Leak Down Results

[writeoff]

Awhile ago my the ceramic exhaust wheel on the rear turbo in my R32 GTR shattered. The pieces ended up in the cat but I had a leak down test performed to check the engine. These are the results:

1989 R32 GTR ~109,000km

Cylinder 1: 5%

Cylinder 5: 4%

Cylinder 3: 10%

Cylinder 6: 7%

Cylinder 2: 12%

Cylinder 4: 5%

Is there anything there I should be concerned about that needs further investigation or can I go ahead and begin the power upgrade to HKS GTSS or N1 turbos, dumps, PFC, 700cc injectors, AFMs etc?

Also do NISMO AFM need the adaptors like the Z32 ones do? Being fitted to HKS pods.

Thanks

David

[Just Jap Racing]

Awhile ago my the ceramic exhaust wheel on the rear turbo in my R32 GTR shattered. The pieces ended up in the cat but I had a leak down test performed to check the engine. These are the results:

1989 R32 GTR ~109,000km

Cylinder 1: 5%

Cylinder 5: 4%

Cylinder 3: 10%

Cylinder 6: 7%

Cylinder 2: 12%

Cylinder 4: 5%

Is there anything there I should be concerned about that needs further investigation or can I go ahead and begin the power upgrade to HKS GTSS or N1 turbos, dumps, PFC, 700cc injectors, AFMs etc?

Also do NISMO AFM need the adaptors like the Z32 ones do? Being fitted to HKS pods.

Thanks

David

Hi David,

Nismo AFM's are a straight replacement for your factory GTR AFM's and will work with a factory airbox and your HKS pods.

Cheers,

Steve

[CruiseLiner]

thats a very healthy motor from my understanding anything under 15% leakage is good condition

[wrxhoon]

Awhile ago my the ceramic exhaust wheel on the rear turbo in my R32 GTR shattered. The pieces ended up in the cat but I had a leak down test performed to check the engine. These are the results:

1989 R32 GTR ~109,000km

Cylinder 1: 5%

Cylinder 5: 4%

Cylinder 3: 10%

Cylinder 6: 7%

Cylinder 2: 12%

Cylinder 4: 5%

Is there anything there I should be concerned about that needs further investigation or can I go ahead and begin the power upgrade to HKS GTSS or N1 turbos, dumps, PFC, 700cc injectors, AFMs etc?

Also do NISMO AFM need the adaptors like the Z32 ones do? Being fitted to HKS pods.

Thanks

David

Are you sure the rear turbo let go? From the results it looks like the front let go, cylinder 2+3 have the most leakage. Have you done a compression test as well?

Anyway its a healthy engine, I would go with the mods you want to do. Nismo AFMs are a straight fit .

Edited February 9, 2007 by wrxhoon

[SteveL]

10% leakage is quite common on a production engine and personally I wouldn't get too concerned about 12% either. For a properly built racing engine <5% is regarded as acceptable, but around 2% is the practical ideal.

[writeoff]

Are you sure the rear turbo let go? From the results it looks like the front let go, cylinder 2+3 have the most leakage. Have you done a compression test as well?

Anyway its a healthy engine, I would go with the mods you want to do. Nismo AFMs are a straight fit .

It was definately the rear turbo. Thanks for your responses guys. Now I can order the parts... Yay!!!!

[wrxhoon]

It was definately the rear turbo. Thanks for your responses guys. Now I can order the parts... Yay!!!!

If thats the case by the look of the results you don't have any damage from the turbo.

[Jordan]

Whats the difference here when you talk about leakdown test, as opposed to a compression test (ie;, how is it measured, and what does it signify?)

[wrxhoon]

Whats the difference here when you talk about leakdown test, as opposed to a compression test (ie;, how is it measured, and what does it signify?)

Different tests dude, comp test gives you the actual pressure when the piston compresses the air when it comes to the top on the compression stroke. Its done with a compression tester and masures in PSI, bar etc...

Leakdown test is done pumping compressed air in the cylinder via a leakdown tester with exhaust and inlet valves shut it will give you a%in lost pressure, anything under 5% is very good, over 25% and the engine is stuffed in most cases ..

[CruiseLiner]

hey jerry is it possible for a comp test to show everything is fine and a leakdown to show otherwise? so say im checking for a broken piston etc and the comp test is perfect, would the leakdown tell me anything the comp test cant?? i realise if the comp test is bad then leakdown helps to detect the exact problem area but would u say its safe to say a comp test that is perfect means the motor is fine?

sorry for the long rambling post but im just wondering

[wrxhoon]

hey jerry is it possible for a comp test to show everything is fine and a leakdown to show otherwise? so say im checking for a broken piston etc and the comp test is perfect, would the leakdown tell me anything the comp test cant?? i realise if the comp test is bad then leakdown helps to detect the exact problem area but would u say its safe to say a comp test that is perfect means the motor is fine?

sorry for the long rambling post but im just wondering

If you have busted ringlands a comp test will show it as very low comp , depending on the crack .

You can have an engine with perfect comp say 160-170 on all cylinders but worn ( evenly) rings or even a just built engine built with big clearences , wrong rings , big ring gaps etc.... This is what a leakdown test will detect as high % leakdown. The engine will run well obviously because you have good and even compression.