Hello.
i didn’t see any new posts about upgrading STRs.
im thinking of upgrading mine.
as for now I bought caldoofy intake tube and K&N air Filter.
if you have any info of nice performance upgrades for this model, please post and if possible with links.
maybe some suggestions of proper tuning of this car?
Plus what are you thoughts on performance exhaust upgrades, hi flow cats
Thank you.

 

What you've done is about it. You could put a different pulley on the SC or port the SC but no real gains should be expected based on feedback shared here on the forum.

 

Have a look here

https://www.jaguarforums.com/forum/x...epower-168474/

 

Interesting read. I stand corrected. Thanks for sharing. I have a XJR myself. I may do some of these things down the line...

 

If you do a pulley upgrade, you can do the next size smaller without pulling the supercharger and no machine work......and it uses the same belt and stock ecu tune if you choose....there are a couple members that have done it.....I am going to do mine, but I am going to wait until it gets cooler here and probably buy a custom made remover.installer from an outfit on eBay

 

The main issue with tuning parts loke this on the STR is is down to the physical restrictions of the supercharger. Basically it can not deliver any more air to the engine than it does in standard form, regardless of the intake pipe or how fast it spins. This max air flow is reached some way before max engine RPM is reached.

However with the bolt on modification you will get a noticeable improvement at lower RPM, but as soon as you put your foot down to accelarate, the gearbox changes down and the engine RPM goes up there is little or no improvement.

It is said that the ¼ mile times can be reduced, this could be down to reaching top gear at a lower engine rpm towards the end of the run.

Claims of up 15 to 20% hp improvement on a dyno are somewhat suspect as it is almost imposable to replicate the conditions needed to get accurate repeatable results for this small amount of gain on a car that already has a high BHP. Changes in air temp, air pressure, engine, gearbox and tyre heat soak and even the humidity can easily make more than 20% difference between runs.

Mellow

 

true to an extent . definitely as far as the pulley alone is concerned .
heat from an overdriven blower is the STR's worst nightmare .
and both Jackra_1 and myself went the extra step with the inter-cooling system .
mentioned in that link , that stuff really goes a long way to retaining the power you've gained .
before it dips off with timing retardation .
but it has been proven that all these mentioned upgrades combined does up the max peak HP ATW .

i have seen over 365 rwhp with these mods on the dyno before . around 440-450bhp
if i recall Robin's car is putting out 444.8BHP with the stock but overdriven eaton m112 on it .
with no nos.
thats one of many i've seen with 40-50 peak hp over stock .
then on this forum there is an XJR which dyno'ed at 580.BHP with NOS on with the eaton .

so the GEN 5 eaton m112 has some party left in it . if done right.

 

I wrote an email to Viezu performance. And they told me they can get 35-40bhp more by tuning ECU. Can it be true?

 

yes but 25hp peak is more likely , somewhere in the graph may be 40+hp ,
any way its a chip tune . your affectively locked out of your PCM for re-programs if ever needed.
if you have a later than 05 with the upgraded PCM . and have access to a Jaguar IDS/SDD and vcm .
then you should PM Cambo for his OLD JAGUAR TUNE , he may know someone near you with the gear to do it also .
. its loaded as the factory does .and reversible .

 

My jag is 2005 model, but made in 2004.
The thing is I’m from Ukraine, and UK is very far from me. Maybe I can take off computer or Smth like that.

 

It doesn't matter where you are if you contact Cambo.

Be aware there are few upgrades and some are costly.

 

That's with 95 RON & a std air filter. With 99 RON & the K+N back in it made a bit more. Oh, that huge s/c whine is so addictive.

Back on the dyno midday this Saturday with the NOS switched back on.

 

apart from what you have done which is same as I have you may want to do a few other mods to gain some power and performance, firstly a smaller pulley, these come in either 6% or 10% increase which can gain you anything from 12-20 bhp at the crank, swallow racing or powerhouse do very good proven pulleys, direct fit and no remap required, I went for the 10% which fires up the supercharger at 1500 revs instead of the stock 2200 revs, so instant power thro the mid range gears 2-3-4-5 no noticeable difference up at top end as it’s virtually impossible to grab high revs up there, also I put on Adamesh stainless exhaust system, quoted 12-14 added bhp but I’m erring more on 8-10 max, also used NGK iridium race spec plugs, not much dearer than stock but a much cleaner and smoother spark achieved, stokes the fire in her belly quicker and longer so must help accelerate the fuel to the heart, plus underneath your air filter there is a hinged “door” which a solenoid opens to allow cold air in and up thro the filter, take it off to offer a constant cold air ram into the box, thus thro into your stainless Caldoofy pipe, it will spin her up nicely and allow it to run cooler and smoother, happy motoring

 

You could also do the Land Rover intake duct mod. Every little bit helps

 

Also check this out

 

What I have found is vastly improved mid range pull. I do not often go WOT as even with an LSD I get both wheels spinning.

However after recently doing just that, a WOT run, all the way near redline to a very illegal speed all was fine until a few days later when I had a P0730 code with restricted performance.

Currently dealing with that in another thread.

 

Check my threads;. Dyno runs, track times
Gain of nearly 100hp crank with basic bolts ons and a tune.. plenty of potential locked in the 4.2 engine and 80% of it is in the (proper) tune
At least on 4.2 xkr cars with a 1.5 lb pulley you will hit limiters in the ECU . money spend on this mod are a waste without a tune...

 

this might be true for your specific model , but my STR is running 100hp more than stock with many mods, and over 4psi more boost than stock . and not hitting any limiters on stock tune . so i don't believe this is true for the early DENSO powered cars .
though i'm sure a tune would further help , its not 80% in the denso cars case .

 

In that case I might we wrong. I need to take a look at a stock file for the s type .
If you don't mind , do you have a smaller puller on a stock supercharger? Dyno numbers, track runs?

 

sorry i have no slip . my car has run a couple of local car club drag runs . my PB is 12.72 @ 110.no prep . also have achieved close to the same no#s with dynolitios 12.74@110.
i used a drag calculator to get an estimation of HP .of just under 500bhp .
we have no local dyno here . nearest is 500km away .
no eaton roots here .
mine has the legendary OG prototype 1.7 autorotor kenne bell twin screw,
first used by a well known legend fellow forum member .
who i would think needs no introduction .
though i bought it 3rd hand .
there are dyno sheets from his XKR 4.0 on the net from way back then with only 20hp less than than my cars estimate ,his had no other mods other than the TS .
its hard for me to fathom that with 200cc more and all my mods i only gained 20hp on his no#s. though i'm not spinning it as hard as he was .
stock 4.2 eaton's run a 2.9'' top pulley at ratio 2.2:1 , mine is 2.5'' running at ratio 2.554:1

i do have some other pulleys to spin it faster still , including the original one used in testing a 2.16'' upper . or NOT AND a eurotoys lower one i will fit in the future .
BOTH these together will brake something for sure !
the stock injectors are max'ed out at 500-550bhp . and no one does a tune for the DENSO. except the canned chip tunes available .
but as soon as i state my mods they retract the availability .
BTW the Denso map is the same as the Denso 04-05 XJR .