Opinions on my GT3076R setup
#106
Rennlist Member
Also, I thought that the earlier 7 blade wheel was more adept at early boost but fell away a bit earlier than the current designs? Maybe I had that backwards.
#107
Rennlist Member
Thread Starter
Greetings Raj:
I think you have a problem that is not related to the turbocharger sizing. If your GT30R is in good mechanical condition there is no way that you have 2 psi @ 3K RPM and should go up to basically 5K RPMs to achieve full boost of 15 psi. The Garret GTR series are ball bearings turbos and spool up faster than non ball bearings turbos. Your dyno sheet shows positive MAP pressure @ 2600 RPM. Which means that your Turbine AR is not the cause for the big turbo lag your experiencing. To the contrary it could be a power robber if you crank up the boost. Remember I have a GT35R with a .82 hot side and my car achieve fool boost (21psi) at about 4K if I remember correctly. My GT35R .82 AR turbine flows more gas than your GT30R .82 AR, which means that my car should have more lag than yours.
Before you spend money and time in a new turbo, I suggest you to check your BOV and your Waste Gate valve. If you have a too soft spring on your Waste Gate Valve it will open before is needed, specially if you have too much backpressure in the crossover pipe. Believe me, it happens to me when I have a #8 hot side installed in my car. Also a defective BOV can leak air not allowing a quick pressure build up on the manifold.
The amount of blades in the compressor wheel or any other efficiency improvement's on current turbos will not improve your lag issue. As another forum member says before, it could mask the problem.
I think you have a problem that is not related to the turbocharger sizing. If your GT30R is in good mechanical condition there is no way that you have 2 psi @ 3K RPM and should go up to basically 5K RPMs to achieve full boost of 15 psi. The Garret GTR series are ball bearings turbos and spool up faster than non ball bearings turbos. Your dyno sheet shows positive MAP pressure @ 2600 RPM. Which means that your Turbine AR is not the cause for the big turbo lag your experiencing. To the contrary it could be a power robber if you crank up the boost. Remember I have a GT35R with a .82 hot side and my car achieve fool boost (21psi) at about 4K if I remember correctly. My GT35R .82 AR turbine flows more gas than your GT30R .82 AR, which means that my car should have more lag than yours.
Before you spend money and time in a new turbo, I suggest you to check your BOV and your Waste Gate valve. If you have a too soft spring on your Waste Gate Valve it will open before is needed, specially if you have too much backpressure in the crossover pipe. Believe me, it happens to me when I have a #8 hot side installed in my car. Also a defective BOV can leak air not allowing a quick pressure build up on the manifold.
The amount of blades in the compressor wheel or any other efficiency improvement's on current turbos will not improve your lag issue. As another forum member says before, it could mask the problem.
My best approach is to dyno the car 1st at WOT and see what I get. It is too much guess work at this point. It would tell me the correct AFR's, Boost level and peak hp and tq.
Once that is out of the way and the graphs match, I can start looking into restrictions/leaks.
#108
Rennlist Member
Thread Starter
Update:
Took the car for its 1st long trip (260 miles back and forth to hershey) and it ran flawlessly. Boost comes on strong but no way to compare until I get her on a dyno. So far, very happy with the results.
Will probably require some tuning to get the afr's right with the smaller hotside. Let's see where she is currently.
More to come..
Took the car for its 1st long trip (260 miles back and forth to hershey) and it ran flawlessly. Boost comes on strong but no way to compare until I get her on a dyno. So far, very happy with the results.
Will probably require some tuning to get the afr's right with the smaller hotside. Let's see where she is currently.
More to come..
Last edited by RajDatta; 09-11-2013 at 05:24 AM.
#110
Rennlist Member
Thread Starter
Thom, no dyno yet but the boost comes on quick and I hit maximum boost aound 3-3.2k. As expected, that dyno run was for tuning purposes only. Been too busy to get the car dynoed, but plan to shorly.