Starting to give the Evo a bit of attention this winter...other mild projects are on-going.

Fresh Motul 660 fluid...young assistant participated in both pedal pushing and bleeder zerk manipulation:


We also bled the clutch system...a bit darker than expected...also found the slave assembly loose! Will surely work better now!:


We also located and received a new old stock HKS Super Drager cat back exhaust! Was supposed to be the 'ONE' to get in the day...:


Nice Japanese detail...nope, it is spelled as "Drager":


4.5 inch tip!


Coming off the 3 inch cat...goes to 2.5 inches...hmm. We may attempt to grind in a bevel to at least smooth the flow a bit vice the ledge!:


And the muffler internally...2.25!


The main reason for a switch is drone on the highway for the custom 'quiet' system. It will make you lose your hearing! It hangs down a bit, but it is lightweight and is a full 3 inch. This 2.5/3.0/2.25 system will certainly be quieter...we hope to not decrease its thrust too much. We may be adding another item to the car to offset this...more to follow (Forced Performance, comes to mind...)

 

I finally took the plunge to downgrade the Evo...smaller (2.5 vs 3 inch), heavier (12 pounds), HKS Super Drager exhaust...in hopes to quiet the cabin levels especially at cruise. I'm surprised the weight gain is minimal considering the heft of the pipes and substantial muffler. I did note the 3 inch catalytic converter to cat back system of 2.5 inch won't be great for flow. I attempted to smooth the flow using my trusty dremel by grinding a 45 degree tapered funnel. I think I only succeeded in covering myself in metal shards and slivers...I just don't learn! Slivers that penetrate the Mechanix gloves and you feel them (ouch!), but can't see! At least I will be able to sleep at night it isn't a .5 inch wall reflecting the gas flow back up the downpipe...


And seems to fit like a Japanese parts does with OEM rubber mounts:


Once the weather warms up, crossing our fingers it passes both the Germany exterior noise and the American interior noise!

 

Well, one step forward and one step backward...wide band O2 sensor is hard into the floor pan. I was confident I could source a right angle adapter to make the car driveable, but...no. Adapter doesn't fit anything...


So, Super Drager exhaust will come off and the custom UK unit will go back on...to get the car inspected and possibly the next upgrade (boost!). We'll have to figure out if another option for the cat as well. The O2 sensor will be relocated (new bung welded), but the current setup of three different aftermarket pieces aren't working well together...and lets the system hang down excessively.

 

Man, that is annoying with the wideband sensor... Was looking forward to hearing that HKS. I had it on my old honda and it sounded amazing.

 

Agree! It is what you get with aftermarket parts, etc. We will overcome in time...until then back to the hipo exhaust and...Post man delivered a fun box...



And a matching exhaust manifold:


Nicely gasket matched porting and coated:



Again, the idea was to use this Force Performance 71HTZ turbo to offset any loss the quieter exhaust may cause. This 'hybrid' turbo combines the original hot side of the OEM Evo 9 turbo (housing) with this larger cold (compressor) side. Supposedly, this will allow a bit more boost and more topend power. Just what a new driver needs! Spa has a long straight uphill...so we need to give her the tools to perform!

All seem high quality and hoping it is a bolt in with existing OEM connections (air intake, exhaust, coolant and oil lines). We will have to redo the tune and we hope to get it on a dyno for a final power number. With the existing 3-inch (loud) exhaust, it should be a bit more lively!

 

New Rival +'s installed...and off to Spa!

 

A lap around SPA is definitely a bucket list item for me!

Thanks for sharing

 

That looks like such a good time! Driving your own build on such a legendary track must be amazing.

 

Completely agree! Even better is the young assistant that did most of the work - took the wheel for a session! It was unfortunate that the day ended early...but no sheet metal was scratched! We will go back to this track...I certainly hadn't run it to my comfort level. Car handled quite well!Update: It has returned! But not to home where we can diagnose...truck is too big! Quite a vehicle!


A few parts have arrived as well:


OEM harmonic balancer is no longer available...fortunately, Fluidamper offers a solution.

 

Well, after a month enroute...the Evo has returned to the home garage...


All wheel drive cars on lowered tire pressures sure don't like to roll!

Time for the disassembly...

 

Well, we may be down for a bit...dug into the car... At Spa, the engine turned off as soon as I got off the throttle at 7000 rpm to brake on the main straight. I didn't notice as we were downshifting from 4 to 2nd...but no power as we rounded the corner to accelerate. During trouble-shooting, we noticed the engine didn't seem to turn over smoothly - like one cylinder had 'compression'? Well, it wasn't compression, but...

Harmonic balancer separated and departed the car:


Serpentine belt shredded and entered the lower cam timing cover...jamming the gear and jumping a tooth:


All 16 valves are now bent when the cam and crank went out of sync:


But the worst part...one valve bent such it broke a portion of the valve guide...which entered the combustion chamber and jammed between piston and head several times...


The head is likely repairable, but the seats will need replacement (along with one guide) which makes finding another head cost effective.


The pistons on the other hand...I'd be happy to run it as it except the #1 piston that has a dent. We are not experienced engine builders, but it seems likely the top piston ring is pinched in vicinity of the dented piston area. However, we are not in a good position to pull/rebuild the engine right now...so we are going to plop another refreshed head on it and run it over summer! Ugh...not looking forward to the installation...All because of a 28-year-old harmonic balancer...still don't know where it went!

 

Wow, that sucksssss. Given your situation, finding a bare long-block might also be something to consider, even bringing one in from Japan.

 

Well, we are going to run it as...with a replacement head. No time to optimize...but this winter may offer an opportunity for a full refresh...At least it was a good story..."There I was at 7 grand on front straight passing a GT3 RS when engine destruction"...(true!)

Thanks for the comment and suggestion!