View RSS Feed

Today at Atelier Kaz - Private NSX Enthusiast, ex-Honda R&D engineer with F1, Indy/CART background

Brake OH, etc 12

Rate this Entry

As reported earlier, the battery holder was in wrong orientation as well as using the wrong tiedown point.
The holder nut was maxed out so not securing the battery properly and just sitting there.




The GND cable terminal was already overtightened many times and even someone placed a washer because of the damage to the terminal.
For now, I squashed the shape to get snag fit but next time, please replace the entire GND cable.

Now installed properly and the battery doesn’t jump.






The rubber seal at the rear IG coil cover was dislocated and allowed water to enter the area freely.
This is the marking of the water on the IG coil head.

The rust on #1 IG coil was severe. In fact, it already rusted the internal metal section as well.

At this stage, there is no misfire on this engine but if anything happens, I would fist replace the IG coils.
Fortunately, you can get all six 3pin style IG coils at really good price from US (about US$115 for all six, yes, not just one but six) so worth replacing if you experience misfire together with the spark plugs.

Just recently, I helped several owners with the misfire issue and all of them were fixed by replacing the 3pin style IG coils. One of them even didn’t trigger the CEL until the very last moment.




Bit of carbon observed at the insulator section close to the centre tip. With the CEL always triggered on this engine, the mixture is bit too rich.



I recommend all owners to take engine compression once a year to keep monitoring the health of their engine.
So, carried out the compression check and forwarded the result to the owner.

All six cyl data were within the window but #1 showed much lower figure than the rest of the cyl.
With VTEC engine, it’s hard to tell whether the cam timing is off or not by just the compression data.
The intake manifold pressure was very steady and idle rpm was very stable but again, that doesn’t 100% guarantee the correct cam timing on VTEC engine.

Having said this, #2 and #3 cyl (that are on the same rear bank as #1 cyl) showed exactly the same and high figure so probably someone touched the valve clearance when they didn’t need to.
I don’t touch my valve clearance for 60K miles or 10 years whichever comes first and I kept taking compression data every year over the last 21 years.



Went out for the test driving session.

As always with the new brake piston seals, you will get completely different pedal feeling.

This is because when the seal is new and piston moving freely, it will push back the piston a little when releasing the brake pedal. The next time when you apply the brake, you feel as if you have to press the pedal further (and it is indeed the case) before you can feel any pressure.
It’s not the spongy feel like when you caught air in the brake system but just extra travel. This is quite normal and one of the reason why I always recommend OEM service kit when refurbishing the callipers as there are lots of knowhow in the shape and the material of the seals that directly affect the pedal feeling.


As same as before the start of the service, felt the same feeling on the engine response. Typical DBW and LEV effect plus the continuous CEL won’t help the situation and with the aftermarket test pipe and back box, the exhaust flow speed slowed down so felt sluggish at low – mid TH pedal region.
The super dirty aftermarket air filter makes the things even worse.


Whenever making changes to the intake and exhaust area, it is very important to pay extra attention to the flow rate as a total package.

The pressure difference before/after the TH butterfly even at WOT doesn’t mean there is bottle nock at the TH body.
There are lots of patents around this area in predicting/measuring the amount of air entering the engine. Changing the diameter and length of the intake/exhaust system changes the flow rate and that directly shifts the torque curve.

Many people pay lots of attention to the max figure measured at the rolling road/dyno pack but these are normally only done at WOT condition and not the transient of going through the partial throttle that is more than 99% of the time used for the street driving condition. For me, rolling road devices are just a tuning tool and not for measuring the actual power of the engine.

The OEM exh manifold on NA1 or OEM header on NA2 looks like single tube structure but they are not.
They are twin tube structure so the actual pipe diameter is much smaller than they look.
If you use larger diameter pipe with certain length for the header, CAT, exh back box, you will loose flow rate and thus, feels slower at low/mid rpm region.

It’s similar to when you first drive OEM 16 or 17inch wheel on the rear and then jump into another NSX with aftermarket 18inch and carry out the same test launch sequence.
It feels much slower than the 16 or 17inch one. The acceleration is just not there.


The metal brake pad still makes some noise but it was much quiet especially when not applying any force to the pedal.


Cool down session and wanted to wash the car but there was no way doing so in this thunder and hail storm so washed the car the following day.


Thank you for using my service and we’ll keep in touch and plan for the next service as it’s best to replace all of the coolant hoses together with the TH body cleaning.



Time to work on the A/C CCU board and Bose AMP for several owners and garages before the next NSX shows up over the weekend.


Regards,
Kaz


Comments