Hello Forum members! I have an 03 XJR with some engine upgrades. I am wondering if water/methanol kits work on these cars? Do they create more HP? What are the dangers to the engine? What are your opinions?

 

I have one in mine. installed myself. They do work. I know several people who use them. Snow Performance is the way to go. Power is noticable when it sprays and intake temps stay a bit cooler so you won't be losing as much power due to heat. I love mine. Make sure you get the stage 3 kit with the dash unit so you can dial in the perfect tune. Not too much danger to the engine unless you run a GIANT nozzle as use more than a 50/50 mix. It's a built in steam cleaner for your motor. Let us know how it goes when you pick it up.

 

I also have a Snow Performance water meth kit installed on my XKR, the car is not as modified as much as the Thunderkitten's car but you can feel the difference. In the winter I am unable to use it as it increases the boost to over 20psi. I highly recomend water meth it is the best upgrade for the money.

 

Water and methanol injection can be likened to an increase in octane. This permits more cam and spark advance without knocking. Therefore, more power. Another effect is that the evaporating water expands, making your motor partially a "steam engine."

These systems were first sold around or after WWII, when gasoline octane was much lower. Another advantage then was that carbon deposits would be scrubbed from inside the combustion chamber. However, modern fuel injection and better gasoline have greatly curbed carbon buildup in contemporary cars.

 

My car setup is as follows: low temp thermostat, K&N filter, 2.5/3psi upper pulley, upgraded lower pulley, ported supercharger, Borla exhaust system, Eurotek intercooler radiator and Eurotek ECU tune. The car was dynoed with a boost rate of 18psi's before the Snow Performance Stage 2 kit. What happens when the boost goes above 20psi's?

 

When are you getting 18 psi of boost ?? I would see the increases in boost in the cold weather & seing you are in the south your advantage is you would not loose as much boost in the very hot weather.

 

Thats almost the same setup as mine had. I saw 18's for boost. Mr. Jaxkr's rolling refrigerator has the all mighty Kenne Belle Twin screw on it now. if the boost gets too high you start breaking things.

 

When I had the Eaton M112 on my car in the winter I saw 20.5 psi @ one point & decided to turn off the water meth for the winter. With my current setup I have also seen that much boost in the cold weather, both times that is with the 3.5" air intake setup fitted.

 

Thundercat what size spray nozzle did your water/meth kit use? Was it the size 5 nozzle (375ml)?

 

I use the 375ml nozzle. I have also used the larger one and found it to be effective. once I'm finished with mods on the car I will probably stick with the bigger one. I like the system though and It's fun to screw around with the injection tuning.

 

My car is reading 310rwhp & 350lb/ft tq. My setup is K&N cone air filter, 2.5/3psi upper pulley, Lower crankshaft pulley (Eurotek), low temp thermostat, Eurotek supercharger intercooler radiator, Snow Perf. Stage 2 Boost Cooler kit and Borla Exhaust System. How do you feel about those numbers after all those upgrades? Is it pretty hard to get consistent HP numbers on these XJR's.

 

Number sounds a bit low. I had a VERY similar setup and I put down 379 at the wheels on a dynojet and 339 on a dyno dynamics. I think your car should be making more. Although i did have a ported supercharger when i dyno'd. Im not sure thats good for 60hp at the wheels though. how was your A/F ratio? how hot was the weather when you did your run? what kind of dyno? i assume your boost number was close to 18psi? strange. I'd put it on the rollers again if I were you.

 

I also have a ported supercharger. The temperature was 94 degrees. I do not know what kind of dyno is it. It's definitely not a DynoJet. The boost close to 18psi's. I will probably take it to the local DynoJet shop next Thursday for some pulls. I am scheduled to pickup the car today from Buckhead Imports. Personally, I am getting a little frustrated with the car.

 

Is your air filter a true cold air intake or is the filter still under the hood?? I have people with the cone isolated but still under the hood. The setup Andre uses as well as myself draws in cold air from outside. You may want to look at your intake as with a 3.5'" intake you can greatly increase your boost & power.

 

I just switched from a K&N air filter element to a K&N air intake system which has jumped the boost back up to 18psi's. The stock airbox was restricting air flow. I will take it to the Dynojet shop on Thursday to do a test for there HP/TQ numbers.

 

It's a Jaguar, keep throwing large amounts of money at it, or buy a Corvette ;-)

I think with all the mods it's low output. Something wrong with the setup. The intake is a good start. To get serious power requires serious mods, for example a TVS charger, or like the UK guys are doing, twin turbos, which I'm considering on a 4.2 block. 700bhp+ on the deck with the next stage. Talking to guys who are tuning Audi RS4's that smoke all. Similar setup could be an option.

 

IMO methanol/water mist injection into the inlet plenum can be beneficial for some turbo cars and I have used them on a few of my wrx's. They can give some detonation protection when you have high ambient temps as we have in South Oz. As for their application in supercharged vehicles I would think they are not really needed. They can just end up being another problem if not set up and monitored correctly.
Better to spend your $$'s setting up the AFR and ignition curves.

 

I was unaware K&N made in intake for the Jags, do you have a photo.

 

Go to eBay search engine and type: K&N air intake system Jaguar XJR

 

Oh boy, you got yourself a ticking time bomb here, didn't bi say anything?
Remember even in stock format you are sucking in at top rpm about 300 liters of air per second, so tucking it in the corner doesn't prevent it from sucking in hot engine bay air. Multiply the hot air with the superfast spinning Eaton that in itself is able to generate even hotter air, doesn't sound very healthy to me. Dump it and get yourself a cold air filter system, and try to go for a larger filter imho.