Same WG,differant ci,turbo,cam,lower boost??
07-01-2011, 06:00 PM
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Same WG,differant ci,turbo,cam,lower boost?? So I have put about 1000 miles on my new setup up so far to break it in. Tunes at speed inc next friday.
Same tial 50mm wg, same tru boost controller and settings as last year running a 347 with a tc78. Off the gate I would get 8lbs, off max setting 15.5psi.
I have a very safe base tune and I went wot for a short amount of time just to make sure im getting good boost before the tune.
Now with the same ls6 intake, same ported 241s but with a 232/236 cam insted of a 224/226 cam both a 115s im only getting 5lbs off the spring and 9.5 at max setting.
this is using a 370ci motor and a 80/79 billet wheel ball bearing comp turbo with a 1.32 ar.
Is this normal? It pulls really hard,feels smooth, just not nearly the boost I was running before.
Alex
Same tial 50mm wg, same tru boost controller and settings as last year running a 347 with a tc78. Off the gate I would get 8lbs, off max setting 15.5psi.
I have a very safe base tune and I went wot for a short amount of time just to make sure im getting good boost before the tune.
Now with the same ls6 intake, same ported 241s but with a 232/236 cam insted of a 224/226 cam both a 115s im only getting 5lbs off the spring and 9.5 at max setting.
this is using a 370ci motor and a 80/79 billet wheel ball bearing comp turbo with a 1.32 ar.
Is this normal? It pulls really hard,feels smooth, just not nearly the boost I was running before.
Alex
07-01-2011, 07:57 PM
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More ci consumes more air. The turbo is flowing the same amount but theres more area to fill so the boost(restriction) is lower. I bet the power is around the same or even more.
07-01-2011, 08:45 PM
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No the gate gets it source from the turbo, gauge is off the manifold. Same as the last setup. I know there could be a differance but with the tc 78 and 347 last year it would be right at 8lbs off the spring.
07-01-2011, 08:50 PM
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First thing I would do is adjust the plumbing so the gate and boost gauge are off the same source. Tie the gauge into the gate line off the compressor. I would suspect you will find that the gate is regulating to the 8 pounds, but that you potentially have a boost leak. I'm not quite sure what else would do something like this.
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07-01-2011, 08:59 PM
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I was thinking that there is a 3lb differance between what comes directly off the turbo compared to that actually gets to the intake. Ill try a boost leak test first.
07-01-2011, 09:09 PM
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It is possible that there is a major pressure drop. Regardless it seems as though the gate is doing what it's suppose to. It'll be interesting to see what you find. Good luck.
07-02-2011, 07:05 AM
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i noticed the same things, If i referenced my compressor housing for ANYTHIING it started ready boost early.
ive also got a An ebay IC, which is what i blame it on.
ive also got a An ebay IC, which is what i blame it on.
07-07-2011, 11:22 PM
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Ok, checked for boost leaks. Found a small one from a pipe to the ic. Fixed it, checked and cleaned all my plugs.
Same thing,i have a aem tru boost,i turn it to off which is the waste gate spring and I only get 5.5lbs. Its an 8lbs spring.
It pulls hard for being on a safe break in tune. Gets to 5.5 almost instantly also.
What else could it be?
Same thing,i have a aem tru boost,i turn it to off which is the waste gate spring and I only get 5.5lbs. Its an 8lbs spring.
It pulls hard for being on a safe break in tune. Gets to 5.5 almost instantly also.
What else could it be?
07-07-2011, 11:33 PM
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reference your wastegate from the manifold and i bet your back up to 8 ps.
The back pressure dynamics of the different engine /turbo combo are effecting when the gate opens, you likely have more backpressure in the downpipe than you had before with the smaller cubes.
The back pressure dynamics of the different engine /turbo combo are effecting when the gate opens, you likely have more backpressure in the downpipe than you had before with the smaller cubes.
07-08-2011, 11:11 PM
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Ok referenced the gate to manifold with similar results. I get 6 maybe 6.2 off the spring but only 10 off the setting that got me 15.5 last year with smaller turbo and engine.
I wonder if somthing is going on with the waste gate.
I wonder if somthing is going on with the waste gate.
07-09-2011, 07:22 PM
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Had a mate having similar issues, he had to have 20lbs spring to make 10 lbs boost.
He built a bigger downpipe and exhaust, and straight away was overboosting and had to add a second wastegate to control boost creep.
How big is your downpipe and exhaust , is wastegate plumbed back or do you run a screamer pipe ?
He built a bigger downpipe and exhaust, and straight away was overboosting and had to add a second wastegate to control boost creep.
How big is your downpipe and exhaust , is wastegate plumbed back or do you run a screamer pipe ?