Here is how to wire 92mm ProM MAF easily
 

Since I have been getting numerous PM requests about wiring my 92mm MAF I'm re-posting this info in this section:

Here is how I wired my 92mm MAF successfully using their pigtail connector:

Wires on the 92 Pro M--------Wires on stock MAF
A: power-------white, blue stripe
B: Ground
C:Ground
D: MAF signal--------Green, white stripe
E: IAT voltage---------Orange This wires to replacement IAT sensor to original harness/connector
F: Ground

I really like to use these awesome connectors so you don't screw up the original wires, these posi-taps are the way to go!
Posi-Tap demonstration and review - YouTube

Posi-Tap- No Crimp Tap

WhiteXKR introduced me to these connectors-they are the best!

The larger MAF really opened up the door for more performance for me.

This allowed the larger intake tube and maxbored stock TB (which went from 75mm to 82mm=20% more flow at the same pressure) to work together to reduce excess vacuum in the intake.

I reduced 2 psi of vacuum in the intake which translates DIRECTLY to +2 psi more boost, but without spinning the blower any faster.

My complete list of intake mods that helped were:
larger 92mm maf
larger 4" to true 3.5" intake tube (get rid of that bottleneck cobrahood over the TB!)
larger TB maxbore.com bores your existing TB for less than $200
I ported the elbow between the TB and supercharger.
I also ported the intake of the supercharger itself,
I had Steig port the blower exit but honestly, once you see the shape he made, you can replicate it easily.

When re-installing larger TB, elbow, etc, you MUST also make the inside of the gaskets larger, else you will not see much gains. Whatever your choke point, that is your limitation, so it is best to do them all.

I reduced the vacuum in the intake by 2 full psi, anyone who tells you there is no vacuum in the stock intake is flat out ignorant.
I know there is a lot of ummm, ehhh, how shall we say..." incorrect" information given on this board that eatons are so severely limited in their potential. To that I say look at this video of my 0-100 run on street tires, at approx 4100 lbs, in approx 10.5 seconds.

Here is the video proof of the run https://www.jaguarforums.com/forum/x...19-psi-108378/

I was very pleased with the results.

WaterDragon you are the man. A legend in my book. Definitely going to look into these mods.

Would love to do this... one day...

For the record, how big is the factory MAF? It seems like you'll still have bottlenecks at the 'cobra head' and throttle body, but obviously every little bit helps

I just tried some stuff. Some worked, some didn't. I know some are very uncomfortable when I call B.S. when I see it, but I think it better that people can have honest and accurate info of what mods produce what results at what real costs.



The factory MAF is 75mm, so going to 92mm is a big difference., HUGE!

Going from the stock TB at 75mm to the 82mm allows it to flow 20% more at the same pressure, a pretty big improvement. I placed the water injection just behind the MAF in hopes that it would cool the air and allow it to become more dense before it hits the smaller 82mm TB. Since the car would run approx 12.6-12.7 on street tires in the 1/4, something is working right.

Do you need to do any calibration of the MAF itself? I'm not sure whether to get a Pro M or Abaco air meter for my STR. I'm planning on using 90mm intake tubing. What would you say is the best MAF to use? I can get a 97mm Abaco for cheap but I think it's too big for my power level.

Did you do any ecu tuning or just plug and play?

Sorry for the long delay in replying, I haven't been to this page and a very long time. Yes it's just plug and play but I did have to add the external IAT sensor

Water Dragon, I saw the pull of your car on YouTube. Sick, in a good way! Has your PCM been tuned? I'd like more top end power on my 02 XJR. Have a lot of questions as to what will give these cars gains, and cooling mods etc. Is there a thread on here with all that info?

I never tuned the PCM. Having added + 8 psi of boost effectively added a lot of timing as it was, so I used water injection and 2 step colder plugs to try to mitigate that a bit.
There are lots of threads by me and others about mods.
Just fyi, I am a complete hack, and the XJR was the first engine I have ever taken apart. I just tried different things to see what worked.
In the end I was able to get the "lowly" eaton to produce 18-19 psi without heat soak
The basics apply, reduce the vacuum before the blower with larger I.D. then inject water vapor before the blower, not after, and add as much on demand cooling as possible. Increasing the ID of everything leading up to the ported supercharger added several pounds of boost.
At some point the injectors max out at +20% fuel delivery, so if you get that far you will need to add the Boost-A-Pump to raise the voltage of the fuel pumps to raise fuel pressure and therefore delivery. <---We can all thank AVOS for this pearl.
"My way" maxes out at about 470-480 HP
if you want more you will have to go with a more efficient supercharger, like the kenny bell, but that will bring an entirely larger order of magnitude of cost and complication.

Good info here. Im currently very interested in the pro-m Maf. I think it may be the best option to "tune" the XJR. I have a similar set up to WaterDragon with the gen 5 eaton and smaller pulley etc. I notice that the power curve is different with these mods and does not match the stock map of the ecu. I get alot of pre-det and pinging and it seems the car is very slow to learn and compensate during each drive cycle. Is anyone else experiencing this?

Add water injection
 

You really NEED to add water injection when you increase the boost. Inject BEFORE the blower, not after.
Also, the 10" pusher fan (from silicon intakes) is surprisingly effective added as a pusher fan on the intercooler radiator

Without adding substantial on demand cooling you will have major problems. Mine had what appeared to be ZERO heat soak with the 10" pusher fan, water injection , and a water spray directly onto the intercooler radiator. I was surprised how well this setup worked.

Link to my video proof.

Very nice, is the water injection automated?

First let me just say I'm not looking to mod my XJ8 because well, it's not an XJR and I have my Harley to satisfy the performance bug in me. Which leads me to this question...How are you advancing ignition timing and adding fuel to the AFR table? Is there a tuner available? If so, is it limited? Can you run open loop?

He’s not advancing ignition timing per se, he’s eliminating the detonation factor which would pull back timing. I have been following WD’s recipe with the exception of the bored out throttle body which can no longer be done on our cars. 😡😡 I would really like to get my hands on a bored out TB.

https://cimg7.ibsrv.net/gimg/www.jag...6c8374827.jpeg
On a side note, look what I got today from the UK. Total bolt in job. I’ll post pix this weekend when it goes in.