Anyone out there running a GT3076R?
#22
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Thanks very much Jason! That is odd how it is breaking up and drops off at 5750-6000 RPM. Maybe in your timing map or your plugs? Just strange that the power doesn't match the plot of manifold pressure at all. As it seems you are boost creeping up to ~17 psi by redline, but not making any additional power past 5750... Odd. It does look like there is a lot more power potential that could be had from this turbocharger setup.
ps - What RPM do you have your VVT kicking in?
ps - What RPM do you have your VVT kicking in?
#23
Thanks very much Jason! That is odd how it is breaking up and drops off at 5750-6000 RPM. Maybe in your timing map or your plugs? Just strange that the power doesn't match the plot of manifold pressure at all. As it seems you are boost creeping up to ~17 psi by redline, but not making any additional power past 5750... Odd. It does look like there is a lot more power potential that could be had from this turbocharger setup.
ps - What RPM do you have your VVT kicking in?
ps - What RPM do you have your VVT kicking in?
#24
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Thanks! Yeah, it would have been nice to see if the VVT was causing this or not... I have also checked out your dyno section thread. Hopefully it gets sorted for you soon. Good luck!
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Based on the RPM vs Pressure plot that Jason provided I was able to make my compressor plot of the GT3076R more accurate and get out of surge territory. I assumed that the turbocharger would be at the full 20 psi by 4300 RPM. Made the plot look much nicer and fit within the surge limit nicely. Thanks for your help with this Jason! It is MUCH appreciated.
Also, in looking at my Source Data for the plot on Excel I was had assumed a 3200 RPM spoolup since this Excel document was originally designed for a GT28 on an SR20DET. Yeah, 4300 makes things much better.
Pic of resulting Compressor Plot:
Also, in looking at my Source Data for the plot on Excel I was had assumed a 3200 RPM spoolup since this Excel document was originally designed for a GT28 on an SR20DET. Yeah, 4300 makes things much better.
Pic of resulting Compressor Plot:
#26
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BTW, if anyone else wants me to do this for them. Just shoot me your specs (bore & stroke, spoolup RPM, and redline RPM) and the turbo (with compressor map link) that you plan to use and I can plot it for you and send you the results via PM. Just looking to help out the community.
#27
Based on the RPM vs Pressure plot that Jason provided I was able to make my compressor plot of the GT3076R more accurate and get out of surge territory. I assumed that the turbocharger would be at the full 20 psi by 4300 RPM. Made the plot look much nicer and fit within the surge limit nicely. Thanks for your help with this Jason! It is MUCH appreciated.
Also, in looking at my Source Data for the plot on Excel I was had assumed a 3200 RPM spoolup since this Excel document was originally designed for a GT28 on an SR20DET. Yeah, 4300 makes things much better.
Pic of resulting Compressor Plot:
Also, in looking at my Source Data for the plot on Excel I was had assumed a 3200 RPM spoolup since this Excel document was originally designed for a GT28 on an SR20DET. Yeah, 4300 makes things much better.
Pic of resulting Compressor Plot:
#28
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This plot is with a 8000 RPM redline... Thus the higher 'top-end' numbers of flow. Also, volumetric efficiency comes into play, thus I made a guess on my calculations. And I have NO idea what it is on the Miata. If someone knows, please feel free to share.
#30
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Haha! Very true... I'm still in the building stage of my engine and already have the turbo, so I know it's going to used. However, this might save someone from buying something that would put them in the surge threshold of their selected turbocharger. Also give an idea at what pressure you are getting the most efficient use out of said turbocharger.
#34
Only technically am I a Supra guy...MkIV guys disown us because of how cheap, unsophisticated, and poor we are. Their fanboy nutswingers follow suit with "they arent real Supras."
Anyways, back on topic. A 30R is a great turbo, but unless you have pretty big power goals, I'd suggest away from it with something smaller. Not having any power until 4500 (as the dyno shows) is extremely annoying. You need to be going for 400-500 to jump up to something that big.
Anyways, back on topic. A 30R is a great turbo, but unless you have pretty big power goals, I'd suggest away from it with something smaller. Not having any power until 4500 (as the dyno shows) is extremely annoying. You need to be going for 400-500 to jump up to something that big.
Last edited by Orion ZyGarian; 04-14-2009 at 11:16 PM.
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In my application, it will be used on a road race car. It is not an actual GT3076R, but is similar. The actual turbocharger is an INCON GTBB37 that was custom ported by Andreas Miko (SR World). So I would not drop below 5000 RPM at anytime except when coming out of a sharp turn, which would allow me to get on the throttle sooner as I wouldn't have full boost built up to cause traction problems while coming out of the corner. Goal is ~350RWHP by the way...
#39
Couple of updates. I have a pretty serious oil leak that might be a contributing factor. It's leaking right at the vvt fitting where it screws into the block. It's bad enough where it may not be getting enough pressure to allow the vvt to function properly.
I plan on pulling the engine again this week and will be able to really get to the source of the problem. When it's out I plan on fixing that leak, running a single oil line from that fitting to a distribution block to use for my turbo and oil pressure sensors, install the coolant reroute and then I'm going to verify that my timing belt is correctly aligned.
If all goes well it will go back to the dyno to get tuned. Although it does have some mechanical issues that I need to fix before I move forward, I am still hoping that the conservative tune is to blame.
I plan on pulling the engine again this week and will be able to really get to the source of the problem. When it's out I plan on fixing that leak, running a single oil line from that fitting to a distribution block to use for my turbo and oil pressure sensors, install the coolant reroute and then I'm going to verify that my timing belt is correctly aligned.
If all goes well it will go back to the dyno to get tuned. Although it does have some mechanical issues that I need to fix before I move forward, I am still hoping that the conservative tune is to blame.
#40
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Sounds like you have things well in hand Jason. Glad to hear! I'm with you on the tuning portion of the problem, as the tune itself will not make the car fall flat on it's face like it did in your previous dynos. However, the VVT not functioning properly could infact do that. Hopefully fixing the oil leak is all that is needed to correct this problem. Can't wait to see the updated dynos after the fix. Best of luck!