Where to start.. July 2012 seams like a good place. Drove home my new hobby, never envisaged it would lead me to distraction!

I'm going to write this in chunks as there is 2 years of stuff to write about and have a demanding wife, who has just stopped me in my tracks as i start!! This could take some time to finish..or even start.

 

I'm going to take you back to the day I first saw the car. It will, I hope, help you understand why I have a need for the changes to the car I want.

I was not looking for a Jag, I actually test drove a 928s v4, manual. This was the car i had pined to my wall when i was a young lad. When I came to drive it I was disappointed! I'd given up a 750cc bike about 10 years earlier - wife!! - and I was expecting to get the same buzz from this, but alas I did not.

At the same show room was the Jag, Spec & Pictures below..

Full paramount performance XKR
Full engine re-build with steel lined 4.2 block and latest style timing chain tensioners and water pump.
ECU re-mapped
Supercharger pullys have been changed to increase spin speed
Revise air induction and added filtration
Grand Prix exhaust
450 BHP
Large Brembo calipers
Vented ceramic disks
20 inch BBS Alloy wheels
Switchable power steering
F1 switch shift paddle change
Unrestricted
Carbon Fibre Arden body kit
2000 MY clear lenses
Lowered number plate plinth
Mesh grills
Lowered suspension
Chrome and Red 450 badge on the front grill
Interior - Jaguar logo embroidered headrests, Aluminium surrounds gear knob and peddles

This looked to be what I was after so took it for a drive, and yes it went well not quiet like my bike but a lot better than the 928s. The sales man told me some story, which I found out later was a load of bull...But what would you expect from a sales man.. (added a new quote to my list of life learning, "People lie, ALL the time").

An impulse buy, which is not like me at all. 2 weeks later I drove her home.

 

First thing for me to do was look up Paramount Performance. They, as we all know, are closed but did answer my email's via another company. After chatting with the respondent for a while I got an invite down to Viezu Tuning - Petrol and Diesel tuning, ECU remapping, car tuning for a free go on the rolling road. Great I thought I will actually see what the BHP is now.

The results were not as I would expect from a car only just sold to me as having 450BHP..

Using the calc

(RPM x Torque) / 5252

I could see the RW BHP was nothing like 450 it was more like 280-285, gutted! What did this mean? Could I get it running at 450?

this is when the mission started......

 

Where to start was my thought. The guys at the rolling road said my problem was the in take route for the air, it was going through a metal filter making the air hot before it got to the engine and causing the under performance...

He also said they had a sister company, which was a lot closer to where I lived would be able to help me out.

I spent the rest of that day on the internet researching what I should really be doing to get my car where it needed to be. This is where Tom Lenthall enters the story..

 

After meeting Tom I decided to split the work up into different Phases.
Phase 1 would be made up of Diff, Gear box, suspension and alignment work.

Phase 2 engine - did not expect there to be a phase 3 or 4....

Phase 1

Remove & replace front suspension lower bushes, fit adjustable camber bolts and carry out geometry setup, new suspension springs were required to get the geometry correct.

Remove differential, fit Quaife TAB centre and replace bearings & seals as necessary, I looked at changing the crown and pinion ratio to a 3.73 ratio but saw that the gear box TCM would need reprogramming and that was only available in the USA at a cost of about £2k! so did not do that. What other model differentials will fit the xk8. - Jaguar Forums - Jaguar Enthusiasts Forum
Maybe if I ever change it to a manual ill look again.

Clean off and underseal vehicle

Remove gearbox solenoids and replace with blue top solenoids for faster gearchange and carry out gearbox service. Was going to have Sonnax Overlap Control Valve kit fitted but decided against it in the end, Sonnax part number 68942-05K.

After this the car drove in a straight line when breaking hard. The gear changes were hard when changing down for the first 500 miles in traffic, they are still occasionally hard but only from 3rd to 2nd.

The car was now ready for the extra power i was looking for and it would stay attached to the road rather than weaving all over it when I put my foot down.

Phase 2 comprised of

4.2 Cylinder heads (x2)

4.2 Heads Porting (x2)

Injection Rails & Intercoolers

Modifying & painting intercoolers

Fuel pressure regulator & pipe work

Fuel pumps (x2)

Air filter

Air flow meter (MAF)

Air intake tube

Intercooler radiato

Intercooler pump Bosch 010 coolant pump

New throttle body 90mm! - there will be more on this later!

Stage 2 Kenny bell from Avos

1 x 2.6LH Twin- kit for 4.0 Jaguar XKR (AJ26) Mine is actually a 4.2 but advised it would still work the same.

 

Great start to the story.

A little hard to tell from the picture, but that MAF sensor looks to be the stock one inserted into a custom (much larger) tube. Unfortunately it isn't so simple with a MAF as they must be calibrated for the tube they go into.

Imagine that the sensor is sampling a small area of the flow through the tube. You make the tube larger, so the total flow is bigger but the sensor sees the same area as before, so now reports less than actual airflow.

It would definitely explain your lean problems mentioned I the other thread.

 

thanks, Looks like Tom and I have a lot to talk through over the next few weeks before I get a solution to the TB and before i change the ECU..

 

So after 1 year I have finally found some time to update the thread and why? Well looks like the issues I had after the engine mods are about to be solved maybe…

During phase 2 there some difficulties getting the engine to fuel correctly with the bigger TB and a handmade 90mm MAF sensor. At per this thread

https://www.jaguarforums.com/forum/j...le-body-79174/

but eventually Tom got it working, well kind of working. He fitted a smaller MAF sensor/Pipe which restricted the air flow and was able to manage to get the AFR ratio correct. The car runs fine and I gained additional 200 HP. See Rolling road output..

One thing to be aware of these are two different rolling roads and therefore the 200hp increase is necessary correct! But there is definitely an increase in power.

 

Great torque lines, and good to hear you have made progress.

If in pdf no 3 also the intake vacuum is measured (not sure though, do you know?), then you still have some room to get more power as you have restriction of about 100 mbar.

Not sure how much of this is due to the MAF you use or the filter setup, can you share a picture?

PS The date shown on the dyno slip is 20140207.

 

The date is correct, it has just taken me some time to get back to updating this thread.

Im not sure about the air filter but the MAF is as per the picture above, I think it is the standard sensor in a slightly bigger pipe. But this is changing as I type...update to follow shortly, maybe..

One thing that is odd, on these charts in the top right hand side is printed 506HP. If I do the maths (Rpm x torque)/5252 I get a different number... See attached XL sheet with before and after graphs, plotting HP. Not sure if i'm not understanding something correctly maybe have a look let me know what you think....

 

Few pictures of the finished engine...not massively exciting but everybody likes an engine picture or 2

 

after 18 months of misery I will be fitting my engine this week.
Because of the header system I have used, I need to fit the block - then bolt the exhaust to the heads and fit the heads, then continue with the assembly and installation. You have inspired me to make it look the part too. Looks great

 

Feb 2015 I started talking to Tom L about how could I get the best out of the mega expensive 90mm TB I had fitted. We talked through a load of option including fitting a new ECU (aem, syvex, omex - 710 Series ECU), he was trying to find a unit he could just simply swap, but no luck.

After reading about the DBX range of digital air sensors and understanding that the output could be modified to fool the ECU, it seemed like there was a way to utilise the 90mm TB..

After spending too much time on solid works (3D modelling tool) with one of the guys at work, I could see that air does not flow through a pipe evenly, the walls of the pipe cause resistance on the air touching it and slowing the flow of air closest to the wall. So fitting a DBX85 with an 85mm pipe would mean that I would have about 82mm of air flowing freely, this in my mind just would not do especially as it is connecting to a 90mm TB..

So decide to fit the DBX97 from Abaco, just like Avos. The inlet to the TS is 90mm and it is designed to have this volume of air going into it so what’s the issue with giving the TS access to more air than it needs to perform at optimum levels?

Abaco Performance LLC

So there was a plan. I booked the car in for May.

 

Thanks, it was inspired by Tom L as I was not keen on colouring in the engine but I'm very happy with the results. I even specced specific clamps that were 317 Stainless so they were always shiny. A chrome oil and water cap, chrome dip stick from these guys

http://www.paragondesignuk.com/engine.htm

 

I have only gone to the DBX97b to be ready for 700 hp ish, the DBX85 has good flow for 600 hp range as I had.

1st you need to establish the vacuum with your current setup (if it is not what was shown in the dyno graph), that will show if you have more to gain with a change of the intake/maf/filter setup.

Sorry I can't help in interpretation these dd dynos (the ones with 2 small drums per wheel). But it does show no decline until redline, that's already a very good sign, which you should also feel when pushing it, as if the car wants to take off ;-).

 

Its currently with these guys, http://www.advancedme.co.uk/index.htm, on there Hub Dyno for a more accurate reading but more on this later

 

Interesting, don't forget to measure the vacuum (after the TB), its an important indicator of what can be gained by optimizing the intake/maf/filter setup.

 

I've read on a few different forums that a Hub dyno gives a higher reading than a traditional/roller Dyno, found this Dynapack and DynoJet head to head comparison


Any thoughts? are the forums wrong?

 

This isn't possible, as the tire friction/wheel inertia forces are of course higher on a dynojet type one, so measured power can only be lower. If not I need these magical tire/wheel combo ;-)

It probably shows differences you can get with dynos. Maybe one (or both) wasn't calibrated right, or as small software glitch/setting? A couple of years back I experienced an issue after a software update, I got an additional 50 rwhp, which I didn’t trust (the dyno operator believed it), and after investigation and dynos from other cars the operator found that during an update of the software a parameter was changed that translated the load power on the drums (eddy current system) wrong, and thus gave more power the more load was on placed.

What where your results?

 

Still waiting!! Will give a full debrief when they car is back, but looking like 500 at the Hub with a 3"pulley and normal fuel.