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I supported Toymods
Location:
Northern Beaches
Registered:
May 2002
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1g boost after new cooler
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Thu, 16 September 2004 08:10
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Hi,
I have just got a new intercooler put on. 450x300x70 with 3inch inlets and outlets.
Now with the old 1g cooler I use to get between 11-12 psi on low boost, im now getting about 14.
I use to run high boost at about 14.
My question is can I now run higher boost because of the intercooler without the turbo's shitting themselves?
I have heard about 14-15 is about the max for 1g turbo's, is this the same case with what I have described above?
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Location:
South Eastern Subs
Registered:
March 2004
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Re: 1g boost after new cooler
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Thu, 16 September 2004 08:26
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I also want to know this as i just brought a HKS GA70 Supra cooler??
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Location:
sydney
Registered:
September 2004
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Re: 1g boost after new cooler
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Thu, 16 September 2004 09:17
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not sure how it goes with toyotas but with nissans getting a new cooler not only improves performance by allowing u to run more boost, but having the same boost but a more "efficient" boost..
so u can have ur car running fast at the 12psi, but get it faster with the SAME boost, with a new and better cooler its a colder 12psi...
i guess the limitations on ur turbos will depend wether or not they can hold it...
i hope im making sense...
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Location:
Inside a giant turbo (syd...
Registered:
June 2002
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Re: 1g boost after new cooler
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Thu, 16 September 2004 10:31
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its most likely because there is less pressure drop across your intercooler, so running at your low boost now gives you 14psi pressure reading at your manifold as opposed to a lower reading from before because there is a lower pressure drop across the better intercooler... that means you can run more than 14-15psi which was your high boost setting because it will now be around 17psi... if you understand? or i could be speaking out of my arse again... 
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I supported Toymods
Location:
Northern Beaches
Registered:
May 2002
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Re: 1g boost after new cooler
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Thu, 16 September 2004 10:40
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yes I have the same theory as you
thats why I asked cos I don't want out of the arse talking like im thinking hehe
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Location:
sunny coast, qld
Registered:
October 2002
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Re: 1g boost after new cooler
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Thu, 16 September 2004 10:58
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it is now my turn to speak out of arse 
I was under the impression that turbos die because of too much heat or too much speed eg. fitting a better flowing dump pipe is supposed to increase turbo life. Going by that reasoning I can't see how the "safe" level of boost could change is the intercooler cools air after the turbo and therefore will not be reducing the heat near the turbo.
Also, a point to note is that my old 1g-gte turbos died at 11psi so...?
Luck of the draw I reckon
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I supported Toymods
Location:
Northern Beaches
Registered:
May 2002
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Re: 1g boost after new cooler
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Thu, 16 September 2004 11:30
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considering stock the gen3 1g's run 11psi or something like that I would say you had some duds 
mine have been going fine on 12 with occasional 14 for 9 months now
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I supported Toymods
Location:
Plumpton/sydney
Registered:
November 2003
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Re: 1g boost after new cooler
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Thu, 16 September 2004 13:49
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I have been running my boost at 17psi from day one with no probs hopfuly with the new cooler instaled I can put it up to 20psi or more
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Location:
Perth
Registered:
July 2004
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Re: 1g boost after new cooler
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Thu, 16 September 2004 14:09
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Is it something to do with real and apparent boost? you have decreased the restriction in the intake side of things where now 14psi of boost can flow to your engine easily. before you were getting the pressure drop.
If you were to increase the max psi with a free flowing intake it would mean the turbo's would have to spin faster to make the real say 16psi of boost?
I think this is why large port rotaries can get high hp on low psi levels. The real psi levels are an accurate reading of what boost is actually getting into the combustion chamber not just the build up of restrictions hence creating the apparent boost.
Someone can prove me wrong im sure...
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I supported Toymods
Location:
Northern Beaches
Registered:
May 2002
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I supported Toymods
Location:
Perth
Registered:
May 2002
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Re: 1g boost after new cooler
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Fri, 17 September 2004 02:22
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| Supralux wrote on Thu, 16 September 2004 22:09 |
I think this is why large port rotaries can get high hp on low psi levels. The real psi levels are an accurate reading of what boost is actually getting into the combustion chamber not just the build up of restrictions hence creating the apparent boost.
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Rotaries make a MASSIF amount of exhaust gas, and hence can run bigger compressors without being laggy and therefore make more efficient boost.
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Location:
south east - melbourne
Registered:
March 2004
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Re: 1g boost after new cooler
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Fri, 17 September 2004 02:53
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GUYS THINK ABOUT IT PROPERLY , just because u getting more boost now doesnt mean u can run more without stuffing the turbo up
remeber the more boost u run the more u turbo will have to spin to get to the required amount of bost u have set on the car so getting an intercooler is not actually helping u turbo , but helping u engine as the air getting to it is cooler than before . but the turbo with the new intercooler is now working more harder than before to get the increased level of boost
so in actual fact bigger intercooler = more cooler air to the engine and more strain on the turbo as it has to now make more boost cause the new intercooler is less restrictive than th stock one , same thing for dump pipes it increases flow thereby making the turbo spin faster so more boost
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Toymods Vice President
Location:
Sydney
Registered:
May 2002
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Re: 1g boost after new cooler
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Fri, 17 September 2004 03:00
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Real and Apparent boost, you say.
The reason why this situation happens is that we are taking two pressure measurements at two different locations of the system.
Your boost guage is connected to the intake manifold, this means that the air pressuring your boost guage has to make it's way through all of the restrictions in the system. The wastegate on the other hand is generally plumbed straight into the compressor housing so it measures boost before any restrictions.
What does this mean?
Lets say we've got a "10psi" spring in the wastegate. The wastgate will always open when the turbo is making 10 pounds of boost. Now if we have an intake tract that introduces 3psi of pressure drop then your boost guage is going to read 7psi. Reduce the restriction of the intake tract between the turbo and the plenum and you will see the boost level at the plenum increase.
As to the limits of the turbines, I believe this is more to do with turbine rpm than actual pressure levels. In your situation the turbine speed at the after modification low boost setting should be roughly the same as it was on the "before modification" low boost setting.
Whether you should run more boost now would be dictated by your supply of replacement turbos in my opinion.
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I supported Toymods
Location:
Perth
Registered:
May 2002
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Re: 1g boost after new cooler
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Fri, 17 September 2004 03:04
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| indian wrote on Fri, 17 September 2004 10:53 |
GUYS THINK ABOUT IT PROPERLY , just because u getting more boost now doesnt mean u can run more without stuffing the turbo up
remeber the more boost u run the more u turbo will have to spin to get to the required amount of bost u have set on the car so getting an intercooler is not actually helping u turbo , but helping u engine as the air getting to it is cooler than before . but the turbo with the new intercooler is now working more harder than before to get the increased level of boost
so in actual fact bigger intercooler = more cooler air to the engine and more strain on the turbo as it has to now make more boost cause the new intercooler is less restrictive than th stock one , same thing for dump pipes it increases flow thereby making the turbo spin faster so more boost
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dude, you think about it. You measure boost at the plenum. The intercooler is in between the plenum and the turbo. You're making 14psi (for example) at the plenum. Stick an intercooler with less restriction in it. The turbos are working just as hard, not harder. There is less restriction between the turbos and the plenum, hence the higher measured pressure.
You are running more boost, but the turbo isn't as restricted and as such more boost reaches the plenum. The colder air is a by-product.
The dump pipe helps the turbo spin freely on the exhaust side, so there is less resistance there, hence making it easier for it to spin and thus not working as hard to produce a given boost level.
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Location:
Perth
Registered:
July 2004
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Location:
Brisbane
Registered:
May 2002
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Re: 1g boost after new cooler
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Fri, 17 September 2004 04:34
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Shaft RPM is an important factor when determining the reliability of a turbo, but heat is a major factor - and in the case of turbos, heat is roughly proportional to power output. If you try to jam 300hp worth of exhaust gas through those tiny exhaust housings, I think it goes without saying the temperature will go through the roof. As with most mechanical components, excessive heat = component failure.
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Location:
Melbourne
Registered:
March 2003
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Re: 1g boost after new cooler
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Fri, 17 September 2004 11:41
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More power through the increased cooling efficiency of the new cooler. Colder air produces more power from combustion than hotter air. So its thermal efficency, which also means that the air is condensed (as cold air takes up less volume), prior to the reading of boost at the plennum. Pressure drop is a result of pipe constrictions, and bends and temperature drop. THe more bends the more pressure drop. The smaller the pipe the higher the pressure, but make the pipes too large and velocity drops!
It seems that to keep pressure up after the intercooler a small reduction in pipe diameter to the plennum is the answer.
That is 3" pipe going into the cooler and a 2 1/2" pipe from the cooler to the plennum. I don't have the figures to back this up, its what i have been told by reliable sources.
I agree, heat kills turbos!
Boost is worth it!!!
Friday night drinks, hope it makes sense
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