Low rwhp on twin turbo setup
08-30-2010, 08:25 PM
#23
hey slowhawk, i actually bought the camshaft from you.... it is perfect for me as a daily driver. Hopefully with more boost, it will hit my goal of 800rwhp. I am assuming with more boost that it will bring my peak hp higher in the rpm range? How much boost can i go without pushing water? i have an o-ringed iron block with copper gaskets and of course forged pistons/rods. Sorry is these are elementary questions but i am new to boost. thanks t
08-31-2010, 10:57 AM
#27
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If you have too much back pressure the dyno graph will look like it's going to make big and start to flatten out and fall off. My opinion is the cam is small but with forced induction you should still see better numbers. A good comparison is look at the horsepower numbers of people running Z06 cams.
Something else to look into is flame out of the plugs, I've seen it show up and look like valve float or a slipping trans. My motor sounded flat, I had to gap my plugs at .022
Remember boost is just a measure of restriction, so when you talk boost numbers it won't be a direct comparision, a free breathing motor with huge turbo, large ported heads and intake might only see 14-18lbs before pushing water, while a different combination might see 20+ before a hint of any problems.
Something else to look into is flame out of the plugs, I've seen it show up and look like valve float or a slipping trans. My motor sounded flat, I had to gap my plugs at .022
Remember boost is just a measure of restriction, so when you talk boost numbers it won't be a direct comparision, a free breathing motor with huge turbo, large ported heads and intake might only see 14-18lbs before pushing water, while a different combination might see 20+ before a hint of any problems.
08-31-2010, 11:13 AM
#28
If you have too much back pressure the dyno graph will look like it's going to make big and start to flatten out and fall off. My opinion is the cam is small but with forced induction you should still see better numbers. A good comparison is look at the horsepower numbers of people running Z06 cams.
Something else to look into is flame out of the plugs, I've seen it show up and look like valve float or a slipping trans. My motor sounded flat, I had to gap my plugs at .022
Remember boost is just a measure of restriction, so when you talk boost numbers it won't be a direct comparision, a free breathing motor with huge turbo, large ported heads and intake might only see 14-18lbs before pushing water, while a different combination might see 20+ before a hint of any problems.
Something else to look into is flame out of the plugs, I've seen it show up and look like valve float or a slipping trans. My motor sounded flat, I had to gap my plugs at .022
Remember boost is just a measure of restriction, so when you talk boost numbers it won't be a direct comparision, a free breathing motor with huge turbo, large ported heads and intake might only see 14-18lbs before pushing water, while a different combination might see 20+ before a hint of any problems.
08-31-2010, 12:43 PM
#29
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The power is there, 610@12 psi ant bad. the cam is not big enough to carry the power
up stairs.
The cam needs to be in the high 230's @ .050 to make good power @ 6500.
The 63a/r is not happy @ 6500 on a motor that big.
.82 or the 1.06 a/r will get it done.
I bet you have more torque than HP.
What you have is a car that is a blast to drive.
The bigger a/r's and cam will take the fun out of it.
up stairs.
The cam needs to be in the high 230's @ .050 to make good power @ 6500.
The 63a/r is not happy @ 6500 on a motor that big.
.82 or the 1.06 a/r will get it done.
I bet you have more torque than HP.
What you have is a car that is a blast to drive.
The bigger a/r's and cam will take the fun out of it.
08-31-2010, 01:06 PM
#30
The power is there, 610@12 psi ant bad. the cam is not big enough to carry the power
up stairs.
The cam needs to be in the high 230's @ .050 to make good power @ 6500.
The 63a/r is not happy @ 6500 on a motor that big.
.82 or the 1.06 a/r will get it done.
I bet you have more torque than HP.
What you have is a car that is a blast to drive.
The bigger a/r's and cam will take the fun out of it.
up stairs.
The cam needs to be in the high 230's @ .050 to make good power @ 6500.
The 63a/r is not happy @ 6500 on a motor that big.
.82 or the 1.06 a/r will get it done.
I bet you have more torque than HP.
What you have is a car that is a blast to drive.
The bigger a/r's and cam will take the fun out of it.
08-31-2010, 03:27 PM
#32
hey slowhawk, i actually bought the camshaft from you.... it is perfect for me as a daily driver. Hopefully with more boost, it will hit my goal of 800rwhp. I am assuming with more boost that it will bring my peak hp higher in the rpm range? How much boost can i go without pushing water? i have an o-ringed iron block with copper gaskets and of course forged pistons/rods. Sorry is these are elementary questions but i am new to boost. thanks t
08-31-2010, 11:18 PM
#36
FormerVendor
Unless for some reason rear mount setups need a lot more cam than a traditional turbo setup I don't see a problem with the cam at all.
Needing high 230's to make power to 6500? We've run many combos with a 232 cam making 1150+rwhp and turning 7800rpm.
Check backpressure at turbine housing (I'll guess it will be quite high). Measure boost at compressor cover(I'll guess it's substantially more than you see at the intake manifold).
Post a dyno graph.
I may have missed it but what are the valvesprings installed height or seat pressure? The more backpressure you have the more seat pressure you need on the exhaust valve for it to run clean up top.
Needing high 230's to make power to 6500? We've run many combos with a 232 cam making 1150+rwhp and turning 7800rpm.
Check backpressure at turbine housing (I'll guess it will be quite high). Measure boost at compressor cover(I'll guess it's substantially more than you see at the intake manifold).
Post a dyno graph.
I may have missed it but what are the valvesprings installed height or seat pressure? The more backpressure you have the more seat pressure you need on the exhaust valve for it to run clean up top.
09-01-2010, 08:31 AM
#38
Check backpressure at turbine housing (I'll guess it will be quite high). Measure boost at compressor cover(I'll guess it's substantially more than you see at the intake manifold).
Post a dyno graph.
I may have missed it but what are the valvesprings installed height or seat pressure? The more backpressure you have the more seat pressure you need on the exhaust valve for it to run clean up top.
Post a dyno graph.
I may have missed it but what are the valvesprings installed height or seat pressure? The more backpressure you have the more seat pressure you need on the exhaust valve for it to run clean up top.
