Yeah, you don't want to create a grenade engine. While Jag has sufficiently over-engineered everything to meet its reliability targets, it won't have gone overboard - you're just eating into the safety margin allowed. That's not a problem, but without knowing how big that margin is, going hung ho could be pretty expensive.

Plus, of course, you're not just dealing with the engine - the rest of the car has multiple brains that will try to hold it back if things exceed their operating limits. The transmission and the ABS/DSC module can tell the ECM to back off as part of their protection mechanisms. Having 700 HP is no use if the TCM keeps telling the ECM to reduce torque to avoid overloading the torque converter. The standard XKR converter had to be beefed up for the 75 and the R-S to reliably handle the extra grunt, which implies that running an XKR up to (say) 600 HP is going to put a lot of strain on the standard converter. Mind you, avos is running crazy HP in his X100 XKR, and that appears to have been reliable (different gearbox, though).

 

Just makes it all the more impressive.

I'm not all that familiar with the AJ133, but did Jaguar take a step backwards from AJ34 4.2L? The 4.2L has forged rods and pistons as stock and a very well built bottom end.

The 4.2 compression ratio is slightly lower than the 5.0 but I'm running 21psi with the twin screw with no problems.

 

I used milltek high flows...:got them from mike @ eurotoys...thats also where i got the pulley and the tune. Special thanks to mike @ eurotoys for the extra hp and great service.

 

Will be posting vids tomorrow...i will link all vids to this thread... Please remember the GT has the performance exhaust with a modified back box as far as i know since part # is different from standard performance exhaust. But i think the only real mod to it was to make room for rear diffusor. Sounded to me extremely similar to a standard rs if not identical before the install of the hfc's

 

I believe we topped out at 11lbs boost. And that was on the 2nd tune viezu sent to mike from eurotoys to put in my car. It was what they considered the most aggressive "safe tune" in there words and they weren't willing to send us anything more aggressive with out further action from us which i would assume would require some type of sign off from me regarding liabilities etc etc

 

Thanks for the back handed apology. I know your sour about something that happened between you and mike from eurotoys previously. Not sure what it was but people make mistakes. I know thats why you jumped the thread imho. The result is 550hp at the wheel on a car tuned by mike@eurotoys who now is currently the only person in the world to tune an xkr-s gt. My apologies avos

 

The funny thing was that I didn’t even read that the Tune was from Viezu (/sold via Mike), I was just interested in the dyno sheet. Only after you brought this whole thing up I noticed LoL. I am sure I could drink a few beers with Mike, but that doesn't mean that I agree with everything he does, thats it.

I also only later found on the pdfs that the environmentals where included on the 2nd page, and after converting them to SAE NET corrected, I am a bit surprised about the results to be honest as its different than I would have expected.

You can calculate it yourself, or you can just ask a re-print, then I would ask Mike to explain it.

And np, apologies accepted, it’s about sharing true experience/data that I appreciate here.

 

The engine is still beefy, 4 bolt cross drilled mains forged connecting rods but cast crank pistons. Since this engine is pretty square, meaning having a close to/or actual 1:1 bore stroke ratio the crank isn't overly stressed as it would be in a high stroke engine. Short stroke engines don't always need forged steel cranks to put out high number, unless your road racing and your engine is under constant stress for hours.

The part that is the unknown to me is the strength of the cast pistons. They are the ones that tend to deform and crack under high boost and pressure then boom. I know Mahle makes a great Hypereutectic cast piston that can withstand 20+ pounds of boost but the make up of that piston versus ours is where I'm not taking a risk. Realizing your up to 20LBS is very impressive and makes me feel good about the engine. I just need to know more about the internals before I feel comfortable going over ~14LBS.

On top of that with ~625HP I'm seeing cooling as an issue on the track. I've driven both stock XKR/S and my car hard on the track and in 15 minutes your in warm weather it get quite hot on a fast track. That last thing you want is a hot engine making tons of boost on a track.

I'm tackling cooling next and reliability next as I'd love to have a 700HP Jag

 

5.0 engine just needs better and bigger SC TVS1900 is made for moderate boost.

 

thanks Russ. I have listened to many exhaust variations on the XKs online. I myself had the stock XKR-S dynamic exhaust, a Mina exhaust and now a custom exhaust. So I am pretty sure I am very clear on how they all sound in comparison. I currently have the x pipe and straight through Magnaflow mufflers. I do not believe that any other system with any sort of muffler would be any louder than mine unless you run straight pipes. So I am very curious to see what the HFCs add. My shop would build me HFCs for about $700 with the cell configuration I want. I would like to hear some before going this route. I had bad experiences with MAF sensors on race cats in the past. I appreciate you sharing your experience with us.

 

I asked the shop owner/dyno operator why he uses uncorrected testing. He said that unless the conditions are severe (humidity, temperature) he does uncorrected testing to tell him what the car really puts down in his shop. He said he only cares about the before & after gains on his dyno.


I appreciate the opportunity to work on a special Jaguar. Russ and his brother Tony are great guys and have Jaguar blood running through their veins! Nice to see some real Jaguar enthusiasts!


BTW, Viezu did a great job, but I am glad that we all kept working at it to get a max aggressive "safe" tune.


Mike

 

just uploaded the vids to you tube




Here is the pre mod dyno run






here is the post mod dyno run. By the way the video does not do justice to what this car sounds like now in real life.








I have more vids that I will be uploading of pre and post runs. Just been a little busy at work today and not that much time to upload




And of the topic here is my 2010 xkr for comparison on dyno with milltek hfc's and quick silver supersport cat back exhaust

 

Thanks Big Mike. Working together was great and it was very nice to finally meet you in person.

 

$700 for a set of HFC's is good. Myself and Max may want to go in on a group buy. Will your supplier make 3 sets and discount the price?

 

Russduka,


Your car looks hot on the dyno. It's so hard to get a good idea of the sound with the HFC's. Recordings leave a lot to be desired compared to the live sound. Do you hear a different sound with the HFCs (louder, more after burn, more Ferrari like, etc.)? Any idea of what the HFCs contributed to over power gain? With your CF interior and power mods you have the hottest modern Jaguar in North America. Congratulations!

 

For 700 I'm in! I just can't justify the 2k for the Millteks.

 

Thanks,




Im not sure what they contributed If anything since we did all mods and ran on dyno after. But to describe the sound I would start with a base rs sound and make it slightly deeper and much louder. Pedestrians on the street were scared when I drove by if I leaned into the throttle. A car next to me couldn't believe the sound the car was making. Its worth the 2 grand alone on sound... it sounds that good. oh and we didn't lose any of the popping on lift off either. Maybe mike from eurotoys can chime in on this since he was in the car also after we took it off the dyno and went for a drive.

 

Is it really you who just typed this message above? lol. I couldn't justify it either when I bought them but they sure as hell worth it since I installed them. I would say go for it if you have the performance active exhaust. But that is with me assuming the gt even though a different part number on back box is still actually the same back box as the PAE. I really think the only change to gt box was for clearance on diffusor.

 

LOL yeah I've been going back and forth on the cats. I have an RSC exhaust and keep getting promised cats but it never comes through, so spending 2k when I might not have to killing me.. I want a little more volume and HP the cats provide, but free versus 2k is stopping me.

 

I'd love to see your XKR-S GT go up against a Nissan GT-R. The XKR-S GT with it's enhanced performance suspension and performance brakes with your tune should give the GT-R a good run. The GT-R has been loosing its edge against some new performance cars such as the Corvette Z06 and Camaro Z28. I sold my 2014 GT-R because of the cheap interior, rough ride, ugly looks and I had the opportunity to bank over $20K over a very short ownership period. I think your car against a GT-R on certain tracks will out perform the GT-R in the hands of a professional driver. Have you watched the youtube video "A leap forward for the cat". I think that is what they named it, featuring the XKR-S GT.


Comparable track times found here:


http://fastestlaps.com/tracks/willow...of_willow.html