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greddy t78 turbo, no rotation at 700rpm?


Spoony

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hi

my greddy t78 doesnt make any rotation in lower rpm´s.

when i push the gas a little bit, its starts, but not when its under 900rpm.

 

i know its a big turbo and it doesnt have bb, maybe a problem with my oil pipes, or is it normal??

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I have been in one t78, it had nothing until 4k at which point the gates of hell opened. My opinion was that it was undrivable until you get it on boost, they was no gradual feed in and no power at all when under 3k. It was the only one i have been in though.

 

the new bb singles seem to have very gradual and low end spool by comparison.

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could i replace the turbo with another one without changing the downpipe?

 

for example if i would go for a gt40 dbb, would the downpipe still fit???

i would prefer to sell the car instead of removing or installing this downpipe again!!!!! :rolleyes:

 

which turbos do fit without welding or changing the downpipe?? its a t4 flage and a 4 bolt exhaust side

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It may produce no power till 4,000 but it still spins...

 

It takes a fair amount of exhaust gas energy to get the turbo spinning, the bigger it is the more it takes.

 

I would imagine the behavior of your turbo is normal.

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to modify a downpipe isnt as much work as you would think

 

i can modify the downpipe very easy, its the removing and installing that im afraid of :D

 

its much easier with a german car, but my jspec has the damn steering wheel on the wrong side. i had to remove a lot of parts until it was possible to get the downpipe and wastegate in the car

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could i replace the turbo with another one without changing the downpipe?

 

for example if i would go for a gt40 dbb, would the downpipe still fit???

i would prefer to sell the car instead of removing or installing this downpipe again!!!!! :rolleyes:

 

which turbos do fit without welding or changing the downpipe?? its a t4 flage and a 4 bolt exhaust side

 

You would have to mod the downpipe as the T78 is 4 bolt fitment and the Gt40 is Vband also it would not meet up.

You would have to lift the turbo with a 10mm spacer aswell to stop it resting on the manifold and modify the intercooler pipework possibly, no big deal for any decent tuner.

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i think i will go for a kkk turbo next year.

a friend of mine knows the sales man from kkk.

he made a real low price for building a custom turbo.

they have some really good and new products, not so known like the garret turbos, but they can repair it really quick and cheap in germany

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Just looked at that vid and there is no residual spin there at all.. it looks stiff! I have a ball bearing turbo, and mine can spin for up to a minute after I have turned the car after idle.... is this normal for a journal bearing?

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it should still spin though? the T3 in my mini was wizzing its arse off at idle and that was/ is a big turbo for a 1293cc

 

is your waste gate closing fully? i could manualy open mine and that stoped it prety good;)

 

and like mike said the minis turbo would still be whining for 30-odd seconds after a good hard boot and shutdown, yours stops very quick

 

maybe you could idle it untill warm and feel the oil return pipe from the tubbie if its warm its getting oil;)

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I don't have any 1st hand experience with the older large turbo's, but every other I've seen (inc T67 & T71 journals) spin easily on idle. As you say the T78 and T88's are very old truck turbo's, but so are many of the turbo's used on 2JZ's

 

With the engine off, if you flick the compressor does it need any force to spin? Any sign of shaft play?

 

Might be worth splitting the cartridge from the exhaust housing to see if the turbine is still intack...

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If there is minimal shaft play and no sign of oil buring take a look at the turbine, the oil supply and drain don't need to be removed for a quick inspection.

 

If it's intact then you can say it's all okay :)

 

i think thats the best idea to make it sure. will do it tomorrow

 

thanks guys!!!

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