Any experience with Jag AFM?

[B-Reight]

I have found a pair of series 3 XJ6s with these fitted in one of my local scrappys, i have heard that these can help with breathing and yield more power. If anyone has any experience with this mod i'd love to hear about it.

Does the mod require any other bits from the jag or is it just plug, twiddle (spring tension & fuel pressure) and play?

Cheers
Ben

[350zwelgje]

Think that in the wedge bible you can find some information on this.
Should use the the proper injectors as well, and even without those the ECU needs to be setup properly to take the improvement=change into account to get the fuelling right. If you have a hotwire ECU you can change the chip. Look for tornado on this forum and probably too much information pops up. Flapper is not so easy to adapt to changes.
Also understood that on a standard 3.5 the AFM upgrade is not worthwhile as it is required for if you have/want a lot more horses than standard....

Rob

[B-Reight]

Just to clarify, its the flapper system i'm talking about on a 3.9 390se.

[Wedg1e]

Same as my car then. I fitted the Jag AFM along with higher-flow injectors (for info, a lot of the Jags did NOT get higher flowing injectors than the 390 has to start with, so check carefully). I then had to DROP the fuel pressure just to get the thing to run (to about 1.8 Bar with engine off, about 1.6 Bar when running), along with a degree of fine-tuning the flap spring tension.
Whether it improves things I can't say; it certainly doesn't run any worse than before. I guess it'd need a dyno session to see what's happening.
I had some running issues a year or so back so I swapped back to the standard AFM, at the moment it has a random stutter that could be several things: fuel pump dying when it gets hot or ignition pickup on its way out (again) would be top of my list. Did 170 miles on Saturday and it didn't get any worse or better...

[B@man]

Hi there,

I also have a Jag afm sat waiting in the wings & a Mez modded 72mm Plenum, the plan was to try this with the standard injectors after finding a baseline AFR with the innovate LM2.

However this has all gone out the window as I'm at 50psi rail pressure with the standard bits to get the correct AFR which leaves no extra fuelling to get the most of the extra air that the AFM & plenum will allow into the engine

So the revised plan is to add the jag injectors (OK I forgot the save up and scour e-bay bit ), reset the base line fuel pressure to work with the jag injectors on the standard set-up, while the LM2 is on the car I can plot some voltage readings from the TPS and the flapper + RPM readings which I can hopefully use to calibrate the jag flapper to give a similar output under similar conditions - Note Hopefully.....

Once the induction is sorted the dizzy's is going to be retired in favour of a Megajolt ignition controller and a couple of coil packs, Oh and move house and finish my other project car....

[grahamw48]

Meanwhile, I will be mostly giving the starting handle on my Moggy a fresh coat of paint.

[sphs2]

not sure without checking the book but it has to be a certain afm, from memory i think it's from a 4.2 xj6. i would also say that the afm i probably not a limiting factor on your car unless you are producing close to 275hp.

Try making better use of the air you already have by making the engine run at around 80 degrees, fitting a smooth bore afm to plenum pipe and fitting an ioslator to the plenum to cool the air down, the colder the air the bigger the bang!

Edited by sphs2 on Saturday 1st August 13:01