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Discussion Starter #1
Ok just a bit of background.

Took my car to a mechanic shop, they are pretty reputable. Anyways I had a S8G transmission installed which is supposedly a JDM transmission from a del sol (shorter gear) than my previous cx transmission.

First question: would a shorter gear transmission push the point of my max boost up into the higher rpms? For example, before I would acheive full spool at around 3200rpm.. now I dont see full spool until late 4000ss like 4500 to 4800...

Second part: My idle is fine, so I do not think there are any boost leaks.

No smoke out tail pipe either..

I do have a oil restrictor on a -3an oil feed line. and I was told that by having this restrictor my turbo, this would cause oil starvation at the turbo.

So my main question here is when I am looking around the engine bay, what signs or things should I focus my attention to, to get an understanding why my car is spooling later than normal.


Engine is
d16z6
vitara h beams
T3 50 trim volvo turbo
 

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I was told that by having this restrictor my turbo, this would cause oil starvation at the turbo.
then take off the restrictor! if the turbo is getting too hot, then the internal bearings are getting too hot and slowing the turbo down and not allowing it to spool correctly.
 

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Why would you restrict oil to something? Especially a turbo.

If you know it causes oil starvation, than you should know that it doesn't need to be on there. Proper lubrication causes less friction. And we all know that the more friction you have, the more resistance you have. Try driving with your handbrake on, then drive with it off. It is much faster with it off. No? Friction.

Oil starvation = friction = wear and tear = slower spool

Properly oiled turbo = less friction = less wear and tear = faster spool.

This may not fix your problem, although it may. But it will definatly save you in the long run
 

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the restrictor is there so you dont blow the seals on the turbo, because some honda oiling systems have 100+psi on start up. its about noot ruining your turbo when you start it
 

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Oil restrictors are commonly used on Honda setups due to the high oil pressures these motors run. I've got well over 40psi by 3000rpm and 85+psi at redline. That's a crap ton of oil pressure that can blow seals in the turbo, and that's why I run a restrictor. Many people run oil restrictors without issue.

How new is the turbo? Could be wear and tear, they don't last forever.
 

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Discussion Starter #7
the thing is, like 2 weeks ago i had no problems its just after the transmission install.
I would think there is no correlation to transmission and spool...

Would I have to drain my oil to remove the restrictor?
 

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the good rule of thumb for oil pressure is to have 10 psi per 1K rpms. does this always happen? no, but its a good rule of thumb. i wouldnt run a restrictor unless it is called for from the manufacture.

you should not have to drain your oil to remove your restrictor, just depends on what all you have to take off and where it is located.
 

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No, just raise the line and let gravity do it's job.
 

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wtf guys?

It has nothing to do with the fucking restrictor, the turbo doesnt need hardly any oil, he probably SHOULD have a restrictor.

A shorter gear transmission WILL make the turbo spool slower because it is not creating as much load.
You had a CX trans before which is long as shit. I dont know what you have now but coming from a tranny that long I wouldnt be surprised to see a dramatic change in spool time when comparing gear to gear.

This is why youre supposed to make your spool measurements in the gear that is closest to 1:1 and youre supposed to start at low RPM.
Im constantly seeing people say "oh well I have 12 psi by 4k rpm, etc, etc"
That means NOTHING. The gearing, vehicle weight, aerodynamics, and temperature will all effect load and spool time.

qqq, there is nothing wrong with your car.. Youre better off having shorter gears and slower spool than shit gears and fast spool.
 

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wtf guys?

It has nothing to do with the fucking restrictor, the turbo doesnt need hardly any oil, he probably SHOULD have a restrictor.

A shorter gear transmission WILL make the turbo spool slower because it is not creating as much load.
You had a CX trans before which is long as shit. I dont know what you have now but coming from a tranny that long I wouldnt be surprised to see a dramatic change in spool time when comparing gear to gear.

This is why youre supposed to make your spool measurements in the gear that is closest to 1:1 and youre supposed to start at low RPM.
Im constantly seeing people say "oh well I have 12 psi by 4k rpm, etc, etc"
That means NOTHING. The gearing, vehicle weight, aerodynamics, and temperature will all effect load and spool time.

qqq, there is nothing wrong with your car.. Youre better off having shorter gears and slower spool than shit gears and fast spool.
:werd: Probably a heavier flywheel(if you're running a lightweight one) would help out with the spool "issue", but it wouldn't make it the same as the longer transmission.
 

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wtf guys?

It has nothing to do with the fucking restrictor, the turbo doesnt need hardly any oil, he probably SHOULD have a restrictor.

A shorter gear transmission WILL make the turbo spool slower because it is not creating as much load.
You had a CX trans before which is long as shit. I dont know what you have now but coming from a tranny that long I wouldnt be surprised to see a dramatic change in spool time when comparing gear to gear.

This is why youre supposed to make your spool measurements in the gear that is closest to 1:1 and youre supposed to start at low RPM.
Im constantly seeing people say "oh well I have 12 psi by 4k rpm, etc, etc"
That means NOTHING. The gearing, vehicle weight, aerodynamics, and temperature will all effect load and spool time.

qqq, there is nothing wrong with your car.. Youre better off having shorter gears and slower spool than shit gears and fast spool.
^^ this is EXACTLY it, couldnt have said it better myself Tilt
.... although you should still listen to everyone else about getting rid of the restrictor.
 

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Its a steel ring. As long as there is a oil return line big enough to handle how much is comming out, everything will be fine.
Uh. No. You seriously haven't read the recommended pressure or flow rates from Garrett or any other manufacturer. Heck, many turbos come with built in restrictors!

the thing is, like 2 weeks ago i had no problems its just after the transmission install.
I would think there is no correlation to transmission and spool...

Would I have to drain my oil to remove the restrictor?
So, someone is starting to wake up to the fact that different gearing puts different loads on the engine.

You're car is accelerating faster because of greater torque multiplication. That generally means less load on the engine, and since turbos respond well to load, and the engine isn't "working" as hard to move the car, your turbo will spool differently. This is usually evident with turbos that have larger turbines or higher turbine A/R housing. Smaller turbos are less effected because the mass flow and energy from the engine at lower speeds is still enough to spool the turbine well.
 

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^^ this is EXACTLY it, couldnt have said it better myself Tilt
.... although you should still listen to everyone else about getting rid of the restrictor.
I could be wronmg about the restrictor. Ive always known people to run them, even though I have personally run without them with no ill effects.

But yah, the gearing is 100% the cause of this change. I looked into it and that S8G trans is pretty short, I looked to be similar to an EX.
Going from a CX to an EX is a massive change in gear ratio from gear to gear
 

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Discussion Starter #16
I recently found out that I have a bent CV shaft. Should I look at getting this repaired/replaced asap? what symptoms does a bent cv shaft give off when it gets worse?
 

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Discussion Starter #17
:werd: Probably a heavier flywheel(if you're running a lightweight one) would help out with the spool "issue", but it wouldn't make it the same as the longer transmission.
running a stock flywheel
 

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Discussion Starter #19
The car was tuned with a cx transmission. From my limited knowledge with eCtune, you can choose which Transmission is in the car before tuning in the ectune base map creator... Does this effect the base parameters of the tune? and would re-tuning the car with the shorter gear transmission yield any noticeable benefits?
 

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Discussion Starter #20
i know I am going to get trolled hard for this, but after the transmission install I have a zing type of vibration (metal on metal) around 3k rpms.. any idea what to zone in on when searching the engine bay?
 
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