Only upper pulley is done, I do also have a larger intercooler (both according to a Jag indy), k&n filters, an H pipe and no backbox.

But when they interrogated the car it was running the stock map. When I had it dyno'd it was running below stick at 493 at the front end. Everyone on this and another forum said that even with the standard map I had to be making above stock..it wasnt feasible that it wouldn't be.

But one thing to note on mine, the dyno operator ran on a transmission loss of 18%, which is standard for most automatics, hence the reason for worse performance if there is a manual derivative with the same engine. I've read quite a few posts that on our cars (IIRC) the tranny loss is between 9-11% as it's quite slick. If that's the case I am making above stock.

I didn't go down the remap route and went for a transmission flash, a pedalbox and a power unit, conservatively it they will give me a max of an additional 35 bhp and 50nm of torque.

But based on what some seem to be saying on this thread, 'a mechanically modified car without a tune won't be any faster or have a higher performance numbers'.

Or have I got the wrong end of the stick/dial?

 

Heard they were good

 

I live just outside Windsor but originally from just north of TO. Coincidentally Budds sold my xkr to a previous owner , I have just had it six months now.

 

I don't know why Stuart making these misleading posts, but he is both correct and missing the point. He said peak boost - and in that he is correct, peak boost will not change in absolute numbers, but it will happen earlier, at lower RPMs, and would result in a leaned mixture throughout RPM range with a stock map.

 

Correct ^ ^ ^ ^ ^ ^ ^ ^
Regardless of any pulleys, the supercharger itself is only capable of pushing so much air, and it is already very close to Max with the OEM setup.
One thing that would help is to remove the blower and related to have it ported and gasket matched. Help how much? Who knows, but at least SOME.
Other than that, get an 'identical' blower that has higher numbers.... I think a Corvette one? I'm not sure, but there is one somewhere I believe.

 

What little you gain down low might actually get hurt up high form parasitic and efficiency looses.

 

Hi SinF,

I'm not making misleading posts at all, or certainly not deliberately. It was just a simple observation that peak boost would be unchanged. Which is correct. Yes, you would see a small amount increase in boost at lower RPMs.

However, you would 100% not see a leaner mixture. Firstly, at lower RPM the car is running in closed loop, and would try to remain in closed loop for as long as possible. What that means is that it is targeting a particular Lambda value, 'checking it's work' to verify that it is producing the targeted value and adjusting fuelling to achieve this. It's possible you could add so much boost that the injectors just couldn't add enough fuel but you would hit overboost codes and/or limp mode for a variety of reasons long before that and it probably isn't even possible to generate enough fuel demand to max out injector duty cycle at low RPM.

When the car transitions to open loop fuelling around 3000RPM, it is no longer 'checking it's work' but is instead running off reference tables. It is fuelling the car based on what it assumes to be correct values but not checking delivered AFR to verify. However, this isn't like the old days of carburetors. The reference tables are still based off of MAF measurements, which means that the ECU is still metering fuel based off of measured Air Mass (using those reference tables.) So even if the bypass valve was jammed open, it's not just throwing the amount of fuel the car needs at OEM boost levels without measuring anything it is accounting for the air mass it actually sees and fuelling based on that. It's somewhat of a Moot point because on an OEM map you wouldn't see any additional boost in closed loop anyway.

Finally, even if you somehow managed, at lower RPM to achieve a leaner mixture in closed loop, there's no reason that would continue into the upper RPM in open loop.

 

At lower RPM, yes it will generate additional boost. However if you read my above post, it explains why the fuelling will not necessarily be wrong. Certainly, with that much additional boost it's possible that the timing curves would require some alteration, although that would usually be seen around peak torque generation or at the very least higher up in the RPM range. The ECU will still pull timing if it detects knock. I would still not suggest any significant amount of hard driving with both pulleys and an OEM map, but one needs to understand that much of what the ECU is doing is not fixed, but is adaptive based off of measured data like MAF, MAP, IAT, etc. etc.

 

I wrote something else originally but it wasn't quite accurate. Chris corrected me. Yes it's still vacuum controlled but it's still operating off other engine data.

 

@R Bhal

Any news on your build?

 

So much great info in this thread.

 

Yikes!I heard tunes can be very bad if you don't retune the whole car,but i don't think it's that bad sense it's the same engine.But i do know this for sure that you're going to have to remap the whole car into the SVR specs and pretty much turn it into an SVR in order for the engine to work properly and be in sync with the transmission or else it's just gone ruin other engine parts that were working perfectly fine at 1st.But it shouldn't be too far off to fix the car with the SVR engine

 

Engine grenading on these cars most likely has nothing to do with the tune, but then again not all ECU tunes are the same. We have several 5.0 cars for several years now running hard , tracked and pushed and with over 700hp ,no issues and no transmission remap...

 

I'm not really sure what you mean by 'remap the whole car into the SVR specs.' The XKR platform never used the Bosch MED17 ECUs, they stayed with Denso because they knew they were phasing out the XK so the car was never converted to Bosch Electronics. When you say 'retune the whole car' are you talking about converting the engine to run on Bosch ECU? I've never heard of that being done, that's an OEM engineering platform level undertaking and would require all sorts of other sensor and electronic parts to be changed and massive, massive amounts of work to get them all talking to each other correctly.

So what do you mean by 'pretty much turn it into an SVR' what parts and/or electronic changes are you talking about?

 

I was talking about the entire engine itself.I don't get too much into details cause idk enough about all that at all to really speak on it,but i do know that you gone have to make the car run the same way the SVR does in order for the engine to work properly cause it's not an XKR-S engine any more once you do a whole engine swap.If that tune not setup right with gearing ratios and so on where people think everything is fine once they do an engine swap and that's it,be stuck wondering why their car catch on fire,blowing it up, transmission gets blown,etc.That's what i was told by a mechanic.You gotta make sure that whole car runs according to the way the engine was made if you want to use just the stock power from it.Idk too much about getting extra horsepower from it.That's a risk all on it's own right there that a true professional have to do for you if you really going for that and want it to work right unless you cool with it breaking down all the time

 

A 5.0 litre SC JLR engine’s the same across all models and platforms since 2010 other than minor production revisions discs such as the infamous timing chain and tensioners. Doesn’t matter if it’s from a Land Rover Range Rover or an XJ or an F-type. The difference’s with the ECU - X150 Denso vs everything else with Bosch.

 

Not quite right, the 2009 - 2011 XFR had the Denso ECU and I think the XJR as well before they all switched to the Bosch ECU for 2012.
And yes the basic engine is exactly the same from 2009 to current except for a few relatively minor changes (if you can call redesigned timing chains, tensioners and guides minor!) such as an electronically controlled SC bypass valve vs vacuum actuated and plastic coolant pipes vs alloy. In all cases the only real difference is the ECU tune, ranging from the first 2009 XF SC with 470 hp (I think!) through to the F-Type SVR and now R with 575 PS, with the current F-Type P450 (450 PS) being the "odd man out" for being a detuned version.
And don't forget the Project 8 with 600 PS although that had a different air intake system.

 

Sorry you misunderstood, I specifically said the 5.0 litre engine. I then referenced the ECU differences between Denso and Bosch fitment in my last sentence.

.

 

is that hood decal stock or did you have it made? I like it.

 

It's custom, Jag only offered that on the RS-GT