if you have a different fuel pump, but it could be dropping fuel pressure up top, ive seen it happen before. Sometimes you can make it the a/f you want but fuel pressure is low.
My 04 GTO did 410hp with a ms3, stock heads, headers/corsa. You should be north of 425 430 with ease..maybe not on ls1 intake but still
My 04 GTO did 410hp with a ms3, stock heads, headers/corsa. You should be north of 425 430 with ease..maybe not on ls1 intake but still
Whether he pulls it to 6000 or 9000, the point at which he made max torque has already been exceeded. Low torque is an indicator or low cylinder pressure during combustion. THE MOTOR IS NOT HEALTHY IF IT MAKES LESS 360 FT/LBS of TORQUE WITH PORTED HEADS, LARGE CAM, 6 SPEED, LONG TUBES, AND EVEN WITH AN LS1 INTAKE.
An LS6 intake might bump him up to 370, maybe 380 torque, but that's still pretty low in my opinion. With that low torque, it's probably a dog under 4000 rpm.
An LS6 intake might bump him up to 370, maybe 380 torque, but that's still pretty low in my opinion. With that low torque, it's probably a dog under 4000 rpm.
We don't have a clue if that dyno reads low or not?
If his TQ cuve stayed flat and he picked up another 20RWHP up higher in the RPM range it would help to know.
The only way to really know is to get the car to the track. How do you know the clutch isn't slipping? Start at the track and go from there.
There's even more variables at a track than on a dyno. Track times are only remotely accurate with an automatic trans. With a 6-speed, there's so many more variables with launch rpm, how quick he shifts, what rpm he shifts etc, and then there's track conditions, weather, air density etc etc.
Fact is, he didn't post a timeslip and ask for help. He posted a dyno sheet and stated that they were low. Look at the title of the thread.
Fact is, he didn't post a timeslip and ask for help. He posted a dyno sheet and stated that they were low. Look at the title of the thread.
How many miles are on the car?
I agree that the LS1 intake is a restriction in higher rpm areas. I am still blaming cylinder pressure bleeding off via valves not sealing properly or bad rings.
Who cares about the dyno number or a track number. Dyno's are merely tuning tools that are not consistent from one dyno to another and the track is loaded with variables.
I agree that the LS1 intake is a restriction in higher rpm areas. I am still blaming cylinder pressure bleeding off via valves not sealing properly or bad rings.
Who cares about the dyno number or a track number. Dyno's are merely tuning tools that are not consistent from one dyno to another and the track is loaded with variables.
Whether he pulls it to 6000 or 9000, the point at which he made max torque has already been exceeded. Low torque is an indicator or low cylinder pressure during combustion. THE MOTOR IS NOT HEALTHY IF IT MAKES LESS 360 FT/LBS of TORQUE WITH PORTED HEADS, LARGE CAM, 6 SPEED, LONG TUBES, AND EVEN WITH AN LS1 INTAKE.
An LS6 intake might bump him up to 370, maybe 380 torque, but that's still pretty low in my opinion. With that low torque, it's probably a dog under 4000 rpm.
An LS6 intake might bump him up to 370, maybe 380 torque, but that's still pretty low in my opinion. With that low torque, it's probably a dog under 4000 rpm.
Ultimately the total flow of the heads will depend on the whole intake track as well as exhaust ports, headers and whatever else you have beyond the header collector.
Leakdown Test IMO is paramount as well as Compression Test.
IF both pan out correct, the fix the intake track issue. IF thats been improved and still cruddy #'s then its either the parts, tune, or something we are not yet seeing. M6 cars at least can give a somewhat accurate dyno # and for our purpouses we should be looking at that.
My example is I have a Vengence Racing VRx4 Cam (228/230 58x" lift ona 112 LSA), and I make 384 RWHP to the tire 363 TQ (peak @ 3,500-4,500), this is on a 6 speed, (textrailia clutch), 3 " steel DS, Moser 12 bolt with Tru trac, 17" WS.6 rims on NItto DR, 2002 untouched and dyno tune. LS6 and hand ported TB. 36k on the motor
The cam on average has made past 405 rwhp in ALMOST EXACT SAME SETUPS!!
So I am calling it a weak cam. I'll be looking for something more.
Whether he pulls it to 6000 or 9000, the point at which he made max torque has already been exceeded. Low torque is an indicator or low cylinder pressure during combustion. THE MOTOR IS NOT HEALTHY IF IT MAKES LESS 360 FT/LBS of TORQUE WITH PORTED HEADS, LARGE CAM, 6 SPEED, LONG TUBES, AND EVEN WITH AN LS1 INTAKE.
An LS6 intake might bump him up to 370, maybe 380 torque, but that's still pretty low in my opinion. With that low torque, it's probably a dog under 4000 rpm.
An LS6 intake might bump him up to 370, maybe 380 torque, but that's still pretty low in my opinion. With that low torque, it's probably a dog under 4000 rpm.
also have a buddy that put down 330/340 on that dyno being m6 si with a ls1 intake...something is up
it is not the dyno and it does not read low...I put down 485rwhp and 410rwtq on the same dyno earlier this year...peaked at 6700...I am sure there was something up with the setup as to why Jim didn't pull it higher or this was one of the few first graphs...
my guess is the motor is hurt...or the new heads are a bad batch where the valves don't seal...there were a couple threads on hardcore that showed these tsp heads and they caught a new record for the most flow at 0 lift...
Jon