Phase IV Twin Intercooled Supercharged 1UZ-FE V8, - Part 2

June 2004

by Peter Scott

Part 2 of the twin intercooled supercharged series. A further look at the Jaguar blower, Jaguar factory specifications, lowering compression, changing injectors and some costs of available upgrades.

Part One - Click for part 1.
Boost and Eaton pulley change

A look at the factory specifications for the Jaguar supercharged V8

Phase I : $7000 fitted Eaton M90 kit Fitted - 240 kW
Phase II : $19 800 fitted -Bigger blower, water air intercooled - (e.g. Starr Performance LS1)
Phase III : +$4 000 minimum - Match factory supercharger specs, compression, fuel, timing etc
Phase IV : +$20 000 to $35 000 - Follow recognised upgrades to factory supercharged systems.

Yikes! - how expensive is all of that!

If fitting a blower was step one, a bigger blower and intercooler step 2, matching factory specs (like compression ratio and injectors) step 3, then following the aftermarket for a factory hotup could be step 4. So total prices could range from $7000 for the Eaton M90 fitted ($6000 for DIY kit) to $19 800 + $4000 + $35 000 = $58 800 fitted. Holy moley!

Here is a near complete supercharged jaguar motor. Notice there is no "Jaguar" on this valve cover - like the 1UZ-FE, this valve cover is obscured by the air intake pipe work. Again check out that rusty exhaust manifold and cat - it must be such a tight fit to have to design it all so tight and restrictive looking. It makes the stock Soarer exhaust manifold look really good!. This is another good pic to see the factory routing for the intercooler coolant. Unlike the Soarer the Jag has a singe butterfly, stumpy throttle body - not a long twin butterfly throttle (for TRC models). At the back you can see the throttle taped up.

The stock motor runs at 12 psi, and the twin intercoolers reduce the temperature of the intake charge from 160 degrees to 60 degrees.

A brand new Jaguar Eaton M112 came up on ebay a few months ago - no intercoolers or anything, just the blower:

My first chance to see the blower without the intercoolers and try and figure out in my mind if it would fit the 1UZ-FE. This is the top of the blower where the air exits. The Eaton blower is custom cast just for the Jaguar. It appears as if the blower bolts to the engine with three bolts - one at the back middle, and two at the front. That rear bolt and associated flange looks as if it will get in the way of the 1UZ-FE starter motor that sits in the middle of the "V". And the 8 rib steel stock pulley wheel has too many ribs for the 6 rib 1UZ-FE serpentine belt. I noticed too the the pulley is cup shaped on the inside - it comes back over the alloy snout - this would make it impossible for a Jag owner to fit a smaller pulley on the supercharger.

The 1UZ-FE starter right plonk in the middle of any blower installation. The two knock sensors are visible too. I heard that removing these and then re-torqueing to a lower spec reduces the sensitivity of them. I did try to unplug one once and the engine went into gutless limp home mode! A water pipe also passes under the manifold and along side the starter (pipe removed in this pic). I made a few rough measurements to see if the blower would fit between the starter motor and the front web of the block - it didn't. Would the whole lot still fit under the bonnet?

The underside of the blower. Big ribs to support the blower are cast in and the three bolts to secure the blower are visible. Of course there are no matching bolt holes on the 1UZ-FE block! How to affix the blower? The pulley snout means there is enough shaft sticking out of the snout to put on a regular pulley and change the number of ribs and pulley size. All I need to do is pull off the pulley with my 3 jaw puller (Wrong!).

The air intake at the back of the blower - a bit hard to see here - but it's below the two shafts, the four bolts hold on the throttle connector. So a custom throttle connector would be needed, and somehow the blower would have to firmly affixed to the block. There is no manifold under the blower for it to bolt on - this is because the air exits upwards, not downwards. The blower as is has to bolted to the engine, then the intercoolers connect to the blower with a rubber seal and hard bolt to the four intake ports on the heads.

So a water/air intercooled big blower kit installed costs $19 800 installed for everything. Some of the prices quoted just to "hot-up" a stock supercharged jag cost even more than that!

Factory Specs for the Jaguar Supercharged Motor

Compression ratio

http://www.jag-lovers.org/xk8/
9:1 for the Jaguar motor, 10:1 for the 1UZ-FE. How to lower the compression? New pistons - but where do you get them? You might be able to import a custom set from USA for $2000 - but then still up for labour and engine removal. Maybe the makers of the Bullet car will sell some pistons - if they even have some:

http://www.bulletcars.com/contact/contactUs.html

Copper head gaskets and relieving the combustion chambers can also lower the compression. David Phan's 1UZ-FE V8 site is a wealth of information:
http://www.lextreme.com/tech.html

more specifically:
http://www.lextreme.com/decompression.htm

and
http://www.lextreme.com/cr.html

This last one talks about gaskets and decompression using headwork.
Porting the heads as per the instructions in Julian Edgar's 21st Century Performance gave a gain in flow of up to 20%.  Frank Intini actually lives in my town Adelaide - cost is $1200 Aud for the pair. To lower the compression by relieving the combustion chambers would cost an extra $300 - $1 500 all up

Fuel and Injectors

Two ways to get more fuel - same injectors with higher fuel pressure - using a rising rate fuel pressure regulator, or fitting bigger injectors.

http://www.autospeed.com/cms/A_0102/article.html - Injector Flows
Great article on injectors.
So, how much power is this injector good for? That depends on the air/fuel ratio that is used, but a good rule of thumb is to divide this flow figure by 5 to get a hp capability. So, 185cc divided by 5 = 37hp maximum fuel flow with this injector. If you want to be pedantic, it's the mass of the fuel (not the volume) which is the critical factor. Assuming a "normal" fuel density, the mass of the fuel in pounds per hour can be worked out by multiplying the cc per minute figure by 10.2. For this Bosch injector, that gives a mass flow of 18.1 pounds/hour. To convert from pounds/hour to horsepower capability, multiply the figure by 2.04. So 18 pounds/hour multiplied by 2.04 gives a horsepower capability of 37hp - the same as we got from the cc/minute figure.

The 1UZ-FE has Nippon Denso injectors. Violet in colour, they flow 251 cc per minute at a test pressure of 290 kPa - the pressure is important - lower pressure gives lower flowrates. This flowrate is good enough for 50 hp per injector or 400 hp. Sometimes the 1UZ-FE injectors are reported as flowing 220 cc/minute - they do - but that's for a lower pressure. 

1UZ-FE injectors are high impedance - that is 13.8 ohms, not the lower 2.9 ohms. To upgrade the injectors they have to have the same impedance and they have to physically fit.

A good upgrade are pink injectors from the Toyota 3SGE or light green injectors from the 7MGE - both flow 315 cc/minute at 290 kPa - good enough for 63 hp each or for eight of them or 500hp - this should be ok for a modified Jaguar 4.2 L V8 supercharged M112. So this just might be the injector to use.

http://www.autospeed.com/cms/A_0349/article.html - Boosting Injector Flows
There are a number of approaches you can take. You can:

* Fit larger injectors - which can be very expensive;
* Add an ancillary injector - which can cause fuel distribution problems when the manifold is then required to flow an air/fuel mix, not just air;
* Or increase the fuel pressure going to the standard injectors - and yes, as with any mods, this also has some potential problems!

http://www.lextreme.com/injectors.htm

http://www.lextreme.com/R&D%20Injector.htm

Fuel and Timing Control

An Apexi SA-FC may come in handy: http://www.lextreme.com/piggyback.html

To control timing as well maybe this could be a solution?
http://www.kalmaker.com.au/page69.html

Kalmaker software on a Delco ECU and tuning on a dyno for fuel and timing? - Heaven! But I don't think it has been done successfully yet and doesn't seem to be worth it.

So a Phase II bigger blower and intercoolers just might fit. Phase III could involve lowering the compression, bigger injectors and fuel and timing control to match the Jag motor which would need so much more money and time. Which way to go? Phase IV would be upgrading the Jag factory specs - bigger heat exchanger up front, bigger high flow exhaust, headers, upgraded fuel, ported heads, more boost, more aggressive timing,   all of the above to get 500 hp at the flywheel reliably as a daily driver. Again how much to do? Do the whole lot at the beginning? some of each? start off easy and see how it goes? - fully develop over a year or two? - how much will it really all cost?

A look at available upgrades for the Supercharged XJR - from http://www.jag-lovers.org/xk8/upgrades.html

Common upgrades are headers, high flow exhaust, bigger heat exchanger, and larger crank pulley (since the supercharger pulley can't be changed).

Racing Green suggest the regular stuff like exhaust, intake and ECU re-map plus a boost increase and sounds like a larger front heat exchanger.

Racing Green Cars - Performance Division

Jaguar XK8/XKR; Performance Upgrades http://www.racecar.co.uk/arden/

Miscellaneous
1. Engine power increase to approx. 430 BHP (XKR only) by incorporating full straight through exhaust system, increased boost pressure, revised supercharger cooling and sports induction filter.

2. Engine management upgrade, incorporated in standard ECU by computer download. Provides improved response in the typical driving range of 2500 to 4500 rpm and gives an extra 35 BHP and 22% torque enhancement (XK8 and XKR).

3. Water methanol injection provides an extra 10 BHP (XK8 and XKR)

4. Sports induction air filter - washable.

5. Racelogic V-max system: Allows the car to run to its unlimited maximum speed.

What else can you do?

Even more smoothness and flow is obtained with the fitting of a Racing Green exhaust:

a) Straight through system (excluding manifolds): Replacement catalysts and silencers with larger bore pipes and chromed oval tail pipes giving a 15-20 BHP increase. Choice of sound levels.

b) Half system: Replacement larger bore pipes and silencers with larger bore pipes and chromed oval tail pipes giving approx. 10 BHP increase. Choice of sound levels.

Torque Development International : http://www.tdi-plc.com/JaguarXKR.html

Notice again that cooling is identified as a big upgrade. Since I don't even have an heat exchanger yet, might as well go straight for the big one. Looking at the pic it's almost as big as the radiator of the Soarer. The supercharger pulley on the blower can't be changed for the smaller one as the pulley goes over the snout of the blower. TDI get around it by increasing the size of the drive pulley on the crank rather than reduce the size of the pulley on the blower. Since I can change the pulley size and position before mounting the blower this won't be a problem. Once again exhaust and intake is targeted for upgrade.

10 hp Exhaust £995
7hp intake £275
50 hp heat exchanger and pulley (boost)  £3,450

+75 hp pack, more boost and ECU upgrade £4,950
+100 hp no cat full power exhaust £2,650

So 100 hp upgrade running 16.5 psi? costs  £7,600 fitted or $19 800 Aud fitted.

Wow! ok so the Starr blower and intercooler fitted costs $19 800 and suggested upgrades cost an extra $19 800 (amazing it's the same amount). So that's $39 600 so far and still yet to lower compression and upgrade fuel. So let's say an even $45 000 all up for an intercooled blower with 500 hp. Plenty of money!


Jaguar XKR currently undergoing rolling road testing of intake temperature versus power output. Preliminary test show (as with the XJR) that significant gains can be made in this area even without raising boost pressure.



Please note: All of our Jaguar upgrades have been designed to keep the refinement that Jaguar intended, and many hours are spent on R&D to ensure that the nature of the vehicle is not compromised in any way.
Stage 1: Performance Enhancement: Exhaust (+10 bhp)

Full stainless steel free-flow exhaust system. Designed to fit 'cat-back' to enable the vehicle to pass MOT emissions test. Many hours have been spent on the design of this system so as to keep the hushed nature of the vehicle as Jaguar intended. Only a slight 'deepening' of the exhaust note is realised. Different styles of tailpipe are available depending on your own preferences. Price £895.00 (supplied) £995.00 (fitted)

Stage 1 option: Free flow induction kit (+7 bhp over above)



This upgrade is classed as an 'option' simply because induction noise is increased slightly, and many of our customers require very low sound levels. For those that want to realise the full potential and V8 induction roar then this option is ideal. The system comprises of a large diameter filter assembly containing a laminated sponge filter. The filter itself is replaceable which means that the system is as good as new for a minimal (£24.95) element price when required. From the filter, air travels along a large bore polished aluminium elbow which smoothly tapers down to the original Jaguar pipework. The vehicle can be returned to original spec. very easily if necessary. High quality silicone joining pipes are used as are stainless steel clamps for durability as well as superb under-bonnet appearances!

Price £190.00 (supplied) £275.00 (fitted)

Stage 2: Performance Enhancement: Boost upgrade (+50 bhp)

The standard Jaguar charge cooling system is limited even on stock boost pressures. Using a larger aluminium intercooler mounted ahead of the water radiator, inlet charge temperatures are dramatically reduced (we have measured drops of an average 50%). This leads to a dense charge which significantly increases horsepower and torque all through the operating range. Together with a specially designed supercharger pulley the package runs an extra 3 psi over standard pressure. In addition to this, a free flow air filter is used for maximum efficiency. Reliability is unaffected due to the very moderate boost increase. Price (fitted only) £3,450.00.



Stage 3: Performance Enhancement: Pack2 Boost increase (+75 bhp)

This upgrade increases boost pressure to 5 psi over standard. To enable the vehicle to run this pressure, we also modify the engine management to supply additional fuel and alter the ignition timing. Hotter grade spark plugs are also fitted as well as the parts used with our Stage 2 upgrade such as uprated intercooler and air filter. Price (fitted only) £4,950.00.

STAGE 4: UPGRADE (+100 bhp)

This upgrade consists of a 'full-power' free flow exhaust system which by-passes the catalytic converters to provide superior exhaust extraction ability. Please note that a vehicle equipped with this system will not pass UK MOT emission requirements and thus should only be used for off-highway purposes. Price £2,500.00 (supplied) £2,650.00 (fitted).

http://www.hennesseymotorsports.com/

If you like horsepower you probably have heard of Henessey, based in Texas, they're usually know as the Viper people. They now have added Jaguar to the list of cars they work on and they have developed a performance package adding 105 hp to the stock XKR (and XJR)... yes 475 hp !

This spectacular boost is achieved through high flow / ported heads, custom stainless exhaust and high flow cats, custom induction and ported / blueprinted supercharger.

Also available are front brakes upgrades and various wheels / tires combinations. Interestingly, Henessey only upgrades the front brakes (Brembo 4 piston calipers, ventilated and cross drilled rotors, performance pads and Motul 600 fluid)

Unfortunately, these 105 hp do not come cheap, it will cost you $ 25 000 and 10 weeks of downtime, but with a limited 3 year / 36 000 miles warranty.

$25 000 US ! - that's like $35 000 Aud !

Well lot's of options. The intake and the exhaust on my car are already done. It would make sense to fit a large heat exchanger up front from the beginning. Perhaps stock injectors, stock heads and mild boost would be a logical starting point and see how things go.

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