Yes absolutely, the cooler you get the charge air, the less it will pull timing out.

 

Is my MAF sensor limiting possible hp gains on my car does anyone know.

I have read several recent posts that state the MAF can only handle about a 10% gain in air throughput at its max.

Thinking about this it has to be the ECU that is reading data from the MAF that might cause an issue not the actual MAF sensor.

 

i've read AVOS has made gains of around 80hp just by swapping to a 2.2l TS SC with the appropriate pulleys . with out swapping MAF's.
so that would point to the eaton roots blower being the bottle neck . at the 40% gain point .
not the MAF .
as i'm aware you can make up to around 100hp before requiring a larger MAF,
there are tests to see if the MAF is reading correctly or not .
and yes the MAF's do go out with age . mine did and caused a lot of problems,
was hard to track down .
it should read accurate iat1 temps .
and idle at around 5g/s and above 380g/s at WOT .
and if its accurate you can use it as a near enough hp calculator as well.
see here
https://www.jaguarforums.com/forum/x...-382-a-175551/

 

Paydase. Quote from XJRengineer today:

"The standard air flow meter will only read up to 1018kg/hr and the standard engine just about reaches this airflow. There is no "reserve" . A scan too, will attempt to display the airflow in grammes/sec, but there is something wrong with the output from the engine ECU, so the data is always out by a factor of 10. If you log the data, you can of course post-process it into the correct units. I have an Eaton M112 supercharger running at 2.5:1 drive ratio. In theory this is 24.4% higher displacement per engine rev than the Eaton M90 running at the standard 2.5: 1 drive ratio. With my Eaton M112 setup, I don't exceed the 1018kg/hr limit until the engine is doing about 4000rpm at wide open thriottle. Therefore I think it extremely unlikely that any M90 based installation, even if fitted with a smaller SC pulley to give a 28% increased drive ratio, will exceed the airflow limit until about 4000rpm. If you keep below 4000rpm at wide open throtle, I think what you are proposing would be "safe". I would be wary of exceeding 5000rpm at any throttle opening with a 28% higher drive ratio, because by then the supercharger will be spinning faster, than even those installations that use a 10% bigger crank pulley and run the engine to its rev limit of 5,950rpm".

The above quote is what concerned me.

 

He was talking about older inline 6 cylinder cars, not the AJV8 ones, there's a big difference. So far I have never heard of pegging the MAF (so go over the limit) with an Eaton setup.

 

Ok avos. Thats good to see. Thank you.

 

A few more pics and more of an explanation on my water/meth installation to answer some questions.

The single injector nozzle I placed about 3/4" back from the front lip of the flattened aluminum input pipe.

I did this so that it could easily be covered up with a new flexible connector pipe that I notched out to fit the nozzle.

I wanted thicker metal than the thin stage one aluminum pipe I have to mount the nozzle in.

I simply put a T piece in the connector hose of the SC bypass valve so as to connect the boost controller which I located in the brake reservoir area.

The black elongated connector in the red high pressure hose at the back of the rhs charge cooler is a one way valve.

I also installed a fused switch so that I can disconnect power to the pump when I want.

 

One pic I forgot is where I connected the power for the pump.

It is the red cable connected to a full 12 volts in the engine compartment fuse box that is switched.

So off when key is off.

 

Great work, noticed any difference?

 

I have not been able to test it. I have been hung up with an alternator issue for weeks. I need to calibrate it and I need my wife to help. Have to catch her in the right mood!!!

I have finally decided to put up with a battery red light as I finally installed a new Jaguar Alternator the same as my original and I know it is charging.
Battery is brand new as well and it is the Exide extreme per Box's recommendation.

I am now dealing with a squeaky pulley. Replaced one and still a squeak. Another arrived today and I will probably fit that tomorrow.

It has just been way too cold in my garage!!

 

Hey Guys. I've likely mentioned this before in the past but the range of a MAF and restriction can be two totally different things. These Eaton twin helix blowers are very sensitive to restrictions before the inlet. Inlet tube size, MAF size, TB size, Inlet volume. Ive not experimented with either of my Jags from a scientific or engineering standpoint but I can tell you that Ive had a lot of experience with the little m90 on the Thunderbird SC's for many years. On that little itty bitty blower (keep in mind eatons don't compress air they move it) even an 85 mm TB was shown to be restrictive when really spinning it. A typical mod list would be a slight port to the SC inlet, a larger volume SC inlet, a 3.5" intake tube, an 85mm TB(they actually made a 90mm) and a 90mm MAF. If your SC inlet is the restriction on a jag (don't know if it is) anything you do after will make little if any difference. I can tell you you though that when I upgraded my XJR's intake tube with a larer one and a modified mina galley CAI I did gain a few lbs of boost. That shows there was a restriction at least on the intake side.


Going off topic a bit I upgraded both to a 1.7 liter AR twin screw and then a 2.2 later on my 3.8 v6 and of course like everyone has seen the twin screw efficiency is much better. Interestingly enough a few guys tried using the jaguar m112 Eatons on their little v6's with little success power wise compared to the m90. Meanwhile twin screws have been jumping power on modified engines to over 500 to the wheels. And when I say modified I'm talking stock ported heads with larger valves and cams as they dont make anything for these cars.


So If you are trying to get max efficiency out of the m112 id be curious to see gains from a modified larger volume inlet, larger pipe tb and MAF. Because I have the twin screw for the XJR I ended up using my rebuilt later model blower complete with ported TB, larger intake tube and a mina CAI on my xkr....Just wish someone that a modified inlet made up...You know AVOS....A nice billet inlet for these later model M112 to fit the earlier XJR and XKR 4.0 cars would be lovely....Along with that 90mm TB and such,,,Just sayin...Id be in for both

 

I've not tested scientifically either, but I agree there must be a bit of power (~20hp?) on the table from improving the intake/inlet in the way you describe even on the Eaton supercharger set-up. I always thought the Eaton itself was the bottleneck, and agree it is to an extent, but some of the later 4.2 AJ34S (X150 XKR/XF SV8 etc) engines seem to be producing over 500hp using the Eaton and stock pullies with just a tune and higher flowing cats which has changed my opinion on the Eaton being a 'heaton'. Cambo's car for example is making power similar to that of the older AJ33S cars with twin screw superchargers. I know they have VVT and a different ECU there, but I believe the engine/supercharger is physically the same apart from that, so some of the extra power must come from the more efficient intake. I wonder why those cars can gain so much more from a tune? Can we not run that ECU in our cars too for better tunability?

 

I think Cambo stated that the gain would be minimal on the pre 2006 MY.

Having said that I think there is some torque "hold back" under acceleration that might be meaningful?

Also no matter what you do to enlarge the input track you still have the elbow below the TB.

I did "port" mine where the elbow joins the SC and were it matches to the TB. Before the porting there were "overlaps" to slightly hinder air flow.

 

Take a look at the before an dafter for my m90 Eaton SC inlet. New inlet has an 85mm opening Old one 65mm.

 

Certainly looks bigger and with a more straightforward flow.

On the M112 set up I think the elbow under the throttle body where it attaches to the SC is a bottleneck and also comes with its kinda sharp bend.

Other than having a completely different set up I dont know what could be done about it.

In the pic you can see the bend before I took it out for the 1st time.

I polished it up and did some porting on the output side where you can see the rubber/neoprene gasket on edge.

This output side where it goes into the back of the SC was not a great match with the SC inlet port and I did smooth out the edges of the SC inlet port.

 

That seems reasonable enough; are you still happy with the quality and sound two + years later?

 

Lots of good info here! but 450 BHP is not easily attainable with parts that are out there except a 2 screw...I would like to install NOS maybe a 75 shot on top...Not looking for 1/4 mile times or street racing light to light. I usually get "engaged" on the highway in a 60 roll or similar situation, which NOS would be a great help...How to tune for it if you can seems very vague on our site...

 

Just seen this now... Still works/looks the same after 2 years, sure the pipes are not shiny anymore. Still sounds great, though does resonate at certain RPMs.
The company which did mine is sadly no longer trading.

 

There was a guy on the s type forums who added 100 shot nitrous. He later did the same on an XJR. Many people didn't believe how aggressive ne was running it.
I followed him on Facebook and charged with him a bit. He sent me some pictures of his setup. I'll see if I can find them.
Saw videos of him racing nodded mustang's and camaros almost weekly. His week spot was definitely the limited slip differential. Not gonna lie was impressed how he abused it no problems.

 

That's a shame; I considered a similar system a while back, but was quoted around £2,200, which didn't seem especially good value, although the company's work quality looked good.
I have seen some of your other mods mentioned elsewhere on here; what do you think were the most worthwhile, and were there any downsides to them?