Big fat (or is that phat?) airflow meter...
Big fat (or is that phat?) airflow meter...
Author
Discussion

wedg1e

Original Poster:

27,002 posts

287 months

Sunday 21st March 2004
quotequote all
Finally got round to taking some pics of the Jag AFM installation I did on the 390SE; spot the hose adapter and new mounting plate...






Just needs a rolling-road session and some 4-pot caliper now...

Ian

dickymint

28,209 posts

280 months

Sunday 21st March 2004
quotequote all
Nice one Ian. But I thought you were doing the blue neons and 24" woofers under the seats!!
Just read your profile...again...always good for a laugh I see youve had it revalued!!

AM400

1,196 posts

285 months

Sunday 21st March 2004
quotequote all
That's a nice install you have done there, if only I hadn't just brought a recon for my 400.....

Andy

danny hoffman

1,617 posts

284 months

wedg1e

Original Poster:

27,002 posts

287 months

Sunday 21st March 2004
quotequote all


Danny, for that money I could buy a CNC machine and mill one from purest Unobtanium..

Must admit to having wondered about opening the throttle body out, but there's not much extra metal in there... and then I'd need a new throttle disc.... and the kids need new shoes.... wife wants a £3K telly...

I was watching a nice 12mm slab of alloy on Ebay that was more than large enough to mill a plenum spacer from, which would be another worthwhile improvement (I gather); alas I forgot when it was due to end... dammit.

Hmmmm... CNC machine....

Ian


wedg1e

Original Poster:

27,002 posts

287 months

Sunday 21st March 2004
quotequote all
dickymint said:
Nice one Ian. But I thought you were doing the blue neons and 24" woofers under the seats!!
Just read your profile...again...always good for a laugh I see youve had it revalued!!


It's just been revalued again, after the latest round of... erm.... 'enhancements'
Strictly in accordance with current trends for modded vehicles, you understand...

Ian

andyy

238 posts

280 months

Thursday 25th March 2004
quotequote all
Ian
I'm looking to do the same on my 400se
any chance you can e-mail me your phone number so I can pick your brains

many thanks Andy

greenv8s

30,997 posts

306 months

Thursday 25th March 2004
quotequote all
wedg1e said:

I was watching a nice 12mm slab of alloy on Ebay that was more than large enough to mill a plenum spacer from, which would be another worthwhile improvement (I gather); alas I forgot when it was due to end... dammit.


Far better to make it from Phenolic sheet though? Not all that expensive to buy, easy to machine, and it keeps the whole plenum top and throttle assembly cool (assuming you've disconnected that daft throttle heater).

wedg1e

Original Poster:

27,002 posts

287 months

Thursday 25th March 2004
quotequote all
greenv8s said:


Far better to make it from Phenolic sheet though? Not all that expensive to buy, easy to machine, and it keeps the whole plenum top and throttle assembly cool (assuming you've disconnected that daft throttle heater).




Hey, Peter, good plan. Would free up more cash to spend on Old Peculier...
The throttle body heater was disconnected some time ago. In fact I removed the whole assembly to clear some room under the throttle to get at the injector wiring etc.
Then the car ran like a bag of spanners. Eventually I realised that two of the heater mounting bolt holes were drilled right through into the plenum... :doh:
I was also watching an inlet manifold that ended last night, along with an air driver. Alas I was after some sniper bidding but Ebay (or my PC) went tits-up and wouldn't accept my bids, so I lost the lot
To be fair, I have enough to do on the Esprit, without pulling any more bits off the TVR.

Summer's on its way....

How's the greenV8S monster these days?

Ian

wedg1e

Original Poster:

27,002 posts

287 months

Wednesday 7th April 2004
quotequote all
Update on this... finally got to drive the damn car tonight! The throttle response has changed. As in... it has more flat spots than a Middle Eastern country after the B52's go in...

OK, bit of an exaggeration: it's 'different'. Seems to have cleaned up some glitches only to create some others. Bearing in mind I was testing in drizzle, and my local test track is having some repairs done, so I couldn't find the outer limits, but I did see 5800 rpm in 4th, and past 6000 in 1st/2nd/3rd so the air and fuel are definitely flowing.
However, it appears that there are more definite 'steps' in the delivery than before, where it was more progressive. Also, dropping the throttle shut at certain points almost has the effect of standing on the brakes - bit unnerving!
I noticed that the resistor network used in the Jag AFM is the same physically as that in the Rover 3.5/ 390 unit. However the actual values of the laser-cut resistor 'ladder' vary a bit, perhaps not enough to matter? Or is this the cause of the steps in the delivery? I'm tempted to swap the ladder from the original AFM to see what that does. Also, I fancy reinstalling the cold start injector and wiring it via a microswitch on the throttle so that it fires at full throttle, just for the hell of it....
Don't laugh, the Audi Quattro did it...

Ian

wedge 420

6 posts

262 months

Thursday 8th April 2004
quotequote all
hi, could you tell me what type of jag the airflow meter came off. i would like to fit one to my 420.
thanks chris

jmorgan

36,010 posts

306 months

Thursday 8th April 2004
quotequote all
Ian, if you are after a plenum insulater I know a place that does them off the shelf for £60. I have one fitted. Superb results.

wedg1e

Original Poster:

27,002 posts

287 months

Friday 9th April 2004
quotequote all
wedge 420 said:
hi, could you tell me what type of jag the airflow meter came off. i would like to fit one to my 420.
thanks chris


Hmmm, not sure. I assume XJ6, maybe XJ40? It's a Lucas type 2AM anyway. The 4AM is the 'hotwire' type and won't work in place of the 2AM.

wedg1e

Original Poster:

27,002 posts

287 months

Friday 9th April 2004
quotequote all
jmorgan said:
Ian, if you are after a plenum insulater I know a place that does them off the shelf for £60. I have one fitted. Superb results.


Cheers J: takes the fun away from DIY though! That's why I have a lathe and a miller.... getting a sandblast cabinet at the weekend as well! No more paying for powder coating....

Ian