3.8 built ready
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Joined: Mar 2009
Posts: 726
From: beirut lebanon
Rep Power: 54
Normal IMO, you might hear the controled leak from the EBC to regulate the boost at it's target. (WG signal pressure is lowered, so the exceeding air goes in the atmosphere)
My today's tests demonstrate me my EBC is correct: even the solenoid bypassed with a simple "T" my effective boost exceeds the WG setting from about 0,3Bar, no leakage, all hoses new, zipped and well routed...
My conclusion is the Alpha's WG are a bit too small when they are used with a 3,8 kit and a real freeflow exhaust, and by winter with nice air density.
I finally setted mine to 0,9 and did some logs, sent to Todd.
The car is pretty strong, 100-200 in 5,5' with pumpgas, 2 persons in, but I need Todd's advice for the following...
My today's tests demonstrate me my EBC is correct: even the solenoid bypassed with a simple "T" my effective boost exceeds the WG setting from about 0,3Bar, no leakage, all hoses new, zipped and well routed...
My conclusion is the Alpha's WG are a bit too small when they are used with a 3,8 kit and a real freeflow exhaust, and by winter with nice air density.
I finally setted mine to 0,9 and did some logs, sent to Todd.
The car is pretty strong, 100-200 in 5,5' with pumpgas, 2 persons in, but I need Todd's advice for the following...
Registered User
Joined: Sep 2012
Posts: 1,215
From: Birmingham, Al
Rep Power: 118
The car has gobs of low end torque and it is significantly more fun
to drive when putting around without boost.
FYI We closed off the internal wg's on the alphas and went with a
pair of 50mm turbosmart units. And you are right, the internal gating
is insufficient if you're a high flow exhaust. (I'm running straight pipes)
And I ran 3.95 100 -200 kph
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Joined: Mar 2009
Posts: 726
From: beirut lebanon
Rep Power: 54
I have a 3.8 w/ alpha 3073 ( 3071 w/ 73mm wheel)
The car has gobs of low end torque and it is significantly more fun
to drive when putting around without boost.
FYI We closed off the internal wg's on the alphas and went with a
pair of 50mm turbosmart units. And you are right, the internal gating
is insufficient if you're a high flow exhaust. (I'm running straight pipes)
And I ran 3.95 100 -200 kph
The car has gobs of low end torque and it is significantly more fun
to drive when putting around without boost.
FYI We closed off the internal wg's on the alphas and went with a
pair of 50mm turbosmart units. And you are right, the internal gating
is insufficient if you're a high flow exhaust. (I'm running straight pipes)
And I ran 3.95 100 -200 kph
Registered User
Joined: Sep 2012
Posts: 1,215
From: Birmingham, Al
Rep Power: 118
gates were overwhelmed and the boost was all over the board until
we closed off the internal WGs and added the external setup.
And from what I understand, there's a marginal increase in power
as well.
IMHO the alpha series internal WGs aren't up for the task of a High
hp application with a super high flow exhaust e.g. straight pipes.
Thread Starter
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Registered User
Joined: Nov 2008
Posts: 833
From: France
Rep Power: 85
Welcome here Randy,
I follow your built for a while!
I'm glad you confirm my theorie: Alpha's WG are a bit small with 3,8 and freeflow exhaust...
I spoke about that with my friend Ofzky and he told me he had same issue in the past with his big K27 twin turbo built (as the CTR when worked by Ruf), WG became too small and boost hard to control.
He told me from the beginning my WG became too small...
I believe I found a good compromise yesterday, boost is well regulated @1,3Bar, no knocking, good timing etc.. (pumpgas)
If not enough I will use your idea and bolt external WG, internal ones locked.
Cheers
P.
I follow your built for a while!
I'm glad you confirm my theorie: Alpha's WG are a bit small with 3,8 and freeflow exhaust...
I spoke about that with my friend Ofzky and he told me he had same issue in the past with his big K27 twin turbo built (as the CTR when worked by Ruf), WG became too small and boost hard to control.
He told me from the beginning my WG became too small...
I believe I found a good compromise yesterday, boost is well regulated @1,3Bar, no knocking, good timing etc.. (pumpgas)
If not enough I will use your idea and bolt external WG, internal ones locked.
Cheers
P.
Registered User
Joined: Sep 2012
Posts: 1,215
From: Birmingham, Al
Rep Power: 118
Welcome here Randy,
I follow your built for a while!
I'm glad you confirm my theorie: Alpha's WG are a bit small with 3,8 and freeflow exhaust...
I spoke about that with my friend Ofzky and he told me he had same issue in the past with his big K27 twin turbo built (as the CTR when worked by Ruf), WG became too small and boost hard to control.
He told me from the beginning my WG became too small...
I believe I found a good compromise yesterday, boost is well regulated @1,3Bar, no knocking, good timing etc.. (pumpgas)
If not enough I will use your idea and bolt external WG, internal ones locked.
Cheers
P.
I follow your built for a while!
I'm glad you confirm my theorie: Alpha's WG are a bit small with 3,8 and freeflow exhaust...
I spoke about that with my friend Ofzky and he told me he had same issue in the past with his big K27 twin turbo built (as the CTR when worked by Ruf), WG became too small and boost hard to control.
He told me from the beginning my WG became too small...
I believe I found a good compromise yesterday, boost is well regulated @1,3Bar, no knocking, good timing etc.. (pumpgas)
If not enough I will use your idea and bolt external WG, internal ones locked.
Cheers
P.
The internally gated alpha series is ok if you don't push them but once you
start making real power, you're gonna have issues.
And yes, you need to go ahead and slap some tial or turbosmart WGs on
that baby right away!
Registered User
Joined: Sep 2006
Posts: 7,481
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k24 , so are you running the internal wastegates still? id so that is your problem , for setups like yours they are worthless, you need to switch to external wastgates.
i had a similar issue, im not running tial 50mm wastegates, with 1 bar springs.
i had a similar issue, im not running tial 50mm wastegates, with 1 bar springs.
Thread Starter
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Registered User
Joined: Nov 2008
Posts: 833
From: France
Rep Power: 85
I will see in the future, if not ok I will go to external WG, or swap the turbos to big boys already ext. WG fitted as GT35s!
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Joined: Apr 2006
Posts: 1,677
From: London (UK)
Rep Power: 156
I was looking into these.
GT3073hta 550bhp each turbo. We will fit a 73hta compressor wheel to the GT30 turbocharger. The GT3073hta with a 0.82A/R Tial v-band external wastegate turbine housing, because of the 73HTA billet wheel spool up will be vastly increased.
Registered User
Joined: Sep 2012
Posts: 1,215
From: Birmingham, Al
Rep Power: 118
Hey Randy, hows the motor going?
I was looking into these.
GT3073hta 550bhp each turbo. We will fit a 73hta compressor wheel to the GT30 turbocharger. The GT3073hta with a 0.82A/R Tial v-band external wastegate turbine housing, because of the 73HTA billet wheel spool up will be vastly increased.
I was looking into these.
GT3073hta 550bhp each turbo. We will fit a 73hta compressor wheel to the GT30 turbocharger. The GT3073hta with a 0.82A/R Tial v-band external wastegate turbine housing, because of the 73HTA billet wheel spool up will be vastly increased.
a thousand dollars! It is the exact same turbo and you need to address
exhaust manifold and add external WGs.
The 3073 spools like a small turbo but hits like a big boy! The 16 billets and
the alpha 28s ran out of steam up top. The 3073s pull HARD to 190 mph.
Admittedly, I have all custom plumbing with hard pipe to the intercoolers,
ported heads, 3.8 liter Ps and Cs, 74mm TB, big ic's, ProEfi / e85 etc....
so I'm maximizing there performance.
The car is an absolute monster and I'm not using monster turbos! It has
power everywhere. Turbo lag is imperceptible and even off boost, it's
strong!
Even in the first setting, 1 bar, my 0-60 is 3.3 seconds. I'm sub 3s in setting
3, 1.4 bar.
Registered User
Joined: Apr 2006
Posts: 1,677
From: London (UK)
Rep Power: 156
If I had it to do over again, that's what I would do. It would saved me
a thousand dollars! It is the exact same turbo and you need to address
exhaust manifold and add external WGs.
The 3073 spools like a small turbo but hits like a big boy! The 16 billets and
the alpha 28s ran out of steam up top. The 3073s pull HARD to 190 mph.
Admittedly, I have all custom plumbing with hard pipe to the intercoolers,
ported heads, 3.8 liter Ps and Cs, 74mm TB, big ic's, ProEfi / e85 etc....
so I'm maximizing there performance.
The car is an absolute monster and I'm not using monster turbos! It has
power everywhere. Turbo lag is imperceptible and even off boost, it's
strong!
Even in the first setting, 1 bar, my 0-60 is 3.3 seconds. I'm sub 3s in setting
3, 1.4 bar.
a thousand dollars! It is the exact same turbo and you need to address
exhaust manifold and add external WGs.
The 3073 spools like a small turbo but hits like a big boy! The 16 billets and
the alpha 28s ran out of steam up top. The 3073s pull HARD to 190 mph.
Admittedly, I have all custom plumbing with hard pipe to the intercoolers,
ported heads, 3.8 liter Ps and Cs, 74mm TB, big ic's, ProEfi / e85 etc....
so I'm maximizing there performance.
The car is an absolute monster and I'm not using monster turbos! It has
power everywhere. Turbo lag is imperceptible and even off boost, it's
strong!
Even in the first setting, 1 bar, my 0-60 is 3.3 seconds. I'm sub 3s in setting
3, 1.4 bar.
It will be something for the future aye.
Die-ing to see some more vids of your car in action!
Last edited by GTRNICK; Dec 16, 2013 at 05:34 PM.
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Joined: Sep 2009
Posts: 2,658
From: GTA, Ontario, Canada
Rep Power: 236
I never get tired of seeing awesome vid clips like that. When you see how quickly you pull away from traffic it really gives the proper perspective of the amount of power you have. Congrats!