** My build w/ boosted performance ST kit!! - lots of pix! **
05-26-2010, 03:12 PM
#263
^^^
I think the T3 with the A/R = .58 will spool fastest.
Based on my own experience with my Greddy's, I'm assuming that the back pressure will not be much of an issue at low rpms. Thus, at a given rpm (in the low rpm range) there will be roughly the same volume of exhaust gases flowing through each of the turbos. With the smaller opening, the exhaust gasses will be flowing faster, which will help the turbines spool faster. At the higher rpms back pressure will become more of an issue, thus inhibiting the exhaust flow volume and velocity to an extent, and thus turbine performance.
Also, the turbine is smaller on the last hypothetical turbo you listed, which means that it should have lower mass. This also should help the smaller turbine to spool faster. In this regard, you are correct that you cannot really compare A/R with turbines of different sizes. A larger turbine will take longer to spool, even if it has the same A/R as a smaller turbine.
I think the T3 with the A/R = .58 will spool fastest.
Based on my own experience with my Greddy's, I'm assuming that the back pressure will not be much of an issue at low rpms. Thus, at a given rpm (in the low rpm range) there will be roughly the same volume of exhaust gases flowing through each of the turbos. With the smaller opening, the exhaust gasses will be flowing faster, which will help the turbines spool faster. At the higher rpms back pressure will become more of an issue, thus inhibiting the exhaust flow volume and velocity to an extent, and thus turbine performance.
Also, the turbine is smaller on the last hypothetical turbo you listed, which means that it should have lower mass. This also should help the smaller turbine to spool faster. In this regard, you are correct that you cannot really compare A/R with turbines of different sizes. A larger turbine will take longer to spool, even if it has the same A/R as a smaller turbine.
05-26-2010, 04:52 PM
#266
I dont know if this was before or after the dyno... but like I told sasha , ive been hearing this weird sound.. coming from the middle of the car.. even when I put the silencer on... it was odd... the noise from the driver side was louder than the actual exhaust.. so I lifted the car back upp... and I see my driver side header ( not header gasket ) the bottom bolt, just completely missing... and the gasket burnt...
Went to buy a new gasket and bolt... but they were closed.. so I installed it anyway.. ( with a spare bolt, no gasket ) .. the noise was still there but not as loud... I went for a ride.. did 3-4 pul.. from a blink of an eye , I saw 6-7 psi..
I gotta install the aem electronic so I can see the numbers better.. the needle in the prosport.. sux
so we will see.. its kind of a good news.. I just have to wait and see what vince can do for me and reschedule for another tune. I got good feelings about it this time.
Last edited by Vas_Z33; 05-26-2010 at 04:53 PM.
05-26-2010, 05:04 PM
#267
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hmmm. boost leak!!!!! vas im gladdd it was such an easy fix if that indeed was the problem which sounds very much like it is!! i cant wait for your results!
05-26-2010, 05:08 PM
#268
they went over everything and smoke tested itI still feel like its dead on 1-2 gear... and doesnt kick in till like 5K... so its like in between.. I guess ill have to see
05-26-2010, 05:44 PM
#271
Guys, it's an exaust leak before the turbo, NOT a boost leak.
If the bolt fell out all together, it was not tight to begin with. So if it was there at the dyno, you would have still had a very bad exhaust leak.
Exhaust will go out through the path of least resistance. In this case, the exhaust was blowing out at the header, and never really reaching the turbo.
The T4 flange gasket was also missing at the dyno (not installed) this would have been another place for exhaust to leak before the turbo. When the T3/4 flanges get welded they warp just a bit. This is something that can not be avoided do to the heat needed to penetrate the 1/2" thick flange.
Either way, Vas has been a great customer and I am sure the results will come. Just have to the litle kinks out, after all, it is just nuts and bolts..
If the bolt fell out all together, it was not tight to begin with. So if it was there at the dyno, you would have still had a very bad exhaust leak.
Exhaust will go out through the path of least resistance. In this case, the exhaust was blowing out at the header, and never really reaching the turbo.
The T4 flange gasket was also missing at the dyno (not installed) this would have been another place for exhaust to leak before the turbo. When the T3/4 flanges get welded they warp just a bit. This is something that can not be avoided do to the heat needed to penetrate the 1/2" thick flange.
Either way, Vas has been a great customer and I am sure the results will come. Just have to the litle kinks out, after all, it is just nuts and bolts..
Last edited by Boosted Performance; 05-26-2010 at 05:45 PM.
05-26-2010, 06:29 PM
#273
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hopefully man.. I got my fingers crossed.. Vince will work his magic... I dont think this was at the dyno though.. because it would be very obvious they went over everything and smoke tested it
I still feel like its dead on 1-2 gear... and doesnt kick in till like 5K... so its like in between.. I guess ill have to see
they went over everything and smoke tested itI still feel like its dead on 1-2 gear... and doesnt kick in till like 5K... so its like in between.. I guess ill have to see
What do u mean by kick in at 5k? Full boost at 5k? Can't be right can it? Or is it jus cuz all the kinks arent worked out yet?
05-26-2010, 07:33 PM
#275
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our cars tend to be max tq around upper 4k lower 5k so that seems about right.
remember, he's talking about 4 psi here, 4psi takes all of about 2200rpm to build so he's all full boost well before 5k.
05-26-2010, 08:44 PM
#276
I took tomorrow off from work, and will finish redoing my pipng to fit the 6262 T4 in there (same turbo as Vas).
I will turn the BC off and see how things go, and then will add the BC if needed. This will tell me what Vas should be geting. The kits (my tomorrow and the one Vas has on) will be indentiacal to the last spec/detal, including the wastegate spring.
I will turn the BC off and see how things go, and then will add the BC if needed. This will tell me what Vas should be geting. The kits (my tomorrow and the one Vas has on) will be indentiacal to the last spec/detal, including the wastegate spring.
05-26-2010, 09:28 PM
#277
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the "kick" you feel isn't full boost on a car it's a spike in tq. depending on how it's tuned there could be a sharp increase in tq up at 5k so that would be felt more than when full boost came on.
our cars tend to be max tq around upper 4k lower 5k so that seems about right.
remember, he's talking about 4 psi here, 4psi takes all of about 2200rpm to build so he's all full boost well before 5k.
our cars tend to be max tq around upper 4k lower 5k so that seems about right.
remember, he's talking about 4 psi here, 4psi takes all of about 2200rpm to build so he's all full boost well before 5k.
I hit full boost at like 3.4kish or so..
05-27-2010, 01:51 AM
#279
I took tomorrow off from work, and will finish redoing my pipng to fit the 6262 T4 in there (same turbo as Vas).
I will turn the BC off and see how things go, and then will add the BC if needed. This will tell me what Vas should be geting. The kits (my tomorrow and the one Vas has on) will be indentiacal to the last spec/detal, including the wastegate spring.
I will turn the BC off and see how things go, and then will add the BC if needed. This will tell me what Vas should be geting. The kits (my tomorrow and the one Vas has on) will be indentiacal to the last spec/detal, including the wastegate spring.
