Hello, I bought a 2003 X308 XJR with the R1 package a few months back. I'm on the process of rebuilding the engine and I thought this is a perfect time to tweak her up.

Is it possible to run the UK powerhouse lower pulley which adds about 4-4.5lbs of boost and a 6% upper pulley which adds about 1-1.5lbs of boost? Other further modifications I will be adding is a intake/cone filter and a better intercooler pump.

I been in the Mustang scene for quite a while and I know the cobra guys usually port the supercharger to prevent further heat soak and they have hand tuners that can adjust the fuel trim, air trim, and timing. From my understanding our lovely Jaguars don't have any sort of a tuning programmer and relay on the MAF and ECM to make the adjustments automatically.

Any suggestion would be helpful. Thank you

 

The only thing that i can tell you is that when running both upgraded lower and upper Eurotek pulleys, I was getting pinging/detonation.
Went back to the stock upper and everything is fine.
Could be california gas?. I don't know

 

Running both pulleys will give you heat issues for sure. I'd stay with just the lower and port the eaton. You can get a tune also after you're done with modifications

 

Most people that have done it seem to find that the Jag M112 supercharger doesn't get nearly the benefits from porting that the Terminator Cobras did. It seems to be worth a LITTLE bit, but not much, and not really worth the effort or cost. One thing you may consider though is putting on the X350 XJR's Gen5 Eaton in place of the Gen3 that came on the X308. The Gen5 blower has better outlet port shapes and doesn't fall off boost as badly on the top end, and has MUCH larger rotor bearings, so it will be a lot more durable. I did it on my 2000 XJR, and it pulls harder on the top end and IATs seem to be lower. It wasn't hard to do, and if anything the bigger bearings give me a lot of piece of mind.

The Jag computer adapts surprisingly well to extra boost without tuning changes as the stock tune is VERY conservative, as it runs very rich in stock form, giving you room to lean it out with more boost. But there is a limit, and it seems to be about an extra 4-5 lbs. After that it's getting outside of it's ability to compensate and will start running lean. This is exacerbated by the X308's marginal cooling capabilities. The 308 doesn't get rid of heat very well (small frontal opening, super densely packed radiator area, tight engine bay with bad flow through), so the additional heat strain of the extra power/boost really taxes the system, and the hotter you run the more likely you are to detonate. I know Eurotoys offered tuning in the past, so he could probably play with the trims and get it set back up, and you can do a few things to these to increase the cooling capacity, like the bigger intercooler pumps and intercooler radiators. But without tuning and cooling mods, I'd stick with one pulley or the other.

 

I would strongly recommend against doing both pulleys because without having a larger MAF, ported TB and elbow, and ported blower, it will get very hot working too hard to try to blow through a bit too small a hole. The extra power will be wasted/consumed by the blower.

Instead I would absolutely do the intake tube, since it is the best bang for the buck, the lower +4 pulley only and for $358, you can install the water/meth injection which will not only give you the extra required octane you will now need from more boost, it will cool the IATs 50-70 degrees, AND, if you inject before the TB, it will give you +1 lb MORE BOOST because it makes the air denser, so the rotors seal better, and gives the rotors something to move.

My setup with the lower pulley and everything ported with water injection at 375 ml/minute was running 18-19 psi. This is with the stock upper pulley. The stock ECU can only adjust the fuel supply up approx 20% or approx 74 HP. Above that you will start to lean out. At approx 17 psi and over you REALLY need to add more fuel supply, without doing so, you are asking for a potentially lean condition which can cause big problems, really big problems.

So, given it starts to get more complex and expensive after hitting the fuel delivery barrier of about +20% or approx 74 hp more than stock, I recommend keeping it simple and doing just the lower pulley and the intake tube, and the water injection. These are all very easy to do. The intake tube will reduce some vacuum which is the same as adding boost, and the water injection will reduce temps, add octane, and will give 1 lb of more boost. The water injection is money better spent than on the upper pulley. You can get it here at $358 delivered. http://www.ebay.com/itm/Snow-Perform...50364c&vxp=mtr
People who have gone this route and kept their stock MAF and TB have been very happy with the power gains.

Do NOT remove the lower pulley yourself, just have your trusted mechanic shop do it for you. Mine charged me just over 1 hours labor.

I'm actually in the process of simplifying my set up to run "only" approx 15 psi of boost and have decided to sell my complete lower pulley.

If you are interested I could sell it to you.


I bought it from PowerHouse off ebay. The costs were:
Cost on Ebay (complete, not the one where you send your stock pulley to be modified and wait 4 months for it to get mailed back)
575 complete lower pulley
101 shipping
70 import tax which comes in the mail later-PowerHouse does not mention this
746 total

I would be happy to sell mine at $595 delivered to your door. I'll give you first dibs. If you don't want it, no worries as I will sell it to the next person who is interested.

I also recommend this 12" pusher fan in front of the super charger radiator as it made a big improvement for me at only $30 http://www.siliconeintakes.com/produ...01b40698565159

If you really only get on it for extended periods on the freeway you won't need the fan, but if you race around as much as I tend to do,this $30 is well spent.

Jeff

 

I forgot to mention, and after just now reading Cabezagrande's post, I should add, I swapped to the 5th Gen Eaton M112 which I then had ported. The porting gave me approx 1 psi more boost, and supposedly reduces temps a bit. This is why I have zero drop off in boost, actually my boost is higher at 5500-6000 rpm than at 4500 as shown on my 0-100 video here

Watch the boost gauge. It finally catches up in 3rd gear showing higher 18psi of boost at the higher RPMs.

And you can clearly see how hard the car pulls in 3rd at the higher rpms. This is Eaton Power. - No NOS was used, only my stated mods.

If you time this run, time it to only 97 mph on the speedo as I am running larger 245 45 18 tires which are 3% larger diameter than stock, so my speedo reads approx 3% low.

I've added 8 psi over stock so approx 100 hp. 100 hp / 8= 12.5 hp per psi which works out to a reasonable guesstimate either way you slice it. This requires more fuel supply than the stock system can deliver.

 

I have some plans that will work very well, I'm even going to go manual if I like the body mods I'm doing........ But...

If you want to play safe, do the bottom pulley only as most have said but if you want to go mad do the top too, add water meth, fit a decent intake, 200 cell cats and beef up the cooling not just the IATs, otherwise you will melt piston 8

With what I am wanting to do I could get 800bhp but I want a usable car so I will keep a conservative 600

 

Ericbilt25 passed on buying the lower pulley, so I'm making it available in the parts for sale section of this board at $595 delivered. This is a complete +4 Powerhouse lower pulley with new o-ring. No exchange needed, no waiting needed.

 

I have done a 3.5" intake and 3# upper pulley. I have been very happy with everything so far. Just bought 200 cell Nameless cats to install next week, the will add water/meth to finish it up. Nice increase in hp for a reasonable amount of $.

 

I would love to buy it, but the engine needs to finish first. Thanks though

 

No worries at all, I'm sure someone will be in the market for one soon. I'm not in any rush.


And yes, since the Snow Performance Stage 1 is boost controlled, it appears that would work fine. Use the 375 ml/minute nozzle before the TB and you are good to go! 50 degrees cooler IAT. I dynoed at +7 more RWHP with the water injection, but it makes running more boost much safer.

 

Do you use a 50/50 mix or other ? ..... Ever tried using screen wash

 

I use the standard "boost juice" 51% water 49% meth. I was using it for "octane" as much as cooling, so I have just used the higher meth mix. I'm sure the less expensive winscreen cleaner at approx 20% meth would be fine at 15 psi.

 

Anyone have pictures of the newer custom intake installed? I'm trying to get an idea of how the exact fitment looks.

 

Take a look at THIS THREAD quite a few pics on there

Thers Dans, Waters, Steve Ms linked by another thread and my aluminium one

 

alright thank you!

 

Some more intake pictures here: https://www.jaguarforums.com/forum/x...95/#post834230