APEX'iEvoIV

My HTA Green failed recently and after inspection at a local turbo company they told me it failed because of lack of airflow, I have a HKS mushroom pod filter with the "racing" element and a 3 inch custom intake pipe with no MAF.

Turbo was purchased new in nov last year and has only been raced once (when it blew)

I have the oil feed line and the oil used was penrite HPR 15-60 'full zinc'

I am told 2 things:

1: The HKS pod doesn't flow well
2: The 3 inch intake pipe is too small

I have been running it at 30psi made ~460whp 400ftlbs atw on E85

filter



more or less the intake set up



turbo damage




I would like oppinions/facts on should I replace just the filter with K&N or BMC larger pod or replace that and the intake pipe with larger diameter

akeric

iTrader: (2)

the only fact I can give you is that a 3" intake pipe will support 700 or more hp, I would doubt that your pipe is to blame and the only way I would blame your air filter is if it was not filtering properly. Most turbo failure are lack of lubrication.

APEX'iEvoIV

Yeah I was a bit dubious on the intake pipe size, the filter, more than a few have said they are a bit ordinary so might be wise to replace regardless, I have the FP oil line fitted and the motor had plenty of oil which was fresh for the event unles I was getting oil surge issues on track.

I will be having the heavy duty thrust bearing fitted on the rebuild and will be running the Racing 10 tenths penrite oil as it has a higher zinc content than the HPR line

the shop told me the bearing had worn and moved blocking the oil feed which was caused by the pressure put on the thrust bearing from the compressor wheel trying to ingest air but not being able to.

94AWDcoupe

iTrader: (125)

strange the turbo didnt have the large thrust bearing. no way it could live with stock thrust at 30psi. it was destined to die early.

APEX'iEvoIV

Yeah the shop it is at now will be fitting the larger thrust bearing

rick1024

iTrader: (7)

wow another fp failure. wtf.

RSMike

iTrader: (1)

+1

there isn't even the extra oil lubrication holes drilled in the thrust plate.
wtf

sparky

iTrader: (1)

Are you running the stock oil pan at the track?

sparky

iTrader: (1)

Was the turbo purchased directly from Forced Performance?

sparky

iTrader: (1)

Did you install the turbo yourself, or did you outsource the installation? I am wondering whether the person installing the turbo "primed" the turbo, lines and filter with fresh oil? Or whether there exists the possibility that the turbo, the feed line and the oil filter were dry and that the engine was started up without pre filling the above with oil?

Just wondering as the 15W motor oil is relatively thick and the thrust bearings may have been starved upon initial startup after the turbo install if the lines and filter had not been pre filled with oil.

sparky

iTrader: (1)

Journal bearings operate in the boundary regime(metal to metal contact) only during startup and shutdown. More precisely, during these two events, shaft speed is insufficient to permit the formation of an adequate oil film. Hence, it is during startup and shutdown when almost all of the damage to the bearing occurs.

The viscosity of the lubricating oil chosen is critical because it directly impacts the oil film thickness between the shaft and the shell. The bearing's shaft and its shell have an almost eccentric relationship due to rotational characteristics of the journal bearing. There does not exist a complete and constant axial concentricity of rotational motion between the shaft and the shell. This is especially evident during startup and shutdown.

Furthermore, too high a viscosity can contribute to oil cavitation. If too high a viscosity of oil is chosen, this increases the likelihood of cavitation due to the creation of high and low pressure zones on either side of the area of minimum oil thickness where the shaft is closest to the shell.

More precisely, cavitation is a result of the expansion of dissolved air in the low pressure zones of the bearing. The resultant air bubble implodes causing damage as it passes through the high pressure contact area of the bearing directly below the shaft.

Bibliographical note: Textual material paraphrased from the article, Journal Bearings and their Lubrication, by Robert Scott, in The Journal of Machinery Lubrication(Noria Publications).

EvocentriK

Why do FP turbos need the larger thrust bearing to survive high boost when BBK Fulls with stock MHI CHRA's can do 30+ psi?

Regardless, that would be the first failure Ive heard of directly attributed to a restrictive air filter. Look at all the people running stock airboxes and making decent power as an example. Maybe its possible I dont know, just an odd thing IMO.

94AWDcoupe

iTrader: (125)

obviosly sparky has never taken a turbo apart. I have a hundred times. there is always plenty of oil on bearings and thrust. the bearings and thrust do not wear at all during start up. the oil does not drip off either at shut down. there is always plenty for a restart. and at idle the turbo isnt spinning fast enough to hurt itself.

sparky

iTrader: (1)

Quote:

Originally Posted by APEX'iEvoIV

My HTA Green failed recently and after inspection at a local turbo company they told me it failed because of lack of airflow....

I am told 2 things:

1: The HKS pod doesn't flow well
2: The 3 inch intake pipe is too small

.....I would like oppinions/facts on should I replace just the filter with K&N or BMC larger pod or replace that and the intake pipe with larger diameter

[QUOTE][/QUOTE]

I think that the local turbo company is blowing smoke rings out their yazoo. This issue is due to inadequate lubrication. It is due to the use of the too small thrust surfaces and inadequate oil supply passages, and or the use of a too high a viscosity oil and/or improper priming and initial "dry" start up of the turbo. It would be interesting if FP could do a failure analysis to determine the cause of failure.

sparky

iTrader: (1)

FYI, I was taking turbos apart when you still needed to climb up on the kitchen stool to steal cookies out of the jar.