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Ominous signs of GT4088R failure


jevansio
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Do you guys know how much water/meth you run, what setup are you using and what size jets.

 

Whats your peak EGT?

I run 100% water (my tank is alloy), I use the middle Aquamist jet on the 1S kit coming on @ 10 PSI. Peak EGT is 950 C in turbine housing (sustained 5th & 6th gear pulls on hot days), maybe around 900-925 C @ top of 3rd & 4th.

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bearing failure is IMO highly unlikely as if this were the case then the old UK death whine would be apparent in these turbos.

 

I think it must be to do with EGT's and the blades dimensions......its been commented on that the blades are thinner than other turbos.

 

The temperature the steel at the extremities of the blade will reach in a turbo with thinner blades, will be higher than a thicker blade (not sure how to quantify this difference) as the only way the steel can disipate the heat is (i think) via conduction through to the turbo shaft/oil/housing. Less material to flow the heat through will mean lower heat conduction away from the tips of the blades and therefore they run hotter.

 

'Perhaps' the tips are getting so hot that the combination of this ,the higher forces acting on the blades (high boost/rpm/flow) and the lack of material, causes the tips to 'yield' elastically and basically get folded/pulled off........

 

The point a metal will yield is a specific point (varying dependant on certain conditions) and could possibly explain how Charlie has escaped this by his meth setup lowering one of the factors a smidge over other setups?

 

When i talk of 'yield' i'm trying to remember stuff from lectures long ago (youngs modulus stress and strain etc etc!) most of which i've forgotten, but basically its where a material is subjected to forces which mean its deformed permanently. The blades of any turbo under will bend/give a little during normal use but will return to the exact same size shape after use as the stresses and conditions are below the point where the steel would yield.

 

 

Just speculation/theory though.........

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I run 100% water (my tank is alloy), I use the middle Aquamist jet on the 1S kit coming on @ 10 PSI. Peak EGT is 950 C in turbine housing (sustained 5th & 6th gear pulls on hot days), maybe around 900-925 C @ top of 3rd & 4th.

 

Do you know what colour ring it has round the jet?

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Sorry to hear about another one Jay :(

Still, its not just common to the 4088's... here's a recent picture of my t67, not looking too healthy.

This turbo has only seen 1.1bar and very little Wot on my car, maybe 5000miles, 98% being off boost motorway miles. I've not noticed any difference in performance, so i'm not in any rush to change it.

 

 

Dam thats not good to see, i was hoping this was just a 4088 problem, does explain why your car looked a little laggy in your dyno print, when my 4088 looked like that i lost 700rpm on my spool in top gear.

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From the top of my head I think it's green Wez, I'll have to confirm this when I see it again though

 

Green, really, green is only 0.5mm and 150cc/m.

 

Where is the jet mounted?

 

I am running a 0.7mm and looking to upgrade by adding another 0.7mm and a 0.4mm elsewhere in the system.

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I think I have asked this before, but never mind. Did these turbos come in Honeywell (Garrett) boxes, and from a Garrett authorised distributor? Or from Ebay? I will see if someone I know, who is independent, and maybe on of Europe's leading turbo experts, albeit an "old guy", can shed light on it. It's beyond my turbo knowledge, which is very limited. I rely on the "old guys" and never have an issue. Sounds damned odd to me.

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I was thinking this, countless tuning books say its unsafe after 1550-1600F, your running an extra 142F, that can't be good, question is how do you lower egt's? Pile on the advance, more water injection, higher octane fuel, I dont know? It would be a big drop

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Yeah I know :D, but it's in Garretts latest GT roller bearing lineup along with the well praised GT35R, GT42R etc, but we don't hear about those failing, I doubt Garrett would use a different design/material on a turbo in the middle of it's lineup, or maybe they would :), either way I migt just turn the anti-lag on this one for 6 months now & have some fun :D

 

That will probably end up finishing off your GT4088 Jevansio...:D

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Mine hasn't seen any high EGTs yet, (630c) perhaps mainly because i haven't had the chance to make any long full boost pulls, and i only run 0.9bar at the moment, but i am also running two 0.5 WI jets, one just after cold side of IC and one just before the throttle body, mapped by boost.

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Dam thats not good to see, i was hoping this was just a 4088 problem, does explain why your car looked a little laggy in your dyno print, when my 4088 looked like that i lost 700rpm on my spool in top gear.

 

Its the only conclusion i have come to with mine, it must have been like that when it went on, as it was 2nd hand (suprahumans), maybe he can shed some light as what sort of life it had on his car? Like i've said, it doesnt see hardly any action in my hands, no high egt's, and i've not noticed any difference's performance, lag, etc, wise since i've had it.

My manifold is also spot on, and there is very little likelyhood of debris coming from elsewhere as the engine is 5k miles old.

 

The turbo shown in my pic is a sound performance t67, otherwise known as a SPSSGT850W.

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Its the only conclusion i have come to with mine, it must have been like that when it went on, as it was 2nd hand (suprahumans), maybe he can shed some light as what sort of life it had on his car? Like i've said, it doesnt see hardly any action in my hands, no high egt's, and i've not noticed any difference's performance, lag, etc, wise since i've had it.

My manifold is also spot on, and there is very little likelyhood of debris coming from elsewhere as the engine is 5k miles old.

 

The turbo shown in my pic is a sound performance t67, otherwise known as a SPSSGT850W.

Marty, when you say low EGT's exactly how low?

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Green, really, green is only 0.5mm and 150cc/m.

Where is the jet mounted?

I am running a 0.7mm and looking to upgrade by adding another 0.7mm and a 0.4mm elsewhere in the system.

I'll double check when i get the car back Wez, I might upgrade to the next jet up in that case then.

 

The jet is mounted in the FMIC to Throttle pipe, about 6" from the throttle.

 

I think I have asked this before, but never mind. Did these turbos come in Honeywell (Garrett) boxes, and from a Garrett authorised distributor? Or from Ebay? I will see if someone I know, who is independent, and maybe on of Europe's leading turbo experts, albeit an "old guy", can shed light on it. It's beyond my turbo knowledge, which is very limited. I rely on the "old guys" and never have an issue. Sounds damned odd to me.

I didn't get it from Garrett Chris & it didn't come in a Honeywell box. It came from Precision in the US. I've emailed Garrett UK & they don't want to know unless it was bought from one of their authorised dealers :(

 

After reading that...rust scale - how's your manifolds boys??

My manifold is OK, (haven't read that link yet but will do at dinner time). My manifold is a Sound Performance item (basically a copy of the HKS one).

 

That will probably end up finishing off your GT4088 Jevansio...:D

No way :D, I'll take that job on :D

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IMO 950 is far too hot pre turbo. I work for an OEM doing calibration work on future engines and 850 degrees is the hottest we run without failure.

 

Try 850 degree port temp and see if the new one survives

 

Have you ever measured the difference's though when the sensor is placed 4" from the exhaust port and then inside the turbine housing of a turbo ;)

 

EGT sensors should be always be placed 3-6 inches from the exhaust port on the hottest known cylinder. With the 2jzgte No 6.

 

Taking readings from anywhere else is just pointless.

 

 

Ryan

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I didn't get it from Garrett Chris & it didn't come in a Honeywell box. It came from Precision in the US. I've emailed Garrett UK & they don't want to know unless it was bought from one of their authorised dealers :(

 

 

 

I think from that I would assume I had bought a cheap copy. If iI buy a Garrett turbo from say Turbo Dynamics, it comes in a Honeywell - Garrett box, with a Garrett core I/D tag, and a Garrett warranty.

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I think from that I would assume I had bought a cheap copy. If iI buy a Garrett turbo from say Turbo Dynamics, it comes in a Honeywell - Garrett box, with a Garrett core I/D tag, and a Garrett warranty.

I guess so :(, well I'm not falling for that one again, I'm going to destroy this turbo when I get the car back :eyebrows:

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