Just a quick update... I've been putting some miles on the tune I installed without the pulleys and other than odd cold start behavior I've attributed to carbon buildup on the intake valves, it's been smooth sailing. As I said before, Mike is a great guy to work with. So, I'm moving forward with the install of the hard parts on Friday. I expect 6-8 hours of leisurely wrenching. Since CeeJay has the same year xkr with just an xpipe and nearly identical mileage we're going to throw his on the dyno for the baseline and then pop mine on there for the comparison. Yeah, totally not scientific at all, but logistics prevent back to back runs on the same car, so it's better than me just saying it feels faster.

Stand by for first impressions Friday and/or Saturday. The dyno will be at a later date.

 

While the upper pulley is baking, it's time for a mid-operation post. Nothing but smooth sailing so far. Here's a couple pictures of the cuts I had to make with a Dremel using a 1.25" cutting wheel. Where I deviated from the directions was that I didn't remove the radiator fan. And while the upper pulley clearance tool spun without any issues, I did touch the gusset on top with a file because it was REALLY close. Installing the uper pulley is basically a one shot deal, so I wanted to make sure there was just a bit more room.






Time is almost up, so I'll post back when everything is in.

 

....... and I missed all of it.
Dang grandkids anyways.

Once you've got all this under your belt (and it makes a noticeable difference) I'll have ya do/help on mine.

 

What is the reason these pulleys are not keyed with a light press fit and a front bolt.

 

Dumb question but what do the cuts accomplish? Do they relieve hub stresses on the shaft or cut off something that's not in the pics?

 

Jagtoes- I would imagine that the extra machining processes required to cut keyways, taper the shaft and thread the end and the associated operations to the pulley would be cost peohibitivery when you can just heat up the pulley and slide it on. Interference fit can transmit a tremendous amount of power and if I recall, the R1900 only requires something between 20 and 40 hp to turn at full blast.

Ranchero- it just loosens the grip of the pulley on the shaft. I tried pulling it off without cutting it and bent up the pulley pretty good:


That was my "well, I'm committed now" moment.

CeeJay- you got it, bud.

OK, fellas... time to get back out there and finish up.

 

OK but no big deal on the pulley as you don't need a taper and just a simple broaching operation for the key way in both the pulley and SC shaft. Also a drill and tap of the shaft front is a simple operation. No problem and considering the cost of the upgrade it wouldn't be an impact. Looks like you didn't use the correct pulley puller . Lucky you got it off.

 

That's interesting. Usually to release tension on an excessively tight shaft we'll drill some small holes parallel to it in the hub.

 

^^^^^ That's the way I usually do it.

 

All righty... everything is back together, no leaks, coolant has been burped... time to go see what "630+ HP" feels like. Death or glory, gents. Death or glory.

 

WHY haven't you updated yet? It's 2-1/2 hours later, for criminy sake!

 

One of the things that impresses me about the XKR is the duality of its personality. Around town, it is refined, reserved, dignified and composed, and about as modest as you can get given the overall package and what it is. But when given a hot supper, it just explodes. You guys know what I mean.

My fear with these parts was that it would diminish the pleasant, non-threatening drivability that we all so enjoy. Being able to go fast in a fast without trying is one thing, but being able to go slow in a fast car without trying is another.

I am very pleased to say that these parts have not changed this aspect of the car at all. If anything, it feels smoother. Throttle response is better and there no longer feels like there's a disconnect between the pedal and the butterfly. It idles far smoother, it has a more sewing machine feel as it moves through the rpm range, and is just overall a more enjoyable experience. But I didn't do this to drive around town stuck behind the vast sea of amorphic blobs clogging our roads...

Dynamic mode on, TRACdsc selected, dial in Sport, and here... we... GO!

This thing f'in' RIPS. Good god damn, does this thing tear through the rpm range, grab the next gear and keep going. The thrust it produces is absolutely relentless and builds with each gear change. The only other vehicle that I've experienced this from was a Ducati Panigale. The mountain torque is just massive, and every bit as accessible as the car you know and love, but there's so much more of it. In fact, that's a good single word description. More. It's still an XKR, but it's an XKR with the dial cranked past 11 and is set somewhere around 14 or 15. It's more. A lot more.

We have some dinner guests arriving soon, so I have to cut this short, but I'll post up my thoughts and observations on the install later.

In short, this was worth every penny and every minute spent on the purchase and installation. If you want more- a LOT more- but don't want to destroy the personality and character of the car, get this stuff. It is so, so, so worth it.

 

So, from reading the SOTP results I'd buy this product just for the enthusiasm. Smiles trump dynos, like it.

 

All right... as for the install of the parts, things were pretty straight forward, no surprises.

Doing the crank pulley will go a lot easier if you have a helper under the car to help guide the T47 torx bit on to the bolts, to help hold the wrench against the bolts, and to hold the strap wrench to hold the crank pulley still while you turn the wrench from above.

And while Mike was right that you can do the heat exchanger from below, unless you have the car way in the air, it will be difficult to get to stuff. For the home gamer laying on his back with the front of the car on jack stands, take the extra 15 minutes to pull the front bumper off. It will give you far better access to the bolts holding the heat exchanger and ac condenser in, and will make getting at the hoses so much easier.

Other than that, it wasn't that hard, but it's not for the beginner. Taking my time, it was about 12 hours. About half of that was the learning curve of figuring out how to get to stuff.
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Jagtoes- that was the correct puller; that's just how things go with these. There's a puller for the 4.2's, but the 5.0's have a different design so you just use a two or three jaw puller and if the pulley bends without coming off, you have to make the cuts.

 

Also see the new pulley is not ribbed so do I assume the belt routing has changed. Do you use the same belt or does it require a different one. Also did you replace the belt tensioner and pulley. If so do I assume this all comes in a kit.

 

That silver thing you see in the first picture is the go/nogo gauge to check for upper pulley clearance.

The belt that is supplied is longer due to the roughly 1/2" increase in diameter of the lower pulley and has a flat out side. The pulley that's changed is the lower fixed idler on the tension side of the loop between the supercharger and crank pulleys. Removing that pulley gives you a lot more room to work with when dealing with the crank pulley bolts, so it just kind of works out. I believe that if you leave the crank pulley alone and only do the upper, you reuse your existing belt. The tensioner and pulley were not replaced. They're so easy to get to, they're not worth doing as a while you're in there sorta thing.

 

Here's a bunch of words in a row about the bad stuff I experienced. As with anything aftermarket, your mileage may vary, so I say this only to pass on my personal first hand experience with these products in open honesty, and is no way an indication that you will have these same issues.

First, the tune only tune I was running for a bit before the hard parts went in ran great. Except for the cold start sequence. There was about a ten second window during the high idle where the engine acted like I was stabbing the gas pedal at random intervals and to varying levels of depression. We tried three variations of the tune and they all exhibited this behavior. Once the idle RPM dropped, the car was great and my previous posts reflect my impressions of just the tune alone. In speaking with Mike, we concluded that decarbonizing the intake valves would probably (but not definitely) eliminate this issue because the behavior was very similar to a cold start misfire caused by carbonized valves. There was also a very slight random miss at idle in gear when warm but the car did this since day one for me, which I also attributed to carbonized valves. On nothing more than a hunch and out of curiosity to see what would happen, I pressed on with installing the hard parts and uploading the final tune before going in to decarbonize the valves. A side note- when I was in there back in September to do the SC torsional isolator, the valves had some carbon on them, but weren't bad and nowhere near the horror show that the German marques experience so I didn't clean them then mainly due to a lack of time available. Anyway, back to this thread... After installing the hard parts and uploading the final tune, both the cold start issue and the idle in gear miss went away completely. During our shakedown ride yesterday, a good bit of time was spent idling- maybe a total of 30 minutes during a 2.5 hour drive- and not once did it miss. I've never felt this car idle so smoothly and is very close to how smoothly an inline six ticks over. So, while I do fully understand the carbon on the valves won't fix itself, it is not nearly as imperative as I thought. Will you have this problem if you go tune only? Well, Mike said he hadn't had this issue with anyone before, so I suspect it may have just been my car being stupid.

Current issue: Using the go/nogo gauge to clearance the supercharger snout, I filed a small section down. Not because it hit, but because it was VERY close and I wanted to make sure the pulley would fit. Once the new pulley was on and cooled off, it rubbed very, very slightly for about 20° worth of rotation. When I say very slightly, I mean that pinching the pulley between my index finger and thumb, I could still rotate the pulley through this interference with very minimal effort. I worked it back and forth in this area for a bit and it seemed to self clearance, so I figured it'd wear in and I ran with it. No sounds, no metal shavings anywhere after the 2.5 hour drive, everything was fine. I went out to start it today and there's a pulley/belt squeak coming from somewhere. I've yet to get my stethoscope out and see exactly where it's coming from so it may be unrelated to the upper pulley. I'm going to email Mike about this as soon as I finish this post and will update this with where it goes. If I have to cut this pulley off and do some more clearancing, and buy another upper pulley then so be it. I figure at this point, a new Eurotoys pulley is orders of magnitude cheaper than a new snout/pulley from Jag.

Overall, I consider this issue very minor and am still at a loss for words at just how GOOD this car is now. I mean, just... damn, is it good.

Further observations:
-Max boost is 12 PSI. Mike said he sees 18 PSI, but he's at a much lower elevation than me.
-AFR at WOT is 11.2:1. There's still more HP to be found by leaning it out a bit and getting the boost up to where it'd be at a lower elevation, but I'll take that margin of safety over absolute numbers any day.
-0-60 is no quicker than stock due to wheel spin through 2nd and a bit into 3rd gear. That's not to say the car is slower below 65ish MPH than stock; rather, it is quite a bit more responsive and playful and the power delivery is much more accessible, but when matted, the wheel spin negates any power increases. I blame cold Michelins and cold pavement. I expect the times to come down when things warm up this spring because when it does find traction, hooooooooly crap, does it squat and go.
-I suspect there may be some adjustments to the transmission map because when driven hard or in any mode other than just Drive or Winter, it shifts quicker and harder. Transmission behavior while driving like a normal person is just as buttery smooth and invisible as what you're used to.

 

It will be interesting to see the dyno before and after numbers look like. Especially the Torque numbers. Good show and good luck.

 

I'm conflicted on focusing on dyno numbers only because of how difficult it is to get a good read from these cars. IE- the transmission will still downshift if you go WOT too early and as far as I'm concerned, unless you're WOT for the whole pull, the data is only good for peak and/or top end figures. It will never give you an accurate depiction of the true area under the curve. But, as I promised- I'll throw it on the dyno right after CeeJay runs his when he and I can get the planets to align.

 

Surging sounds more like it was trying to go closed loop too early.

Clearancing the pulley can be done with sand paper wrapped around the pulley. Start fine and work your way up as the clearance grows.

Per performance difference, maybe a do a locked in 4th 60-110 mph WOT sprint. Should show an improvement without blowing the tires off. If it does spin, try 5th or 6th.