Tuning the V8R engine.Time, costs, effects and difficulty.

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Tuning the V8R engine.Time, costs, effects and difficulty.

Postby J44EAG » Tue Dec 13, 2016 1:52 pm

PTJS1 suggested I summarise the tuning work done to my 4.2 XJR over the past year. These modifications are also applicable to S-type R, XKR and XFR 4.2 models. The top to bottom list below runs in my own suggested application order that I now consider would be most beneficial as a gradual build towards what can eventually become quite a seriously quick car. However you can mod in your own order as time and money allow. All mods have a gradual cumulative effect with effects from earlier mods becoming more significant as later mods exponentially add to the increases.



My estimate for my own mods now stands at around £2942 plus costs of buying a die grinder, yet another new compressor, updated tool kit, beer fags and trips to the hospital for personal repair. Lets say a total of about £3500 all in to add around 150-175 extra horse power. That works out at about £1000 per 50hp gain. How else could you buy 50hp for £1000! Bargain!!

Remember that some of this figure has included professional time and cost so the overall costs really are not outrageous at all. Had all this work been completely done by professionals, I imaging the figure would have come in at around £6000- £6500.

Final performance figures will be posted once I have rolling road confirmation.

Mike
X350 Co-ordinator

2004 XJR

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Re: Tuning the V8R engine.Time, costs, effects and difficult

Postby PTR200Jag » Wed Dec 14, 2016 4:54 pm

Did the mods add any significant cost to your insurance?

I presume it must have done but what sort of percentage of the base premium did the upgrades attract?

Nice job by the way ! :-)
XK8 MY2002

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Re: Tuning the V8R engine.Time, costs, effects and difficult

Postby J44EAG » Wed Dec 14, 2016 7:09 pm

Yes, Peter. About 70%. I can tell you, getting it wasn`t easy.

Motor insurance irritates me greatly. It is not the car that is the risk but the abilities or lack of ability of clot driving it! Many people are not safe driving a pedal car let alone even the lowest powered, slowest vehicle ever to appear on our roads. Those drivers are intrinsically unsafe at any speed or in any car. Accidents are caused by human errors of judgement. One sees it at its worst on dual carriage ways. A nasty little underpowered car, closing on a lorry on the inside lane. Brake lights go on, no indication of a manoeuvre about to take place. Then they pull out into the right hand carriageway having not looked in the mirror to see if that carriage way isn`t occupied by a fast moving vehicle. So we do the driving for them and predict what is about to occur before they have even seen the need to take some action. To add insult to injury, they then take the next ten minutes to pass the inside lane vehicle and another five to return to the inside lane. Our experience gained over many years and active checking of ones own actions helps make driving safer for all. Ones own driving record, (in my case unblemished, and a clean record of accident free driving) should dictate insurance rates, rather than the power or performance of the vehicle you are driving. IMHO.

Mike
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2004 XJR

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Re: Tuning the V8R engine.Time, costs, effects and difficult

Postby PTR200Jag » Thu Dec 15, 2016 5:42 pm

That's a fair size jump ! but I guess when get pretty good rates for our "elderly status" :roll: 70% isn't a big hike !

Just re insured the XK at a reasonable £200 including valuation.
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Re: Tuning the V8R engine.Time, costs, effects and difficulty.

Postby 3.8etypephil » Wed Mar 20, 2019 1:38 pm

PTJS1 suggested I summarise the tuning work done to my 4.2 XJR over the past year. These modifications are also applicable to S-type R, XKR and XFR 4.2 models. The top to bottom list below runs in my own suggested application order that I now consider would be most beneficial as a gradual build towards what can eventually become quite a seriously quick car. However you can mod in your own order as time and money allow. All mods have a gradual cumulative effect with effects from earlier mods becoming more significant as later mods exponentially add to the increases.



My estimate for my own mods now stands at around £2942 plus costs of buying a die grinder, yet another new compressor, updated tool kit, beer fags and trips to the hospital for personal repair. Lets say a total of about £3500 all in to add around 150-175 extra horse power. That works out at about £1000 per 50hp gain. How else could you buy 50hp for £1000! Bargain!!

Remember that some of this figure has included professional time and cost so the overall costs really are not outrageous at all. Had all this work been completely done by professionals, I imaging the figure would have come in at around £6000- £6500.

Final performance figures will be posted once I have rolling road confirmation.

Mike
"Final performance figures will be posted once I have rolling road confirmation."

Did you ever put the car on a dynamometer Mike?
Phil

2013 XFR
2008 XJR
http://jagchat.net/

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Re: Tuning the V8R engine.Time, costs, effects and difficulty.

Postby J44EAG » Wed Mar 20, 2019 11:20 pm

No, that never happened, Phil. Life changed for me and other matters took priority.

What I can tell you is that two years on, the XJR remains as gutsy as ever. Power delivery is instant rather than the hard fought progression of a standard car where it takes time for RPM to climb to the point where the supercharger comes in with a jolt towards to upper end of the power curve. It is a shame that Jaguar issued the car with such a large charger pulley. Even fitting the larger of the two smaller after market goodies makes a useful addition to daily drivability.

What makes the modifications so useful? It isn`t so much about what occurs, but the way in which the engine delivers its power and torque. When things happen lower down the RPM range, power flow becomes so much more useful and rather more fluid. At slow speeds to have the consummate ability to produce without fluster or delay makes the car so much easier to drive. If you need a quick squirt of power to get onto a roundabout, then it is there. Stomp on the pedal to get past an articulated lorry on the by-pass and you are past the leviathan in a flash. No more side to side elephant racing!

Paul S and I did Brooklands Test Hill a couple of years ago. Next day I took a phone call from the organisers office to thank me for attending with the car. An unofficial hill time for my dashes apparently put my time up the hill as the third fastest ever recorded. Rocketing up that hill in a trench barely wider than the car took intense concentration and huge courage to stay on the loud pedal towards the summit. My first run was my best. My concentration tailed off on the second and third runs. It was 29 degrees in blazing sun and I think a bit of mental dehydration set in as we all fried alive! I recall I felt totally exhausted when I switched of at the end of that third run. Paul and I agreed we had both experienced an absolute hoot of a day and that we should do it again sometime. Sadly family issues precluded me attacking that hill again last year. May be this year...it depends on how things pan out.

Mike
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2004 XJR

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Re: Tuning the V8R engine.Time, costs, effects and difficulty.

Postby 3.8etypephil » Sat Mar 23, 2019 10:21 am

No, that never happened, Phil. Life changed for me and other matters took priority.

What I can tell you is that two years on, the XJR remains as gutsy as ever. Power delivery is instant rather than the hard fought progression of a standard car where it takes time for RPM to climb to the point where the supercharger comes in with a jolt towards to upper end of the power curve. It is a shame that Jaguar issued the car with such a large charger pulley. Even fitting the larger of the two smaller after market goodies makes a useful addition to daily drivability.

What makes the modifications so useful? It isn`t so much about what occurs, but the way in which the engine delivers its power and torque. When things happen lower down the RPM range, power flow becomes so much more useful and rather more fluid. At slow speeds to have the consummate ability to produce without fluster or delay makes the car so much easier to drive. If you need a quick squirt of power to get onto a roundabout, then it is there. Stomp on the pedal to get past an articulated lorry on the by-pass and you are past the leviathan in a flash. No more side to side elephant racing!

Paul S and I did Brooklands Test Hill a couple of years ago. Next day I took a phone call from the organisers office to thank me for attending with the car. An unofficial hill time for my dashes apparently put my time up the hill as the third fastest ever recorded. Rocketing up that hill in a trench barely wider than the car took intense concentration and huge courage to stay on the loud pedal towards the summit. My first run was my best. My concentration tailed off on the second and third runs. It was 29 degrees in blazing sun and I think a bit of mental dehydration set in as we all fried alive! I recall I felt totally exhausted when I switched of at the end of that third run. Paul and I agreed we had both experienced an absolute hoot of a day and that we should do it again sometime. Sadly family issues precluded me attacking that hill again last year. May be this year...it depends on how things pan out.

Mike
I have always liked playing with my cars, especially the numerous Jaguars, and like to see how others have approached things; you seem to have attacked it in much the same way as I did with my X358, except that wishing to retain the subtle Q car aspect, I have omitted the intake and exhaust alterations. I wouldn't have accused the standard car of lacking bottom or mid-range punch, perhaps that's a result of VVT; certainly the earlier ones which I tested when hunting for the R were less impressive.
The 10% pulley, coupled with a bespoke map to exploit that and 99 octane fuel, were the most noticeable improvements. Living quite close to the Old Which Test Track in Gosfield gave me the opportunity to get some performance data to compare with a standard car:

http://jagchat.net/thread/1226/gosfield-test-track

Hopefully I we can compare notes at a meeting one of these years. I will be marshalling at the CSCC meeting at Snetterton on 06-07 April

https://snetterton.msv.com/SN-19-CSCC

and attending the UK South East Eighth Annual Convoy & Meet Event 26 May 2019

http://www.spanglefish.com/JaguarForumsUK/

and doubtless others during the season.
Phil

2013 XFR
2008 XJR
http://jagchat.net/

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Re: Tuning the V8R engine.Time, costs, effects and difficulty.

Postby J44EAG » Sat Mar 23, 2019 11:33 am

VVT does add a very useful 20hp on the later cars. Certainly a pre-facelift 06 XJR I drove not so long ago had a very strong pull at lower RPM and in that respect helped with slow speed pick up. When I was looking for my XJR, I did tend to shy away from those later cars due to the rather higher annual road tax liability. OK, I`m a skin flint but I knew I could gain that extra 20hp and vastly more by tuning in the way I`ve described in my epic thread!

As my car now stands, it now does what I hoped it would always do. Yes, it is a bit louder at the exhaust and at the air intake. The effect from the increased noise from those departments is minimal and the car retains its fundamentally refined character. Only the searing acceleration and blacked out chrome items give any hint that the car has been played with. Despite the age of the car, it is still worth staying with. I`d have to spend mega bucks to replace it and in any case the car still does what I require of it. Of all the cars I`ve ever owned, this is a vehicle that has retained my interest and desire to continue to own. There cannot be that many cars around that provoke that kind of positive reaction. It is all good and long may that continue.

Mike
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2004 XJR

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Re: Tuning the V8R engine.Time, costs, effects and difficulty.

Postby 3.8etypephil » Sat Mar 23, 2019 12:46 pm

I'm with you all the way Mike. I picked the X358 because of its history, condition and spec; I would have been equally happy with a X350, with or without VVT, and gone from there. The VED is irritating, but in reality it's only an extra fiver per week.
I have seen a few photos of your car; the painted out chrome makes it look just a little bit different, and more modern; a good move, IMO.
Phil

2013 XFR
2008 XJR
http://jagchat.net/


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