Hello Everyone. As some of you may know I have a 03 XJR R1 with some major upgrades:
1.) Air Intake
2.) Water/Meth Kit
3.) Low Temp Thermostat
4.) 3psi Upper Supercharger pulley (PORTED ALSO)
5.) Larger crankshaft pulley
6.) Upgraded intercooler radiator
7.) BIP Custom Headers w/ 200 cell CATS
8.) Quaife ATB Limited Slip Differential
9.) Eurotek ECU Upgrade
10.) BORLA Cat-back system NOW GONE in favor of a MagnaFlow X-pipe exhaust system ( 2.5 inch piping, X-pipe, Mid resonator and 2 ceramic axle back straight thru mufflers)


DYNO TESTED: (CAN BE SEEN ON YOUTUBE)
With BORLA setup (horsepower): 351 RW hp
(torque) : 359 lb/ft RW tq




DYNO TESTED:
MAGNAFLOW X-pipe (horsepower): 351 RW hp
(torque) : 367 lb/ft RW tq


As you can see the improvements are in the torque range. The X-Pipe really helps at high speeds when you are passing and merging onto the highway. It's very noticeable from 75mph to 95mph. The XJR pulls strongly like a LOCOMOTIVE!!! The X-pipe is louder than the Borla due to the removal of 2 upfront mufflers but calms down nicely at cruising speeds. The X-Pipe gives the car a lot more personality. My best 1/4mi time is 12.78sec @109.92mph. I will take it to the dragstrip this Fall to see if it can break the Dragtime 1/4mi record of 12.412sec @109.52mph.

 

A Maxbore ported throttle body would help get you closer to that 1/4 mile goal.

 

Will it require another ECU upgrade/tune?

 

Agreed, that's quite a drop in torque at the top end, which is likely caused by two issues, firstly not enough air getting in, and secondly, overdriving the SC and getting increased intake temps.

You have water/meth injection, so that should be helping with the intake temps. Opn up that intake and let her breathe, and you should see even more gains

 

nice gains!

I wouldn't think you'd need a tune as the regular program can adapt to changing air levels, but I am by no means an expert

 

Here forum 1/4mile standings:

https://www.jaguarforums.com/forum/m...andings-84783/

 

I'll jump in here since my set up was somewhat similar to yours:

Your dyno figures are excellent!

Your stock 75mm MAF and TB is acting as the choke point in the system, especially since you have upper and lower pulleys. I only had the lower and was getting 18 psi. Best to send your TB to Maxbore.com and get 20% more flow at the same pressure. I recommend porting the "elbow"/thing between the TB and blower (what is the proper name for this??) also to reduce vacuum there too. Just remember to port the gaskets too when you re assemble. This will unlock the rest of your system to make more PowAH! When I went to the ProM 92mm MAF really felt a difference. At that time my TB was already bored. http://www.promracing.com/home-page-.../pro-m-92.html

Also, you are at the limit of your stock fuel delivery system, that is also holding you back.

What were your Air Fuel ratios on your dynos? This is important to know. Most canned ecu "tunes" advance timing and lean out the AFR mixture which can make your car run DANGEROUSLY LEAN. I talked to the guy at Eurotek and he was completely untrustworthy. Search this forum and you will find others also found him to be full of it. He did admit his tune was designed for a stock car with no mods and that it did lean out the mixture and advance the timing. Also, that he does not have a "tuner" on staff or even access to any tuner for his "tunes". This is a possibly fatal situation for your motor, so it is very important to check your AFRs on your dyno print out at all rpms. I'm guessing your engine is completely relying on the water/meth to effectively add fuel supply and reduce timing enough that you are getting away with it, but this also means if you run out of water/meth supply you could instantly have a major problem. The meth is fuel and it helps to mask the fuel shortage. I think the stock ecu can only adjust fuel supply up approx 20% or 74ish HP. You are at/beyond that limit and I think it is solely the meth kit bridging the gap.

As you are probably well aware, adding boost adds timing. I was relying on the water/meth and torco accelerator octane boost to add the required octane not to go BOOm. http://www.ebay.com/itm/TORCO-UL-ACC...e9158a&vxp=mtr This truly adds up to 7 octane.

What injection rate are you injecting water/meth at? and what mixture meth? I was running 375 ml/minute of 49%meth/51% water. When I ran 450 ml/minute @ 12 psi boost I thought it could have been quenching a little bit and liked the 375 ml nozzle better.

My guess is if you added fuel supply and removed the MAF TB restrictions you could improve your 1/4 mile by at least 3/10ths to reach your goal, likely more.

I found that adding a kenne bell boost a pump was super easy, as it just splices into the existing wires (see my post in the engine section). You could get the adjustable single unit and add it to the 2ndary pump only. Here is the easiest solution http://www.ebay.com/itm/Kenne-Bell-B...8de1f2&vxp=mtr This will allow you to somewhat fine tune your AFRs on the dyno just by turning the dial that controls the voltage to the 2nd pump, and better yet, get a wideband AFR gauge and you will always know the most important piece of information for any hopped up car. AEM make a really nice wideband AFR and boost gauge in one:
Another possibly better, but more difficult option is to increase the size of the 2ndary fuel pump. If you wish to go this route, ask Steve M exactly what he did.

Also, I found that adding a 12" pusher fan in front of the inter cooler radiator made a HUGE difference, since it really doesn't matter how big it is if there is no air moving over it, like at low speeds or at a stop. This is a good fan, http://www.siliconeintakes.com/produ...69f36458daeb3f I wired mine through a relay and on/off switch in the cabin. This way you can really cool your intercooler system before a run while at a stop. I was running 18 psi boost with the water/meth and pusher fan I had almost zero heat soak run after run after run.

 

The short answer here is another question of " Where can you get a tune designed for your engine with all your extra boost?" It is not Eurotek, he only has the one canned tune designed for a stock engine.

You really need one that retards timing to compensate for all the added boost.