What Turbo
12-25-2007, 03:13 PM
#31
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Originally Posted by slimjim8201,Dec 25 2007, 03:44 PM
The exact specs you choose should depend on the type of response you want. I had a GT3076 of sorts with a 0.48 A/R turbine housing. The small housing caused very high turbine flow velocities in the mid-range yet resulted in a good deal of flow restriction up top. The effect was a very stout mid-range torque curve. Had I gone with a larger turbine housing (something like a 0.63 or a 0.82), the curve would have been pushed further up in the rev range. Since the housing would be less restrictive, I'd be able to open up a good deal of HP up top, at the expense of mid-range HP.
What are your power goals? What do you want your torque curve to look like?
What are your power goals? What do you want your torque curve to look like?
Here's my .02 from my personal headaches via Inline Pro:
Originally had a GT3076R w/ a .48 turbine housing, and due to a couple of factors, one important factor being that AP2 cams are DIFFERENT than AP1 by that AP2 cams are designed for low-midrange power as AP1 cams are deisgned for up top power, could only make ~330whp with Inline Pro's kit @ 17 psi, the tune was there, no malfunctions with the injectors, boost leaks, plugs, wires, EMS, etc. The other reason for the lack of power with the F22C with a smaller A/R housing is b/c they believe that the .2L more displacement requires a bigger turbine housing to push exhaust through.
Now, I don't know the validity about the bigger displacement theory, but I do know for a fact about the cams being a huge impactor, AND that as soon as the .48 A/R turbine housing was swapped for the .82 one, I made 400whp easily. IT IS NOT SIMPLY ABOUT SHIFTING THE POWER CURVE. I agree that when one goes larger with turbos, this shift happens; however, there is something about such a small exhaust housing that WILL cripple your power with the F22C.
Oh, last note, 750s with a good tune WILL net you 500whp. I am running 675 cc's and made 450whp on a dyno dynamics that reads on average 5-10% lower than a dynojet...you can do the math. I also do NOT have my frame notched and make more torque than almost any GT35R S2K pushing 400-500whp on an inline pro kit.
12-25-2007, 03:24 PM
#32
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Originally Posted by slimjim8201,Dec 25 2007, 06:44 PM
The exact specs you choose should depend on the type of response you want. I had a GT3076 of sorts with a 0.48 A/R turbine housing. The small housing caused very high turbine flow velocities in the mid-range yet resulted in a good deal of flow restriction up top. The effect was a very stout mid-range torque curve. Had I gone with a larger turbine housing (something like a 0.63 or a 0.82), the curve would have been pushed further up in the rev range. Since the housing would be less restrictive, I'd be able to open up a good deal of HP up top, at the expense of mid-range HP.
What are your power goals? What do you want your torque curve to look like?
What are your power goals? What do you want your torque curve to look like?
My goals are 400hp with a max of 15 psi. Would like to see full boost at 4.5k and keep it steady to redline.
Whats the difference between the 3071 and 3076?
12-25-2007, 04:02 PM
#33
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05turbo guy has no clue what he's talking about.
The ball bearing turbos spool up quicker, run cooler, and last longer. If I'm not mistaken, the Precision ball bearing that 05turbo guy was talking about is only a single ball bearing turbo. The Garrett's are dual ball bearings.
I think that more people should look into the GT3082 (also called the GT3040). It has the compressor wheel of the GT40 (GT35 uses this too) but the smaller turbine wheel of the GT30 series.
This turbo allows the spool up of the 30 series but can make more power like the 35's - so it's somewhat in between. In my opinion it's the perfect turbo for the S2k.
The ball bearing turbos spool up quicker, run cooler, and last longer. If I'm not mistaken, the Precision ball bearing that 05turbo guy was talking about is only a single ball bearing turbo. The Garrett's are dual ball bearings.
I think that more people should look into the GT3082 (also called the GT3040). It has the compressor wheel of the GT40 (GT35 uses this too) but the smaller turbine wheel of the GT30 series.
This turbo allows the spool up of the 30 series but can make more power like the 35's - so it's somewhat in between. In my opinion it's the perfect turbo for the S2k.
12-25-2007, 05:42 PM
#34
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Originally Posted by AirborneS2K,Dec 25 2007, 07:13 PM
Here's my .02 from my personal headaches via Inline Pro:
Originally had a GT3076R w/ a .48 turbine housing, and due to a couple of factors, one important factor being that AP2 cams are DIFFERENT than AP1 by that AP2 cams are designed for low-midrange power as AP1 cams are deisgned for up top power, could only make ~330whp with Inline Pro's kit @ 17 psi, the tune was there, no malfunctions with the injectors, boost leaks, plugs, wires, EMS, etc. The other reason for the lack of power with the F22C with a smaller A/R housing is b/c they believe that the .2L more displacement requires a bigger turbine housing to push exhaust through.
Now, I don't know the validity about the bigger displacement theory, but I do know for a fact about the cams being a huge impactor, AND that as soon as the .48 A/R turbine housing was swapped for the .82 one, I made 400whp easily. IT IS NOT SIMPLY ABOUT SHIFTING THE POWER CURVE. I agree that when one goes larger with turbos, this shift happens; however, there is something about such a small exhaust housing that WILL cripple your power with the F22C.
Originally had a GT3076R w/ a .48 turbine housing, and due to a couple of factors, one important factor being that AP2 cams are DIFFERENT than AP1 by that AP2 cams are designed for low-midrange power as AP1 cams are deisgned for up top power, could only make ~330whp with Inline Pro's kit @ 17 psi, the tune was there, no malfunctions with the injectors, boost leaks, plugs, wires, EMS, etc. The other reason for the lack of power with the F22C with a smaller A/R housing is b/c they believe that the .2L more displacement requires a bigger turbine housing to push exhaust through.
Now, I don't know the validity about the bigger displacement theory, but I do know for a fact about the cams being a huge impactor, AND that as soon as the .48 A/R turbine housing was swapped for the .82 one, I made 400whp easily. IT IS NOT SIMPLY ABOUT SHIFTING THE POWER CURVE. I agree that when one goes larger with turbos, this shift happens; however, there is something about such a small exhaust housing that WILL cripple your power with the F22C.
I've always been curious to see how my turbo would have performed with a tubular turbo manifold. Honestly, I think the mid-range torque output would have been too much for the engine.
It's good to document what setups worked and didn't work with the various combinations of components.
In effect, the A/R does tend to "place" the power curve. Had I tested my setup with a 0.63 and 0.82 housing along with my 0.48, we'd see the torque peak shifted up in the engine range. Can't really compare to your setup as our supporting components weren't identical.
12-25-2007, 05:50 PM
#35
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Originally Posted by Silver S2k4,Dec 25 2007, 07:24 PM
I'm already getting the GT3071R so I can't really decide too much at this point and I'm not buying a new turbo.
My goals are 400hp with a max of 15 psi. Would like to see full boost at 4.5k and keep it steady to redline.
Whats the difference between the 3071 and 3076?
My goals are 400hp with a max of 15 psi. Would like to see full boost at 4.5k and keep it steady to redline.
Whats the difference between the 3071 and 3076?
The 71 sized unit is perfect for your power goals. Assuming you'd never want to upgrade past 400 rwhp, you should go with a compressor wheel that is just large enough for your goals. It will maximize response and efficiency throughout the engine range.
Do you know the turbine A/R for your unit?
12-25-2007, 06:03 PM
#36
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Originally Posted by afwfjustin,Dec 25 2007, 08:02 PM
I think that more people should look into the GT3082 (also called the GT3040). It has the compressor wheel of the GT40 (GT35 uses this too) but the smaller turbine wheel of the GT30 series.
This turbo allows the spool up of the 30 series but can make more power like the 35's - so it's somewhat in between. In my opinion it's the perfect turbo for the S2k.
This turbo allows the spool up of the 30 series but can make more power like the 35's - so it's somewhat in between. In my opinion it's the perfect turbo for the S2k.
) and so on...Your GT3082 would be great for a tubular setup. Since the manifold is so efficient and doesn't impose a huge backpressure on the engine like a cast manifold, you can get away with a smaller and more restrictive A/R housing. Slap something like that on a cast setup, and the backpressure on the engine will either rise high enough that the boost pressure required to achieve high flow rates will necessitate better-than-pump gas or it will put the compressor out of it's efficiency range.
This is one of the reasons I'd like to see someone test the turbo I had picked with a tubular manifold. My super restrictive turbine housing coupled with a cast manifold hindered top-end power (which was ok with me as 400 rwhp is rediculous for the street). But this unit on a more efficient setup would be crazy.
12-26-2007, 02:30 PM
#38
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Originally Posted by slimjim8201,Dec 25 2007, 10:03 PM
Turbo recommendations are a bit tricky since how each turbo responds is dependent on a LOT of factors. Compression ratio, turbine housing (huge), exhaust restriction, cams (for you Airborne ) and so on...
Your GT3082 would be great for a tubular setup. Since the manifold is so efficient and doesn't impose a huge backpressure on the engine like a cast manifold, you can get away with a smaller and more restrictive A/R housing. Slap something like that on a cast setup, and the backpressure on the engine will either rise high enough that the boost pressure required to achieve high flow rates will necessitate better-than-pump gas or it will put the compressor out of it's efficiency range.
This is one of the reasons I'd like to see someone test the turbo I had picked with a tubular manifold. My super restrictive turbine housing coupled with a cast manifold hindered top-end power (which was ok with me as 400 rwhp is rediculous for the street). But this unit on a more efficient setup would be crazy.
) and so on...Your GT3082 would be great for a tubular setup. Since the manifold is so efficient and doesn't impose a huge backpressure on the engine like a cast manifold, you can get away with a smaller and more restrictive A/R housing. Slap something like that on a cast setup, and the backpressure on the engine will either rise high enough that the boost pressure required to achieve high flow rates will necessitate better-than-pump gas or it will put the compressor out of it's efficiency range.
This is one of the reasons I'd like to see someone test the turbo I had picked with a tubular manifold. My super restrictive turbine housing coupled with a cast manifold hindered top-end power (which was ok with me as 400 rwhp is rediculous for the street). But this unit on a more efficient setup would be crazy.
12-28-2007, 02:05 AM
#40
Originally Posted by Silver S2k4,Dec 25 2007, 12:53 AM
Off topic butif the waste gate has a 7psi spring, could I raise the boost level with the EMS or boost controller or do I need to change the spring. The way I understand it is that the spring just sets the minimum and then the rest is set with the boost controller/EMS right?