Compression test after 106.000 km

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20 January 2008
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704
Location
France
I did a compression test on my LoveFab turboed NSX today.
The idea was triggered after reading [MENTION=18194]Honcho[/MENTION]'s thread "Long road to Imola"( http://www.nsxprime.com/forum/showthread.php/207052-Honcho-s-Long-Road-to-Imola-Type-S-Zero/page12) as I couldn't quite believe the results with an average of 190 psi corrected for altitude at 230 psi or 16,16 kg/cm^2!
The Honda manual states 14 kg/cm^2...
The other reason for the test was to determine if I kept the turbo setup and continue attending track days or ...move to something else.
Well the result surprised me as the readings were slightly over 16 kg/cm^2 totally in line with what Honcho measured.
This is with an engine that has had the turbo setup for 25 thousand km and previously a CTSC supercharger for the same mileage.
Hats off to Honda's engineers specially when one knows about Porsche's issue with their IMS ( intermediate shaft) that caused many catastrophic engine failures.
Here's the article (in french) that explains the issue: https://911andco.fr/comprendre-solution-probleme-ims-porsche-911-type-996-997/
I will now have the valves adjusted and the timing belt changed along with a new water pump for a few more years of fun chasing the Porsches!
 
Last edited:
I did a compression test on my LoveFab turboed NSX today.
The idea was triggered after reading [MENTION=18194]Honcho[/MENTION]'s thread "Long road to Imola"( http://www.nsxprime.com/forum/showthread.php/207052-Honcho-s-Long-Road-to-Imola-Type-S-Zero/page12) as I couldn't quite believe the results with an average of 190 psi corrected for altitude at 230 psi or 16,16 kg/cm^2!
The Honda manual states 14 kg/cm^2...
The other reason for the test was to determine if I kept the turbo setup and continue attending track days or ...move to something else.
Well the result surprised me as the readings were slightly over 16 kg/cm^2 totally in line with what Honcho measured.
This is with an engine that has had the turbo setup for 25 thousand km and previously a CTSC supercharger for the same mileage.
Hats off to Honda's engineers specially when one knows about Porsche's issue with their IMS ( intermediate shaft) that caused many catastrophic engine failures.
Here's the article (in french) that explains the issue: https://911andco.fr/comprendre-solution-probleme-ims-porsche-911-type-996-997/
I will now have the valves adjusted and the timing belt changed along with a new water pump for a few more years of fun chasing the Porsches!

That is a fantastic result! Especially considering the boost + track running conditions of the car. You must have a great tune for that turbo. What oil are you running? Do you have the factory 3.0 head gaskets?
 
That is a fantastic result! Especially considering the boost + track running conditions of the car. You must have a great tune for that turbo. What oil are you running? Do you have the factory 3.0 head gaskets?
You are going to laugh... the turbo kit was tuned by Cody Loveland by exchanging e-mails.
I did 3rd gear runs from 2000 to 8000 rpm and sent him the resulting AFR chart.
After the third run it was done.
It's probably not perfect but the car starts easily and I also installed an independent AFR meter as a safety measure.
The AFR does dip below 12.0 at WOT but that must help the engine cooling.
The car is a 1994 model so it must have the improved head gasket I suppose?
I've owned the car for 20 years now and have always used Motul 300V competition 15W-50 oil.
 
Not really abnormal. An "off the shelf" turbo kit on a stock engine isn't going to require much tweaking car to car. He just started with a conservative base map and made a few changes based on AFR logs.

1994 uses the same crappy composite head gaskets. They didn't switch to MLS until 1997 with the NA2 model.

Sounds like you've taken pretty good care of the car.
 
Not really abnormal. An "off the shelf" turbo kit on a stock engine isn't going to require much tweaking car to car. He just started with a conservative base map and made a few changes based on AFR logs.

1994 uses the same crappy composite head gaskets. They didn't switch to MLS until 1997 with the NA2 model.

Sounds like you've taken pretty good care of the car.

I just read your thread on your engine rebuild... quite frightening and very courageous on your side!
BTW did you do a compression test before pulling the engine apart?
 
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