RPM power band
- Thread starter twin74s
- Start date
JSM
Active member
Re: RPM power band
As Gerber asked turbo can shift this power band around more than just about any mod.
Here is a stock turbo/stock head strong running truck dyno sheet just to give you an example.
http://gallery.jsmanufacturing.com/main.php?g2_view=core.DownloadItem&g2_itemId=985&g2_serialNumber=2
Peak HP and Torque around 3200rpm, by 5400 rpm HP was only half of what it was down low.
Stock turbo/heads/cam can't breathe.
Yours will be a bit better with cam and heads you have. But don't think a turbo motor is a high reving engine, you really want to take advantage of the torque.
As Gerber asked turbo can shift this power band around more than just about any mod.
Here is a stock turbo/stock head strong running truck dyno sheet just to give you an example.
http://gallery.jsmanufacturing.com/main.php?g2_view=core.DownloadItem&g2_itemId=985&g2_serialNumber=2
Peak HP and Torque around 3200rpm, by 5400 rpm HP was only half of what it was down low.
Stock turbo/heads/cam can't breathe.
Yours will be a bit better with cam and heads you have. But don't think a turbo motor is a high reving engine, you really want to take advantage of the torque.
Re: RPM power band
Its stock ECU that has been tuned with tuner pro. Valve springs are comp to match the cam it was a whole kit bought by the previous owner. Turbo is a 58mm Garrett. It just flat falls off at 5200. im also having knock issues on 16lbs of boost and 91/93...Im going to try a different turbo at lower boost and see what happens. Sure seems like this thing some run better than it does. I have some tuning knowledge and have been workin on the tune just havent got it figured out yet.
Its stock ECU that has been tuned with tuner pro. Valve springs are comp to match the cam it was a whole kit bought by the previous owner. Turbo is a 58mm Garrett. It just flat falls off at 5200. im also having knock issues on 16lbs of boost and 91/93...Im going to try a different turbo at lower boost and see what happens. Sure seems like this thing some run better than it does. I have some tuning knowledge and have been workin on the tune just havent got it figured out yet.
Re: RPM power band
you probably have more than one issue your battling here, but this isnt surprising at all. the 412 cam runs out of steam right at 5000rpm...... although if your feeling a huge drop in power above 5200 then you have somthing else going on as well. it should just feel like its slightly faster at lower rpm, but not really drastic. unless you have a stock turbo, then what your describing is exactly right, and perfectly normal.
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twin74s said:
you probably have more than one issue your battling here, but this isnt surprising at all. the 412 cam runs out of steam right at 5000rpm...... although if your feeling a huge drop in power above 5200 then you have somthing else going on as well. it should just feel like its slightly faster at lower rpm, but not really drastic. unless you have a stock turbo, then what your describing is exactly right, and perfectly normal.
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James Thomas
"NO CLASS"
Re: RPM power band
Like mentioned above, stock turbo / small turbos and L35's (unported) are done by 5000 rpm or so and you may have other tuning issues to boot. Sounds about right if you don't have an upgraded turbo and heads.
_________
James
Like mentioned above, stock turbo / small turbos and L35's (unported) are done by 5000 rpm or so and you may have other tuning issues to boot. Sounds about right if you don't have an upgraded turbo and heads.
_________
James
Re: RPM power band
the heads arnt done by 5krpm in my experience. the 412 however runs out of steam right around there, and if he has a stock turbo on a motor with heads and cam, the turbowill nose over pretty sharply about 4krpm.....and it really has little to do with how much boost your running, its more related to inadiquit airflow for a given mafiold pressure level across the board, because the turbo is so undersized for the combination. your way off the efficiency curve of the compressor.
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the heads arnt done by 5krpm in my experience. the 412 however runs out of steam right around there, and if he has a stock turbo on a motor with heads and cam, the turbowill nose over pretty sharply about 4krpm.....and it really has little to do with how much boost your running, its more related to inadiquit airflow for a given mafiold pressure level across the board, because the turbo is so undersized for the combination. your way off the efficiency curve of the compressor.
e